Robust Sliding-Mode Control for the Problem of Trajectory Tracking of Autonomous Marines Vehicles

In this paper, we study the problem of trajectory tracking control for autonomous marines vehicles using robust sliding-mode controller. The proposed algorithm achieves good tracking performance of marine vehicle in the open sea in which there exist severe environmental disturbances and unknowns dynamic parameters. First, the dynamic model in task space of the marine vehicle system in horizontal motion is designed. By using position and velocity tracking errors, a robust controller is then developed based on a linear sliding-mode surface. The designed algorithm is chattering free due to hyperbolic tangent function in switching part. Based on the Lyapunov theorem, the stability in closed-loop system is guaranteed and the convergence of the position and velocity tracking errors are obtained. In addition, the robustness of the controller is verified when disturbances and uncertainties are introduced in the system. Extensive simulations are conducted to demonstrate the validity of the proposed algorithm.