Impedance control of a spatial redundant manipulator used for relaxing muscle fatigue

This paper presents a redundant manipulator with a new application to relaxing human-body muscle fatigue. The environment between human-body and the manipulator end-effector is modeled as a mass-spring-damper system. Then the generalized impedance control method is used to control the manipulator in the task space as well as the null space. To get the optimized solutions, the objective function is combined into the null space motion controller and the stability of controller in the null space is analyzed. A 4-DOF(degree of freedom) spatial manipulator is built up to verify the proposed control law in the simulation and the results show the effectiveness of the proposed method.