Trajectory Tracking Control of an Underactuated Autonomous Surface Craft in the Presence of Environmental Disturbances

This paper presents a nonlinear trajectory tracking controller for an autonomous surface craft under the presence of external time-varying environmental disturbances generated by wind, wave and ocean current. The proposed controller is able to drive the craft towards an arbitrarily small neighborhood of a smooth desired trajectory, obtaining global practical stability as the vehicle eventually remains within that neighborhood for all time. To demonstrate the efficacy of the designed control strategy, we give and analyze simulation results.