Trajectory Tracking Control of Underwater Vehicle-Manipulator Systems Using Uncertainty and Disturbance Estimator

The underwater vehicle manipulator system (UVM-S) plays a vital role in ocean exploration. However, the system's parametric uncertainty and external disturbance increase the difficulty in designing an appropiate controller. In this paper, the term including parametric uncertainty and external disturbance is estimated using uncertainty and disturbance estimator (UDE). Then, the term is incorporated into a sliding mode control (SMC) method to compensate the uncertainties in hydrodynamic parameters of the vehicle and reject the external disturbance. The proposed UDE-SMC control scheme do not include the switching functin of SMC, which descreases the chattering effect of SMC. In addition, due to the system's kinematic redundancy, the inverse kinematic method based on pseudo-inverse of Jacobian matric is presented to investigate redundancy resolution. The main contribution of this paper is that it presents a simple model-based trajectory tracking controller for UVMS. Finally, the numerical simulations along with the comparative study are conducted. The simulation results illustrate the effectiveness and robustness of the proposed method.