热轧恒压供水系统智能Smith预估多模控制策略研究

Algorithmic design of intelligent Smith prediction multi-model controller for constant-presure water supply in hot mill

针对热轧恒压供水系统的非线性和时滞性特点,提出了一种智能Smith预估多模控制策略。当供水压力差绝对值大于等于设定值的20%时采用了PD控制,在设定值的10%到20%范围内采用PID控制,小于设定值的10%时采用了模糊自适应PID控制,通过模糊规则在线调整PID控制器的三个参数,并引入Smith预估器对供水系统的纯滞后现象进行补偿。基于推导出的典型恒压供水模型,利用MATLAB软件对常规Smith-PID、Smith-模糊PID、智能Smith预估多模控制器进行仿真分析。仿真结果及现场应用表明:相比常规的PID-Smith和Smith-模糊PID控制器,智能Smith预估多模控制器具有鲁棒性强、动态响应快及稳态精度高的优点。

With regard to features of nonlinear and time-delay in constant-presure water supply system in hot mill,a new intelligent smith prediction multi-model controller is developed in this paper.When the absolute value of pressure error exceeds or equal to 20% of the setting input,PD control may be adopted,and PID control may be adopted when the value is in the range of 10% to 20% of the setting value.When the error absolute value is less than 10% of the setting input,fuzzy adaptive PID control may be adopted,in which three parameters of PID controller are adjusted online through fuzzy rules.Furthermore,according to the pure lag phenomenon in water supplying system,Smith predictor is adopted to compensate it.Based on the typical constant-pressure water supply model of variable frequency,the analysis in dynamic performance PID-Smith controller,Fuzzy PID Smith controller and intelligent smith prediction multi-model controller is done by MATLAB toolbox.The simulation results and site applications show that intelligent smith prediction multi-model controller has stronger robustness,faster response and higher static accuracy than traditional PID-Smith controller.