P14007: Wheelchair Assist

Introduction Che-An Lee – Industrial and Systems Engineer Dan Schuster – Mechanical Engineer Phil Medalie – Mechanical Engineer Tom Elliot – Electrical Engineer

Agenda Problem Statement Current Product Expected Project benefits Deliverables Customer Requirements Benchmarking Specs Engineering Requirements

Problem Statement Current State Desired State Project Goals Current anti-roll back devices exist that can be added onto wheel chairs, as well as motorized wheel chairs to provide movement assistance Majority of manual chairs do not come standard with these devices Many of these assistance devices are expensive and inhibit some of the benefits of manual chairs Desired State The device should maintain all of the benefits of a manual wheel chair(light weight, small turning radius, compact, etc.) The device should also be able to aid the user when traversing inclines and declines, as well as prevent roll back when moving up an incline Project Goals Design a system that encompasses the desired properties while maintaining the key benefits of a manual chair Key Desired Properties Ability to provide movement assist up inclines Ability to decelerate the user when moving down declines Ability to prevent the wheel chair from rolling back down a hill and slipping out from under user Constraints The wheel chair should still meet ADA standards regarding size constraints(doorways, buildings, etc.) System Cost

Current Product Anti-Rollback Devices MagicWheels Manual Chairs Motorized Chairs Image References: http://www.rehabmart.com http://www.magicwheels.com/

Expected Project benefits Solutions for manual wheelchair users Engineering design experience Basis for future senior design project

Deliverables Functional prototype that has the potential to be manufactured Test data verifying engineering requirements Bill of materials Detailed design with documentation User’s guide for operation

Customer Requirements

Benchmarked Wheel Chair Values Engr. Requirement (metric) Benchmarking Specs Benchmarked Wheel Chair Values rqmt. # Importance Source Engr. Requirement (metric) Unit of Measure Marginal Value Target Value Manual Powered S1 9 C1 Maximum weight at incline of 10 degrees where the wheel chair does not roll backwards lbf 260 300 298.3 308.33 S2 C12 User/Assistor disengageable Hill Holder seconds 5 2 - S3 User/Assistor engageable Hill Holder 1 0.5 S4 Maximum incline angle, before tipping over backwards with user weight of 300lbf Same as original Better than original  - -  S5 C2 Maximum downhill speed at decline of 10 degrees at 300lbf user weight mph 4 3 4.58 S6 User/Assistor disengagable Gradual Grade S7 User/Assistor engagable Gradual Grade Seconds S8 C3 Desired Movement Assist Input Force Ratio Ratio 1.5 S9 User/Assistor Disengagable movement assist S10 User/Assistor engagable movement assist .5

Benchmarking Specs Cont’ Benchmarked Wheel Chair Values rqmt. # Importance Source Engr. Requirement (metric) Unit of Measure Marginal Value Target Value Manual Powered S11 3 C5 Wheel Chair Assist System Weight lbf 20 15 - S12 Total System Weight(Chair Plus Assist) 50 40 33.7 197.3 S13 C7 Cost of Wheel Chair Assist System $ 1000 500 $676.60 $3,824.50 S14 C6 Wheel chair width when folded in 26 18 S15 9 C9 Wheel chair turning radius ft 2 1 2.12 S16 C4 Time to remove wheel chair assist system minutes 10 S17 C10 Length of Wheel Chair + Movement System 48 30 29.58 36.21 S18 Width of Wheel Chair + Movement System 23.58 23.5 S19 C8 Critical mechanical components have X number of use cycles cycles 4000 5000

Engineering Requirements rqmt. # Importance Source Function Engr. Requirement (metric) Unit of Measure Marginal Value Target Value Ideal Value Comments/Status S1 9 C1 System Operation Maximum weight at incline of 10 degrees where the wheel chair does not roll backwards lbf 260 300 400 Assuming the wheelchair doesn't tip over during test S2 C12 User/Assistor disengageable Hill Holder seconds 5 2 1 Can be disengageable by user/assister; should work like an on/off switch S3 User/Assistor engageable Hill Holder 0.5 0.1   S4 Maximum incline angle, before tipping over backwards with user weight of 300lbf Degrees Same as original Better than original S5 C2 Maximum downhill speed at decline of 10 degrees at 300lbf user weight mph 4 3 User Varied S6 User/Assistor disengagable Gradual Grade S7 User/Assistor engagable Gradual Grade S8 C3 Desired Movement Assist Input Force Ratio Ratio 1.5 Without system/with system S9 User/Assistor Disengagable movement assist S10 User/Assistor engagable movement assist

Engineering Requirements Cont’ rqmt. # Importance Source Function Engr. Requirement (metric) Unit of Measure Marginal Value Target Value Ideal Value Comments/Status S11 3 C5 System Portability Wheel Chair Assist System Weight lbf 20 15 10 User and chair not included in weight S12 Total System Weight(Chair Plus Assist) 50 40 35   S13 C7 System Operation Cost of Wheel Chair Assist System $ 1000 500 200 Production level costs S14 C6 Wheel chair width when folded in 26 18 Unchanged original width Based on the customer's wheelchair S15 9 C9 Wheel chair turning radius ft 2 1 S16 C4 Time to remove wheel chair assist system minutes 5 S17 C10 Length of Wheel Chair + Movement System 48 36 Unchanged from original S18 Width of Wheel Chair + Movement System S19 C8 Critical mechanical components have X number of use cycles cycles 4000 5000 6000 This will be tested computationally and/or with a finite element analysis

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