A model predictive control (MPC) method with linear extended state observer (LESO) is presented to address the problems of the input constraints, uncertain parameters and external disturbances for path following of under-actuated surface ships without velocity measurements. The line of sight (LOS) guidance algorithm is employed to convert the path following into the heading control flexibly. The proper reference paths at waypoints are formulated by a variable acceptable radius approach. The matters of the heading control, input constraints including rudder amplitude and rate limit are addressed by virtue of MPC method employing the Norrbin model as the internal model. The LESO is introduced to estimate the uncertain parameters and external disturbances for the improvement of the internal model accuracy and the controller robustness. Moreover, the nonlinear observer and LESO are used to approximate the surge velocity, sway velocity and yaw rate, respectively. The effectiveness of the proposed control law is demonstrated via the compared simulations.

中文翻译：

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基于状态观测器模型预测控制的欠驱动船舶路径跟踪

针对欠驱动水面舰船在没有速度测量的情况下路径跟随的输入约束、不确定参数和外部干扰问题，提出了一种具有线性扩展状态观测器（LESO）的模型预测控制（MPC）方法。采用视线（LOS）制导算法，将路径跟随灵活转换为航向控制。航路点的正确参考路径由可变的可接受半径方法制定。通过采用Norrbin模型作为内部模型的MPC方法解决了航向控制、包括舵幅和速率限制在内的输入约束问题。引入LESO来估计不确定参数和外部扰动，以提高内部模型精度和控制器鲁棒性。而且，非线性观测器和 LESO 分别用于逼近喘振速度、摇摆速度和偏航率。通过比较模拟证明了所提出的控制律的有效性。