End-effector Stabilization of Manipulator Based on Sliding Mode Controller and Disturbance Observer

Abstract

In order to solve the problem of end-effector position jitter in inertial space caused by carrier motion of manipulator base, an end-effector stabilization method combining sliding mode controller and disturbance observer is proposed. The kinematic and dynamic models of the manipulator are established, and the end-effector stability control scheme of the manipulator is constructed. The end-effector stabilization problem is divided into two parts: disturbance compensation and trajectory tracking. For the friction torque, the dynamic effect of carrier disturbance and the uncertainty of the model, a disturbance observer is designed to compensate the control torque and actively eliminate the disturbance influence. For the end-effector position decoupling, a sliding mode controller is designed to reduce the tracking error and jitter. The experimental results show that compared with the traditional independent joint PID controller, the method based on the combination of sliding mode controller and disturbance observer can effectively improve the accuracy of position stability, and the average disturbance isolation degree is 25.2dB.