Slide 1

System Design Review P15007: Anti-Rollback Wheelchair Jessica Jeffrey Industrial Engineer / Project Manager Jacob McCarthy Mechanical Engineer Warren Roser Mechanical Engineer John Sweet Mechanical Engineer

Slide 2

Agenda Background (~2 min) Action Items and Resolutions (~3 min) System Architecture (~1 min) Functional Decomposition (~6 min) Morphological Analysis (~2 min) Pugh Chart (~10 min) Concept Selection (~2 min) Benchmarking (~10 min) Scope (~3 min) Risk Assessment (~5 min) Feasibility (~6 min) Test Plan (~1 min) Project Plan (~2 min) 9/30/2014 2 P15007 Anti-Rollback Wheelchair

Slide 3

Background 9/30/2014 P15007 Anti-Rollback Wheelchair 3 Users of manual wheelchairs encounter issues when traversing up an incline or down a decline

Slide 4

Action Items and Resolutions 9/30/2014 P15007 Anti-Rollback Wheelchair 4 Updated Engineering Requirements Updated Use Scenario Repair Alpha Prototype Monroe Wheelchair Visit Benchmarking Alpha Prototype

Slide 5

Updated Engineering Requirements 9/30/2014 P15007 Anti-Rollback Wheelchair 5 Key 9High 3Moderate 1Low

Slide 6

Updated Use Scenario 9/30/2014 P15007 Anti-Rollback Wheelchair 6 Aid Assists Client into Chair Client Propels Themselves on Flat Terrain Aid Available for Steep Inclines/Declines Aid Instructs Client to Engage/Disengage Hill Holding System Client Continues Self Propulsion on Flat Terrain Aid and Client Interaction

Slide 7

System Architecture 9/30/2014 P15007 Anti-Rollback Wheelchair 7 Manual Wheelchair Disc Braking System Ratchet and Pawl System Client / Aid Input Engagement

Slide 8

Functional Decomposition (1 of 3) 9/30/2014 P15007 Anti-Rollback Wheelchair 8 Main Function: Control Motion

Slide 9

Functional Decomposition (2 of 3) 9/30/2014 P15007 Anti-Rollback Wheelchair 9 Stop Backwards Motion Ratchet and Pawl System

Slide 10

Functional Decomposition (3 of 3) 9/30/2014 P15007 Anti-Rollback Wheelchair 10 Impede Forward Motion Braking System

Slide 11

Morphological Analysis 9/30/2014 P15007 Anti-Rollback Wheelchair 11

Slide 12

Selection Criteria 9/30/2014 P15007 Anti-Rollback Wheelchair 12 Material CostEase to Transport Labor CostAbility to Complete in 2 Semesters Additional System WeightReliability Additional WidthSafety COTS ComponentsAbility to steer down decline Ability to prevent rollbackErgonomic Adjustability Ability to slow on declineMaintenance Ability to stop on declineSystem Adaptability Ease of CollapsibilityEase of Installation

Slide 13

Pugh Chart (1 of 2) 9/30/2014 P15007 Anti-Rollback Wheelchair 13 DATUM: Manual Wheelchair Key +Improved 0Equal -Diminished

Slide 14

Pugh Chart (2 of 2) 9/30/2014 P15007 Anti-Rollback Wheelchair 14 DATUM: Alpha Prototype Key +Improved 0Equal -Diminished

Slide 15

Concept Selection 9/30/2014 P15007 Anti-Rollback Wheelchair 15 Beta Concepts 1 & 2 Multiple Pawls Mechanical Disc Brakes User Controls

Slide 16

Benchmarking: Alpha Prototype 9/30/2014 P15007 Anti-Rollback Wheelchair 16 Team MemberErgonomicsSystemSafety Jessica133 Jacob133 Warren131 John133 Key 9Excellent 3Good 1Poor

Slide 17

Benchmarking: Monroe Wheelchair Visit 9/30/2014 P15007 Anti-Rollback Wheelchair 17 Jonathan Walters, Vice President Custom VS Standard Options Rigid Frame VS Collapsible Frame Spoked Wheel VS Spokeless Wheel

Slide 18

Benchmarking: Major Brands 9/30/2014 P15007 Anti-Rollback Wheelchair 18

Slide 19

Benchmarking: Major Brands 9/30/2014 P15007 Anti-Rollback Wheelchair 19

Slide 20

Benchmarking: Competitive Solutions 20 Parameters/ Products Grade AidMagic WheelsThe Pivote-motionD's LocksADI Disc Brake Cost$180~$5000~$4770$7,675.00 +$500+ $750+ (some over $1,150) Weight~3 lbs~10 lbs (additional)~ 12 lbs (additional)10 lbs (additional) +2 lbsNot Available FunctionAnti-rollback for incline Hill holding and gear reduction Dual levers, Parking brake, anti-rollback hill holder Slows Rollback and assists motion Locks wheels to prevent chair from moving when transferring in / out of chair. Manual Braking System Interfacing Replaces factory wheel locks Replaces stock wheels Replacing quick-release rear wheels Replaces stock wheels Attaches to wheel and stock axle Attaches to quick detach wheels on custom chairs Limitations Works best with inflatable tires Price Mostly Replaces current wheels entirely Maximum Range of 16 miles, increases width by 1-1.5" Only used when stationary Needs to be a quick detach wheel MaintenanceNot Available Sealed gearbox, factory serviced only Not Available Battery Recharge & Replacement none Occasional to replace pads or rotor Universality Fits most Quickie wheelchairs Fits most manual wheelchairs with supplied adapter(s), customers are asked to call for verification Tube diameters 22.2mm, 25.4mm, 28.6mm, 30mm, and 31.8mm (7/8", 1", 1 1/8", 1.2", and 1 1/4"). Only Compatible with manufacturer specified wheelchairs. Compatible With specified chairs, approx 50 models. Compatible with a various custom chairs

Slide 21

Benchmarking: Grade Aid 9/30/2014 P15007 Anti-Rollback Wheelchair 21

Slide 22

Benchmarking: Ds Locks 9/30/2014 P15007 Anti-Rollback Wheelchair 22

Slide 23

Benchmarking: ADI Disc Brake 9/30/2014 P15007 Anti-Rollback Wheelchair 23

Slide 24

Scope: Retrofittable 9/30/2014 P15007 Anti-Rollback Wheelchair 24 Possible Target Wheelchairs Standard (Not Custom) Collapsible Frame (Not Rigid) Standard Wheels (Not Quick-Release)

Slide 25

Scope: Users 9/30/2014 P15007 Anti-Rollback Wheelchair 25 Target Users: Men and Women Age 65+ Any WheelchairManual wheelchairElectric wheelchair Number (1000s) % of population Number (1000s) % of population Number (1000s) % of population Total 1,5990.611,5030.581550.06 Age Under 18 880.12790.11180.02 18-64 6140.395600.35900.06 65+ 8972.878642.76470.15 Gender Male 6580.526060.48840.07 Female 9410.78970.67710.05

Slide 26

Risk Assessment (1 of 2) 9/30/2014 P15007 Anti-Rollback Wheelchair 26

Slide 27

Risk Assessment (2 of 2) 9/30/2014 P15007 Anti-Rollback Wheelchair 27

Slide 28

Feasibility (1 of 3) 9/30/2014 P15007 Anti-Rollback Wheelchair 28 How long does our device have to last? Average wheelchair lifespan, 5-15 years Insurance company funds replacement every 5 years Average wheelchair uses travels 1.6km per day Assume 24 wheel 1524678 revs in 5 years 4574034 revs in 15 years

Slide 29

Feasibility (2 of 3) 9/30/2014 P15007 Anti-Rollback Wheelchair 29 What loads does our device have to support? Assumed 300 lb load limit Load applied directly at wheelchair center

Slide 30

Feasibility (3 of 3) 9/30/2014 P15007 Anti-Rollback Wheelchair 30 22 Inch Wheel Teeth \Pawls 123 401.730.860.58 601.150.580.38 800.860.430.29 24 Inch Wheel Teeth \Pawls 123 401.880.940.63 601.260.630.42 800.940.470.31 26 Inch Wheel Teeth \Pawls 123 402.041.020.68 601.360.680.45 801.020.510.34 What is the resolution of the ratchet and pawl and how can we improve it?

Slide 31

Test Plan 9/30/2014 P15007 Anti-Rollback Wheelchair 31 TestEngineering Requirement Test ergonomics of controls Component life tests through theoretical analysisDesigned test life Test force input to brake down an incline using force gauge. Use wheelchair ramp on campus that is standard 1:12 slope to conduct test. Grip force exerted by user to brake on decline Measure wheelchair width with and without system installed, and compare. Do this for the wheelchair in the folded state and in use state. Increase of wheelchair width when in use; Component interference when wheelchair is folded Test hold on incline with maximum rated load for standard wheelchair. Force exerted by user to hold position on incline Measure total additional weight from installation of the systemTotal system weight Measure time it takes to detach the system and revert to original wheelchair configuration Time to revert to original configuration

Slide 32

Project Goals: Phase III 9/30/2014 P15007 Anti-Rollback Wheelchair 32 Further Evaluate Feasibility of Concept 1 & 2 Cost Analysis Maintainability Functionality Choose Final Ratchet and Pawl Design Develop Prototype

Slide 33

Phase III Benchmark Opportunities 9/30/2014 P15007 Anti-Rollback Wheelchair 33 Dr. Day: CP Rochester Southside Medical Supply Westside Medical Supply Access Lifts & Ramps

Slide 34

Thank You! 9/30/2014 P15007 Anti-Rollback Wheelchair