Inverse Decoupling Control Of Cold Rolling Integrated System

The cold tandem rolled plates and strips are produced below crystallization temperature under ambient temperature with hot rolled coils as stock. The cold rolled strips are characterized with good surface quality and high surface finish. The cold rolling can produce extremely thin strips which hot rolling can’t produce. The mass accuracy of the cold-rolled steel strip mainly refers to the thickness and shape, and they are determined respectively by size and shape of the nip, there are strong decoupling relationship across the thickness control system, the control system of the plate-shaped, tension control system during rolling process, which restraint severely further improvement of strip production quality, so as to,the decoupling of cold rolling system is of great important to improve the quality of flat steel. Currently, decoupling control of the rolling process has become an important topic in the rolling fields.The cross coupling process across strip flatness, gauge geometry dimension accuracy and tension control is real-time and dynamic. In view of large cold rolling strip of one factory, a coupling model of cold tandem rolling system which described coupling relationship between the shape control system, thickness control system and tension control system is established on the basis of anglicizing the rolling process combined with rolling theory and knowledge of control theory, the decoupling of cold rolling integrated control system is achieved in the process set by design decoupling control strategy, the effectiveness of the decoupling control strategy is proved by simulation experiments and the quality of thickness and shape is improved.This thesis first introduces the development status of the cold rolling control and the multivariable decoupling control theory. Then according anglicizing the rolling process and the theory of shape control, thickness control and tension control, considered them as a whole, a cold rolling complex coupling model is established based on increment mathematical equation of tandem cold rolling process. Then according to the characteristics of coupling model, least squares support vector machine inverse system method is introduced, and Simulation of the method proved that this method is effectively. Then, based on the mathematical model of cold rolling system and inverse system theory, analysis of the reversibility of the system, using the least squares support vector machine method described in this article together with the integrator to construct the inverse model of the controlled system in order to achieve the system decoupled; Finally, PID controller is designed decoupled pseudo-linear composite system for closed-loop control and improve the robustness of the system, and enhance the anti-jamming capability, to further improve the strip the control accuracy of the material to improve the quality of the finished product.The research proposed a new control method for plate and strip rolling, and new ideas and approaches of cold rolling system decoupling control in the actual production.