离散变结构控制及在船舶舵机中的应用

研究离散时间系统的变结构控制设计问题，提供了一种新方法。首先，提出一种具有原点稳定性的趋近律，可以消除传统离散趋近律自身参数导致的抖振；其次，研究了一种不确定性估计算法，可使估计误差动态与滑模动态解耦，只要不确定性变化率有界，即可保证闭环系统的鲁棒稳定性，不会产生抖振。将所提方法用于船舶自动舵系统的控制，仿真结果表明，无论是否存在不确定性，所设计的控制器均可快速、准确地跟踪设定航向。

Discrete Variable Structure Control Design and Its Application in a Ship Autopilot

This paper presents a new approach to the discrete-time variable structure control design. Firstly, a new discretereaching law, which is stable at the origin and can eliminate the chattering caused by conventional discrete reaching law parameters, is proposed. Subsequently, an algorithm for uncertainty estimation is developed. It can be shown that the estimation error dynamics can be decoupled from sliding surface dynamics using the proposed scheme. Robust stability of the closed-loop system can be ensured in the presence of uncertainties with bounded changing rate. No chattering occurs. The proposed algorithm is applied to the control of a ship autopilot servo system. Simulation results show that the proposed controller can track a desired course well whether uncertainties are present or not.