An Anti-Disturbance Sliding Mode Controller for Ship Path Tracking Based on Adaptive Line-Of-Sight Guidance Law

The marine economy is experiencing rapid growth. It includes advancements in marine resource development and maritime transportation. Various complex offshore operations such as undersea pipeline laying and drilling platform positioning have increasingly high requirements for accurate ship control. The motion of ships is characterized by nonlinearity, large time delays, and significant inertia, which is easily disturbed by wind, waves and currents. So it leads to a great challenge in the motion control. Therefore, it is necessary to design an anti-disturbance ship path tracking algorithm. To address the aforementioned challenges, an anti-disturbance sliding mode controller based on adaptive line-of-sight (ALOS) guidance law is designed in this paper. Firstly, the desired heading angle of the ship is obtained by the ALOS guidance law. Subsequently, taking into account the disturbances from wind, waves, and currents, we design a sliding mode controller that incorporates an upper bound estimation of disturbances to track the desired heading angle and speed. Lastly, we analyze the stability of the control system and conduct simulation for ship path tracking. The simulation results demonstrate that the designed controller keeps the ship's path tracking error within 5 meters under the given disturbances.