四辊CVC冷带轧机板形预测控制研究

Study on Flatness Predictive Control for CVC-4h Cold Mill

针对某1420mm冷连轧机第1机架板形闭环控制系统,客观存在带钢运行速度慢(时滞严重)、轧制力不稳定、轧辊磨损严重和来料带钢板廓波动剧烈等因素,目前在线使用的PID控制算法难以满足进一步提高板带轧机板形控制精度的要求。为实现其精确控制,应用模型预测控制(MPC)理论,设计预测控制器,并采用滚动优化、反馈校正的控制策略。构造状态预测观测器,使闭环系统的时滞项移至系统闭环结构之外,从而使其优化控制规律完全可按无时滞系统进行设计。仿真研究结果表明该方法远比目前带钢生产中广为采用的PID控制策略优越,系统的响应快,超调小,鲁棒性强。

Aiming at the flatness closed-loop control system of the first stand of 1420mm cold tandem mill, an objectively existing the strip running slow （ delay serious）, rolling force unstable, roll wear serious and incoming strip profile volatile factors and so on, the PID control algorithm is hard to meet the requirements of further improving the strip mill flatness control accuracy. To realize the precise control, the model predictive control was applied to design the predictive controllers, and strategy of the receding-horizon optimization, and the feedback correction were adopted. The state predictive observer was constructed, which made the time-delay term of closed-loop systems transferred to the outside of the system＇s closed-loop structure. Therefore, control lows can be designed according to optimal control methods of systems without time-delay. The simulation result indicates the control effect using the presented method is better than the using the traditional PID control which is comprehensively used in the strip production.