Model And Guiding Predictive Control For Deviation In Hot Aluminum Strip Continuous Rolling

Abstract:Deviation, a dynamic process affected by lateral asymmetric incentives, is of high frequency in hot aluminum continuous rolling, bring serious problems to production, such as enlargement of crown, uneven quality, locking of strip, tensile failure, damage of bead cutter and working rolls, etc. It is a failure that threats the production safety and shortens the equipments, hence the great significance of research on the deviation guiding control. Main contents of this research are as below.Based on the mechanism and kinematic analysis, differential equation for deviation in single mill was built, according to which transfer functions of lateral deviation and rolling force difference disturbed by roll gap difference and initial lateral wedge were set up. Then the dynamic responses of lateral deviation and rolling force difference under the disturbances were analyzed. Then the minimum advised adjusting amount and minimum adjusting time. Meanwhile, the dynamic response model of deviation disturbed by tension fluctuation was built.According to the transfer functions of deviation and rolling force difference, as well as the transfer functions of the whole control system, the deviation guiding control system was built for F1and F2-F4respectively, according to their feature of disturbance. For F1, the system takes rolling force difference as main control signal, ATC tension measuring signal as the feed forward signal, and roll gap difference as the inner loop feedback signal. For F2-F4, the system takes rolling force difference as main control signal, initial lateral wedge as the feed forward signal, roll gap difference as the inner loop feedback signal. Predictive functional control technology was brought in to the control system. The control effect was compared with that of PID control technology. The soundness of the cascade deviation guiding control strategy was then proved, and the superiority of predictive function control than PID control in deviation guiding control process was also declared. The results of this research and relevant data can be a guidance of the practical rolling production.