Dynamic positioning (DP) system is an advanced positioning system widely used in various special operation ships, and the design of control strategies to cope with different constraint conditions is the core technology of DP system research. In this study, a novel dual-loop control law is proposed to effectively tackle the control challenges encountered by DP ships, particularly in the presence of input saturation and error constraints. Firstly, a saturation handling model is designed to avoid input saturation in the system. Subsequently, a dual-loop DP control scheme is developed. The outer-loop is responsible for the ship's position and heading control, while concurrently providing the command velocity signal essential for the inner-loop. Specifically, a prescribed performance control strategy is designed in the outer-loop to ensure precise control over positioning errors within predefined ranges and achieve desirable transient and steady-state performance. The inner-loop controls the ship's velocity signal, in which a feedback control law is designed based on Hamilton-Jacobi-Issacs (HJI) inequality to estimate generalized faults of the DP system. Finally, the proposed control law is validated through numerical simulations on a 76.2 m supply ship, demonstrating superior transient and steady-state performance compared to existing methods.

中文翻译：

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具有规定性能的动力定位船舶双环控制设计

动力定位（DP）系统是广泛应用于各类特种作业船舶的先进定位系统，应对不同约束条件的控制策略设计是DP系统研究的核心技术。在这项研究中，提出了一种新颖的双环控制律，以有效解决动态定位船舶遇到的控制挑战，特别是在存在输入饱和和误差约束的情况下。首先，设计饱和处理模型以避免系统中的输入饱和。随后，开发了双环DP控制方案。外环负责船舶的位置和航向控制，同时提供内环所需的命令速度信号。具体来说，在外环设计了规定的性能控制策略，以确保将定位误差精确控制在预定范围内，并实现理想的瞬态和稳态性能。内环控制船舶速度信号，其中基于Hamilton-Jacobi-Issacs (HJI)不等式设计反馈控制律来估计DP系统的广义故障。最后，通过对一艘 76.2 m 补给舰的数值模拟验证了所提出的控制律，与现有方法相比，证明了其优越的瞬态和稳态性能。