Robust Output Feedback controller for a Serial Robotic Manipulator with Unknown Nonlinearities and External Disturbances

Abstract

This paper presents a robust output feedback controller for a n-link serial robotic manipulator with unknown dynamics and external disturbances. First, the robotic manipulator's model is formulated with unknown dynamics, including joint coupling, nonlinearities, and external disturbances. Second, an output feedback controller is proposed by combining a backstepping controller and an extended high-gain observer to estimate the unknown dynamic and external disturbances in addition to the system states. Experiments on 4 DOF robotic manipulators verify the proposed control approach. The proposed control approach achieved the end-effector's desired trajectory under unknown system dynamics and disturbances.