船舶航向非线性迭代滑模变结构PID控制

Nonlinear iterative sliding mode-PID control and its application to ship autopilot

针对一类不确定非线性受扰动系统,提出非线性迭代滑模变结构PID控制方法.通过对系统输出迭代设计非线性滑模函数,并引入传统PID控制,综合了滑模变结构控制与PID控制的鲁棒性强的特点,避免了传统PID控制积分引起的超调以及变结构控制的抖振问题.设计了船舶航向控制器.仿真结果表明,非线性迭代滑模变结构PID控制下的系统阶跃响应超调明显减小,定常干扰下的静态误差得到消除,稳定时间明显缩短并可通过设计参数调节,表明控制算法具有强鲁棒性.

Nonlinear iterative sliding mode-PID control method was presented for a class of nonlinear perturbed system. The proposed design algorithm, in which the nonlinear sliding mode VSC（variable structure control） method was iteratively applied based on system output feedback, incorporated the robustness of VSC（variable structure control） and conventional PID control. Both problems of overshoot resulted from integrating actions in PID control and of chattering in VSC were circumvented in the proposed algorithm. Numerical simulation results on ship autopilot with several models were presented to validate the effectiveness of the proposed controller.