Summary: Journal of Intelligent and Robotic Systems 34: 315329, 2002.
© 2002 Kluwer Academic Publishers. Printed in the Netherlands.
Semi-autonomous Navigation of a Robotic
ANTONIS ARGYROS, PANTELIS GEORGIADIS, PANOS TRAHANIAS and
Institute of Computer Science, Foundation for Research and Technology Hellas (FORTH),
Vasilika Vouton, P.O. Box 1385, 71110 Heraklion, Crete, Greece;
Abstract. The present work considers the development of a wheelchair for people with special
needs, which is capable of navigating semi-autonomously within its workspace. This system is ex-
pected to prove useful to people with impaired mobility and limited fine motor control of the upper
extremities. Among the implemented behaviors of this robotic system are the avoidance of obstacles,
the motion in the middle of the free space and the following of a moving target specified by the
user (e.g., a person walking in front of the wheelchair). The wheelchair is equipped with sonars,
which are used for distance measurement in preselected critical directions, and with a panoramic
camera with a 360 degree field of view, which is used for following a moving target. After suitably
processing the color sequence of the panoramic images using the color histogram of the desired
target, the orientation of the target with respect to the wheelchair is determined, while its distance