1 P14471 Vibration Testing Apparatus II Final Review 5/13/2014
Brett Billings Jacob Gardner Nick Greco Ron Sparky Jimbo Claire
Kobal Ryan Selig Ashley Waldron
Slide 2
Agenda 2 Revisit of Requirements Build Test Issues Lessons
Learned Project Management Appendix
Slide 3
3 Revisit of Requirements
Slide 4
Customer Requirements 4
Slide 5
Engineering Requirements 5 NumberRequirement Raw Score Units
Ideal Measure 1 Displacement of luminaire69in1/32 2 Vibration of
luminaire69cycles/min2000 3 Duration of vibration test69hours35 4
Isolate motor from oil spills45BinaryYes 5 Maintenance
Documentation44Survey (easy to follow)80% 6 Mount pendant
configuration35BinaryYes 7 Operation Documentation33Survey (easy to
follow)80% 8 Machine won't operate if crankshaft enclosure is
open25BinaryYes 9 Completely stop machine with Emergency
Stop25seconds< 10 10 Maximum voltage of Motor25V AC240 11
Minimize number of operators21people2 12 Max weight of mounted
luminaire20lbs> 150 13 Visually display settings and status of
test18BinaryYes 14 Steps to set up16steps< 10 15 Setup
Time16seconds< 120 16 Low Sound15dBA< 85 17 Minimize pinch
points15Count< 3 18 Total materials cost15$< 4,000 19 Mount
stanchion configuration7BinaryYes 20 Mount yoke
configuration7BinaryYes 21 Mount trunnion configuration7BinaryYes
22 Machine footprint5in 2 < 34X48
Slide 6
House of Quality 6
Slide 7
UL844 7 2000 RPM 1/32 displacement 35 hours
Slide 8
8 Build
Slide 9
Frame Assembly 9 Steel was assembled and welded in shop All
welded joints were annealed to relieve hardness caused by the heat
during welding C-channel was machined to fit on top of frame and to
hold flange assembly Baseplate for crankshaft mechanism was
modified and mounted to frame
Slide 10
Crankshaft Modifications 10 Modifications to improve
adjustment: Added access holes to connecting rod Replaced 3/8-24
set screw with a 3/16-100 set Re-machined T-block for bushing
Replaced springs with weaker ones Access hole added to rear
guard
Slide 11
Additional Work 11 Dial Gauge Added magnetic back plate Created
alignment block to ensure gauge is perpendicular to box (cosine
error) Top guard was re-machined in order to ensure adequate
overhang for bolts Painted steel frame to resist rusting
Slide 12
Belt Guard Mount There was a misunderstanding in the machine
shop and half of our original belt guard was thrown away A new,
rectangular guard was fabricated Elongated holes were drilled in
the L- brackets to allow for vertical adjustment Issue: Seems like
there might be a lot of vibration. Never tested with machine on.
12
Slide 13
Encoder Mount Original design: Attach mount to bottom of belt
guard Issue: Belt guard adjustment requires encoder to be adjusted
as well Final design: Metal arm extending horizontally from
L-bracket with rubber pad to prevent excess movement 13
Slide 14
Control of Motor Variable Frequency Drive added to control
motor frequency VFD specd based on: Remote start/stop Remote ramp
up or ramp down the speed of the motor External faults that could
be used as an E-Stop 14
Slide 15
Feedback from Apparatus Closed loop control system RPM read by
rotary encoder and sent to MCU Raw feedback from the encoder is
processed and displayed on LCD Encoder needs to have high enough
resolution to keep the error within 1% of 2000 RPM 15
Slide 16
Microcontroller: Programming 16 Microcontroller Unit (MCU) is a
product of Texas Instruments (TI) under the MSP430 family
MSP430G2452 Main program and LCD communication MSP430G2553 VFD
switching logic TI Launchpad board used to reprogram MCU
Slide 17
Microcontroller: Interfacing 17 Supply voltage is 3.3 V DC from
voltage regulator unit MSP430G2452 Drives control and logic for the
test LCD (10 pin connections) Feedback from Encoder Output A (1024
PPR) Control switch to manually pause/resume test (10 k pull-up)
Primitive serial data to MSP430G2553 (2 pin connections)
MSP430G2553 Directly controls VFD through switches Toggles
transistors (switches) used to send digital data to VFD Additional
control switch to power on and off both MCUs and LCD
Slide 18
Display Unit 18 20x4 HD44780 (Hitachi) Liquid Crystal Display
(LCD) with LED backlighting Implements ASCII printable characters
Character display: 4 rows, 20 columns Commands entered as parallel
data Data [7..0]; Register Select; Enable Write mode; fixed
contrast and lighting
Slide 19
Microcontroller: Logic/Implementation 19 Initialization Wait
for about a second for display to power on before writing Set
internal clock frequency to 16 MHz Varying clock speed essentially
varies all delays and timing involved Configure input and output
pins Write static items to display Initialize integer variables
Configure and enable Timer and Edge Triggered interrupts Interrupt
handlers Timer A: Increments a time-keeping variable Edge 1:
Increments frequency counter from Encoder output Edge 2: Toggles a
pause variable from pause/resume control switch
Slide 20
Microcontroller: Logic/Implementation 20 Display routines Send
Command Simple routine to send commands in form of parallel data
Command specified as binary string e.g.: SendCommand("1101010010");
sets character position to the start of line four Enable
automatically set low and then high to send the full command Write
Character Converts inputted character to binary equivalent and
sends the command Direct ASCII compatibility due to HD44780
controller Write String Writes a sequence of characters; e.g.:
WriteString(Hello world!);
Slide 21
Microcontroller: Logic/Implementation 21 Main algorithm
(simplified) Test paused (or stopped) Signal VFD to stop motor Hold
state, including timer and latest status message on display Test
resumed (or started) Signal VFD to start motor and set to default
speed (~2000 RPM) Resume state For each passing second Update time
both internally and on display Count up to a specific frequency
from encoder signal Use specific frequency and time passed to
accurately calculate RPM RPM within 1% of target: normal operation;
else within 5%: ramp motor speed up or down through VFD; else
outside 5%: pause test Pause test if no encoder signal detected or
35 hours elapsed
Slide 22
22 Test
Slide 23
Current Testing Status 23
Slide 24
Encoder Testing Initial testing done independent of apparatus
with a DC motor to evaluate following components: Output signals
amplitude Output frequency Power and control connections Allowed
encoder to be integrated with apparatus and connected to MCU to
display speed on LCD 24
Slide 25
VFD Control Testing The VFD control signals were also tested
independently on a proto-board for isolation purposes The VFD was
programed for the motor used as well as for the digital outputs
needed for the control signal To remotely control the VFD power
transistors were used as switches The control of these switches
would be coming from the MCU 25
Slide 26
Safety Test 26 Failed at RIT 6 of 14 items are No Labeling,
lockouts, 2 nd E-stop Will pass at CCH in Syracuse Ordered
additional lockout & lock
Slide 27
Setup Test 27 Did not meet original engineering metrics Target:
2 minutes, 10 steps Actual: 16 minutes, 14 steps Should have used
previous team as benchmark Drastic improvement vs 49 minutes &
31 steps Can be done with one person though
Slide 28
Setup Test 28 Standard Work for CCH steps, time, visual aids
Method to reach displacement in 2 adjustments Use of dial gauge
Quick reference table 1 turn =.019 Reliable to +/- 3%
Slide 29
29 Issues
Slide 30
Luminaire Vibration 30 Luminaire vibrates more than machine
Extra conduit was threaded Set screw was tightened CCH not able to
help by email/phone Resolution: Try plumbers tape Consult CCH in
Syracuse during final testing
Slide 31
Motor Mount Excess vibration in motor mount at 1/3 speed Mount
was reinforced with t-shaped brace Top View 31
Slide 32
Electrical VFD damaged during initial testing Root cause
analysis performed VFD replaced by CCH All future wiring done by
licensed electrician 32
Slide 33
Electrical 33 Encoder mounting Coupler needed to be modified
Coupler broke right before shipping Enclosures Shipped apparatus
without LCD stuff Control changes from CCH at demo
Slide 34
34 Lessons Learned
Slide 35
Experience Gained 35 Combined structural mechanics with
vibration Required learning more in-depth features of structural
mechanics & natural frequency Required learning of ANSYS
Workbench to analyze the stress at the operating frequency and the
natural frequency of the frame Electrical component selection &
wiring
Slide 36
Lessons Learned 36 Review the previous MSD teams work more
thoroughly before starting Verify existing parts match CAD models
Communicate effectively between both team members and others
helping with the project Weigh the risks of using free help vs.
hired professionals
Slide 37
Lessons Learned 37 Iterative design process Escalate issues
when you cant solve them yourself Compromise on differences of
opinions between team members Work together to meet internal
deadlines Clearly define team member roles e.g. Document
owners
Slide 38
38 Project Management
Slide 39
Budget 39 Original Budget = $4,000.00 Current Costs = $2,978.88
Parts = $2,540.33 S/H = $198.55 Expected Travel = $240.00 Items
saved on: CCH donated VFD & replacement ($290x2) CCH paid for
shipping ($600) No welding fees ($400) No electrician fees ($200)
https://edge.rit.edu/edge/P14471/public/WorkingDocuments/Detailed%20Design/BOM_rev6_tracking.pdf
Slide 40
Risk Analysis 40
Slide 41
Whats Left? Remaining work: Finalize technical paper Travel to
Syracuse for final testing Test Plan Bs Fix issues detected during
testing Solve excessive luminaire vibration Deliver maintenance
& operation documentation If we dont finish by 5/22: Enough
work for a Phase III? Work for a Co-op? 41
Slide 42
Questions? 42
Slide 43
43 Appendix
Slide 44
Room Layout 44
Slide 45
Selected Design 45 Interchangeable Conduits Motor with V-belt
VFD Digital Dial Gauge Encoder LCD, Microcontroller Polycarbonate
Guards E-stop Paint for Rust Protection
Slide 46
Test Plans 46 Refer to Excel document
https://edge.rit.edu/edge/P14471/public/WorkingDocuments/MSDII_B
uild%20Test%20Documentation/P14471 Test Plans_Rev2.xlsx
https://edge.rit.edu/edge/P14471/public/WorkingDocuments/MSDII_B
uild%20Test%20Documentation/P14471 Test Plans_Rev2.xlsx or EDGE
https://edge.rit.edu/edge/P14471/public/Build%2C%20Test%2C%20Do
cument
https://edge.rit.edu/edge/P14471/public/Build%2C%20Test%2C%20Do
cument
Slide 47
Full Risk Analysis 47 See EDGE
https://edge.rit.edu/edge/P14471/public/ProjectManageme
nt/Risk%20Analysis.pdf
https://edge.rit.edu/edge/P14471/public/ProjectManageme
nt/Risk%20Analysis.pdf