Modeling And Intelligent Decoupling Control Of Looper Multivariable System

Constant looper height and constant small tension control is a basic characteristic of modern hot rolling mill. But in the rolling process, there is always dynamic speed drop which is caused by bitting and other external disturbance, so it is difficult to always keep mass flow balanceable among stands. We need to have the support of looper to detect and absorption the loop height which is caused by speed change and keep constant small tension.In this paper, with the background of the 1700mm hot rolling of the Anshan Iron and Steel, We mostly researched the looper system. The main research contents and achievements are presented as follows:Firstly, we analyzed the features of nonlinearity, strong coupling, uncertainty and multi constrained of the looper system and built a dynamic mathematical model of hydraulic looper system at the vicinity of the working point. And got the system state equation, then worked out the transfer function and discrete. So the basis of multivariable decoupling control is formed.Secondly, The PID was introduced to decouple the system and improve control effect. The results of the simulation show the effectiveness of this method, but also show the weakness of bad anti-interference. Therefore the CMAC-PID was proposed. Simulation results show the effectiveness and remarkable of this method.Finally, Based on these problems such as high overshoot of the CMAC-PID, a modified CMAC-PID is introduced to decouple the looper system and improve control effect. The simulation results indicate that this method retained the advantages of CMAC-PID, such as fast convergence and suppression of the interference, and at the same time this method overcomes the shortcomings.