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Control of a Multi Function Wheelchair

for Disabled/Elderly Mobility

Nor Maniha Abdul Ghani

Dr. Osman Tokhi

Department of Automatic Control and Systems Engineering

The University of Sheffield

UKACC PhD Presentation Showcase

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Introduction/Problems

Common mobility assistive techniques and recent advances in curb and stair climbing devices;

crawler, leg, hybrid, wheeled types suffer from certain issues:-

Complex design, incorporate many wheels and of large size [1-6].

Reliance on personal assistant or handrail to perform stair climbing tasks [7].

Lack of stability control assessment [1-7].

Use conventional control methods, PID [7], PLC [5], FLC [4] but not to extensive levels.

Sunwa, 2006 WL-16RII, 2005 Wheelchair.q, 2009 iBOT, 2001

UKACC PhD Presentation Showcase

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Objectives/Methodology

To develop a simple and compact wheelchair mechanism for indoor usage.

To develop a suitable control strategies for climbing mechanism and ensure stability of the

whole wheelchair.

To design a transformation mechanism (sit and stand) manoeuvres.

To apply bio inspired algorithm for optimizing the parameters of developed controller.

A cluster/link rotation mechanism

developed in VN to perform stair climbing

by rotating a cluster to bring up the rear

wheels over the front ones while

maintaining stability of the overall system

without slipping or tipping over the

staircase.

A humanoid model developed as a rigid

body in Visual Nastran [8-9] with 1.5 m in

height and weight of 71 kg, and a

staircase of slope 29o and steps height, h

of 0.185m, depth, d of 0.335m and

minimum width, w of 0.762m [10].

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Ascending/Descending Stairs Control

(DPMFLC)

DPMFLC

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0 1 2 3 4 5 6-100

-50

0

50

100

Time (s)

Ang

ular

pos

ition

of

link

for 1

st s

tep

(deg

ree)

0 1 2 3 4 5 6-200

-100

0

100

200

Time (s)

Ang

ular

pos

ition

of

link

for 2

nd s

tep

(deg

ree)

0 1 2 3 4 5 6-3

-2

-1

0

1

Time (s)

Tilt

angl

e (d

egre

e)

+1000N

-1000N

undisturbed

+1000N

-1000N

undisturbed

+1000N

-1000N

undisturbed

Results

Slide 5

1st step

2nd step

0 2 4 60

0.1

0.2

0.3

0.4

Time (s)

Dis

tanc

e1

(m)

0 2 4 60

0.1

0.2

0.3

0.4

0.5

Time (s)

Dis

tanc

e2

(m)

0 2 4 6-0.2

0

0.2

0.4

0.6

0.8

Time in (s)

Fron

t axl

e po

sitio

n(m

)

0 2 4 60.2

0.4

0.6

0.8

1

Time (s)

Rea

r axl

e po

sitio

n(m

)

0 1 2 3 4 5 680

85

90

95

Time (s)

Yaw

ang

le (d

egre

e)

+1000N

-1000N

undisturbed

+1000N

-1000N

undisturbed

+1000N

-1000N

undisturbed

0 2 4 60

200

400

600

800

1000

Time (s)

Torq

ue (N

m)

0 2 4 6-1000

-500

0

Time (s)

Torq

ue (N

m)

Train of Positive and Negative Impulse Disturbances

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Conclusion & Future Work

Conclusion A DPMFLC has been implemented to perform stair ascending/descending

task with an automatic mode wheelchair system.

It has been demonstrated that the control system is able to perform

effectively in order to ensure stability of the maneuvering tasks.

The designed controller is robust to positive and negative impulse

disturbances.

Future Work Transform the wheelchair from sitting to standing position.

Investigate bio-inspired optimization to optimize the parameter of

developed controller.

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References

Slide 7

[1] Sunwa Co.Ltd (2006). (1st April 2012), [Available from] http://www.sunwa-jp.co.jp/en/accessibility/.

[2] Top Chair, (2003). The first stair-climbing powered wheelchair, (1st April 2012), [Available from]

http://www.topchair.fr/.

[3] Lawn, M. J., Sakai, T., Kuroiwa, M. & Ishimatsu, T. (2001). Development and practical application of a stair

climbing wheelchair in Nagasaki. Journal of HWRS-ERC, 2, 33-39.

[4] Teng, Y., Wang, T., Yao, C. & Li, X. (2010). The Research of Tension Optimal Estimation and Stair-Climbing

Ability of Transformation Wheelchair Robot. Proceeding of 29th Chinese Control Conference, 3716-3721.

[5] Noborot (2012). Robotic vehicle could lead to stair-climbing wheelchair by 2017, (6th November 2012),

[Available from] http://www.gizmag.com/nororot-stair-climbing-robotic-vehicle/24878/ .

[6] Nakajima, S. (2010). Proposal for step-up gait of RT-Mover, a four wheel-type mobile robot for rough terrain

with simple leg mechanism. Proceeding of IEEE International Conference on Robotics and Biomimetics, 351-

356.

[7] Johnson & Johnson Company (2001): Independence Ibot mobility system. Johnson & Johnson Company.

http://www.ibotnow.com/index.html. Accessed 1 April 2012.

[8] Wang, S.L. (2001). Motion simulation with working model 2D and MSC. Visual Nastran 4D. J. Comput. Soft.

Engin. 1 (2), 193-196.

[9] Winter, D.A. (1990). Biomechanics and Motor Control of Human Movement. Wiley-Interscience, New York.

[10] Canadian Centre For Occupational Safety And Health ( 2010). (28thNovember 2012), [Available from]

http://www.ccohs.ca/oshanswers/safety_haz/stairs_fallprevention.html

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