船舶航向保持的滑模变结构自适应模糊控制研究

Study on Self-adapting Fuzzy Control with Sliding-mode Variable Structure for Course Keeping of Ship

针对船舶航向非线性控制系统中存在未知控制增益,参数不确定性和外界干扰的影响,通过引入Nussbaum函数,利用模糊逻辑系统的逼近能力,将多滑模控制与自适应模糊控制相结合,提出一种新的多滑模自适应模糊控制算法,实现了船舶航向的跟踪控制,并且在设计过程中,避免了控制器奇异值问题的发生。借助Lya-punov函数证明了所设计控制器使船舶运动非线性系统中所有信号有界,且跟踪误差收敛到零的某个邻域内。仿真结果表明,所设计的控制器能够快速准确地跟踪设定航向,对参数摄动和外界扰动具有较强的鲁棒性。

Considering the characteristics of unknown control gain,parametric uncertainties and disturbances in nonlinear control of ship course,a new multiple sliding-mode adaptive fuzzy control algorithm was proposed by combining Nussbaum gain technology,the approximation property of fuzzy logical system and multiple sliding-mode control algorithm.Based on the Lyapunov function,it was proved in theory that the controller made all signals in the nonlinear system of ship motion uniformly bounded,with tracking errors converging to a neighborhood of zero.The simulation results showed that the controller design could track a desired course fast and accurately.It also exhibited strong robustness against system uncertainties.