Trajectory Tracking Control of a Hydraulic System Using TSMCSPO based on Sliding Perturbation Observer

This paper proposes a new designed trajectory tracking method for a hydraulic manipulator, which is the terminal sliding mode control with sliding perturbation observer (TSMCSPO). The dynamics of the hydraulic system are complex and uncertain, it also generates a large reaction force when working as an excavator or a dismantling robot. In this paper, the new control law is designed to force the trajectory of the hydraulic system to follow the reference despite complex dynamics, modeling error, the huge reaction force, and dynamic uncertainties. The sliding perturbation observer (SPO) in TSMCSPO estimates all disturbances from the outside environment, dynamic uncertainties, and modeling errors in real time. We included a simulation and an experiment to verify the approach, and to demonstrate the performance compared with other controllers (SMCSPO, SMC, and TSMC). Stabilities of SPO and TSMCSPO were analyzed based on the Lyapunov stability theory.