1. MODIFICATION OF A GEARBOX
GO-KART TO ALLOW FOR FULL
HAND CONTROL OPERATION
Final Year Report Presentation
By: James King
2. PROJECT BACKGROUND
Project Introduction
Physically impaired drivers struggle to continue driving their vehicle
without hampering comfort, ergonomics and safety. In a competitive
situation (such as shifter karting), these factors could affect driver
competitiveness and safety.
Subjects Drawn Upon
3D CAD Modelling
Technical Communications
3. PROJECT OBJECTIVES
Project Objectives
Research available human motions
Determine optimum motion for each control
Determine optimum method to actuate controls (How?)
Generate and Evaluate concept ideas
Generate 3D model of final concept design
4. SOURCES
Assistive Technology Partners (2011) Adaptive driving for persons with
physical limitations
Case, K., Porter, M., Gyi, D., Marshall, R. and Oliver, R. (2001) Virtual fitting
trials in ‘design for all’. Journal of Materials Processing Technology. [Online]
Vol.117 (s 1–2), pp.255–261.
Dilullo, G., Kocienski, S. and Zopatti, D. (2013) Development of Zero-Leg
input manual transmission driving interface A major qualifying project.
Bachelor Thesis. [Online]. Worcester Polytechnic Institute.
Dols, J. F., García, M. and Sotos, J. J. (2014) Procedure for improving the
ergonomic design of driving positions adapted for handicapped people.
[Online] Vol.12.
5. SOURCES
Federal Aviation Administration, Ahlstrom, V. and Longo, K. (2003) Human Factors
Design Standard (HFDS).
Gartner, N., Messer, C. J. and Rathi, A. K. (2001) Revised monograph on traffic flow
theory [Online].
Gyi, D. ., Sims, R. ., Porter, J. ., Marshall, R. and Case, K. (2004) Representing older and
disabled people in virtual user trials: Data collection methods. Applied Ergonomics.
[Online] Vol.35 (5), pp.443–451.
Kong, Y.-K., Kim, D.-M., Lee, K.-S. and Jung, M.-C. (2012) Comparison of comfort,
discomfort, and continuum ratings of force levels and hand regions during gripping
exertions. Applied Ergonomics. [Online] Vol.43 (2), pp.283–289.
Koppa, R., J., McDermott Jr., M., Raab, C. and Sexton, D., J. (1980) HUMAN FACTORS
ANALYSIS OF AUTOMOTIVE ADAPTIVE EQUIPMENT FOR DISABLED DRIVERS.
6. SOURCES
Lawton, C., Cook, S., May, A., Clemo, K. and Brown, S. (2008) Postural support strategies of
disabled drivers and the effectiveness of postural support aids. Applied Ergonomics.
Vol.39 (1), pp.47 – 55.
Li, J., Deng, F., Liu, S. and Hu, H. (2012) Analysis of the influence of clutch pedal to vehicle
comfort. Proceedings of the FISITA 2012 World Automotive Congress. [Online] Vol.5,
pp.15–20.
McGinnis, P. M. (2013) Biomechanics of sport and exercise with web resource and Maxtraq
2D software access-3rd edition. 3rd ed. Champaign, IL: Human Kinetics Publishers.
Monacelli, E., Dupin, F., Dumas, C. and Wagstaff, P. (2009) A review of the current situation
and some future developments to aid disabled and senior drivers in France. IRBM.
[Online] Vol.30, pp.234–239.
Peters, B. (2001) Driving performance and workload assessment of drivers with tetraplegia:
An adaptation evaluation framework. Journal of Rehabilitation Research and
Development. [Online] Vol.38 (2), pp.215–224.
7. SOURCES
Reed, M. R., Manary, M. A., Flannagan, C. A. C. and Schneider, L. W. (2000)
Effects of vehicle interior geometry and Anthropometric variables on
automobile driving posture. Human Factors. [Online] Vol.42 (4), pp.541–
552.
Richter, R. L. and Hyman, W. A. (1974) Driver’s brake reaction times with
adaptive controls. Applied Ergonomics. [Online] Vol.5 (4), p.237.
The Motor Sports Association (2015) The MSA Yearbook 2016 [Online].
Staines, Middlesex: The Royal Automobile Club Motor Sports
Association Ltd.
Vink, P., Koningsveld, E. A. P. and Molenbroek, J. F. (2006) Positive
outcomes of participatory ergonomics in terms of greater comfort and
higher productivity. Applied Ergonomics. [Online] Vol.37 (4), pp.537–
546.
8. MAIN FINDINGS
Anthropometrics and Ergonomics are key
Drivers often shift position under braking/
cornering
Forces acting on driver due to cornering and
braking
Accelerator should not be actuated using
push motion
Available forces of different human motions
(Right)
Forces required to actuate different controls
systems
11. DESIGN BRIEF
High End Objective
Must allow for driver to actuate all control systems without removing
hands from wheel.
Product Design Specification
Survive in track environment with max. vibration frequency of
Approximately 10hz
Must adhere to MSA (Motor Sport Association) safety and technical
regulations (Section H and Section J)
Remove requirement for driver to take hand off steering wheel
12. DESIGN BRIEF
Accelerator – precise, accurate activation with max.
force 25N
Brake – precise, accurate activation, safe with max.
force 200N
Clutch – only required ONCE, max. force 100N
Gear Change – Driver can quickly and comfortable
change gear within 0.1 seconds
Installation – Quickly and easily, Clamp onto
steering column
Maintenance – Easy to maintain on the move
14. ANALYSIS OF MOTIONS
AND FORCES
► Analysing data from tables collected from Federal
Aviation Authority (2008)
► Determining Optimum Elbow Flexion position (CEM
Table)
► Determining optimum actuation motion for each
control sub-system:
► Accelerator
► Brake
► Clutch
► Gears
15. ELBOW FLEXION ANALYSIS
► Concept Evaluation Matrix Table
► Looked at:
► Forces Available
► Practicality and Comfort
► Ergonomics with wheel
► 150 Degrees deemed optimum
► Closest to natural driving position (Right)
16. ACCELERATOR MOTION SELECTION
Maximum Force 25N
Requires accurate motion for
actuation
All motions capable of force
requirement
Pull, Push and Grip better
Ergonomically
17. BRAKE MOTION SELECTION
Maximum Force 200N
Only Pull, Push and Grip motions get
close to force.
Pull and Grip motions again more
ergonomic
Grip motion selected for use in final
concept design
18. CLUTCH MOTION SELECTION
Maximum Force 100N
Pull, Push and Grip motions best to
actuate
Most comfortable and ergonomic for
driver
Grip Motion selected for use
19. GEAR CHANGE SELECTION
Current gear change system requires driver to remove hand from wheel
May result in driver instability, affecting drive and safety
Ideal system removes this requirement
Ideas Proposed
Push Button
Flappy Paddle
Bicycle Gear Change
Problems
Uncertainty around rules, system would need to be verified by MSA
Karting governing body.
21. CONCEPT 1 – TRIGGER THROTTLE
Uses motorcycle brake system with master cylinder
Modified brake lever for better ergonomics/ comfort
Trigger fly-by-wire throttle located at top of brake lever
using RC servo system
Problems
Fingers joined by same muscle, no independent
movement (Right)
22. CONCEPT 2 – 2 PADDLE DESIGN
Uses 2 levers to actuate accelerator and brake sub-
systems
Same braking system (motorcycle brake), modified handle
Accelerator lever fly-by-wire system using RC servo
Problems
2 paddles require slight hand position adjustment from
one to the other
23. CONCEPT 3 – THUMB THROTTLE
Fly-by-wire thumb throttle using RC servo
Thumb motion works independently from fingers (Below
Right)
Allows neater control packaging space
Suitable for use in final concept
24. CONCEPT 4 – BICYCLE BRAKE CLUTCH
Clutch only required ONCE, during get away
Use bicycle brake lever to actuate
Mount to back of steering wheel
Once released, moves out of way
Problems
Doesn’t allow for tidy package with other controls
25. CONCEPT 5 – GRIP LEVER CLUTCH
Motorcycle brake lever system (similar to brake sub-
system)
Allows for neater product design package
Suitable for use in final design package
29. PROJECT LIMITATIONS
Ambiguity around gear change regulations
Design layout due to Internet source model
Limitation in references on subject
30. CONCLUSION
Aim was to design an alternative control system for a gear shift Go-Kart.
This was achieved by:
Analysing available forces from human motions
Determining which motions are suited for each control
Identifying the optimum control actuation method
Generate and analyse concepts
Create final concept design
31. FUTURE WORK
Optimising package size
Clearer understanding of gear change rules
Look into linkages between controls and systems
Look into materials and manufacture of parts
Build and test prototype in controlled environment
Test for Functionality and Safety
