Reversible Four-roll Mill Hagc System Research

Thickness accuracy of plate and strip is an important quality indicator, HAGC system asan important branch of the plate and strip automatic gauge control technology, its controlperformance has a direct impact on the thickness accuracy of plate and strip. So, this articleresearch on the control performance of HAGC system, enhance the response characteristicsof the control system, thereby improving the quality of the plate and strip.The HAGC system combined the advantages of automatic gauge control technology andhydraulic servo technology, had made great progress than before. Hydraulic servo system hadthe characteristics of non-linearity, hysteresis, time-varying and complexity of the rollingprocess, and they would have a great influence on the performance of control system. Usinglinear PID controller optimization the control performance of the system was limited, andcould not meet the requirements of high-precision rolling. For these reasons, this paperdesigned fuzzy self-adaptive PID controller. Its advantage was that not requiring controlobject had specific mathematical model. The experience and knowledge were accumulated byoperator (expert) through long-term practice, could establish the fuzzy control rules, thenusing fuzzy reasoning, would be able to solve these problems.Under the linear PID and the fuzzy self-adaptive PID two different control strategies,established pass block diagram of the HAGC position control system in reversing four-highmill. By analyzing the simulation results in Matlab software, compared indicators of thecontrol system, such as rapidity, stability, accuracy and robustness. We could see that the controlperformance of the HAGC position control system under the fuzzy self-adaptive PIDcontroller were better than the linear PID controller.There were many factors of HAGC system in reversing four-high mill, could influencethe control performance. First of all, established the HAGC position control system model inAMESim software, and the parameters of PID controller in the model were online self-tuningcontrol parameters of the fuzzy self-adaptive PID controller. Then, research on the controlparameters as proportional gain of the servo amplifier and the dead volume of hydrauliccylinder. Through the simulation results, analyzed the control parameters how to influence thecontrol performance of HAGC system, and application of batch method summed up theoptimal control parameters. In this paper, through studying on the control system, application of advanced controlstrategies, improved the dynamic performance and robustness of HAGC system in thereversing four-high mill, and analyzed the factors which can influence the performance ofcontrol system, obtained the optimum value of the control parameters. Taken this method cangreatly improve HAGC system performance, and provide a feasible control strategies andmethod for the HAGC system optimization design.