Prescribed performance dynamic surface control for trajectory-tracking of unmanned surface vessel with input saturation

For realizing the trajectory tracking of unmanned surface vessel (USV) with unknown disturbances and input saturation, a robust adaptive prescribed performance dynamic surface control (PPDSC) scheme is proposed. Firstly, a simple non-logarithmic performance function is used to ensure that the tracking errors converges to a certain neighborhood of the origin. Secondly, owing to use the dynamic surface technique and introduce an auxiliary dynamic system (ADS), the double advantages are established, i.e., the negative effects of the differential operation for the intermediate control law and input saturation of the intermediate control law are avoided. Thirdly, a novel nonlinear disturbance observer (NDOB) is designed to estimate external disturbances and a feedforward compensation is produced for control amount. Finally, according to the Lyapunov stability theory, all signals are semi-globally uniformly ultimately bounded (SGUUB), and the trajectory can be maintained within the desired values with prescribed tracking performance. The effectiveness of the proposed control protocol is validated based on a 76.2 m supply fully actuated USV by the simulation results.

Automated summary

A robust adaptive control scheme for trajectory tracking of unmanned surface vessels (USVs) is proposed, utilizing an auxiliary dynamic system and a novel nonlinear disturbance observer to handle unknown disturbances and input saturation. The effectiveness of the control protocol is validated through simulation results on a 76.2 m supply fully actuated USV, demonstrating its ability to maintain trajectory within desired values with prescribed tracking performance.