Page 69 - Mechatronics for Safety, Security and Dependability in a New Era

Ch12-I044963.fm Page 53 Tuesday, August 1, 2006 9:08 PM
1, 2006
Tuesday, August
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Ch12-I044963.fm
9:08 PM
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GUIDANCE OF ELECTRIC WHEELCHAIR
BY THE LEAD TYPE OPERATING DEVICE
WITH DETECTING RELATIVE POSITION TO ASSISTANCE DOG

T. Uemoto, H. Uchiyama and J. Kurata
Department of Mechanical Systems Engineering, Kansai University
3-3-35, Yamatechou, Suita, Osaka 564-8680, Japan

ABSTRACT

A guidance control method to let an electric wheelchair follow an assistance dog is proposed. In this
method, electric wheelchair employs the guidance unit composed of a lead, a winder and two
potentiometers. The lead connected to the winder is reeled out or in as the relative position between
the assistance dog and the guidance unit is changing. The length and the direction angle of the lead
are detected by two potentiometers. Both translational and rotational signals used to control the
electric wheelchair are generated by these two detected information. In this report, we described an
opinion about an adjustment of the control system by some results of simulated experiment.

KEYWORDS
Electric wheelchair, Assistance dog, Guidance control, Human friendly machine, Optimum control

INTRODUCTION
The number of electric wheelchair's user is growing in these years. Some users of electric wheelchair
hope to choose the most suitable input device for themselves from various types. Control stick, the
typical input device for electric wheelchair, is designed for common user. Therefore, it's probably not
true that this device is fitted well to each user. We proposed the push button type of input device and
the bi-state operating controller as one example for diversification of input device, Maeda (2002) and
Uemoto (2003). After the Law Concerning Assistance Dogs for the disabled was executed in October
2003 by Japanese government, the expectation for activity of an assistance dog has been swelled.
Now, we are focusing our attention on assistance dogs and their owners. Assistance dog performs the
request of picking up of a thing, assistance of attachment and detachment clothes and change of
posture, standing up and the support in the case of a walk, opening and/or closing of a door, operation
of a switch, the rescue in case of emergency and so on. Additionally, assistance dog sometimes leads
a wheelchair. However, this work forces the head and back of assistance dog a great corporal burden,
for example Coppinger (1995). In this report, we propose the device for an assistance dog guiding an
electric wheelchair in order to make this burden mitigate, and also as one proposal for the
diversification of input device, Maeda (2003). We confirmed fundamental mobility of electric
wheelchair by simulated experiments, and described the result and knowledge.