Critical Design Review SPECTRE Solar-sail Pitch Enabling Controller Through Root Excitation Michael Andrews, Brendon Barela, Austin Cerny, Corinne Desroches, Kyle Edson, Conrad Gabel, Chris Riesco, Justin Yong
Transcript
Critical DesignReviewSPECTRE
Solar-sail Pitch Enabling Controller Through Root Excitation
Michael Andrews Brendon Barela Austin Cerny Corinne Desroches Kyle Edson Conrad Gabel Chris Riesco Justin Yong
Intr
oduc
tion
2
Briefing Overview and Context
bull SPECTRE seeks to design and prototype a sail blade damping augmentation controller for flapping and twisting blade oscillations for a proposed heliogyro CubeSat mission
bull SPECTRE is a continuation of last yearrsquos GHOST senior design project which focused on sail blade deployment and a blade pitching controller
Customer
Dr Keats Wilkie
NASA Langley
Advisor
Dr Xinlin Li
LASP
Department of Aerospace Engineering Sciences CU
Content Breakdown
Introduction
Design Solutions
Verification and Validation
Project Risk
Project Planning
Intr
oduc
tion
3
Heliogyro Backgroundbull Propulsion system using solar radiation
pressure
bull Solar sail ldquobladesrdquo are held in place with centripetal forces
bull Spins similarly to a helicopter
bull Solar pressure instead of air
bull Proposed heliogyros have long blades (gt1 km) but no heliogyro mission has ever flown
bull NASA would like a CubeSat demonstrator
bull GHOST developed a deployment system
bull Pitching was not completed
bull SPECTRE demonstrates the ability to pitch the solar-sail blades and damp oscillations in the blades
Illustration of proposed heliogyro solar sail rendezvous with Halleyrsquos Comet (source NASAJPL)
GHOST 2 Blade CubeSat DesignDimensions 10cm x 20cm x 30cm Blade Dimensions 15cm x ~30m
Housing
Bus
Intr
oduc
tion
4
Solar Sail Blade MaterialProperties
bull Constructed from Aluminum coated Mylar total thickness of 264 m
bull Maximum areal density of 60 g allows for 23 g of support materialbull Blades are stiffened by edge loading the sail with Kapton tapebull Further stiffened by adding tip mass equal to 10 of the total blade mass
Thrust
bull Blades provide 4510-6 N of thrust per based on solar pressure at 1 AU
bull Solar sail will need to accelerate the spacecraft at least 01 mmto be usefulbull For a 6U cubesat weighing approximately 8 kg ~45 deployed area neededbull Two bladed CubeSat with 2U width needs ~350 m blade lengthbull Aspect Ratio of 23331
Tip Mass
KaptonTape
15 cm
Intr
oduc
tion
5
Orbital Operationsbull Blade can pitched in and out of solar
flux to modulate the moment for attitude control and the thrust for orbit control
bull To increasedecrease spacecraft orbit velocity blades must pitch over a 90 degree range
bull Two 90deg pitch maneuvers are performed during 1 LEO orbit to maximize a change in velocity
Blade dynamics need be sensed while in the Earthrsquos shadow
Sun
Blades pitched 90deg parallel to solar pressure
Earth
Blades pitched 90deg perpendicular to solar pressure
Blades hit by solar flux and generate thrust
orbital velocity increases
Blades parallel to solar flux orbital
velocity unchanged
119889119881
120596
120596
120596
120596
Intr
oduc
tion
6
Blade Oscillationsbull A major concern of heliogyro designs is blade oscillation
bull Pitching manuvers and moving blades in and out of solar flux induces twisting and flapping oscillationsbull First modes of these oscillations behave similarly to swinging pendulums
bull Mode shapes are known deflection measurements made at the root can be used to calculate tip deflections
Blade RootBlade Root
Blade TipBlade Tip
Housing
θflapNominalBlade
DeflectedBlade
Flapping
θtwist
Blade Root
Blade Tip
Twisting
>
>
Intr
oduc
tion
7
Mode FrequenciesEarth Behavior
bull Flapping Mode Frequenecy can be approximated as a pendulum
bull Period Depends on the bladersquos mass (M) moment of inertia (I) and center of gravity (R) measured from the blade root g remains constant for Earth testing
bull
bull The torsional mode is best estimated from the flapping mode
bull
Space Behaviorbull Frequencies directly tied to spacecraft angular
velocity
bull Angular velocities of proposed heliogyro missions typically ~13 RPM
120596
Based on the expected mode frequencies for space operations and the constraints of Heliogyro missions the controller is required to demonstrate a damping ratio of 00136
Intr
oduc
tion
8
Testing Constraintsbull Full scale blade cannot be built or tested
bull 22 meter blade analog will be used to simulate space environment
bull Controller can still be validated by showing it can function with blade conditions similar to those seen in space
bull Graviational forces will be present during testing
bull Centripetal force of the spinning spacecraft will be simulated with these gravitational forces
bull Air viscosity will contribute to damping
bull Damping provided by the controller will need to be distinguishable from damping provided by air
Intr
oduc
tion
9
Blade Controller RequirementsController housing must be able to accommodate one blade capable of providing useful acceleration (~350 m in length)
Controller must be able to pitch blades to plusmn 90deg with plusmn 5deg of accuracy
Controller must demonstrate a damping ratios for flapping and twisting modes of
Controller must be capable of sensing blade deflections without an ambient light source
Controller and blade occupy 2U of volume (10cm x 10cm x 20cm)
Controller must run on approximately 5 watts of power
Controller must conform to Cubesat weight requirement ~13 kgU total of 26 kg
Intr
oduc
tion
10
Design Solutionbull Blade housing can accommodate a
blade of 15 cm by 350 mbull Rotational actuator with a range of
motion of 360degbull Camera senses motion of blade
bull Closed loop controller damps oscillations
bull Linear actuator provides damping ratio of 00077 for flapping mode
bull Rotational actuator provides damping ratio of 0015 for twisting mode
bull LED near camera for low light conditionsbull Blade housing has 14U volume
electronics require 04U in CubeSat busbull Total of 18U
bull System requires 20 Wbull Total mass of 2 kg
Intr
oduc
tion
11
Blade Housing
Linear Actuator
Camera
Image Processor
Blade Analogue
7 cm
10 cm
20 cm
Intr
oduc
tion
12
CubeSat Bus
Microcontroller
Actuator Drivers
Rotational Actuator
Dimensions in cm
Kyle Edson
Fill in blanks better estimate on volume
Intr
oduc
tion
13
Rope Ladder Analogbull Current heliogyro reseach uses a rope ladder assumption to
investigate blade dynamicsbull Extremely thin sail material (264 thickness) has negligible internal forcesbull Assumes the sail blade material has no stiffness or internal damping
bull Rope ladder assumption allows for blades to be constructed from support materials alone for blade testingbull Reduction in surface area results in less damping being provided by airbull 22 meters in length
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Intr
oduc
tion
2
Briefing Overview and Context
bull SPECTRE seeks to design and prototype a sail blade damping augmentation controller for flapping and twisting blade oscillations for a proposed heliogyro CubeSat mission
bull SPECTRE is a continuation of last yearrsquos GHOST senior design project which focused on sail blade deployment and a blade pitching controller
Customer
Dr Keats Wilkie
NASA Langley
Advisor
Dr Xinlin Li
LASP
Department of Aerospace Engineering Sciences CU
Content Breakdown
Introduction
Design Solutions
Verification and Validation
Project Risk
Project Planning
Intr
oduc
tion
3
Heliogyro Backgroundbull Propulsion system using solar radiation
pressure
bull Solar sail ldquobladesrdquo are held in place with centripetal forces
bull Spins similarly to a helicopter
bull Solar pressure instead of air
bull Proposed heliogyros have long blades (gt1 km) but no heliogyro mission has ever flown
bull NASA would like a CubeSat demonstrator
bull GHOST developed a deployment system
bull Pitching was not completed
bull SPECTRE demonstrates the ability to pitch the solar-sail blades and damp oscillations in the blades
Illustration of proposed heliogyro solar sail rendezvous with Halleyrsquos Comet (source NASAJPL)
GHOST 2 Blade CubeSat DesignDimensions 10cm x 20cm x 30cm Blade Dimensions 15cm x ~30m
Housing
Bus
Intr
oduc
tion
4
Solar Sail Blade MaterialProperties
bull Constructed from Aluminum coated Mylar total thickness of 264 m
bull Maximum areal density of 60 g allows for 23 g of support materialbull Blades are stiffened by edge loading the sail with Kapton tapebull Further stiffened by adding tip mass equal to 10 of the total blade mass
Thrust
bull Blades provide 4510-6 N of thrust per based on solar pressure at 1 AU
bull Solar sail will need to accelerate the spacecraft at least 01 mmto be usefulbull For a 6U cubesat weighing approximately 8 kg ~45 deployed area neededbull Two bladed CubeSat with 2U width needs ~350 m blade lengthbull Aspect Ratio of 23331
Tip Mass
KaptonTape
15 cm
Intr
oduc
tion
5
Orbital Operationsbull Blade can pitched in and out of solar
flux to modulate the moment for attitude control and the thrust for orbit control
bull To increasedecrease spacecraft orbit velocity blades must pitch over a 90 degree range
bull Two 90deg pitch maneuvers are performed during 1 LEO orbit to maximize a change in velocity
Blade dynamics need be sensed while in the Earthrsquos shadow
Sun
Blades pitched 90deg parallel to solar pressure
Earth
Blades pitched 90deg perpendicular to solar pressure
Blades hit by solar flux and generate thrust
orbital velocity increases
Blades parallel to solar flux orbital
velocity unchanged
119889119881
120596
120596
120596
120596
Intr
oduc
tion
6
Blade Oscillationsbull A major concern of heliogyro designs is blade oscillation
bull Pitching manuvers and moving blades in and out of solar flux induces twisting and flapping oscillationsbull First modes of these oscillations behave similarly to swinging pendulums
bull Mode shapes are known deflection measurements made at the root can be used to calculate tip deflections
Blade RootBlade Root
Blade TipBlade Tip
Housing
θflapNominalBlade
DeflectedBlade
Flapping
θtwist
Blade Root
Blade Tip
Twisting
>
>
Intr
oduc
tion
7
Mode FrequenciesEarth Behavior
bull Flapping Mode Frequenecy can be approximated as a pendulum
bull Period Depends on the bladersquos mass (M) moment of inertia (I) and center of gravity (R) measured from the blade root g remains constant for Earth testing
bull
bull The torsional mode is best estimated from the flapping mode
bull
Space Behaviorbull Frequencies directly tied to spacecraft angular
velocity
bull Angular velocities of proposed heliogyro missions typically ~13 RPM
120596
Based on the expected mode frequencies for space operations and the constraints of Heliogyro missions the controller is required to demonstrate a damping ratio of 00136
Intr
oduc
tion
8
Testing Constraintsbull Full scale blade cannot be built or tested
bull 22 meter blade analog will be used to simulate space environment
bull Controller can still be validated by showing it can function with blade conditions similar to those seen in space
bull Graviational forces will be present during testing
bull Centripetal force of the spinning spacecraft will be simulated with these gravitational forces
bull Air viscosity will contribute to damping
bull Damping provided by the controller will need to be distinguishable from damping provided by air
Intr
oduc
tion
9
Blade Controller RequirementsController housing must be able to accommodate one blade capable of providing useful acceleration (~350 m in length)
Controller must be able to pitch blades to plusmn 90deg with plusmn 5deg of accuracy
Controller must demonstrate a damping ratios for flapping and twisting modes of
Controller must be capable of sensing blade deflections without an ambient light source
Controller and blade occupy 2U of volume (10cm x 10cm x 20cm)
Controller must run on approximately 5 watts of power
Controller must conform to Cubesat weight requirement ~13 kgU total of 26 kg
Intr
oduc
tion
10
Design Solutionbull Blade housing can accommodate a
blade of 15 cm by 350 mbull Rotational actuator with a range of
motion of 360degbull Camera senses motion of blade
bull Closed loop controller damps oscillations
bull Linear actuator provides damping ratio of 00077 for flapping mode
bull Rotational actuator provides damping ratio of 0015 for twisting mode
bull LED near camera for low light conditionsbull Blade housing has 14U volume
electronics require 04U in CubeSat busbull Total of 18U
bull System requires 20 Wbull Total mass of 2 kg
Intr
oduc
tion
11
Blade Housing
Linear Actuator
Camera
Image Processor
Blade Analogue
7 cm
10 cm
20 cm
Intr
oduc
tion
12
CubeSat Bus
Microcontroller
Actuator Drivers
Rotational Actuator
Dimensions in cm
Kyle Edson
Fill in blanks better estimate on volume
Intr
oduc
tion
13
Rope Ladder Analogbull Current heliogyro reseach uses a rope ladder assumption to
investigate blade dynamicsbull Extremely thin sail material (264 thickness) has negligible internal forcesbull Assumes the sail blade material has no stiffness or internal damping
bull Rope ladder assumption allows for blades to be constructed from support materials alone for blade testingbull Reduction in surface area results in less damping being provided by airbull 22 meters in length
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Intr
oduc
tion
3
Heliogyro Backgroundbull Propulsion system using solar radiation
pressure
bull Solar sail ldquobladesrdquo are held in place with centripetal forces
bull Spins similarly to a helicopter
bull Solar pressure instead of air
bull Proposed heliogyros have long blades (gt1 km) but no heliogyro mission has ever flown
bull NASA would like a CubeSat demonstrator
bull GHOST developed a deployment system
bull Pitching was not completed
bull SPECTRE demonstrates the ability to pitch the solar-sail blades and damp oscillations in the blades
Illustration of proposed heliogyro solar sail rendezvous with Halleyrsquos Comet (source NASAJPL)
GHOST 2 Blade CubeSat DesignDimensions 10cm x 20cm x 30cm Blade Dimensions 15cm x ~30m
Housing
Bus
Intr
oduc
tion
4
Solar Sail Blade MaterialProperties
bull Constructed from Aluminum coated Mylar total thickness of 264 m
bull Maximum areal density of 60 g allows for 23 g of support materialbull Blades are stiffened by edge loading the sail with Kapton tapebull Further stiffened by adding tip mass equal to 10 of the total blade mass
Thrust
bull Blades provide 4510-6 N of thrust per based on solar pressure at 1 AU
bull Solar sail will need to accelerate the spacecraft at least 01 mmto be usefulbull For a 6U cubesat weighing approximately 8 kg ~45 deployed area neededbull Two bladed CubeSat with 2U width needs ~350 m blade lengthbull Aspect Ratio of 23331
Tip Mass
KaptonTape
15 cm
Intr
oduc
tion
5
Orbital Operationsbull Blade can pitched in and out of solar
flux to modulate the moment for attitude control and the thrust for orbit control
bull To increasedecrease spacecraft orbit velocity blades must pitch over a 90 degree range
bull Two 90deg pitch maneuvers are performed during 1 LEO orbit to maximize a change in velocity
Blade dynamics need be sensed while in the Earthrsquos shadow
Sun
Blades pitched 90deg parallel to solar pressure
Earth
Blades pitched 90deg perpendicular to solar pressure
Blades hit by solar flux and generate thrust
orbital velocity increases
Blades parallel to solar flux orbital
velocity unchanged
119889119881
120596
120596
120596
120596
Intr
oduc
tion
6
Blade Oscillationsbull A major concern of heliogyro designs is blade oscillation
bull Pitching manuvers and moving blades in and out of solar flux induces twisting and flapping oscillationsbull First modes of these oscillations behave similarly to swinging pendulums
bull Mode shapes are known deflection measurements made at the root can be used to calculate tip deflections
Blade RootBlade Root
Blade TipBlade Tip
Housing
θflapNominalBlade
DeflectedBlade
Flapping
θtwist
Blade Root
Blade Tip
Twisting
>
>
Intr
oduc
tion
7
Mode FrequenciesEarth Behavior
bull Flapping Mode Frequenecy can be approximated as a pendulum
bull Period Depends on the bladersquos mass (M) moment of inertia (I) and center of gravity (R) measured from the blade root g remains constant for Earth testing
bull
bull The torsional mode is best estimated from the flapping mode
bull
Space Behaviorbull Frequencies directly tied to spacecraft angular
velocity
bull Angular velocities of proposed heliogyro missions typically ~13 RPM
120596
Based on the expected mode frequencies for space operations and the constraints of Heliogyro missions the controller is required to demonstrate a damping ratio of 00136
Intr
oduc
tion
8
Testing Constraintsbull Full scale blade cannot be built or tested
bull 22 meter blade analog will be used to simulate space environment
bull Controller can still be validated by showing it can function with blade conditions similar to those seen in space
bull Graviational forces will be present during testing
bull Centripetal force of the spinning spacecraft will be simulated with these gravitational forces
bull Air viscosity will contribute to damping
bull Damping provided by the controller will need to be distinguishable from damping provided by air
Intr
oduc
tion
9
Blade Controller RequirementsController housing must be able to accommodate one blade capable of providing useful acceleration (~350 m in length)
Controller must be able to pitch blades to plusmn 90deg with plusmn 5deg of accuracy
Controller must demonstrate a damping ratios for flapping and twisting modes of
Controller must be capable of sensing blade deflections without an ambient light source
Controller and blade occupy 2U of volume (10cm x 10cm x 20cm)
Controller must run on approximately 5 watts of power
Controller must conform to Cubesat weight requirement ~13 kgU total of 26 kg
Intr
oduc
tion
10
Design Solutionbull Blade housing can accommodate a
blade of 15 cm by 350 mbull Rotational actuator with a range of
motion of 360degbull Camera senses motion of blade
bull Closed loop controller damps oscillations
bull Linear actuator provides damping ratio of 00077 for flapping mode
bull Rotational actuator provides damping ratio of 0015 for twisting mode
bull LED near camera for low light conditionsbull Blade housing has 14U volume
electronics require 04U in CubeSat busbull Total of 18U
bull System requires 20 Wbull Total mass of 2 kg
Intr
oduc
tion
11
Blade Housing
Linear Actuator
Camera
Image Processor
Blade Analogue
7 cm
10 cm
20 cm
Intr
oduc
tion
12
CubeSat Bus
Microcontroller
Actuator Drivers
Rotational Actuator
Dimensions in cm
Kyle Edson
Fill in blanks better estimate on volume
Intr
oduc
tion
13
Rope Ladder Analogbull Current heliogyro reseach uses a rope ladder assumption to
investigate blade dynamicsbull Extremely thin sail material (264 thickness) has negligible internal forcesbull Assumes the sail blade material has no stiffness or internal damping
bull Rope ladder assumption allows for blades to be constructed from support materials alone for blade testingbull Reduction in surface area results in less damping being provided by airbull 22 meters in length
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Intr
oduc
tion
4
Solar Sail Blade MaterialProperties
bull Constructed from Aluminum coated Mylar total thickness of 264 m
bull Maximum areal density of 60 g allows for 23 g of support materialbull Blades are stiffened by edge loading the sail with Kapton tapebull Further stiffened by adding tip mass equal to 10 of the total blade mass
Thrust
bull Blades provide 4510-6 N of thrust per based on solar pressure at 1 AU
bull Solar sail will need to accelerate the spacecraft at least 01 mmto be usefulbull For a 6U cubesat weighing approximately 8 kg ~45 deployed area neededbull Two bladed CubeSat with 2U width needs ~350 m blade lengthbull Aspect Ratio of 23331
Tip Mass
KaptonTape
15 cm
Intr
oduc
tion
5
Orbital Operationsbull Blade can pitched in and out of solar
flux to modulate the moment for attitude control and the thrust for orbit control
bull To increasedecrease spacecraft orbit velocity blades must pitch over a 90 degree range
bull Two 90deg pitch maneuvers are performed during 1 LEO orbit to maximize a change in velocity
Blade dynamics need be sensed while in the Earthrsquos shadow
Sun
Blades pitched 90deg parallel to solar pressure
Earth
Blades pitched 90deg perpendicular to solar pressure
Blades hit by solar flux and generate thrust
orbital velocity increases
Blades parallel to solar flux orbital
velocity unchanged
119889119881
120596
120596
120596
120596
Intr
oduc
tion
6
Blade Oscillationsbull A major concern of heliogyro designs is blade oscillation
bull Pitching manuvers and moving blades in and out of solar flux induces twisting and flapping oscillationsbull First modes of these oscillations behave similarly to swinging pendulums
bull Mode shapes are known deflection measurements made at the root can be used to calculate tip deflections
Blade RootBlade Root
Blade TipBlade Tip
Housing
θflapNominalBlade
DeflectedBlade
Flapping
θtwist
Blade Root
Blade Tip
Twisting
>
>
Intr
oduc
tion
7
Mode FrequenciesEarth Behavior
bull Flapping Mode Frequenecy can be approximated as a pendulum
bull Period Depends on the bladersquos mass (M) moment of inertia (I) and center of gravity (R) measured from the blade root g remains constant for Earth testing
bull
bull The torsional mode is best estimated from the flapping mode
bull
Space Behaviorbull Frequencies directly tied to spacecraft angular
velocity
bull Angular velocities of proposed heliogyro missions typically ~13 RPM
120596
Based on the expected mode frequencies for space operations and the constraints of Heliogyro missions the controller is required to demonstrate a damping ratio of 00136
Intr
oduc
tion
8
Testing Constraintsbull Full scale blade cannot be built or tested
bull 22 meter blade analog will be used to simulate space environment
bull Controller can still be validated by showing it can function with blade conditions similar to those seen in space
bull Graviational forces will be present during testing
bull Centripetal force of the spinning spacecraft will be simulated with these gravitational forces
bull Air viscosity will contribute to damping
bull Damping provided by the controller will need to be distinguishable from damping provided by air
Intr
oduc
tion
9
Blade Controller RequirementsController housing must be able to accommodate one blade capable of providing useful acceleration (~350 m in length)
Controller must be able to pitch blades to plusmn 90deg with plusmn 5deg of accuracy
Controller must demonstrate a damping ratios for flapping and twisting modes of
Controller must be capable of sensing blade deflections without an ambient light source
Controller and blade occupy 2U of volume (10cm x 10cm x 20cm)
Controller must run on approximately 5 watts of power
Controller must conform to Cubesat weight requirement ~13 kgU total of 26 kg
Intr
oduc
tion
10
Design Solutionbull Blade housing can accommodate a
blade of 15 cm by 350 mbull Rotational actuator with a range of
motion of 360degbull Camera senses motion of blade
bull Closed loop controller damps oscillations
bull Linear actuator provides damping ratio of 00077 for flapping mode
bull Rotational actuator provides damping ratio of 0015 for twisting mode
bull LED near camera for low light conditionsbull Blade housing has 14U volume
electronics require 04U in CubeSat busbull Total of 18U
bull System requires 20 Wbull Total mass of 2 kg
Intr
oduc
tion
11
Blade Housing
Linear Actuator
Camera
Image Processor
Blade Analogue
7 cm
10 cm
20 cm
Intr
oduc
tion
12
CubeSat Bus
Microcontroller
Actuator Drivers
Rotational Actuator
Dimensions in cm
Kyle Edson
Fill in blanks better estimate on volume
Intr
oduc
tion
13
Rope Ladder Analogbull Current heliogyro reseach uses a rope ladder assumption to
investigate blade dynamicsbull Extremely thin sail material (264 thickness) has negligible internal forcesbull Assumes the sail blade material has no stiffness or internal damping
bull Rope ladder assumption allows for blades to be constructed from support materials alone for blade testingbull Reduction in surface area results in less damping being provided by airbull 22 meters in length
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
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36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
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39
Connection Diagram
Ele
ctro
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40
Power
Ele
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41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
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42
Software
Ele
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43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
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55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
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56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
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57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
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Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
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Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
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Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
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64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
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Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
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Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
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Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
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Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
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Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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Linear Motion Requirement
θ
bull
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Binding Ratio
L
D
a
Bac
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Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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Gear Ratio bull
r
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Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
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Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
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Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
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Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
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Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
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Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
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Camera Requirements Geometry
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Encoder Wiring
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Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
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RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
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LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Intr
oduc
tion
5
Orbital Operationsbull Blade can pitched in and out of solar
flux to modulate the moment for attitude control and the thrust for orbit control
bull To increasedecrease spacecraft orbit velocity blades must pitch over a 90 degree range
bull Two 90deg pitch maneuvers are performed during 1 LEO orbit to maximize a change in velocity
Blade dynamics need be sensed while in the Earthrsquos shadow
Sun
Blades pitched 90deg parallel to solar pressure
Earth
Blades pitched 90deg perpendicular to solar pressure
Blades hit by solar flux and generate thrust
orbital velocity increases
Blades parallel to solar flux orbital
velocity unchanged
119889119881
120596
120596
120596
120596
Intr
oduc
tion
6
Blade Oscillationsbull A major concern of heliogyro designs is blade oscillation
bull Pitching manuvers and moving blades in and out of solar flux induces twisting and flapping oscillationsbull First modes of these oscillations behave similarly to swinging pendulums
bull Mode shapes are known deflection measurements made at the root can be used to calculate tip deflections
Blade RootBlade Root
Blade TipBlade Tip
Housing
θflapNominalBlade
DeflectedBlade
Flapping
θtwist
Blade Root
Blade Tip
Twisting
>
>
Intr
oduc
tion
7
Mode FrequenciesEarth Behavior
bull Flapping Mode Frequenecy can be approximated as a pendulum
bull Period Depends on the bladersquos mass (M) moment of inertia (I) and center of gravity (R) measured from the blade root g remains constant for Earth testing
bull
bull The torsional mode is best estimated from the flapping mode
bull
Space Behaviorbull Frequencies directly tied to spacecraft angular
velocity
bull Angular velocities of proposed heliogyro missions typically ~13 RPM
120596
Based on the expected mode frequencies for space operations and the constraints of Heliogyro missions the controller is required to demonstrate a damping ratio of 00136
Intr
oduc
tion
8
Testing Constraintsbull Full scale blade cannot be built or tested
bull 22 meter blade analog will be used to simulate space environment
bull Controller can still be validated by showing it can function with blade conditions similar to those seen in space
bull Graviational forces will be present during testing
bull Centripetal force of the spinning spacecraft will be simulated with these gravitational forces
bull Air viscosity will contribute to damping
bull Damping provided by the controller will need to be distinguishable from damping provided by air
Intr
oduc
tion
9
Blade Controller RequirementsController housing must be able to accommodate one blade capable of providing useful acceleration (~350 m in length)
Controller must be able to pitch blades to plusmn 90deg with plusmn 5deg of accuracy
Controller must demonstrate a damping ratios for flapping and twisting modes of
Controller must be capable of sensing blade deflections without an ambient light source
Controller and blade occupy 2U of volume (10cm x 10cm x 20cm)
Controller must run on approximately 5 watts of power
Controller must conform to Cubesat weight requirement ~13 kgU total of 26 kg
Intr
oduc
tion
10
Design Solutionbull Blade housing can accommodate a
blade of 15 cm by 350 mbull Rotational actuator with a range of
motion of 360degbull Camera senses motion of blade
bull Closed loop controller damps oscillations
bull Linear actuator provides damping ratio of 00077 for flapping mode
bull Rotational actuator provides damping ratio of 0015 for twisting mode
bull LED near camera for low light conditionsbull Blade housing has 14U volume
electronics require 04U in CubeSat busbull Total of 18U
bull System requires 20 Wbull Total mass of 2 kg
Intr
oduc
tion
11
Blade Housing
Linear Actuator
Camera
Image Processor
Blade Analogue
7 cm
10 cm
20 cm
Intr
oduc
tion
12
CubeSat Bus
Microcontroller
Actuator Drivers
Rotational Actuator
Dimensions in cm
Kyle Edson
Fill in blanks better estimate on volume
Intr
oduc
tion
13
Rope Ladder Analogbull Current heliogyro reseach uses a rope ladder assumption to
investigate blade dynamicsbull Extremely thin sail material (264 thickness) has negligible internal forcesbull Assumes the sail blade material has no stiffness or internal damping
bull Rope ladder assumption allows for blades to be constructed from support materials alone for blade testingbull Reduction in surface area results in less damping being provided by airbull 22 meters in length
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
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36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
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38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
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39
Connection Diagram
Ele
ctro
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40
Power
Ele
ctro
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41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
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43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
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55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
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56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
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Work Plan
Sp
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g B
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Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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Work Plan Critical Path
Sp
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Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
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Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
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Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
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Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
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64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
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Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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Requirements for Actuators
Linear accelerationAngular Acceleration
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Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
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73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
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74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
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Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
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Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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Linear Motion Requirement
θ
bull
Bac
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82
Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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84
Gear Ratio bull
r
Bac
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85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
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87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
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Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
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89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
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90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
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Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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92
Camera Requirements Geometry
Bac
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93
Encoder Wiring
Bac
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94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
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95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
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LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Intr
oduc
tion
6
Blade Oscillationsbull A major concern of heliogyro designs is blade oscillation
bull Pitching manuvers and moving blades in and out of solar flux induces twisting and flapping oscillationsbull First modes of these oscillations behave similarly to swinging pendulums
bull Mode shapes are known deflection measurements made at the root can be used to calculate tip deflections
Blade RootBlade Root
Blade TipBlade Tip
Housing
θflapNominalBlade
DeflectedBlade
Flapping
θtwist
Blade Root
Blade Tip
Twisting
>
>
Intr
oduc
tion
7
Mode FrequenciesEarth Behavior
bull Flapping Mode Frequenecy can be approximated as a pendulum
bull Period Depends on the bladersquos mass (M) moment of inertia (I) and center of gravity (R) measured from the blade root g remains constant for Earth testing
bull
bull The torsional mode is best estimated from the flapping mode
bull
Space Behaviorbull Frequencies directly tied to spacecraft angular
velocity
bull Angular velocities of proposed heliogyro missions typically ~13 RPM
120596
Based on the expected mode frequencies for space operations and the constraints of Heliogyro missions the controller is required to demonstrate a damping ratio of 00136
Intr
oduc
tion
8
Testing Constraintsbull Full scale blade cannot be built or tested
bull 22 meter blade analog will be used to simulate space environment
bull Controller can still be validated by showing it can function with blade conditions similar to those seen in space
bull Graviational forces will be present during testing
bull Centripetal force of the spinning spacecraft will be simulated with these gravitational forces
bull Air viscosity will contribute to damping
bull Damping provided by the controller will need to be distinguishable from damping provided by air
Intr
oduc
tion
9
Blade Controller RequirementsController housing must be able to accommodate one blade capable of providing useful acceleration (~350 m in length)
Controller must be able to pitch blades to plusmn 90deg with plusmn 5deg of accuracy
Controller must demonstrate a damping ratios for flapping and twisting modes of
Controller must be capable of sensing blade deflections without an ambient light source
Controller and blade occupy 2U of volume (10cm x 10cm x 20cm)
Controller must run on approximately 5 watts of power
Controller must conform to Cubesat weight requirement ~13 kgU total of 26 kg
Intr
oduc
tion
10
Design Solutionbull Blade housing can accommodate a
blade of 15 cm by 350 mbull Rotational actuator with a range of
motion of 360degbull Camera senses motion of blade
bull Closed loop controller damps oscillations
bull Linear actuator provides damping ratio of 00077 for flapping mode
bull Rotational actuator provides damping ratio of 0015 for twisting mode
bull LED near camera for low light conditionsbull Blade housing has 14U volume
electronics require 04U in CubeSat busbull Total of 18U
bull System requires 20 Wbull Total mass of 2 kg
Intr
oduc
tion
11
Blade Housing
Linear Actuator
Camera
Image Processor
Blade Analogue
7 cm
10 cm
20 cm
Intr
oduc
tion
12
CubeSat Bus
Microcontroller
Actuator Drivers
Rotational Actuator
Dimensions in cm
Kyle Edson
Fill in blanks better estimate on volume
Intr
oduc
tion
13
Rope Ladder Analogbull Current heliogyro reseach uses a rope ladder assumption to
investigate blade dynamicsbull Extremely thin sail material (264 thickness) has negligible internal forcesbull Assumes the sail blade material has no stiffness or internal damping
bull Rope ladder assumption allows for blades to be constructed from support materials alone for blade testingbull Reduction in surface area results in less damping being provided by airbull 22 meters in length
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
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43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
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62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
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64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
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67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
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69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
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85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
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91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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92
Camera Requirements Geometry
Bac
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93
Encoder Wiring
Bac
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94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Intr
oduc
tion
7
Mode FrequenciesEarth Behavior
bull Flapping Mode Frequenecy can be approximated as a pendulum
bull Period Depends on the bladersquos mass (M) moment of inertia (I) and center of gravity (R) measured from the blade root g remains constant for Earth testing
bull
bull The torsional mode is best estimated from the flapping mode
bull
Space Behaviorbull Frequencies directly tied to spacecraft angular
velocity
bull Angular velocities of proposed heliogyro missions typically ~13 RPM
120596
Based on the expected mode frequencies for space operations and the constraints of Heliogyro missions the controller is required to demonstrate a damping ratio of 00136
Intr
oduc
tion
8
Testing Constraintsbull Full scale blade cannot be built or tested
bull 22 meter blade analog will be used to simulate space environment
bull Controller can still be validated by showing it can function with blade conditions similar to those seen in space
bull Graviational forces will be present during testing
bull Centripetal force of the spinning spacecraft will be simulated with these gravitational forces
bull Air viscosity will contribute to damping
bull Damping provided by the controller will need to be distinguishable from damping provided by air
Intr
oduc
tion
9
Blade Controller RequirementsController housing must be able to accommodate one blade capable of providing useful acceleration (~350 m in length)
Controller must be able to pitch blades to plusmn 90deg with plusmn 5deg of accuracy
Controller must demonstrate a damping ratios for flapping and twisting modes of
Controller must be capable of sensing blade deflections without an ambient light source
Controller and blade occupy 2U of volume (10cm x 10cm x 20cm)
Controller must run on approximately 5 watts of power
Controller must conform to Cubesat weight requirement ~13 kgU total of 26 kg
Intr
oduc
tion
10
Design Solutionbull Blade housing can accommodate a
blade of 15 cm by 350 mbull Rotational actuator with a range of
motion of 360degbull Camera senses motion of blade
bull Closed loop controller damps oscillations
bull Linear actuator provides damping ratio of 00077 for flapping mode
bull Rotational actuator provides damping ratio of 0015 for twisting mode
bull LED near camera for low light conditionsbull Blade housing has 14U volume
electronics require 04U in CubeSat busbull Total of 18U
bull System requires 20 Wbull Total mass of 2 kg
Intr
oduc
tion
11
Blade Housing
Linear Actuator
Camera
Image Processor
Blade Analogue
7 cm
10 cm
20 cm
Intr
oduc
tion
12
CubeSat Bus
Microcontroller
Actuator Drivers
Rotational Actuator
Dimensions in cm
Kyle Edson
Fill in blanks better estimate on volume
Intr
oduc
tion
13
Rope Ladder Analogbull Current heliogyro reseach uses a rope ladder assumption to
investigate blade dynamicsbull Extremely thin sail material (264 thickness) has negligible internal forcesbull Assumes the sail blade material has no stiffness or internal damping
bull Rope ladder assumption allows for blades to be constructed from support materials alone for blade testingbull Reduction in surface area results in less damping being provided by airbull 22 meters in length
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
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85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
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89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
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90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
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91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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92
Camera Requirements Geometry
Bac
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93
Encoder Wiring
Bac
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94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
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95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
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96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Intr
oduc
tion
8
Testing Constraintsbull Full scale blade cannot be built or tested
bull 22 meter blade analog will be used to simulate space environment
bull Controller can still be validated by showing it can function with blade conditions similar to those seen in space
bull Graviational forces will be present during testing
bull Centripetal force of the spinning spacecraft will be simulated with these gravitational forces
bull Air viscosity will contribute to damping
bull Damping provided by the controller will need to be distinguishable from damping provided by air
Intr
oduc
tion
9
Blade Controller RequirementsController housing must be able to accommodate one blade capable of providing useful acceleration (~350 m in length)
Controller must be able to pitch blades to plusmn 90deg with plusmn 5deg of accuracy
Controller must demonstrate a damping ratios for flapping and twisting modes of
Controller must be capable of sensing blade deflections without an ambient light source
Controller and blade occupy 2U of volume (10cm x 10cm x 20cm)
Controller must run on approximately 5 watts of power
Controller must conform to Cubesat weight requirement ~13 kgU total of 26 kg
Intr
oduc
tion
10
Design Solutionbull Blade housing can accommodate a
blade of 15 cm by 350 mbull Rotational actuator with a range of
motion of 360degbull Camera senses motion of blade
bull Closed loop controller damps oscillations
bull Linear actuator provides damping ratio of 00077 for flapping mode
bull Rotational actuator provides damping ratio of 0015 for twisting mode
bull LED near camera for low light conditionsbull Blade housing has 14U volume
electronics require 04U in CubeSat busbull Total of 18U
bull System requires 20 Wbull Total mass of 2 kg
Intr
oduc
tion
11
Blade Housing
Linear Actuator
Camera
Image Processor
Blade Analogue
7 cm
10 cm
20 cm
Intr
oduc
tion
12
CubeSat Bus
Microcontroller
Actuator Drivers
Rotational Actuator
Dimensions in cm
Kyle Edson
Fill in blanks better estimate on volume
Intr
oduc
tion
13
Rope Ladder Analogbull Current heliogyro reseach uses a rope ladder assumption to
investigate blade dynamicsbull Extremely thin sail material (264 thickness) has negligible internal forcesbull Assumes the sail blade material has no stiffness or internal damping
bull Rope ladder assumption allows for blades to be constructed from support materials alone for blade testingbull Reduction in surface area results in less damping being provided by airbull 22 meters in length
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
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Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
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Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
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Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
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Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
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Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
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Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
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Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
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Requirements for Actuators
Linear accelerationAngular Acceleration
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Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
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Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
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Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
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Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
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Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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Linear Motion Requirement
θ
bull
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Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
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Gear Ratio bull
r
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Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
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94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
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RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Intr
oduc
tion
9
Blade Controller RequirementsController housing must be able to accommodate one blade capable of providing useful acceleration (~350 m in length)
Controller must be able to pitch blades to plusmn 90deg with plusmn 5deg of accuracy
Controller must demonstrate a damping ratios for flapping and twisting modes of
Controller must be capable of sensing blade deflections without an ambient light source
Controller and blade occupy 2U of volume (10cm x 10cm x 20cm)
Controller must run on approximately 5 watts of power
Controller must conform to Cubesat weight requirement ~13 kgU total of 26 kg
Intr
oduc
tion
10
Design Solutionbull Blade housing can accommodate a
blade of 15 cm by 350 mbull Rotational actuator with a range of
motion of 360degbull Camera senses motion of blade
bull Closed loop controller damps oscillations
bull Linear actuator provides damping ratio of 00077 for flapping mode
bull Rotational actuator provides damping ratio of 0015 for twisting mode
bull LED near camera for low light conditionsbull Blade housing has 14U volume
electronics require 04U in CubeSat busbull Total of 18U
bull System requires 20 Wbull Total mass of 2 kg
Intr
oduc
tion
11
Blade Housing
Linear Actuator
Camera
Image Processor
Blade Analogue
7 cm
10 cm
20 cm
Intr
oduc
tion
12
CubeSat Bus
Microcontroller
Actuator Drivers
Rotational Actuator
Dimensions in cm
Kyle Edson
Fill in blanks better estimate on volume
Intr
oduc
tion
13
Rope Ladder Analogbull Current heliogyro reseach uses a rope ladder assumption to
investigate blade dynamicsbull Extremely thin sail material (264 thickness) has negligible internal forcesbull Assumes the sail blade material has no stiffness or internal damping
bull Rope ladder assumption allows for blades to be constructed from support materials alone for blade testingbull Reduction in surface area results in less damping being provided by airbull 22 meters in length
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
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Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
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g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
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g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
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g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
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Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
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62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
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Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
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64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
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Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
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Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
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73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
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Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
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Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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Linear Motion Requirement
θ
bull
Bac
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82
Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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84
Gear Ratio bull
r
Bac
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85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
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87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
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88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
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89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
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90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
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91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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92
Camera Requirements Geometry
Bac
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93
Encoder Wiring
Bac
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94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
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95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
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96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Intr
oduc
tion
10
Design Solutionbull Blade housing can accommodate a
blade of 15 cm by 350 mbull Rotational actuator with a range of
motion of 360degbull Camera senses motion of blade
bull Closed loop controller damps oscillations
bull Linear actuator provides damping ratio of 00077 for flapping mode
bull Rotational actuator provides damping ratio of 0015 for twisting mode
bull LED near camera for low light conditionsbull Blade housing has 14U volume
electronics require 04U in CubeSat busbull Total of 18U
bull System requires 20 Wbull Total mass of 2 kg
Intr
oduc
tion
11
Blade Housing
Linear Actuator
Camera
Image Processor
Blade Analogue
7 cm
10 cm
20 cm
Intr
oduc
tion
12
CubeSat Bus
Microcontroller
Actuator Drivers
Rotational Actuator
Dimensions in cm
Kyle Edson
Fill in blanks better estimate on volume
Intr
oduc
tion
13
Rope Ladder Analogbull Current heliogyro reseach uses a rope ladder assumption to
investigate blade dynamicsbull Extremely thin sail material (264 thickness) has negligible internal forcesbull Assumes the sail blade material has no stiffness or internal damping
bull Rope ladder assumption allows for blades to be constructed from support materials alone for blade testingbull Reduction in surface area results in less damping being provided by airbull 22 meters in length
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
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57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
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67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
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80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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81
Linear Motion Requirement
θ
bull
Bac
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82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
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85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
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89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
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91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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92
Camera Requirements Geometry
Bac
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93
Encoder Wiring
Bac
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94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Intr
oduc
tion
11
Blade Housing
Linear Actuator
Camera
Image Processor
Blade Analogue
7 cm
10 cm
20 cm
Intr
oduc
tion
12
CubeSat Bus
Microcontroller
Actuator Drivers
Rotational Actuator
Dimensions in cm
Kyle Edson
Fill in blanks better estimate on volume
Intr
oduc
tion
13
Rope Ladder Analogbull Current heliogyro reseach uses a rope ladder assumption to
investigate blade dynamicsbull Extremely thin sail material (264 thickness) has negligible internal forcesbull Assumes the sail blade material has no stiffness or internal damping
bull Rope ladder assumption allows for blades to be constructed from support materials alone for blade testingbull Reduction in surface area results in less damping being provided by airbull 22 meters in length
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Intr
oduc
tion
12
CubeSat Bus
Microcontroller
Actuator Drivers
Rotational Actuator
Dimensions in cm
Kyle Edson
Fill in blanks better estimate on volume
Intr
oduc
tion
13
Rope Ladder Analogbull Current heliogyro reseach uses a rope ladder assumption to
investigate blade dynamicsbull Extremely thin sail material (264 thickness) has negligible internal forcesbull Assumes the sail blade material has no stiffness or internal damping
bull Rope ladder assumption allows for blades to be constructed from support materials alone for blade testingbull Reduction in surface area results in less damping being provided by airbull 22 meters in length
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Intr
oduc
tion
13
Rope Ladder Analogbull Current heliogyro reseach uses a rope ladder assumption to
investigate blade dynamicsbull Extremely thin sail material (264 thickness) has negligible internal forcesbull Assumes the sail blade material has no stiffness or internal damping
bull Rope ladder assumption allows for blades to be constructed from support materials alone for blade testingbull Reduction in surface area results in less damping being provided by airbull 22 meters in length
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
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28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
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29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
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36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
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38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
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39
Connection Diagram
Ele
ctro
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40
Power
Ele
ctro
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41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
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Software
Ele
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Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
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55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
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56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
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Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
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Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
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Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
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Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
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Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
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Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
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Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
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Requirements for Actuators
Linear accelerationAngular Acceleration
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Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
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Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
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Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
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Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
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Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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Linear Motion Requirement
θ
bull
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82
Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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84
Gear Ratio bull
r
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Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
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87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
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Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
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89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
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90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
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Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
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Camera Requirements Geometry
Bac
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Encoder Wiring
Bac
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Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
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RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
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LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Intr
oduc
tion
14
FBDBlade Housing
CubeSat Bus
Power Supply
LabVIEW VI(CubeSat processor)
Rotational Actuator
Linear Actuator
Camera
LED
Gum
stix
Arduino Due
Actuator Drivers
Mode Angle Rate (UART)Images
Voltage
Voltage
RS232 instructions
Angle Logic (UART)
Blade
Linear Motion
Pitching Motion
Legend
- Power
- Data
- Command
s
- Motion6 V
6 V
6 V
5 V
9 V
gt1 V
18 V
Intr
oduc
tion
15
Intr
oduc
tion
16
CPEs
bull Control Law
bull Actuators
bull Sensing
bull Electronics
Kyle Edson
Add updated CAD
Control Law
Con
trol
Law
18
Control Law Introduction
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
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28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
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29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
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40
Power
Ele
ctro
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41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
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g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
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Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
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g
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Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
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67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
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69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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81
Linear Motion Requirement
θ
bull
Bac
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82
Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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84
Gear Ratio bull
r
Bac
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85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
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87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
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89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
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90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
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91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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92
Camera Requirements Geometry
Bac
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93
Encoder Wiring
Bac
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94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
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95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
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96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Intr
oduc
tion
15
Intr
oduc
tion
16
CPEs
bull Control Law
bull Actuators
bull Sensing
bull Electronics
Kyle Edson
Add updated CAD
Control Law
Con
trol
Law
18
Control Law Introduction
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Intr
oduc
tion
16
CPEs
bull Control Law
bull Actuators
bull Sensing
bull Electronics
Kyle Edson
Add updated CAD
Control Law
Con
trol
Law
18
Control Law Introduction
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
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63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Control Law
Con
trol
Law
18
Control Law Introduction
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
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Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
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29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
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Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
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Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
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Work Plan
Sp
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reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
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Work Plan Critical Path
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Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
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Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
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Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
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Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
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Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
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Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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Requirements for Actuators
Linear accelerationAngular Acceleration
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Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
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Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
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Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
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Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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Linear Motion Requirement
θ
bull
Bac
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Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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84
Gear Ratio bull
r
Bac
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Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
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Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
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Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
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89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
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90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
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Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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Camera Requirements Geometry
Bac
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Encoder Wiring
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Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
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RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
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LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Con
trol
Law
18
Control Law Introduction
bull Control Law adds damping by moving the root based on movements at the tip of the solar sail
bull Control Law sets the requirements for the system Minimum resolution of the cameras Minimum range of motion (linearrotary) Minimum resolution of the actuators (linearrotary) Maximum computational time Minimum required acceleration
Con
trol
Law
19
Requirements For SensorsLinear sensor Rotary sensor
Minimum Sampling Rate
frac12 second frac12 second
Resolution gt5 degree gt5 degree
Con
trol
Law
20
Requirements For ActuatorsLinear Actuator Rotary
Actuator
Range of Motion +- 13 cm +- 90 degrees
Resolution 15 mm 3 degrees
Maximum acceleration
08 ms^2 10 rads^2
Con
trol
Law
21
Requirements For Computational Time
Twisting mode Flapping Mode
Max Computational Time frac14 second frac14 second
Con
trol
Law
22
Summary of the Control Law Flapping (Linear Motion)
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
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28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
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29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
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Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
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62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
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64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
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67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
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69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
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73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
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80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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81
Linear Motion Requirement
θ
bull
Bac
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82
Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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84
Gear Ratio bull
r
Bac
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85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
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91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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92
Camera Requirements Geometry
Bac
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93
Encoder Wiring
Bac
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94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
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95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
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96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
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55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
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g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
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g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
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62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
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63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
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64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
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67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
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69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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81
Linear Motion Requirement
θ
bull
Bac
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82
Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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84
Gear Ratio bull
r
Bac
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85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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92
Camera Requirements Geometry
Bac
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93
Encoder Wiring
Bac
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94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
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95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
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96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
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60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
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62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
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63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
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64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
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67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
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69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
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73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
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74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
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Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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81
Linear Motion Requirement
θ
bull
Bac
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82
Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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84
Gear Ratio bull
r
Bac
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85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
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87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
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88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
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89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
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90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
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Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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92
Camera Requirements Geometry
Bac
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93
Encoder Wiring
Bac
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94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
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RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
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LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
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29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
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33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
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36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
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38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
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39
Connection Diagram
Ele
ctro
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40
Power
Ele
ctro
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41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
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42
Software
Ele
ctro
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43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
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Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
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62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
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63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
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64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
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67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
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69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
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Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
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Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
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Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
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Linear Motion Requirement
θ
bull
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Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
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Gear Ratio bull
r
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Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
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87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
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88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
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89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
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90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
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Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
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Camera Requirements Geometry
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Encoder Wiring
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Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
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RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
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LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
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Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
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Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
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31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
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Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
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Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
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Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
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36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
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Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
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Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
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Connection Diagram
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Power
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Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
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Software
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Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
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Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
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Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
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Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
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Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
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Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
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Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
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Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
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Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
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Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
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Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
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Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
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Requirements for Actuators
Linear accelerationAngular Acceleration
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Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
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Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
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State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
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Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
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Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
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Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
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Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
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Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
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Linear Motion Requirement
θ
bull
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Binding Ratio
L
D
a
Bac
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Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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Gear Ratio bull
r
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Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
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87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
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88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
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89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
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90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
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Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
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Camera Requirements Geometry
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Encoder Wiring
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Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
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RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
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LED Light intensity 7000mcd Powered separately Alkaline battery
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include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
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Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
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Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
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Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
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Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
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Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
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36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
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37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
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Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
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Connection Diagram
Ele
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Power
Ele
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Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
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Software
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Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
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Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
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g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
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Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
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62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
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64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
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67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
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69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
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73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
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80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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81
Linear Motion Requirement
θ
bull
Bac
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82
Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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84
Gear Ratio bull
r
Bac
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85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
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90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
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91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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92
Camera Requirements Geometry
Bac
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93
Encoder Wiring
Bac
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94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
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95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
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96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
uato
rs
28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
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55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
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g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
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Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
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62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
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63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
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64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
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67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
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69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
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73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
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80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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81
Linear Motion Requirement
θ
bull
Bac
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82
Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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84
Gear Ratio bull
r
Bac
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85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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92
Camera Requirements Geometry
Bac
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93
Encoder Wiring
Bac
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94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
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95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
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96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
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28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
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29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
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Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
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Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
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Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
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Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
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36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
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38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
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39
Connection Diagram
Ele
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40
Power
Ele
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41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
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43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
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55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
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56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
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Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
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Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
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Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
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Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
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Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
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Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
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Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
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Requirements for Actuators
Linear accelerationAngular Acceleration
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Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
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Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
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State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
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Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
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Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
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Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
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Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
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Linear Motion Requirement
θ
bull
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Binding Ratio
L
D
a
Bac
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Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
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Gear Ratio bull
r
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Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
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Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
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Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
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Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
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Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
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Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
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Camera Requirements Geometry
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Encoder Wiring
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Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
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RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
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LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
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Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
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Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
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Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
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Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
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Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
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Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
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Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
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37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
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Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
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39
Connection Diagram
Ele
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Power
Ele
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Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
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Software
Ele
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Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
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Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
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Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
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Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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g
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Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
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Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
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Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
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Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
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Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
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67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
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69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
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73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
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74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
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80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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Linear Motion Requirement
θ
bull
Bac
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Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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Gear Ratio bull
r
Bac
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85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
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87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
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88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
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89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
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90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
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Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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Camera Requirements Geometry
Bac
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93
Encoder Wiring
Bac
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Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
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RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
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LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Electrical WiringTo ArduinoElectrical Wiring to Image Processor
Electrical Wiring to DriverFront View Deployed Blade
Deployed Blade
Act
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28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
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29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
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39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
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41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
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42
Software
Ele
ctro
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43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
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55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
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Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
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g
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Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
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g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
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Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
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Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
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Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
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Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
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Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
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Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
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Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
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Requirements for Actuators
Linear accelerationAngular Acceleration
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Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
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73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
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74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
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80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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Linear Motion Requirement
θ
bull
Bac
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Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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Gear Ratio bull
r
Bac
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Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
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89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
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90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
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91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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92
Camera Requirements Geometry
Bac
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93
Encoder Wiring
Bac
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Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
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RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
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LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Act
uato
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28
Linear Actuator Requirements and Solution
Actuator Requirement
Parent Requirement
SolutionLinear Servo Motor
Range of Motion +- 25 cm
Control Law Range of Motion +- 40 cm
Precision 45 mm Control Law Precision 004 mm
Velocity 31 cms Control Law Velocity 80 cms continuous
Force gt 053Nm Control Law Force 103 N continuous
Horizontal Length lt 25 mmAxial Length lt 93 mm
Design Horizontal Length 8 mmAxial Length 82 mm
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
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Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
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64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
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Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
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69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
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73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
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74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
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75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
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80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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Linear Motion Requirement
θ
bull
Bac
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82
Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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84
Gear Ratio bull
r
Bac
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85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
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86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
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87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
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88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
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89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
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90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
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91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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92
Camera Requirements Geometry
Bac
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93
Encoder Wiring
Bac
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Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
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95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
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LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Act
uato
rs
29
Mass Budget Housing Interface Assembly
Subsystem Components Mass
Mechanical -Hollow Precision Rod-Radial Bearing
-Turntable Bearing
-Mounting Components(Machined)
10 g
20g
30g
50g
Total Mass 110g
Requirement Design
Mass less than 26 kg
Total Mass 17 kg
Volume gt= 2U Total Volume 2U
Design Requirements
50 cm
318 cm
318 cm
1111 cm 4695 cm
75 cm
Electrical wires
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
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77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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81
Linear Motion Requirement
θ
bull
Bac
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82
Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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84
Gear Ratio bull
r
Bac
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85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
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92
Camera Requirements Geometry
Bac
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93
Encoder Wiring
Bac
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94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
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95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
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97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Sensing
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
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g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
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62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
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63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
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Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
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65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
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66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
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67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
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68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
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69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
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70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
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71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
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81
Linear Motion Requirement
θ
bull
Bac
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82
Binding Ratio
L
D
a
Bac
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83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
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84
Gear Ratio bull
r
Bac
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85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Sen
sing
31
Sensor Design
Camera is mounted inside the blade housing pointed towards one surface of the blade
Reflective tape will be placed on the blade facing the camera and will be illuminated via LEDs mounted to blade housing
Image processing algorithm will locate the center of the reflective tape within the camera frame and compare the location against the known position of the sensing point at no deflection
Blade will move between +- 20 degress for flapping oscillation and between +- 90 degrees for twsiting oscillation
Sen
sing
32
Camera Requirements and Selection
θmin= 5deg
θrange= 40deg
Camera Requirement Parent Requirement
Caspa VL
Field of View gt 436deg x 10deg
Blade Range of Motion
786deg x 593deg(752x480 Pixels)
Pixel Density gt 2 pixelsdegFOV
Blade Range of Motion
95 pixelsdegFOV
Frame Rate gt 2 fps Control Law 60 fps
Width = 257 cm
Length = 39 cm
Sen
sing
33
Range of Motion - Markers
ProcessedImage
Flap ModeMarkers movesame direction
Nominal marker
positions
Marker position at 20deg flap
ProcessedImage
Twist ModeMarkers move
opposite directions
Nominal marker
positions
Marker position at 90deg twist
The green box outlines the section of the image that needs to be processed It encompases a total area of 015 Megapixels
Deflection Angles
θtwist= +- 90deg θtwist per pixel= 106deg
θflap = +- 20deg θflap per pixel= 011deg
Sen
sing
34
Sensor Deflection Calculations
Raw Image Filtered Binary Image
50 lt L lt 255 0 lt Cr lt 125 0 lt Cb lt 255
Marker 1328 626
Marker 2396 624
Marker Centroid Locations In
Pixels
Flap angle ~0 degrees
Twist angle ~0 degrees
Deflection Angles Calculated1cm x 1cm teflon tape
markers located 2 meters from the camera
Electronics
Ele
ctro
nics
36
Motor Controller
To Bus
To Gumstix From Gumstix
From Bus
84 MHz Processor
Requirements Arduino DUE
2 Receive and 2 Transmit Pins
4 Receive and 4 Transmit Pins
2 USB Ports 2 USB Ports
Fit in 2U CubeSat Volume
1016 cm x 5334 cm
Serial Receive and Transmit Pins(TTL)
1016 cm
5334 cm
Language based on C
Ele
ctro
nics
37
Image Processor Overo
Ribbon Connection
Mini SD Card Slot
1 GHz Processor
Ribbon Connection built to be compatible with selected camera (Caspa VL)
1 GHz processor512 MB RAM (81 MB in imagessec)Mini SD Card slot for additional storage
Requirements Overo
Interface with camera Ribbon Connection
Provide angular rate and mode at least 2 times a second
Predicted to give angular rate and mode 7 times a second
Store up to 48 Gigabytes in images from camera
Mini SD Card slot allows up to 64 GB SD Card
Fit in 2U CubeSat Volume 58 cm x 17 cm x 042 cm
1 USB Port No USB Port Need Expansion Board
17 cm
58 cm
042 cm
Runs Linux (Ubuntu) code written in C image processing library is OpenCV
Ele
ctro
nics
38
Expansion Board Pinto
762 cm
23 cm
USB Port
Requirements Pinto
1 USB Port 1 USB Port
Interface with Overo Connects directly to Overo
Overo Connector
Overo Connector
Ele
ctro
nics
39
Connection Diagram
Ele
ctro
nics
40
Power
Ele
ctro
nics
41
Power BudgetDevice Source Voltage
RequirementsCurrent Draw Continuously
PoweredPower
Encoder Faulhaber 45-55 V 9 mA Yes 004-005 W
Linear Motor and controller
Faulhaber 5 V 278 mA No 139 W
Rotary Motor and controller
Faulhaber 5 V 27 A No 134 W
Pinto-TH Gumstix Overo 5 V 250 mA Yes 125 W
Airstorm-P Gumstix Overo 4 V 250 mA Yes 1 W
Arduino Due SparkFun 7-12 V 50 mA Yes 035 - 06 W
(2x TTL-RS232 converters)
SparkFun 33 V 10 mA Yes 007 W
LED Thumb Lite 15 V 400 mA Yes 06 W
Peak Power 185 - 188 W
Continuous Power 41 - 44 W
Ele
ctro
nics
42
Software
Ele
ctro
nics
43
Image Processor
Component What it Does Time
Receive Image Enable 91 bits at 9600 baud 00095 sec
Camera ActuationStore Takes picturestores picture
00167 sec
Image Processing Function Calculates Angle Rate Mode
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Contingency Plan Testing can be performed in a lighted environment Cameras can be moved to closer to the markers
Risk 2 Controller requires faster sampling than the sensors can provide
Contingency Plan Larger blades (~4m) can be tested decreasing mode frequencies and sampling rate requirments by (~50) Electronic baud rates can be increased from 9600 to 57600 Baud
Risk 3 Mode coupling disrupts operation of the Controller
Contingency Plan Smaller gains can be applied to the controller Modes of the blade can be excited mechanically Larger tip masses can be used to give the blade more in
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Project Planning
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Pla
nnin
g
55
Organizational Chart
SPECTRE
Micheal Andrews
Software Lead
Financial Coordinator
Brendon Barela
Manufacturing Lead
Austin Cerny
Testing Lead
Project Manager
Corinne Desroches
Electronics Lead
Kyle Edson
Systems Lead
Safety Lead
Conrad Gabel
Mechanical Lead
Chris Riesco
Sensing Lead
Justin Yong
Controls Lead
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Pla
nnin
g
56
Work Breakdown Structure
SPECTRE
ManufacturingTesting
Bus Assembly
Blade Root Housing Assembly
Test Blade Analog
Mechanical
Installed Linear Actuator
Installed Rotary Actuator
Installed Gearbox Connection
Software
C++ Image Processing Algorithm
C++ Control Law Algorithm
Controls
Torsional Mode Model
Flapping Mode Model
Electronics
Installed Motor Controller
Installed Image Processor
Systems
Power Connection to all Electronic
Components
ControllerDriver Interface
Connection
Image ProcessorControlle
r Interface Connection
Sensing
Installed Cameras
Image Processing Subsystem
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Pla
nnin
g
57
Work Plan
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Pla
nnin
g
58
Work Plan Critical Path
Sp
rin
g B
reak
Classes Start MSR TRR Spring Final Report Symposium
ManufacturingSoftwareMechanicalElectricalSystems
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Pla
nnin
g
59
Cost Plan
Component Number Needed
Lead Times (Weeks)
Cost per Component
Total Price
Overo Firestorm-P 1 3 $15900 $ 15900
Pinto 1 3 $ 2750 $ 2750
Power Adapters 2 3 $ 1000 $ 2000
Caspa VL 1 3 $ 7500 $ 7500
Micro SD 1 0 $ 5000 $ 5000
Arduino DUE 1 6-8 $ 5000 $ 5000
USB Cable 3 0 $ 300 $ 900
Linear Motor 1 3 $69000 $ 69000
Linear Motor Driver 1 8 $22600 $ 22600
Rotary Motor 1 3 $22000 $ 22000
Rotary Motor Driver 1 6-8 $22600 $ 22600
LEDs 2 0 $ 1000 $ 1000
Aluminum Sheet 1 1 $ 5000 $ 5000
Misc Wires 0 $10000 $ 10000
Misc Screws 0 $10000 $ 10000
Rotary Encoder 1 3 $ 5000 $ 5000
Hardened Steel Shaft 1 1 $ 2400 $ 2400
Linear Bearing with Pillow Block 1 1 $ 4000 $ 4000
Shaft Support 2 1 $ 4400 $ 4400
Bevel Gear 1 1 $ 5000 $ 5000
Turntable Bearing 1 1 $ 500 $ 500
Radial Berings 1 1 $ 500 $ 500
Precision Shaft (hollow) 1 1 $ 4000 $ 4000
Mounting Components 1 1 $ 4000 $ 4000
TOTAL $ 230050
Margin=$269950
gt50 Total Budget
enough to repurchase every component in case of failure
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Pla
nnin
g
60
Test Plan
TestApproxima
te DateDescription Purpose
Sensors Collecting Data
EquipmentFacilities Needed
1 Feb 2 -9Camera Takes Image of
Test BladeMarkers
Ensure markers are visible and Image Processesing
Filter is accurateOvero Camera
Dark 1 Story Room 1-4 wall outlets
1-4 power supplies
2 March 2-9
Blade Flapping and Pitching Modes are
Excited and Filmed With Camera
Confirm sensors are installed correctly and angle measurement
sampling rate is sufficent
Overo Camera
3March 9 -
16Blade Is Commanded to
Pitch 90 degrees
Confirm actuatorsdrivers are correctly installed controller has required
range of motion
Rotary Encoder
4 April 6-20Blade Flapping and Pitching Modes are
Excited and Damped
VerficationValidation of Controller
Rotary Encoder Overo Camera
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Backup Slides
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
62
Frequency Testing Tested Bladesbull Several ldquoRope Ladderrdquo blades with similar masses to sail blades of the same area were built to
test the accuracy of the frequency estimatesbull Modes were excited manually and filmed to observe frequenciesbull Blade Frequencies matched predicted frequencies lt 3 error
Blade Length (m)Width (m) AR Mblade(g) Mtip(g)
1 15 01 15 0034 012
2 15 01 15 0034 204
3 1 01 10 0023 013
4 15 02 75 0034 024
Blade
Predicte
d
Observe
d
Error
Predicted
Observe
d
Error
1 0420 0428 200 0588 0600 204
2 0407 0400 171 0571 0577 105
3 0509 0508 004 07122 0732 273
4 0414 0417 072 0579 0588 115
Scaled Test Blade Being Filmed
MarkerCameraMotion of
Blade
Blade Tip
Bac
kups
63
Damping RatiosBlades oscillations need to be small enough to preserve 95 of the
surface area of the blade exposed to the solar flux
TwistingMaximum amplitude of 125 minute window (18 orbital period in LEO) for blades to settle201 radminute oscillation frequency
FlappingMaximum amplitudes (~1-2) always less than50 damping in frac12 orbital period (45 minutes)293 radminute oscillation frequency
Bac
kups
64
Time Requirements
The Controller Continues to act like a controller at 91 seconds
At 1 second the controller does not display the desired characteristics
1 second Time step91 Second Time step
Bac
kups
65
Requirement for Actuators
Linear Actuator Position Rotary Actuator Position
Bac
kups
66
Requirements for Rotary Actuators
Resolution of 3 degreeResolution of 4 degree
Bac
kups
67
Requirements for Linear Actuators
Resolution of 14mmResolution of 3mm
Bac
kups
68
Requirements for Actuators
Linear accelerationAngular Acceleration
Bac
kups
69
Requirements for damping system
Addition of ⅓ computation time
Flapping ModeTwisting Mode
Bac
kups
70
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
71
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
72
State Space model Twisting Mode Kgyro is non existent in
the earth setting only 2-DOF were used
for the model
Bac
kups
73
Membrane-Ladder Assumption
Assumes no materialstructural damping
The membrane in between the elements are mass-less
Experimental results have shown good correlation with this FEM theory
Can accurately predict the motion of the pitching mode
Gyroscopic stiffness is not included on earth
Centripetal stiffness is now sitffness by gravity
SourceHeliogyro Solar Sail Blade Twist Stability Analysis of Root and Reflectivity Controllers
Bac
kups
74
Control Law Assumptions
The Solar Sail material has almost no material damping
Without the Control Law the flapping mode of the solar sail acts like an air damped pendulum
The twisting and flapping mode are considered uncoupled and can not influence each other
Root
Tip
Solar Sail
Bac
kups
75
Control Law Design
Takes in the error in the deflection angle from the reference angle
Outputs the Moment produced at the root
Bac
kups
76
Control Law Design
Takes in the moment needed to damp the solar sail
Exports the deflection of the solar sail
u = Mroot
Bac
kups
77
Key Elements to be PurchasedElement Manufacturer
SupplierModel Number Cost Lead Time
Rotary Motor FaulhaberMicromo BLDC 0824D $22000 1-3 weeks
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
79
Parallel Shaft Misalignment MitigationProblem Shafts are misaligned from shaft support tolerancemisalignmentSolutionReduce Size of spool rod by expect misalignment dx total
dx2dx1
dxtotal =dx1+dx2
bearings
Spool rod
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
80
Linear actuation Tolerancing
dx1
θ1
θ2
L
θ
1
θ1 = θ2
dx = Lsin(θ1 )θ1max = 1o
dx1max allowable = 01108 mm
dx2
dx2 = tolerance in shaft support s= 0003rdquo=0076 mm (worst case)
Shaft Hardness = 015192 mmfootdx3 = 008 mm
dx3
Max Possible Error = dx2 + dx3 = 0156 mm = 17o
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
81
Linear Motion Requirement
θ
bull
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
82
Binding Ratio
L
D
a
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
83
Binding Preventionbull Lever arm distance = 15cm
bull Can prevent binding by increasing length between bearings or by decreasing μs
bull For typical ball bearing μs = 0005 need L gt15 mm
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
84
Gear Ratio bull
r
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
85
Gear Backlashbull 21 Gear Ratio with 2cm
radius gear translates into 0350 mm (0014 in) backlash for a 1o error
bull Backlash = Rθ
bull Diametral Pitch of 24-48 gives accuracy of 015o
R = 2cm
Θmax=1oBacklash
Average stock Gear Backlash(Bevel Gear)
httpwwwbostongearcompdfgear_theorypdf
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
86
Image Processing in Space
Image processing methods are similar for space applications
Oscillations seen at any point along the blade can be used to extrapolate the state of the 350m blade
Sensing the blade at a location 2m from the root will require similar camera characteristics for the flapping mode
The twisting mode will require a smaller field of view and higher specific resolution
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
87
Expected Deflections (Flapping)
In the flapping mode the flap angle of the blade is constant over the entire length of the blade (simple pendulum assumption)
Sensing a point at 2m from the root will have identical requirements to our testing case The same camera can be used to detect the full range of flapping motion
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
88
Expected Deflections (Twisting)
In the twisting mode the twist angle increases along the length of the blade
Deflections seen at a location 2m from the root will have a displacement of ~1 times that of the tip
This narrows the required field of view of the camera to sense the small motions of the sensing point
The resolution requirement (pixelsdegFOV) is unchanged
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
89
Camera Requirements (Space)
To accommodate small twisting mode deflections the field of view must be changed from 437deg to 023deg
This can be done through optical zoom requiring a focusing lens being added to the camera system
The lens must supply 190x optical zoom
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
90
Camera Setup (Space)
The flapping mode requires an unchanged field of view and the twisting mode requires a significantly smaller field of view
It is proposed that two separate cameras are used Each is mounted within the blade housing on separate sides of the blade
Integrating the 190x focusing lens with one of the two cameras will allow the sensing of both modes independently
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
91
Camera Requirements Geometry
α = Vertical angle from camera axis to sensing location
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
92
Camera Requirements Geometry
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
93
Encoder Wiring
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt
Critical Design Review SPECTRE Solar-sail Pitch Enabling Contro
Briefing Overview and Context
Heliogyro Background
Solar Sail Blade Material
Orbital Operations
Blade Oscillations
Mode Frequencies
Testing Constraints
Blade Controller Requirements
Design Solution
Blade Housing
CubeSat Bus
Rope Ladder Analog
FBD
Slide 15
CPEs
Control Law
Control Law Introduction
Requirements For Sensors
Requirements For Actuators
Requirements For Computational Time
Summary of the Control Law
Actuators
Actuation Design
Mass Budget
Rotary Actuator Requirements and Solution
Mass Budget (2)
Linear Actuator Requirements and Solution
Slide 29
Sensing
Sensor Design
Camera Requirements and Selection
Range of Motion - Markers
Sensor Deflection Calculations
Electronics
Motor Controller
Image Processor Overo
Expansion Board Pinto
Connection Diagram
Power
Power Budget
Software
Image Processor
Motor Controller (2)
Verification and Validation
Test Setup
Manual Mode Excitation
Test Setup Air Damping
Flapping mode Control Law
Twisting Mode Control Law
Project Risk
Risk Assessment
Risk Management
Project Planning
Organizational Chart
Work Breakdown Structure
Work Plan
Work Plan Critical Path
Cost Plan
Test Plan
Backup Slides
Frequency Testing Tested Blades
Damping Ratios
Time Requirements
Requirement for Actuators
Requirements for Rotary Actuators
Requirements for Linear Actuators
Requirements for Actuators
Requirements for damping system
Control Law Design
Control Law Design (2)
State Space model Twisting Mode
Membrane-Ladder Assumption
Control Law Assumptions
Control Law Design (3)
Control Law Design (4)
Key Elements to be Purchased
Mechanical Components to be Purchased
Parallel Shaft Misalignment Mitigation
Linear actuation Tolerancing
Linear Motion Requirement
Binding Ratio
Binding Prevention
Gear Ratio
Gear Backlash
Image Processing in Space
Expected Deflections (Flapping)
Expected Deflections (Twisting)
Camera Requirements (Space)
Camera Setup (Space)
Camera Requirements Geometry
Camera Requirements Geometry (2)
Encoder Wiring
Motor Power
RS232 Level Shifter
LED
Slide 97
Labview Setup
Image Processing and Motor Control
Motor Controller Code
Image Processor Code
Communication Drivers
Arduino Functions
Camera Drivers ISP
Bac
kups
94
Motor PowerRotary motor Back-EMF constant 0624 mVrmp Current constant 0168 AmNm 03 mNm maximum 96 rpm 595 mV at 27 A (minimum 5V for driverhall sensors)
Linear Motor Back-EMF constant 158 V(ms) Force constant 194 NA Maximum force 054 N maximum speed 5 cms 0079 V at 278 mA (minimum 5V for driverhall sensors)
Bac
kups
95
RS232 Level Shifter
TTL Serial interface and supply(Rx Tx GndUcc)
DB9 female connector (RS232)
Max baud rate 115200 bpsVariable voltage level depends on TTL level able to run on 33 V
Bac
kups
96
LED Light intensity 7000mcd Powered separately Alkaline battery
Bac
kups
97
include ltstdiohgt include ltstdlibhgt include ltusrlocalopencv-249includeopencvcvhgt include ltmathhgt