Study On Cold Tandem Rolling Process Control System And Its Advanced Control Algorithm

High-speed rolling is one of the most important characteristics of modern cold tandem rolling mill.When the rolling mill runs fast, the dynamic response and the control of rolling mill are very important, and the result of dynamic control depends on the dynamic model which reflects the dynamic process of tandem rolling mill.Based on Strong Electrical Engineering Co. LTD. practical project, which is the "rolling process control system and optimization algorithm of cold tandem rolling mill control".This studay aims to investigate the dynamic model of rolling process and the control algorithm.The autocontrol systems of tandem rolling mill are nonlinear, strong coupled complex systems with many variables.Every stand contact each other via a steel strip, especially with the tension.Hence, once the regulated variable or the disturbance of one stand varies, the stable rolling process of this stand will be destroyed, and the stable rolling process of other stands will also be destroyed via the variety of tension,so as to destroy stability of the whole rolling system.The yield and quality of rolling mills will be influenced seriously. In order to improve complexity of rolling process control system, to eliminate the interference between abutting stands, and also to improve the stability of the rolling process, this studay presents a optimal decoupling algorithm.Take the repetitive property of rolling process into account, an algorithm of ILC(Iterative Learning Control) of cold tandem rolling mill is proposed.First, the computer control technique of cold tandem rolling mill is summarized, and the principle of ILC and the applied actuality of ILC domestic and oversea are introduced. Secondly, the components of cold tandem rolling process control system are introduced.This studay also analyzes the frame and the control theory of ATC(Automatic Tension Control) system, AGC(Automatic Gauge Control) system and AFC(Automatic Form Control) system particularly. Thirdly, the basic parameters and equations of rolling process are presented.A linearized dynamic model which illustrates the interference between abutting stands is presented. For instance the linearized dynamic models of cold tandem rolling mill with three stands, an optimal decoupling controller has been designed in this note, and the simulation result shows the effectiveness and correctness of the proposed approach.Considering the high real time property, repetitive property and uncertainty of cold tandem rolling process ,an algorithm of ILC is presented.This studay also proves the convergence of this algorithm.These provide theory basis for using ILC theory in cold tandem rolling process control. At the same time, this is a sample of using ILC theory in practical industrial systems.