一类滑模变结构控制系统的抖振控制

Chatter control in sliding variable structure control systems

对于带有一个积分环节的线性定常能控系统,分析了指数趋近率下滑模变结构控制的抖振过程,给出了抖振幅度、周期和趋近率参数、控制量的变化率之间的定量关系。超薄快速铝铸轧机前箱液位控制系统中,为防止塞棒挂渣,要求塞棒以一定幅度和频率抖振,这正好可以利用滑模变结构控制有抖振的特点,但必须对抖振加以控制。该文为此系统设计了变结构控制器,进行了系统仿真并与PID控制器进行了比较,验证了理论结果,也表明了滑模变结构控制的优越性。

This paper analyzes the chatter in a sliding mode variable structure control (VSC) of linear time-invariant controllable systems with integral element assuming an exponential reaching law. Relations for the chatter amplitude and frequency are derived as functions of the parameters of the exponential reaching law and variable rate of the control function. The relations are used in the design of a pre-roller tank level VSC for a continuous aluminium casting and rolling system. Some plug chattering is needed in the pre-roller tank level control of a continuous aluminium casting and rolling system to avoid sediment sticking. This system uses the chatter from the VSC to avoid sediment sticking, but the chatter must be under control. Simulation results using a variable structure controller for this system were compared with PID control to verify the theoretical model and show that this VSC is much better than PID control.