Research On The Looper Control System Of The 2300 Hot Rolling Production Line

With the development of rolling technology, the requirements of steel grade,quality, production of strip in modern hot rolling is higher and higher. In the process of hot rolling, looper control is a key technology which determines the thickness and the width of strip, currently, the technology is active in development both at home and abroad.The background of this paper is a digesting and absorbing project of a 2300 hot-rolling production line, with the looper control system of finishing mills as a study. It analyses looper system, and derive the mathematical model of the height of looper and the tension of the product in the process of hot rolling. Based on the analysis of the looper control procedures of the production line, it introduces the Process of the control of the looper in the production line, at the same time, it researches and analyses two control methods while the looper is running Stable:conventional control and ILQ (Inverse Linear Quadratic).Conventional control is currently used widely in hot rolling, with the closed-loop control of angle and the Open-loop control of tension, changing the output torque of hydraulic cylinder through actual angle and the target tension to control the tension. This method is better in the initial stage, but it will be difficult to meet the demands if we use this method to the end.ILQ control was uesd on the last 3 loopers of the 2300 hot rolling. ILQ control has higher precision and faster response than conventional control. It is a perfect example of ILQ theory used in the industry. This article is focused on ILQ looper control system used in hot rolling production line, introduces the design methods of the controller based on ILQ theory, and designs looper controller based on ILQ. Then it simulates and analyses the effects of ILQ control, that prove the characteristics of the ILQ control.Finally, the author design a MR-ILQ(Model Reference Inverse Linear Quadratic) looper control system, as to overcome the shortcomings of ILQ.MR-ILQ control system combines the model reference and ILQ control.By choosing a suitable reference model and error compensation, it can make the output of the system follow the ideal output. Then I simulate the MR-ILQ looper control system, and the results prove that the MR-ILQ system has better decoupling and faster response than ILQwd system. At the same time, it can make sure that the effects stable when the model parameters are changed.