Gait tracking based triple-step nonlinear control for a lower limb rehabilitation robot

Abstract

A triple-step nonlinear control strategy based on the dynamic model is proposed for a rehabilitation robot which interact with the human body in real-time. And the control strategy mainly includes three parts: the steady-state controller, the feed-forward controller, and the feedback controller. The trajectory tracking experiment is carried out on a recruited subject with a lower limb rehabilitation robot (LLRR). And the results show that each joint of the human-robot system can follow the reference gait trajectory well under different interaction torque levels. It indicates that the triple-step nonlinear controller is valid in practical application.