Gauge Control Based On A Steel Cold Rolling

Plate and strip products for a variety of materials, uses a very wide range, mainly used in automobile manufacturing, packaging, building materials, and so on. With the socio-economic development and infrastructure construction, industrial production on the plate and strip production and a higher quality requirements. And strip thickness accuracy is one of the two major quality indicators, thickness control technology is the field of strip rolling two key technologies. Therefore, in-depth study mill thickness control is essential to modern control theory is applied to rolling mill gauge control system also has important theoretical and practical value.Talking about automatic gauge control (AGC) means , there are feedback, feedforward, thickness meter type, tension type and so on. As the hydraulic servo system, fast response, high dynamic accuracy, and now not only have adopted the new mill with hydraulic control of computer systems, and even many old mill is also transformed into hydraulic AGC mill.Mill thickness control in the hydraulic AGC system, an important link is composed by a hydraulic position servo loop (Automatic Position Control, APC). Its output signal is the location of roll, which directly affects the accuracy of the thickness of the mill. With the continuous development of control theory, hydraulic AGC system also is gradually taking advanced control strategies to replace the traditional PID control.In this paper, a domestic steel five-stand cold rolling mill for the study, the analysis of the rolling mill hydraulic AGC system and its operation mechanism based on the servo valve to the basic equation, continuity equation of hydraulic cylinder, hydraulic cylinder and load force balance equation, the establishment of the electro-hydraulic position servo control system model and the model simulation tool using MATLAB into state space form. Then the introduction of sliding mode control method, but due to sliding mode control in discontinuous nature of the switching characteristics of the system will cause "chattering", in view of this, this paper introduces the dynamic sliding mode control theory that This method can effectively reduce buffeting. In this paper, the switching function is selected, constant rate after reaching the design of the dynamic sliding mode control, the cold rolling mill will be applied to the first frame, and used MATLAB language designed for dynamic sliding mode controller a simulation study. The results show that the dynamic sliding mode control method with the traditional PID control method, a faster response time and effective inhibition of the chattering.