p14007: wheelchair assist
DESCRIPTION
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 - PowerPoint PPT PresentationTRANSCRIPT
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
– 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.comhttp://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 Requirementsrqmt. # Importance Customer Requirement
C1 9 "Hill Holder"C2 9 De-acceleration downhillC3 1 Movement assist up hillC4 3 Detachable designC5 3 Low weightC6 3 CollapsibleC7 9 Low costC8 9 Medically approved for useC9 3 Small turning radiusC10 3 Size, overallC11 3 Large user weight rangeC12 3 Disengagable devices
Benchmarking SpecsBenchmarked 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 9 C12 User/Assistor disengageable Hill Holder seconds 5 2 - -
S3 9 C12 User/Assistor engageable Hill Holder seconds 1 0.5 - -
S4 9 C1 Maximum incline angle, before tipping over backwards with user weight of 300lbf Same as original Better than
original - - -
S5 9 C2 Maximum downhill speed at decline of 10 degrees at 300lbf user weight
mph 4 3 - 4.58
S6 9 C12 User/Assistor disengagable Gradual Grade seconds 5 2 - -
S7 9 C12 User/Assistor engagable Gradual Grade Seconds 1 0.5 - -
S8 9 C3 Desired Movement Assist Input Force Ratio Ratio 1.5 2 - -
S9 9 C12 User/Assistor Disengagable movement assist seconds 5 2 - -
S10 9 C12 User/Assistor engagable movement assist Seconds 1 .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 Weightlbf
20 15 - -
S12 3 C5 Total System Weight(Chair Plus Assist) lbf 50 40 33.7 197.3
S13 3 C7 Cost of Wheel Chair Assist System $ 1000 500 $676.60 $3,824.50
S14 3 C6 Wheel chair width when folded in 26 18 - -
S15 9 C9 Wheel chair turning radius ft 2 1 0 2.12
S16 3 C4 Time to remove wheel chair assist system minutes 15 10 - -
S17 3 C10 Length of Wheel Chair + Movement System in 48 30 29.58 36.21
S18 3 C10 Width of Wheel Chair + Movement System in 48 30 23.58 23.5
S19 3 C8 Critical mechanical components have X number of use cycles
cycles 4000 5000 - -
Engineering Requirementsrqmt. # Importan
ce 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 backwardslbf 260 300 400
Assuming the wheelchair doesn't tip
over during test
S2 9 C12 System Operation
User/Assistor disengageable Hill Holder seconds 5 2 1
Can be disengageable by user/assister; should
work like an on/off switch
S3 9 C12 System Operation
User/Assistor engageable Hill Holder seconds 1 0.5 0.1
S4 9 C1 System Operation
Maximum incline angle, before tipping over backwards with user
weight of 300lbfDegrees Same as
originalBetter than
original
S5 9 C2 System Operation
Maximum downhill speed at decline of 10 degrees at 300lbf
user weightmph 4 3 User Varied
S6 9 C12 System Operation
User/Assistor disengagable Gradual Grade seconds 5 2 1
Can be disengageable by user/assister; should
work like an on/off switch
S7 9 C12 System Operation
User/Assistor engagable Gradual Grade seconds 1 0.5 0.1
S8 9 C3 System Operation
Desired Movement Assist Input Force Ratio Ratio 1.5 2 3 Without system/with
system
S9 9 C12 System Operation
User/Assistor Disengagable movement assist seconds 5 2 1
Can be disengageable by user/assister; should
work like an on/off switch
S10 9 C12 System Operation
User/Assistor engagable movement assist seconds 1 0.5 0.1
Engineering Requirements Cont’rqmt. # Importa
nce 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 3 C5 System Portability
Total System Weight(Chair Plus Assist) lbf 50 40 35
S13 3 C7 System Operation
Cost of Wheel Chair Assist System $ 1000 500 200 Production level costs
S14 3 C6 System Portability Wheel chair width when folded in 26 18 Unchanged
original widthBased on the
customer's wheelchair
S15 9 C9 System Operation Wheel chair turning radius ft 2 1 0
S16 3 C4 System Portability
Time to remove wheel chair assist system minutes 15 10 5
S17 3 C10 System Operation
Length of Wheel Chair + Movement System in 48 36 Unchanged from
originalBased on the
customer's wheelchair
S18 3 C10 System Operation
Width of Wheel Chair + Movement System in 48 36 Unchanged from
originalBased on the
customer's wheelchair
S19 3 C8 System Operation
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
Questions/Comments?