迭代滑模增量反馈及在船舶航向控制中的应用

针对一类不确定非线性受扰动系统，提出一种基于非线性迭代滑模变结构的增量反馈控制算法．通过对系统输出迭代设计非线性滑动模态，并利用增量反馈控制，无需对不确定项的估计，在系统输入增益符号已知的条件下可自动寻找使系统稳定的控制量，避免了变结构控制的抖振以及输出反馈控制的稳态误差与超调问题，强化了变结构控制的不变性特点．对不同船型及舵机模型的船舶航向控制进行了仿真，结果表明，系统阶跃响应超调得到有效抑制，定常干扰下的静态误差得到消除，且控制器对模型摄动及干扰变化不敏感、设计参数易于调节．

Iterative sliding mode based increment feedback control and its application to ship autopilot

An increment feedback control method based on nonlinear iterative sliding mode variable structure control is presented for a class of uncertain nonlinear perturbed system.The nonlinear sliding modes are designed in the augmented states space in a decentralized and iterative procedure based on system output feedback.Then an increment feedback control law is developed and proved to asymptotically stabilize the closed-loop system without uncertainty estimating.Overshoot resulted from integrating action,static error caused by constant disturbances and chattering in variable structure control are circumvented.A robust controller is designed for ship course steering autopilot.Numerical simulation results on several ship models verify that the controller is robust against the systemic variations or disturbances and the parameters are easy to be adjusted.