Wheelchair obstacle avoidance based on fuzzy controller and ultrasonic sensors

Abstract

Electric wheelchair is one of the most used for the movement of disabled and aged people. This work introduces an obstacle avoidance system aimed for providing more autonomous navigation of a electric wheelchair (EW) in unknown indoor environments. These technologies seek to increase the independence of people with disabilities and improve their quality of life by making the most of each individuals abilities. Furthermore, the integration of an ultrasonic sensor to avoid obstacle and a fuzzy controller to generates velocity for aim to join the target position. A prototype of EW has been equipped with control unit based on two micro-controller. The first for manage the motors velocity. The second for explore the ultrasonic sensors. Two micro-controller exchanges the information with a PC board type PC 104, which is used to process data from sensors and encoders. The information is processed by a control algorithm based on fuzzy logic. The control algorithm is optimized using the gradient method to minimize the path traveled to reach the desired position. The practical implementation demonstrates the algorithm validity for obstacle avoidance and goal achievement with a minimum path and greater security.