msd ii subsystem integration p15044 – intelligent mobility cane3/19/2015

MSD IISubsystem Integration

P15044 – Intelligent Mobility Cane 3/19/2015

RIT MSD P15044 –Intelligent Mobility Cane

Agenda● Customer Feedback & Integration● Subsystem Overview● Subsystem Integration Overview● Risk Management● Project Plan & Budget● Looking Forward- 3 week plans● Peer Reviews & Lessons Learned

2

Customer Feedback and Integration


Low Profile Enclosure

4


Haptic Feedback• ABVI User Testing• Hard to distinguish individual vibrations

• Designing motor pulsing to mitigate• Test rig being implemented

5


Length of Cane• Testing indicated extended length not desirable

• Cost• Redesign time

6

Current State


Cost Drivers

8

Overall System Cost (Old)Subsystem Unit Cost per 1 Unit Cost per 1000

Electronic Components $46.51 $19.12Unmounted Electrical Components $99.65 $75.25Mechanical Structure Components $31.51 $11.22Miscellaneous Components $0.00 $0.00

TOTAL $177.67 $105.59

Overall System Cost (New)Subsystem Unit Cost per 1 Unit Cost per 1000

Electronic Components $46.51 $21.12Unmounted Electrical Components $99.65 $75.25Mechanical Structure Components $31.51 $11.98Miscellaneous Components $0.00 $0.00

TOTAL $177.67 $108.35

Even with design changes, we meet the required cost of <$125


Mechanical Current State

9


Mechanical Current State

10


Electrical Current State

11

• First Revision boards assembled• All electrical hardware has been

debugged• Second Revision boards ordered

and shipped (3/18/2015)


Software Current State• All code is

written.• Waiting for new

board revision for debug.

• 4/9/2015 – start debug

Task Code Debug

Utilities

Write ADC Utilities 100% 0 %

Write PWM Utilities 100% 0 %

Write Timer Utilities 100% 0 %

Write EEPROM Utilities 100% 0 %

Detection

Write Dropoff Detection Algorithm 100% 0 %

Write Object Detection Algorithm 100% 0 %

Write Low Power Detection 100% 0 %

Control

Setup 100% 0 %

Main Control Flow 100% 0 %

Event Handlers 100% 0 %

OtherPing The Ultrasonic Sensors 100% 0 %

Pulse Vibration Motors 100% 0 %

Subsystem Validation


Validation Matrix

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Link to the Validation Matrix in EDGE

http://edge.rit.edu/edge/P15044/public/Validation/Subsystem%20Testing/Test%20Plans/Requirement%20Validation%20Matrix_P15044.xlsx


COMSOL Simulations

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Crosstalk Testing

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2 4 6 8 10 12 14 16 180

50

100

150

200

250

300

350

400

R² = 0.980118493777089

Cross Talk Test, 4 ft

Sensor 2

Linear (Sensor 2)

Object 2 Distance (ft)

AD

C R

ead

ing

s (1

0 b

it)

2 4 6 8 10 12 14 16 180

50

100

150

200

250

300

350

400

R² = 0.98240962848521

Cross Talk Test, 10 ft

Sensor 2Linear (Sensor 2)Sensor 1

Object 2 Distance (ft)

AD

C R

ead

ing

s (1

0 b

it)


Mechanical SubsystemProblem Tracking

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Electrical SubsystemProblem Tracking

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IDCurrentStatus Priority

IssueDescription

Assigned ToOwner

System Affected

ExpectedResolutio

nDate

ImpactSummary

ActionSteps

IssueType

DateIdentifie

dEntered

By

ActualResolution

DateFinal Resolution

& Rationale1 Closed Critical Problems with PCB Foot print Dan, Justine Electrical

(Hardware)02/06/15 Budget Impact- however,

has already been planned in budget

Set date to order new after bug fixes have been made, so that it will not impact schedule

System 02/03/15 Justine 02/17/15 Set to order new board 2/17

4 Closed Medium

The connectors on the Main Board are too close to where the IR sensor will sit.

Dan,Marisa, Ben

Electrical (Hardware)

02/25/15 assembly and function

We'll need to either change where the connectors are on the board or change where the board sits in the housing

System 02/08/15 Justine 02/25/15 Transfered to Mechanical Team

8 Closed Low ABVI concern for size of enclosure Andrew, Marissa

Mechanical Electrical

03/08/15 Customer Satisfaction Cross talk testing (sat), imlempent design changes

System 02/12/15 Justine 03/12/15 Cross Talk Test proved low profile model would work, design changes are being implememted.

13 Closed Medium Wiring harness doesnt fit above processing board (see #4)

Andrew, Ben Electrical (Hardware)

03/03/15 Assembly Move board back in enlosure. System 02/12/15 Andrew 02/26/15 Moved board back .11", harness clears obstruction. See Rev D of IMC-201

20 Closed High Analog Readout of Ultra Sonic Sensors likes to jump around and will give correct values about half the time. Either is a timing issue or a cap is needed on the output.

Ben, Marisa Electrical (Hardware)

03/19/15 Function Add filter to output of the sensors, play with timing of when to read the analog value. If all else fails an average could be used to cut down on the error.

System 03/10/15 Ben 03/11/15 Arduino Digital Pin was not going LOW, causing crosstalk between sensors which caused the random weird readdings. Once timing and pinging was done correctly, there were very little speratic readings.

22 Closed Critical There is no Debug Port on the Processing Board

Dan Electrical (Hardware)

03/11/15 Assembly and Function Move Inputs around to make room for JTAG Port

Informational

03/07/15 Dan 03/08/15 Fixed in Schematic and BRD file. Re-ordered Boards

23 Closed High Soldering directly to the battery is hard, potentially unsafe, all around bad?

Dan, Ben, Andrew


Function (Robustness) Investigate BAttery Tabs, and other mounting options

System 03/03/15 Dan 03/14/15 New Battery Mount Board

Going Forward


Problems in Progress

20

IDCurrentStatus Priority

IssueDescription

Assigned To

OwnerSystem Affected

ExpectedResolution

DateImpact

SummaryActionSteps

IssueType

DateIdentified

Entered By

ActualResolution

Date21 Work In

ProgressCritical Power switch too small. Toggling

power very difficult.Ben, Dan Electrical

(Hardware)03/19/15

FunctionTest out different press fit caps to elogate the power switch. Look for substitute swithces/buttons that can fit in the handle.

System 03/11/15 Ben

7 Work In Progress

High Hard to distinguish between vibrations on cane handle

Allan, Dan, Marisa


04/02/15 Function of Handle

Met with Vibration Expert (Dr. Ghoneim), purchased low stiffness rubber on Tuesday, 2/24/15, Experiment with pulsing motors,

Informational

02/12/15 Justine

11 Work In Progress

Medium PCB slots don't fit boards (power and processing)

Andrew, Allan

Mechanical 03/12/15 Assembly Make wider slots. Glue may be required on final assembly. Test sections and matrix have been designed, to be printed 3/5

System 02/12/15 Andrew

15 Work In Progress

Medium Stress concentration at corner of motor cutouts in handle makes handle prone to breaking under load

Andrew, Allan

Mechanical 03/12/15 Function (robustness/durability)

Add radius to corner. If that is insufficient, increase wall thickness. Ran simulation, discuss factor of safety with Andrew

System 02/19/15 Allan

19 Work In Progress

Low Drawing Tolerance too tight on flanges that mate Handle Sections together

Allan, Andrew

Mechanical 03/12/15 Function Open Slots or Narrow tabs System 03/15/12 Allan


Risk Management

21

RISK LIKLIHOOD SEVERITY TOTAL IMPACT MITIGATION PLANMITIGATION DATE

Overall lack of team "work" time 3 3 9

Implement three 4 hour sessions for weekends in April, in order to cover anything we need to get done by the end of the semester- ex documentation, posters, paper, etc.. Set for 4/5, 4/12 and 4/19. 4/5/2015

Not enough time to debug Software 3 2 6

Allocate remaining tasks that were previously on programmer to other team members so that debugging can be number one priority for Dan 4/5/2015

Shock causes electrical components to shift or fail 2 3 6Complete shock test 4/4/2015Too many false positives on our sensors 2 3 6Change positioning of sensors 4/4/2015Sensor Beam angles too large 3 2 6Testing in same configuration, use directing cones 4/4/2015Unforeseen loading/ shock causes failure 2 2 4More robust shock and load tests, computer simulations 4/4/2015

The processor is too slow 1 2 2Bump up frequency of processor extra 4 kHz 3/14/2015Redesign of the battery section with tabs makes the cane uncomfortable for user 1 1 1Accept


3 Week Plans3 Week Plans

22

https://docs.google.com/spreadsheets/d/1cH6ohhchWI5p8QHL75r-UBR2wbDv2i19UaJsgM-eiNE/pubhtml?gid=200538189&single=true


ImagineRIT Obstacle Course

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Featured Obstacles:5 ft Overhang5 ft Wall6 in Step(s)6 in Ramp/Drop Off


Project Plan

24


Planned vs Actual Budget

25

We are on track to be under our budget of $1000.


Lessons Learned

• Check test equipment before performing test• Be as critical as necessary during Peer

Reviews

26

msd ii subsystem integration p15044 – intelligent mobility cane3/19/2015

Documents

electronic components

miscellaneous components

required cost

new cane

desirable costredesign

individual vibrations

extended length

mitigatetest rig