Semiautonomous Low Cost Wheelchair for Elderly and Disabled People

In this paper, a semiautonomous low-cost wheelchair robot to supplement impaired mobility of handicapped or elderly people is presented. The motion of the wheelchair is controlled by the joystick and the sonar sensor in such a manner that the sonar sensor has higher priority than joystick in normal conditions. The wheelchair uses two permanent magnet DC motors which are differentially driven using pulse width modulation (PWM) control signals. The motors drive the worm to drive the wheelchair. The semiautonomous wheelchair is equipped with four ultrasonic range finders in the front, one at the back to avoid the obstacles in its path and another one near the foot rest to detect steps. The system totally uses six ultrasonic sensors. The semiautonomous wheelchair was successfully tested under various conditions and satisfactory results were obtained.