Vision-Based Navigation for an Electric Wheelchair Using Ceiling Light Landmark

This paper presents an autonomous wheelchair system with the capability of self-location and obstacle avoidance. The wheelchair is equipped with two TV cameras that are used for self-location and obstacle avoidance, respectively. In this system, the fluorescent ceiling lights are chosen as landmarks since they can be easily detected and do not require an additional installation. A recognition procedure of landmarks is described by which the desired landmark images in the navigational environment can be retrieved. A self-location technique using ceiling light landmarks is proposed. Using this self-location function, the wheelchair can locate itself in a world coordinate system. The path planning based on landmark and the method of generating a control scheme are presented so that the wheelchair is capable of navigating along any path from start position to goal position. A low cost and high-speed vision system for the detection and avoidance of obstacle is developed and the principal of obstacle avoidance is introduced. A number of navigation experiments are conducted for the wheelchair in an indoor environment. The experimental results indicate the effectiveness of the wheelchair system.