Abstract

In rehabilitation robotics, rehabilitation algorithms determine an appropriate magnitude and direction of assistive force, which is to help the patient perform desired motions. In this paper, proxy-based impedance control is proposed as a rehabilitation algorithm of a cable-driven assistive system. The proposed method applies an assistive joint torque when the human joint angle deviates from the position of the proxy. A free space is assumed around the proxy such that a free motion of the human joint is allowed in a certain range. If the desired inertia of the human body is different from a nominal value, the proposed method also applies assistive torques to compensate for the inertia mismatch. The implementation of rehabilitation algorithms is challenged by actuator dynamics. The proposed method is designed considering the actuator dynamics, and its performance is verified by experiments.