Path following of underactuated MSVs with model uncertainty and ocean disturbances along straight lines

This paper addresses the problem of path following for underactuated MSVs with dynamical uncertainty and time-varying ocean disturbances. The path is made up of straight-line segments connected by n waypoints. A robust adaptive path following strategy is proposed based on a LOS guidance scheme and a novel velocity controller. Specifically, the velocity controller employs an NN to identify the dynamical uncertainty and time-varying ocean disturbances. The predictor errors are utilized to construct the novel iterative updating laws for NN weights. Using a Lyapunov-Krasovskii functional, it is proven that the underactuated MSV is able to follow a piecewise linear path, and tracking errors converge to a small neighborhood of the origin. Simulation result is given to show the effectiveness of the proposed method.