LAUSR

Abstract An improved adaptive integral line-of-sight guidance law and path following control system for Unmanned Surface Vehicles (USVs) with uncertainties is proposed in this paper. The dynamic equations of the tracking errors are established in the Serret-Frenet coordinate system with the consideration of the time-varying ocean currents. In order to eliminate tracking errors, three adaptive variables are constructed to design the guidance law instead of the unmeasurable ocean currents and sideslip angle, and the adaptive variables are adjusted online according to the tracking errors. The desired heading angle is computed by using the designed guidance law, then a heading controller based on backstepping method is designed to track the desired heading angle, so as to realize the path following of USVs. The designed guidance subsystem is proved to be uniformly ultimately bounded by Lyapunov method, and the simulation results show that the path following control system designed in this paper can make the USV follow the desired path quickly and accurately.