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.

提出了一种改进的具有不确定性的无人水面机器人自适应视距制导律和路径跟随控制系统。考虑到时变的洋流，在Serret-Frenet坐标系中建立了跟踪误差的动力学方程。为了消除跟踪误差，构造了三个自适应变量来设计制导律，以替代无法测量的洋流和侧滑角，并根据跟踪误差在线调整自适应变量。利用设计的制导律计算出期望的航向角，然后设计基于反步法的航向控制器跟踪期望的航向角，以实现USV的路径跟踪。