Team John DeereFinal Presentation

Josh EbelingJamari Haynes

James JuneMike RenoBen SpiveyGary Twedt

Outline

Project Outline and Goals Existing and New Designs Analysis and Design Selection Prototype and Final Design Prototype Testing Conclusion

Project Goals

Modification of the Gator Utility Vehicle for handicapped accessibility

Limited or no operational interference

Ergonomic and easy to use for all potential users

Kit-ready final design

Project Constraints Must operate within existing

layout of the Gator Utility Vehicle

Must allow sufficient space for driver and passenger to sit comfortably

Must allow full operation with both new controls and pedal controls

Must be no significant modifications or alterations to install device

Description of Desired Motion Brake Motion – normal

motion of the brake pedal depression causes brake lever to raise up

Gas Motion – normal motion of gas pedal depression causes gas activator to be pulled down

Two motions must be combined for accessibility with one hand

Existing Technology and Market Current industry standard and most

prevalent design is the Braun 3500 Hand Control

Easily integrated for a variety of car sizes and types – however, difficult for user to install

Less than desirable required dexterity and force to operate

Overall design concept desirable, application of product for specific use with the Gator not desirable

Initial Designs and Comparisons Initial design concepts

included direct depression of both pedals by device (Designs 1 & 2)

One design concept included direct depression of only one pedal by the device, with the other pedal pulled down through the motion of a cable (Design 3)

Pull Handle

Cable

Pulley

Brake Pedal

Pull Handle

Cable

Pulley

Brake Pedal

Pull Handle

Cable

Pulley

Brake Pedal

Design 3

Design 2Design 1

Final Design - Initial Selection In order to take

advantage of unique Gator design layout, a straight bar extending out from underneath the dashboard was selected

Rough prototype of design worked well

Analysis necessary to determine force needed to depress brake

Engineering Analysis

Final Force: 50 lbs at a displacement of 30º

Pros: Design allows for monotonically increasing force

Cons: 50 lbs of force may be too much for users

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Handle Rotation Angle (Degrees)

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Handle Force Pedal Force

Final Design – Second Iteration L-Bar designed to give

mechanical advantage to the user, allowing rotation of the Brake Lever with less force than straight bar

Pros: Force well within desirable range

Cons: Force is not monotonically increasing, contact between L-Bar and Brake Lever a point of failure, more space taken up by support, harder to install

Engineering Analysis – Second Iteration

Maximum Force: 35 lbs at Maximum Displacement of 20º

Final Force: 28 lbs at Final Displacement of 33º

Decreasing force at the end of the force-displacement curve is extremely undesirable – disrupts the design more than the 50 lbs of maximum force for the straight bar

Further alteration of design possible – curving bar

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Handle Rotation Angle (Degrees)

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Support Force Handle Force Pedal Force

Final Design – Third Iteration L-Bar still lowers Brake

Lever, with less user-supplied force than straight bar

Curved bar designed to raise force necessary at end of force-displacement curve

Pros: Force well within desirable range

Cons: Force is still not monotonically increasing, contact between L-Bar and Brake Lever a point of failure, more space taken up by support, harder to install

Engineering Analysis – Third Iteration

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Handle Rotation Angle (Degrees)

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Support Force Handle Force Pedal Force

Maximum Force: 31 lbs at Maximum Displacement of 22º

Final Force: 30 lbs at Final Displacement of 34º

Decreasing force at the end of the force-displacement curve still present – even leveling of force displacement curve is undesirable according to Industrial Design group members

Straight bar provides best curve at small cost

Final Design Selection

Force-displacement problems ultimately resolved in the selection of the straight-bar design over the L-bar design

Monotonically increasing force-displacement curve vastly more important to ergonomics than minor strength concerns

Final Design Composition Final design comprised

of three main subsections:• Brake handle

• Provides the user with mechanical advantage with which to operate brake

• Brake clamp• Stabilizes brake handle

• Gas clamp• Activates gas through

tension on cable

Final Design and Prototype Comparison

Final design matches prototype in nearly all ways – however, there are two key differences:• Brake Clamp modified

for ease of machining at the expense of stability of the prototype

• Range of motion of the gas handle is less than was desired

Clamps and Stabilizations

Machined clamp connects to brake pedal lever with hose clamp

Provides significantly less lateral and rotational stability than the machined part for the Final Design

Stability issues solved with rudimentary cross-tied support

Supports

Demonstration of Motion - Brake

Video of brake motion

Demonstration of Motion - Gas

Video of gas motion

Acceleration Comparison

Lack of full play on the gas handle results in an inability to achieve full acceleration with use of handle – only a prototype flaw

Results for comparison:• Pedal average point-to-

point travel time: 4.84 s

• Handle average point-to-point travel time: 7.82 s Acceleration comparison videos

Braking Comparison

Brake handle actual provides easier braking than pedals because of decreased necessary force

Results for comparison:• Pedal average point-to-

point travel time: 1.755 s

• Handle average point-to-point travel time: 1.635 s

Braking comparison videos

Possible Improvements

Improvements to the project are mainly limited to stricter adherence of the handle to the Final Design as drawn

Development of detailed product installation manual only possible last step

Conclusion

In conclusion, group design met all project goals, including: • Operating within existing layout of the Gator Utility

Vehicle

• Allowing sufficient space for driver and passenger to sit comfortably

• Allowing full operation with both new controls and pedal controls

• All with no significant modifications or alterations to install device

Design considered a success

Questions?