Abstract
Human-friendly electrically powered wheelchair (EPW) with good riding comfort becomes a real requirement of aging society. Many factors are related to the riding quality of EPW, the body tilting for the acceleration and deceleration of EPW is one of important factors. Especially in the case of speed control by the joystick a sudden acceleration or deceleration is easily to be caused and the riding comfort becomes bad. In this study, an improvement on riding comfort has been tried by applying the state feedback control with state observer based on the modeling of EPW system including an operator. A sensory test on riding comfort for the handicapped and healthy subject was carried out, and the effectiveness of the control method was verified.