Development of a Power Assist System of a Walking Chair (Proposition of the Speed-Torque Combination Power Assist System)

Abstract

In this paper, we discussed the mechanism and control strategy of the power assist systems for the walking chair and proposed a new power assist system. The composition of the leg mechanism, which generates the motion for periodic walk at horizontal plane by driving the input link at constant velocity, and driving torque of the leg mechanism of the prototype walking chair were presented. Velocity variation in user’s cranking operation was also presented. We proposed a system architecture for driving the walking chair by human’s and assisting actuator’s powers. We proposed a hybrid power assist system with two assisting actuators for reducing the effects of variations in user’s driving velocity and in driving torque of the leg of the walking chair on the output velocity of the walking chair and on user’s discomfort.