Nonlinear-Gain Based Adaptive Control for Autonomous Surface Vehicles

This paper investigates the accurate motion control for Autonomous Surface Vehicles (ASVs) in the presence of complex marine conditions, such as time-varying external disturbances and unmodeled dynamics. In order to solve these issues, we propose a nonliner-gain-based adaptive control scheme, which effectively improves the robustness of rejecting disturbance. The projection-type adaptive law is designed to achieve the bounded and reasonable estimation results. It is strictly proved that with the motion controller, all the closed-loop ASV system signals are globally bounded, and the ASV can achieve asymptotic tracking to the reference trajectory by virtue of the adaptive technique. Finally, simulations are conducted on the benchmark CyberShip II to validate the effectiveness, robustness and practicability of the proposed control scheme.