The Optimum Control Of The Electromechanical Screw Down For Hot Rolling Mill

As the national economy has been growing rapidly, there is a great demand for plate andthe requirement for thickness accuracy is becoming more and more high in the market. Inorder to adapt to the development and requirement of production technique, the optimalcontrol algorithm is often used in the control system. The electromechanical screw downautomatic position control (APC-Automatic Position Control) system of the hot rolling mill isthe inner ring of automatic gauge control system(AGC-Automatic Gauge Control), so thedesign of the electromechanical screw down automatic position control system is veryimportant. it with the synchronization control and the fast accurate positioning control of theoperation side and the drive side for the electromechanical screw down automatic positioncontrol system of the hot rolling mill, that plays a critical role for the quality of the finishedproducts. So it is very necessary for careful study to the electromechanical screw downposition control system of the hot rolling mill. Make the system achieve bettersynchronization, rapidity, and improve the precision of products, reducing wear and tear ofthe equipment, in order to prolong the service life of equipment, reduce the enterprise cost.The major function of the electromechanical screw down position control system isunder the premise that control the synchrony movement of both side screw down motor. Theelectromechanical screw down automatic position control system is available to realize thefast and accurately locate the position bit. Drive screw lifting or reduction under pressure onboth sides. In the technique within the time required to achieve timely reference position thathave setted, to realize the setting of roll gap for the rolling mill.we know that the relationcurve of the roll gap position deviation and the setting of speed by analyzing. if we use themethod of control in the engineering practice. It need to carry on the massive calculations,and reduces the execution speed of the program, this does not meet the speed responserequirement of the electromechanical screw down system.Many of the existing the electromechanical screw down automatic position controlsystem of hot-rolling production lines, the setting of speed is produced using the staticalgorithm of the speed setting curve with multi-linear models, or make the system work bythe experience of manually set a speed. the synchronous control of the electromechanical screw down on both sides of the motor is using the method of mechanical hard connectionthat like the electromagnetic clutch and so on. This makes it hard to satisfy the requirementsof product quality,and cause a big wear to the enterprise equipment. the maintenance cost ishigh, the efficiency is low, it is very high that the technical level of expertise and experienceof operators.In recent years, with the theory of rolling, the theory of optimal control, thetheory of adaptive control, the theory of fuzzy control and so on, and the research andapplication in the rolling process. It has biggish enhancement that it makes the index of thethickness accuracy and quality of strips produced.This article is on the background of the two roll reversible hot rolling mill productionline that new mounting in a group company of Zhejiang. I propose the dynamic algorithmthat based on the modern control theory and the method of optimal control. That combinedthese theory of control arithmetic and the actual production. the design of theelectromechanical screw down automatic position control system and the synchronymovement control system of both side screw down motor by the algorithm of optimal controlthat double integrator model shortest time control and linear quadratic optimal controlmethod. To improve that the problems bring about by the electromechanical screw downcontrol system. And the system model is set up in the MATLAB\simulink and used insimulation. and the algorithm is applied to a hot rolling mill production line; simulationresults and the actual operating results show that the control system is carried out by thealgorithm of optimal control than the servo system by traditional PID composed has manyobvious advantages of great synchronization, for example, the good rapidity, withoutovershoot, without static error, anti-interference capability is strong and so on.