Research And Simulation Of The Automatic Gauge Control Algorithm In Continuous Rolling Mills

With the continuous development of computer ability and control theory,the automation of rolling system is gradually improved.Steel plate,as an indispensable resource of modern industry,robot and military industry,has been put forward the expectation of higher quality index.So the accuracy of strip thickness is undoubtedly one of the important indexes of its finished product quality.Therefore,it is necessary to study the algorithm of rolling system thickness control.Combining with the classical mill spring equation,this paper discusses the influence of various interference factors on the exit thickness of the plate,and analyzes the hydraulic AGC system and rolling principle of the rolling mill.Considering the influence of strip tension on the thickness,establishes a model of cold rolling mill based on the main drive system,roll gap system and frame system.Utilize correlation algorithm to get reduced-order and linearization model.Suitable relative variables are selected to obtain the state space model of the coupling of the thickness and tension.There exists different kinds of uncertainties and disturbances on the rolling system.In the process of modeling,a considerable linearization or simplification is done,so the robustness of the system is worthy of concern.In this paper,a robust control law based on H infinity control theory is designed.Selecting reasonable performance index,we designed state feedback robust control,observer based state feedback robust control,output feedback robust control,and mixed sensitivity control respectively in the form of static state feedback and dynamic output feedback.The design of robust controller for rolling process system is realized.To solve the tension and thickness coupling problem,from the perspective of decoupling,based on classical decoupling method and inverse system decoupling method,a generalized inverse system is added to decouple and support vector regression is used to identify the system.Considering the problem of inaccurate learning and unforeseeable interference,the feedback filter and the input filter are designed in combination with the internal model control theory.The internal model control for disobey linear composite system is realized,and the control law that makes the system have good response characteristics is obtained.In order to further verify the control effect,a set of semi physical simulation platform is developed in this paper.The virtual rolling mill system that bases on the hardware in the loop simulation platform takes WPF as the tool to put it into the industrial computer.Various functions are developed,and the high-level control algorithm is programmed on the TDC side with the CFC language.The simulation results show that the partial control law designed before in this paper could be implemented in the actual controller.The control system has the better dynamic and static characteristics with strong robustness.