Robust Path Following Control of Autonomous Surface Vessels

This work presents a robust path following control method for autonomous surface vessels (ASVs) based on sliding mode control. To describe the control problem, the desired path of the vehicle is parameterized by one parameter and a parallel-transport path frame. The error dynamics of the path following system consisting of the position following error and the parameter speed's error are subsequently derived in the body-fixed coordinates of the vessel. Based on the path-following error, a geometric tracking control law is proposed at the kinematic level, i.e., as reference velocities, under which the path following task can be achieved asymptotically as time diverges. We then develop a robust force controller to steer the vehicle' velocity to track the reference velocity asymptotically and exponentially fast. Rigorous stability analysis is provided to show the effectiveness of the proposed control method.