This paper is concerned with the problem that fast-transient response and excellent robustness cannot be satisfied simultaneously in the process of dynamic positioning (DP) for underactuated surface vessel (USV) in shallow water. By combing the improved L1 adaptive control with backstepping method, a novel control scheme is designed, which can ensure a fast adaptation with a guaranteed smooth transient response without any overshoot and chattering phenomenon. System uncertainties and disturbances are estimated by the nonlinear observer. Moreover, the optimized extremum seeking control (ESC) is employed to reduce energy consumption under environmental disturbances. Rigorous theoretical analysis shows that all closed-loop signals are bounded-input bounded-state. Simulation and sea test results are presented to illustrate the effectiveness and the robustness of the proposed strategy under the condition of external disturbances and parametric uncertainties.

中文翻译：

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基于 L1 自适应反步控制的欠驱动水面船舶动态定位

本文关注的是浅水欠驱动水面舰艇（USV）动态定位（DP）过程中不能同时满足快速瞬态响应和优良鲁棒性的问题。通过将改进的 L1 自适应控制与反步法相结合，设计了一种新颖的控制方案，该方案可以确保快速自适应，并保证平滑的瞬态响应，没有任何超调和颤振现象。系统的不确定性和扰动由非线性观测器估计。此外，优化的极值搜索控制（ESC）用于减少环境干扰下的能源消耗。严格的理论分析表明，所有闭环信号都是有界输入有界状态。