一种非线性变结构双模伺服控制器

A Novel Nonlinear Variable Structure Servo Controller

提出了一种非线性变结构双模伺服控制器，这种控制器在偏差较大时采用具有“时间最优开关平面”的滑模控制，使系统在时问最优指标下工作；当偏差较小时，系统根据状态变量的幅值自动转化为ＰＩＤ控制，使系统在最优二次型指标下工作。仿真结果表明：这种控制系统具有动态响应快、超调小、易于工程实现等优点。

Servo system has been widely used in many domains. Unfortunately, to my best knowledge, the switching surface of the traditional servo controller (such as slide mode controller)restricts severely the response speed. Lee et al[1], Dai et al[2], and He et al[3]have recently made some progress. We, in this paper, develop for the first time 'Time-Optimal Switching-Surfaced, which ensures that the system response speed is time optimal.We present a novel variable structure controller. It employs the slide mode controlwhich posseses the'Time-Optimal-Switching-Surface' when the state is far from the equilibrium one, and it can automatically turn into PID controller when the state is near the equilibrium point. It is believed that this controller has the following two distinguishing features.(1) It possesses simultaneously five advantages: (a) nearly time-optimal responsespeed, (b) very small overshoot, (c) strong robustness, (d) no static error, (e) no chattering.(2) It can save control energy and its simple control law can be implemented by eitheranalog or digital means.