Backstepping Sliding Mode Control of Underactuated Unmanned Surface Vehicle Based on Finite Time Observer

Addressing the challenge of the unmanned ship's susceptibility to external environmental disturbances and the impact of model parameter uncertainty on its control system is paramount. Herein, leveraging the motion characteristics of the unmanned vessel, we establish both its kinematic and dynamic models for a three-degree-of-freedom underactuated system. A finite-time observer-based backstepping sliding mode control approach is crafted to anticipate model uncertainties and environmental perturbations. Incorporating the LOS (line-of-sight) guidance law into the controller design aims to mitigate controller input chatter and enhance convergence speed and tracking precision. Furthermore, a first-order filter signal is employed as a substitute for the virtual control law, thereby circumventing differential explosions triggered by its derivative. Validation of the control algorithm's feasibility and practicality is achieved through rigorous simulation experiments.