P11017: Tactile Navigation InterfaceChristian SeemayerRob ProettiTim DeBellisTim GiguereWill Kelly

Design Review Outstanding Issues How does the device tactile perception become affected due to device and

strap sensations? Orientation of Servos as a perfect diamond Stress Analysis

Housing displacement should allow translation Servo-Arm stress due to Servo stall torque

Fatigue Analysis Endurance Limit for Aluminum

Electrical Analysis concerns PCB board with test points at all nodes Size of PCB traces depending on current 45° angles for PC trace corners Battery Life based on % used during day Use of keypad interrupts instead of polling

Heat Generation from internal components Test Plan updates MSD II schedule changes

Device and Strap Sensation EffectsMeeting at ABVI on 2/18/2010 with Alexis

Read and Richard What we discussed

Retested more tip designs out of curiosity with preference being large bowl shape (Screw head)

Concept of generating diagonal directions through pulsing

Directional Testing (2 Tests) Basic Test Armband and weight applied Test

What We LearnedResults: 100% accuracy from participants. Extra sensations demonstrated no effect on accurate

direction interpretation. Direction recognition training quicker then expected.

Short (~1 minute)training period Proper Training approach – Diamond Construction

Participants disliked diagonal direction idea4 directions good, 8 creates confusion.

Revamped analysis based on recommendations from Design Review

Put tiny clear dots on the buttons (For sale in Vision Shop at ABVI, 6 dots for $2)

Tip Redesign after ABVI visitSwitch from sharp

point to more circular area.

AdvantagesMore blunt surface Enables more

pressure on skinLarger surface makes

it more perceptible to user

Adjustment of Servo OrientationServos oriented

to create perfect diamond

Required pegs to be different lengths

Stress Analysis: HousingDevice Housing

Switched boundary condition from All DOF to fixed displacement in load direction

Accounted for translation that can occur.Servo-Arm

Accounted for servo stall torque

New Housing Stress

In the Bottom: 482 psi

Servo-Arm Stress AnalysisIgnoring Stress

ConcentrationStress of 6,637

psiDeflection of

5.775e-3 inches

Servo-Arm Hand Calculations

Fatigue Analysis

PCB Board Re-design

Battery Life Analysis

Motor Control Circuitry Analysis

Motor Control Circuitry Analysis

Motor Control Circuitry Analysis

Motor Control Circuitry Analysis

Servo Control Schematic

MCU/Power Unit Schematic

Team Interfacing DataCompletely new documentReview posted document on EDGE under

Miscellaneous Documents

Heat Generation Effects 

Test Plan UpdatesListed engineering specifications correlated to each test

Can be found under test description and on Specs PageAddition of Test #3 – Electronic Component Testing

Aims to test individual components to ensure proper functioning before beginning assembly period

Eliminated Destructive Tests (Device Drop and Compression)Moved up test dates in scheduleRearranged testing order to account for test with similarities

Direction Relay Test to be conducted with Servo Positioning Test On/Off Switch Test to be conducted in Week 2 or 3 based upon

assembly

MSD II UpdatesTest Plan Date updates incorporated directly into

scheduleCreated a more specific focus on machining of

componentsCreated a focus toward part assembly times for both

mechanical and electrical componentsRough Draft of paper to be started Week 3

75% complete by Week 8Final draft by Week 9

Rough Draft of Poster constructed for Imagine RITTo be finalized during Week 10

Project Plan for MSD I has helped define each member’s role within the team and establish reasonable goals

Evolution of Overall Project PlanDriven to focus on customer needs

Created specific and sometimes last minute alterations

Altered to account for switches in project design

Accounted for simplification of overall project goalDevice becoming stand alone with self inputs

Risk Assessment UpdatesThermal EffectsElectronic components fail to workPCB does not act with circuitCircuit does not match PCBOutside tactile sensation impede user

perception of directionsSystem noise distorts system signals

Final BOM

Where do we go now?At ABVI meeting, design was discussed to ensure customer

needs were still satisfiedAll standing issues have been reanalyzed in the

presentation Design subsystems were reviewed and updated as a result

Currently all documentation is available on EDGEFrom the BOM

What is available here at RIT and where? What do we have to order?

Non-issues Small lead times for parts (1 week is maximum) Testing can begin as soon as components gathered Current cost is far below $1,500 budget, currently only

$428.31 Is the project a “Green Light?”

If yes, when can we begin ordering?