Adaptive prescribed-time trajectory tracking control for USVs with disturbance and input saturation
摘要
This paper proposes an Adaptive Practical Prescribed-Time Control (APPTC) method integrated with a Prescribed-Time Disturbance Observer (PTDO) to address the trajectory tracking problem for Unmanned Surface Vehicles (USVs) under strict time constraints and environmental disturbances. A novel Saturated Prescribed-Time Adjustment (SPTA) function is introduced to design both the PTDO and the controller, ensuring bounded control gains and continuous transitions. The PTDO accurately estimates lumped disturbances within a prescribed time. The APPTC, developed within an actor-critic framework using backstepping and reinforcement learning (RL), guarantees convergence of tracking errors and neural network parameters within a user-specified time, independent of initial conditions. RL is employed to optimize the long-term cost function, balancing tracking performance and energy efficiency by approximating the Hamilton-Jacobi-Bellman equation, thus enhancing adaptability to nonlinear dynamics and disturbances. An auxiliary system mitigates input saturation, improving practical applicability. Simulation experiments validate the effectiveness of the proposed method.