船舶航向非线性系统的多滑模自适应模糊控制

针对参数未知的船舶航向非线性控制系统数学模型，在考虑舵机伺服机构特性的情况下，船舶航向控制问题就成为一个虚拟控制系数未知的非匹配不确定非线性控制问题.基于多滑模设计方法和模糊逻辑系统的逼近能力，提出了一种多滑模自适应模糊控制算法，通过引入非连续投影算法和积分型Lyapunov函数，提高了系统在抑制参数漂移、控制器奇异等方面的能力.借助Lyapunov函数证明了所设计控制器使最终的闭环非匹配不确定船舶运动非线性系统中的所有信号有界，且跟踪误差收敛到零.仿真研究表明:该算法与传统的PID控制相比，具有较好的跟踪能力和自适应能力.

Multiple sliding mode adaptive fuzzy controller for nonlinear marine autopilot systems

When a ship course controller must deal with unknown parameters, the maneuvers of the ship must be described using an unmatched and uncertain nonlinear mathematical model with unknown virtual control coefficients and unknown parameters. To deal with this situation, an adaptive fuzzy control algorithm with multiple sliding modes was proposed. It combined multiple sliding mode design technology with the approximation capability of a fuzzy logic system. In order to solve the problem of parameter drift and the controller’s singularity problem, a non continuous projection algorithm and an integral type Lyapunov function were employed in the proposed algorithm. By means of the Lyapunov function, it was theoretically proven that the proposed controller makes all signals in the resulting closed loop adaptive system uniformly bounded, with tracking error converging to zero. The simulation results showed that, compared to conventional proportional integral derivative (PID) controllers, the controller discussed in this paper provided better adaptability and tracking capabilities.