Adaptive robust slide mode trajectory tracking controller for lower extremity rehabilitation exoskeleton

Abstract

An adaptive robust slide mode controller (ARSMC) was designed for lower extremity rehabilitation exoskeleton whose joints are driven by DC motors works in torque mode. The innovation point is that an adaptive robust controller was used in human gait tracking control for lower extremity rehabilitation exoskeleton. To complete the designed of the controller, the dynamic model of the robot was proposed in first; Then an adaptive robust controller was designed based on the dynamic model which was proposed forward. To satisfy the requirement of the robust performance a sliding surface which in Proportional-differential-integral form was proposed. Besides, a reaching law that has high rate of convergence and trifling buffeting with adaptive parameters was proposed in the permission of Lyapunov stability in order to resist external disturbance and make the system more adaptive to satisfy the veracity with different patient. Then the controller was simulated in MATLAB and was compared with PID controller to prove the superiority of this controller.