S-Plane-Based Trajectory Tracking Control of Underactuated Ship

It is well known that traditional trajectory tracking model-based control methods of underactuated ship are not able to adapt to complex and dynamic ocean environment. In this paper, taking into consideration of dynamic parameter uncertainty of the underlying underactuated ship model and unknown time-varying environmental disturbances, an S-plane-based controller with self-tuning parameters is proposed. The main contributions of this work are: (1) The Extended State Observer (ESO) and proportional control of PID are introduced into the S-plane control strategy to enhance robustness of the controller and fast convergence of tracking errors. (2) A self-tuning strategy for adaptively tuning the controller parameters is proposed. (3) Leveraging on the proposed self-tuning strategy, a new controller based on the Q-learning algorithm is designed so that the parameters of the controller can be adjusted independently. Simulation results show that the proposed control method is superior to the state-of-the-arts methods in terms of speed and accuracy of trajectory tracking.