Prescribed Performance Trajectory Tracking Control of Underactuated Autonomous Surface Vehicles

Facing the complexity in ocean engineering, the demands of better performance for autonomous surface vehicles (ASVs) trajectory tracking control have been dramatically increased. However, the uncertainties caused by hydrodynamic changes and time-varying environmental disturbances may decay the trajectory tracking control performance. This study proposes a composite control strategy for the trajectory tracking of ASVs subject to model uncertainties and external disturbances. First, an adaptive prescribed performance control based on backstepping recursive framework is developed to achieve pregiven tracking precision within the prescribed time. In addition, a novel performance function is designed to relax the dependence on initial value of error and reflect convergence time directly. Numerical Simulation results show that the tracking error converges in finite time, with tracking performance satisfying the output constrains. Besides it is proved that the strategy has strong robustness against unknown external disturbances.