Fuzzy Sliding Model Decoupling Control Of Thickness And Tension System In The Cold Rolling

The static analysis of interaction is the main research object in cold rolling. The tension and thickness system is researched by using the design principle of single variable control system. As the tension and thickness system is a real-time system with nonlinear factors and strong coupling. So the original design can not improve the thickness precision. The analysis method and control strategy have become a problem to be solved for the system.The tension calculation is one important parameter in the process of strip rolling. And the interconnected of each frame was established by tension. In traditional control methods, the control of tension and thickness is running completely independently, and the coupling relationship between thickness and tension does not be considered. In fact, with the thickness changing, great changes would take place in the dynamic torque, so the tension between frames would also change. In other words, the tension and thickness system is a typical two-input-two-output decoupling system. In strip rolling process, there is coupling between strip tension, rolling force and rolling speed. They interact so heavily that it destroys the effective control. The mathematical model of tension change regularity and rolling factors are studying decoupling methods to solve this problem.This article is based on five-frame tandem cold rolling of a certain precision sheet metal company. Decoupling control of tension and thickness is studied. The main contents and results of research are as follows:This paper first analyzed the nonlinear, strong coupling, multi-constraint of the tension and thickness system. Based on the characteristics of the system, the author established the coupling model between strip tension and thickness. The transfer function is established derive from field data. And it is discrete. So the decoupling algorithm is presented in this paper.Then, the PID was introduced to decoupling the system model and prove the control effectively. The results of the simulation show the effectiveness of this method, but the weakness of anti-interference and decoupling response was shown. So this paper proposed fuzzy sliding decoupling control.Last, this algorithm can soften the control signal, but there is still chattering in system. So the system needs filters. The two filters are used to smooth control signal and suppress output noise at some extent. Simulation results show the effectiveness of the algorithm and reduce the control chattering, it has better control effect after decoupling.