Cascaded Design for Robust Trajectory Tracking Control of an Underactuated Surface Vehicle

The trajectory tracking control problem for an underactuated surface vehicle is addressed in this paper based on the cascaded design. The tracking error dynamics are established with the reference trajectories generated by a virtual target vehicle and converted into a novel cascaded structure, then the primitive control problem can be decomposed into the stabilization problems for the two interconnected systems, which is different from the Lyapunov based recursive design that relies heavily on constructing the Lyapunov function for the overall system. Moreover, the persistent of excitation condition on the yaw angle can be removed in the resulted cascaded structure. Sliding mode control method is utilized to stabilize the states under model uncertainties for the perturbing system. Then, the satisfaction of the sufficient conditions for the the stability of the cascaded system is verified. Finally, the simulation results are presented to show the effectiveness of the proposed robust cascaded control.