具有预设性能约束的无人艇预设时间轨迹跟踪控制方法

Prescribed-time Trajectory Tracking Control for USV with Prescribed Performance Constraints

摘要:

为解决具有外部海洋环境干扰、模型不确定性以及推进器输入饱和约束的水面无人艇高精度轨迹跟踪控制问题,本文提出一种具有预设性能约束的预设时间轨迹跟踪控制方案。首先,设计一种预设时间集总扰动观测器,对由外界环境干扰和模型不确定性构成的集总非线性进行快速精确重构和补偿。其次,设计一种新的预设时间性能约束函数,提高系统的瞬态和稳态性能。基于扰动观测器技术、预设性能约束、预设时间稳定性理论和动态面控制技术,提出一种预设时间精确跟踪控制算法,使得系统跟踪误差在预设时间内快速精确收敛并始终保持在预设性能约束边界内。通过李雅普诺夫稳定性理论证明了闭环系统的预设时间稳定性。最后,设计仿真实验验证了所提控制方案的有效性和优越性。

Abstract:

In order to address the issue of high-precision trajectory tracking control of unmanned surface vehicles with marine environmental disturbances, model uncertainties and thruster saturation, a prescribed-time trajectory tracking control scheme with prescribed performance constraints was proposed. Firstly, a prescribed-time lumped disturbance observer (PTLDO) was designed to accurately reconstruct and compensate the lumped nonlinearities composed of external environmental disturbances and model uncertainties. Secondly, a novel prescribed-time prescribed performance function (PTPPF) was designed to improve the transient and steady-state performance of system. Based on the disturbance observer technology, prescribed performance constraints, prescribed-time stability theory and dynamic surface control technique, a prescribed-time precision tracking control scheme was proposed, which made the trajectory tracking error converge quickly and accurately within the prescribed time and always remain within the prescribed performance constraint boundary. In addition, the rigorous prescribed-time stability analysis of the entire closed-loop control system was carried out and strictly proved by employing the standard Lyapunov stability theory, which further demonstrated that all internal signals of the closed-loop system remain uniformly bounded and the tracking error can converge to a sufficiently small neighborhood of the origin within the prescribed time. Finally, a series of comparative numerical simulation experiments were systematically designed and implemented under different working conditions to comprehensively verify the effectiveness, feasibility and superior control performance of the proposed prescribed-time trajectory tracking control scheme with prescribed performance constraints.