Automatic Berthing Control of a Ship Using Adaptive Sliding Mode Controller and Generalized Extended State Observer

This study introduces a novel methodology for controlling sway movements during ship berthing by combining an adaptive sliding-mode controller (ASMC) with a generalized extended state observer (GESO). This control system was specifically developed to address the complexities associated with nonlinear dynamics and external disturbances often encountered during low-speed maneuvers in berthing scenarios. The ASMC is designed to minimize the chattering effect, a common issue in traditional sliding-mode controllers, while ensuring robust performance under uncertain conditions. GESO enhances the system&quots capability by precisely estimating and compensating for external disturbances and system uncertainties. The stability of the proposed control approach was theoretically verified using Lyapunov’s stability theory. Additionally, control allocation techniques were employed to optimize the distribution of thrust across the ship’s propulsion units, thereby enhancing energy efficiency and control precision. Simulation results indicate that the ASMC, when used with GESO, surpasses conventional control methods in terms of disturbance rejection and trajectory tracking accuracy, presenting a viable solution for the autonomous berthing of unmanned surface vehicles.