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Brian Saghy (CE) Team Leader & Programming Lead
Alejandro Lam (EE) Integration Lead
Nathan Pendleton (EE) Electronics Lead
Brian Payant (EE) E&M Lead
Gaurav Patel (ME) Mechanical Lead
Multidisciplinary Engineering Senior Design
Project 05400 Construction of 3-D Objects and Displays
using Swarms of Intelligent Microsystems
Preliminary Design ReviewMay 11, 2005
Presentation Overview
• Introduction
• Past Work
• Detailed Description Gen1b
• Problems with Gen1b
• Critical Parameters
• Requirements
• Project Plan
• Redesign Concepts, Ideas, and Feasibility Assessments
• Future Considerations
• Summary
• Questions
Project Introduction and History
Swarms of small, intelligent objects can form a large shape.
Future MEMS technology could make for microscopic robot.
Previous Work Inertial Drive
Does not work due to lack of static friction in fluid, and symmetric design.
Previous WorkMagnetic Field Propulsion•Tank has six high power magnetic coils on each side
•Chunxil drives itself by turning on internal coils to attract it to the desired wall
•Chunxil is able to determine location in tank by the strength of the EMF fields induced by the external coils
•Control Problems
Timing Diagram
N S E W F B N S E W F B W
N S E W F B N N S E W F B B N
S E W F B E N S E W F B S N S
E W F B F N S E W F B N N S E
Wake Up Signal Post Wake Up Delay Sleep Timer Running
North AC Signal Asserts Interrupt,
Begin GETAC routineDELD2 used here
DELAC used hereDELDC used here
600ms 2000ms 1200ms 1000ms
DELD2 used here
Considerations and Objectives
•Our main goal during this term is the control of the Chunxil •Secondary goals include assembly ease, modularity, programmability and charging ease.•Start with small steps, rather than trying to tackle the whole project at once. Start with 1 Dimension.•Utilize improvements over the last few years in microcontrollers and batteries
Critical Parameters-----------------ENGINEERING CHARACTERISTICS-------------------
Chunxil Redesign Rev1C RE
LA
TIV
E I
MP
OR
TA
NC
E*
Bat
tery
Siz
e
Bat
tery
Life
Bat
tery
Vol
tage
Bat
tery
Cha
rge
Tim
e
Max
imum
Bat
tery
Cur
rent
Mic
ropr
oces
sor
Siz
e
Mic
ropr
oces
sor
Cur
rent
Mic
ropr
oces
sor
Vol
tage
Mic
ropr
oces
sor
Spe
ed
Mic
ropr
oces
sor
A-D
res
olut
ion
Mic
ropr
oces
sor
Re-
prog
ram
abili
ty
Inte
rnal
Coi
l Sha
pe a
nd U
nifo
rmity
Inte
rnal
Coi
l Siz
e
Inte
rnal
Coi
l Gau
ge
Inte
rnal
Coi
l Cur
rent
Inte
rnal
Coi
l # T
urns
Ext
erna
l Coi
l Sha
pe a
nd U
nifo
rmity
Ext
erna
l Coi
l Siz
e
Ext
erna
l Coi
l Gau
ge
Ext
erna
l Coi
l Cur
rent
Ext
erna
l Coi
l # T
urns
Tan
k D
imen
sion
s
Chu
nxil
Sha
pe
Chu
nxil
Dim
ensi
ons
Str
aigh
tnes
s of
Fie
ld L
ines
Wat
erpr
oofin
g
CUSTOMER REQUIREMENTS mm mAhV hr mA mm mA V Hz bits mm GaugemA turns mm GaugemA turnsin in degrees1 Run Time 6 10 6 4 6 6 102 Speed 4 3 8 8 8 3 8 8 8 7 73 Reliability and Control 10 3 3 4 8 5 5 7 9 8 2 104 Small Chunxil Size ( < 1") 8 7 7 8 8 105 Large Tank Size 4 8 106 Chunxil can move in three dimensions2 8 9 107 System Operation Power Usage 3 2 2 108 Safe to operate 4 3 8 9 79 Chunxil is easily visible 8 10 7 7 5 4
10 Nesting of Multiple Chunxils 2 10 511 Sustainability/Upgradability 10 8 8 10 5 9
ABSOLUTE IMPORTANCE 56 170 42 86 54 56 36 36 56 98 100 62 146 12 92 96 82 234 88 98 32 124 100 178 170 150RELATIVE IMPORTANCE 0.2 0.7 0.2 0.4 0.2 0.2 0.2 0.2 0.2 0.4 0.4 0.3 0.6 0.1 0.4 0.4 0.4 1 0.4 0.4 0.1 0.5 0.4 0.8 0.7 0.6
* 10 = ABSOLUTELY ESSENTIAL, 7 = VERY IMPORTANT, 5 = MODERATLY IMPORTANT, 3 = NOT VERY IMPORTANT, 1 = UNIMPORTANT
** 10 = CR DRIVEN BY THIS PARAMETER, 5 = CR MODERATELY INFLUENCED BY THIS PARAMETER, 1 = CR NOT SIGNIFICANTLY INFLUENCED BY THIS PARAMETER
RequirementsHigh-level Objectives • An small intelligent robot, called a Chunxil, shall be designed to navigate to a
predetermined position within somewhere in a constrained 3-D space, most likely ocupied by a fluid.
• As a method of control, only 1-dimensional positioning will be required for the scope of this project.
• If One-Dimension is attained, then multiple dimensions will be explored, given appropriate amount of time.
• The Chunxil should be designed with nano-technology limits in mind. Extra hardware should be avoided if possible, considering the possibility of placing the entire chunxil in a system-on-chip configuration for future generations. The less things used in the Chunxil, the more feasible it would be to get them to a very small size at a low production cost.
Size and Shape a. Tank • The Tank size shall remain the same as before, a cube, 6"x6"x6" +- 0.5". b. Chunxil • The Chunxil's weight, height, nor depth shall excede 1" in dimension. • The Chunxil shall be a regular shape such that it can nest, or at least sit
plush with another Chunxil. • The Chunxil enclosure should be designed for relatively easy replication,
allowing for multiple Chunxils to be built for testing.
RequirementsMotion • The first revision of this project shall be designed to limit the
Chunxil to 1-dimension of motion. Should this task be accomplished, then more dimensions of freedom will be granted.
• The values should be able to be programmed statically, meaning that each Chunxil is pre-programed with a pre-determined numeric set of data corresponding to a location in the tank.
• The Chunxil shall be able to move to and maintain a position in within 1/4th of the measured diameter of the Chunxil from any starting position within the given working dimension.
• Discrete positions shall be defined within the tank,with corresponding values that should be programmed in the Chunxil to achieve such positions.
• In one dimension, tilt of axis (spinning and rotation) is not of concern. However, in two or more dimensions the angle of the chunxil from any wall of the tank shall not excede 10 degrees.
Weight a. DistributionThe center of mass of the Chunxil shall be +- 10% of the measured physical center. b. Density The Chunxil shall be neutrally bouyant, +- 10% of the density of the medium (liquid) in the tank.
RequirementsPower • The minimum battery shall be defined as supplying enough energy for the
Chunxil• to make 10 round trip cycles from extreme opposite corners of the tank. • The battery shall be rechargeable. • The battery must conform to the Chunxil Size and Weight requirements. • Recharging time should be under 5 hours. • Charging nor tank operation shall excede the wall power, voltage or
current• specifications defined by RGE and safety regulations. Visibility • The medium (liquid) in the tank shall be transparent. • The sides of the tank shall be at least 80% visible, defined by surface area
of visible• portion to non-visible portion.
RequirementsSafety • All external wires on the tank shall be insulated. • Electrical components shall be isolated from the liquid
medium. • Coil current should be within reasonable specifications for the
given amount of time that they are powered. • No component shall excede temperature capable of burning
human skin or starting fire. If such a component can occur, it shall be properly cooled and shielded.
Modularity and Sustainability • The Chunxil shall be reprogrammible without replacing any
physical parts. • The Chunxil should not have to be opened for programming,
recharging the batteries, or connecting to a debugger. • Each Chunxil shall have a standard, compatible method to
program, recharge, and debug so that the same programming and charging device can be used for all Chunxils.
-3/2 0 N1 N2 I1 I2 R12 A2 z
Force = --------------------------------- (R1
2 + z2)5/2
X
Y
Z
External coil
Internal coil
With: R1 = radius of the external coilR2 = radius of internal coilN1 = Number of turns of the external coilN2 = Number of turns of the internal coil
And the distance X, Y and Z:
dt
di
XRZYX
XRRNN
emf *)(2
)(******
2/3221
222
22
22
1210
Force Equations
Stabilization of Chunxil Axes
1) Widen Tank CoilsAdvantages:
Straighten Field Lines Inside Tank.
Increase Visibility
Disadvantages:
Physical Modification of Tank
Invalidate Past EMF Values
Stabilization of Chunxil Axes
2) Simultaneous Activation of Opposite Coils Inside Chunxil
Advantages:
Greater Resistance to Spin
Opposing Field Directions on Opposite Chunxil Faces
Disadvantages:
Greater Power Consumption in Chunxil
More Complex Circuitry
More Complex Mathematical Model
Stabilization of Chunxil Axes
2) Simultaneous Activation of Opposite Coils Inside Chunxil
Advantages:
Greater Resistance to Spin
Opposing Field Directions on Opposite Chunxil Faces
Disadvantages:
Greater Power Consumption in Chunxil
More Complex Circuitry
More Complex Mathematical Model
Stabilization of Chunxil Axes
3) Simultaneous Activation of Opposite Coils On Tank
Advantages:
Straightens Field Lines Inside Tank
Disadvantages:
Needs Two Coils Inside Coil Activated
Greater Chance of Chunxil Spinning on “Pushing” Half of the Tank
More Complex Tank Circuitry
More Complex Mathematical Model
Stabilization of Chunxil AxesHybrid Model
Movement Cycle External InternalE W E W
West to East - West Side of Tank 1a + On On1b + - Off Off
West to East - East Side of Tank 1a + On On1b + - On On
+ = “Pulls Toward”
- = “ Pushes Away”
Velocity Control
• Increase Tank Coil Diameters
• Decrease Current
• Lessen # of Turns on Coil
• Pulse Coils
Electronics Requirements
• The electronics should not take up more than 50% of the volume of a 1” cube Chunxil.(Leaving 50% volume for the coils.)
• Chunxils will be pre-programmed to a specific route, but must be easily reprogrammed.
• The battery must be rechargeable, & able to recharge in less than 5 hours.
• A Chunxil shall be recharged, reprogrammed & debugged without being disassembled.
• All Chunxils must conform to a common interface standard, such that a universal reprogramming, recharging, and debugging method can easily be used for all Chunxils.
• A Chunxil must be able to make 10 round trip cycles across the diagonal of the tank.
Battery Feasibility AssessmentEvaluate each additional concept
againstthe baseline, score each attribute as:
1 = much worse than baseline concept2 = worse than baseline3 = same as baseline4 = better than baseline5 = much better than baseline
[Presumed][Presumed]SanyoSanyo
CR-1/3NCR-1/3N LIR2032LIR2032 LIR2430LIR2430 LIR2450LIR2450 LIR2477LIR2477
Rela
tive W
eig
ht
Rela
tive W
eig
ht
Weight / Mass (grams)Weight / Mass (grams) 3.0 3 2 1 1 14%
Size (mm)Size (mm) 3.0 5 4 3 1 25%
Voltage (v)Voltage (v) 3.0 4 4 4 4 11%
Normal Capacity (mAh)Normal Capacity (mAh) 3.0 1 1 2 3 18%
Max. Discharge rate [continuous] (mA)Max. Discharge rate [continuous] (mA) 3.0 4 4 5 5 21%
Internal Impedance (ohms)Internal Impedance (ohms) 3.0 4 4 5 5 0%
Average Lifespan (cycles)Average Lifespan (cycles) 3.0 3 3 3 3 4%
Price ($)Price ($) 3.0 5 5 5 4 7%
Weighted ScoreWeighted Score 3.0 3.6 3.2 3.2 2.8
Normalized ScoreNormalized Score 83.2% 100.0% 89.1% 89.1% 78.2%
Battery Specifications
• LiR2032 Rechargeable Li-Ion coin cell
• 3.7 V nominal voltage
• 35mAh nominal capacity
• 70mA Max. drain current
– Dimensions: 20mm dia. * 3.2mm thick
• Mass: 3.0 grams
• Unit price: $1.26
PIC Choices
Desired Traits:
•Reprogrammable
•Low Power
•Backward compatible with current code
•High Resolution A-D Converter
•Programmable in-circuit
PIC Feasibility AssessmentEvaluate each additional concept against
the baseline, score each attribute as: 1
= much worse than baseline concept 2 =
worse than baseline 3 = same as
baseline 4 = better than baseline 5=
much better than baseline
Cur
rent
( P
IC16
C17
6)
PIC 1
6F819
Pic
16F88
Pic
18F13
20
TI
MS
P430F11
3
Rel
ativ
e W
eigh
t
Suffi cient Student Skills? 3.0 3.0 3.0 3.0 1.0 2%
Size/ Weight/ Nano-Feasibility 3.0 3.0 3.0 2.0 1.0 13%
Cost of Chips 3.0 3.0 3.0 2.0 3.0 8%
Cost of Programmer,Burner, and Sof tware 3.0 3.0 3.0 3.0 1.0 3%
Compatible I SA 3.0 2.0 2.0 1.0 1.0 10%
Compatible Pin Layout/ Voltages 3.0 2.0 2.0 2.0 1.0 5%
Memory (Flash, Ram) 3.0 4.0 5.0 5.0 5.0 13%
Program in-circuit 3.0 5.0 5.0 5.0 5.0 12%
Suffi cient bit-ADC 3.0 4.0 4.0 4.0 4.0 18%
Power Usage 3.0 5.0 5.0 4.0 1.0 15%
Hardware Multiplier 3.0 3.0 3.0 5.0 5.0 3%
Low-Power Programming 3.0 5.0 5.0 3.0 5.0 5%
Weighted Score 3.3 4.1 4.2 3.7 3.1
Normalized Score 77.7% 96.8% 100.0% 88.0% 74.9%
Cube Feasibility Assessment*Evaluate each additional concept against
the baseline, score each attribute as: 1
= much worse than baseline concept 2 =
worse than baseline 3 = same as baseline
4 = better than baseline 5= much better
than baseline
Cur
rent
Chu
nxel
Cub
e (6
Sep
arat
e
Sid
es)
Prot
otyp
e 1:
Tw
o
shel
ls p
ut t
ogue
ther
Prot
otyp
e 2: U
se o
f
Exi
stin
g
Com
mer
cial
ly
Ava
ilable
1*1
*1 inc
h
Rel
ativ
e W
eigh
t
Chunxil Cube Size 3.0 1 5 25%
I nner Space for other components 3.0 2 4 21%
Waterproofi ng Capabilities 3.0 3 3 18%
Cost of Purchased Components? 3.0 4 2 4%
Ease of Assembly of a Full Chunxil
Everything I nside 3.0 2 4 7%
Modularity of Physical Parameter 3.0 3 3 7%
Nesting Ability 3.0 4 2 4%
Charging and Programming I nterface 3.0 5 1 14%
Weighted Score 3.0 2.6 3.4
Normalized Score 87.5% 75.0% 100.0%
Future Implementations & Ideas
• Recharging and Programming using only inductors (No physical Connection)
• Wireless control of the Chunxil
• Use of multicolor LED’s inside, for color replications. Will add realism to the shape formed
•Making it smaller and smaller.. nanotechnology
•“Freeze Mode” after Chunxils are all nested together.
INIT
RUN
calculate target differences
reset sleep timer
record NOIZ
wait for int, check flags
Power On
None
go flagsleep flag
interruptturn off a-d, etc
clear flagsenable ints,a-d,etcreset sleep timer
SLEEP
disable interrupts
wait for port b sig
meas VX,VY,VZcheck alignment
calc positon diffs
set move flagsif unaligned, set all move flags
set drive flags
stall .5 ac cycle
stall dc time
clear outputs++DCCNT
stall down time 2
re-enable interruptsclear flags
reset sleep timer
DCCNT==6?
drive flag,DCCNT==1?
stall down time
drive a coilyes
no
clr DCCNT
no
set SLP flag
save state
check source of interrupt
set GO flagdisable port b int
reset sleep timer
disable sleep timer
restore state
port b intothersleep timeout
interrupt GO FLGSLP FLG
Proteus Gen 1B Control Flow Chart
Proteus Gen 1B Communications Cycle
N S E W F B N S E W F B W
N S E W F B N N S E W F B B N
S E W F B E N S E W F B S N S
E W F B F N S E W F B N N S E
Wake Up Signal Post Wake Up Delay Sleep Timer Running
North AC Signal Asserts Interrupt,
Begin GETAC routineDELD2 used here
DELAC used hereDELDC used here
600ms 2000ms 1200ms 1000ms
DELD2 used here
Proteus Gen 1B Navigation ControlDifference = North Voltage – South Voltage
NO
RT
H C
OIL
SO
UT
H C
OIL
X Position
50mV
40mV
30mV
20mV
10mV
Target: Difference=30mV
D=20mV
D=0mV
D=40mV
D=30mV