Sliding Mode Control of Rigid Flexible Hybrid Structure Manipulator with Compound Disturbance and Measurement Noise Using VGESO

A controller design based on singular perturbation theory is studied in this paper to investigate the trajectory tracking and vibration suppression of a rigid flexible hybrid manipulator. Applying the singular perturbation theory, the dynamic model of the manipulator is decomposed into a slow subsystem and a fast subsystem using different time scales. For the slow subsystem with compound disturbance and measurement noise, a novel variable gain extended state observer (VGESO) is proposed, which can alleviate the sensitivity to high-frequency noise while ensuring the desired estimation performance. A sliding mode controller based on VGESO is designed to act as a trajectory tracking controller. The boundedness of the estimation error of VGESO is demonstrated using the Lyapunov approach. For the fast subsystem, the LQR controller is employed to suppress the vibration of flexible links. Numerical simulation verifies the effectiveness of the control method proposed in this paper.