为实现三自由度无人水面船（ USV）在风浪流引起的海洋环境干扰下的轨迹跟踪，设计一种非线性扰动观测器（NDO）和动态面控制（DSC）的鲁棒控制器。首先，提出一种新的NDO来在线估计并补偿外界环境干扰。与传统干扰观测器不同，该扰动观测器具有有限时间收敛的特点；然后，在运动学回路中利用反演法设计虚拟控制律来镇定跟踪误差，并其通过一阶低通滤波器避免了由对虚拟控制求导而带来的计算复杂性，同时通过NDO对未知海洋干扰进行实时补偿，利用Lya-punov稳定性定理证明了USV闭环系统的误差信号半全局最终一致有界（ SGUUB）。最终，仿真实验证明了所设计控制策略的有效性。%A robust controller based on nonlinear disturbance observer( NDO) and dynamic surface con-trol(DSC) for 3 degrees of freedom unmanned surface vehicle (USV) under the presence of ocean envi-ronmental disturbances is presented .Firstly,a NDO was constructed to estimate and compensate for the environmental disturbances online .Unlike conventional disturbance observers ,the proposed NDO had the characteristics of finite time convergence .In the kinetic loop ,a virtual control was designed to stabilize the tracking error by back-stepping technique .A first order filter was introduced to avoid the complexity of computation caused by the derivation of virtual control .NDO was adopted to compensate for unknown o-cean disturbance .The Lyapunov stability theory shows that all the signals of the closed system are semi-global uniformly ultimately bounded (SGUUB).Finally,numerical simulation results are given to verify the practical feasibility of the proposed approach .
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