Research On Automatic Gauge Control And Simulation Of Rolling System

With the development of the science and technology, the automation level of rolling mill increases gradually,and thus the requirement for the strip production quality are growing higher and higher. As an important quality performance, a high precision and in-depth study of automatic gauge control is very necessary. By virtue of its high control accuracy, fast response speed and simple and reliable overload protection characteristics, hydraulic AGC (Automatic Gauge Control) is widely used in modern rolling production.In this thesis, based on the mill deformation curve and the strip plastic deformation curve, the influences of some factors on the strip exit gauge is analyzed. Through the analysis of the hydraulic AGC system and operation mechanism in the strip mill, the mathmatical model of HGC (Hydraulicic Gap Control) system is built according to the basic equation of servo valve, the continuity equation of hydraulic cylinder and the equation of force equilibrium with load and hydraulic cylinder.Relied on the Siemens SIMATIC TDC control platform, we have gotten the difference equation of HGC system through its discrete mathematical model, and then used the CFC (Continuous the Function Chart) language in STEP7to build the HGC computer control system. With high-speed processing capability of the TDC and on the basis of AGC theory,we have designed Gaugemeter AGC (including absolute AGC and relativeAGC),the Feedforward AGC and Monitor AGC control algorithm and given its control block diagram and programming flow chart. The rolling force limiting control and roll gap leveling function are also designed to protect the mill.Finally,based on the TCP/IP communication protocol,we have used WinCC to complete the communication with the TDC. A human-machine interface of the data collection and monitor during the AGC process is designed to provide the relevant variables trend display and fast archiving alarm information.On this basis,we have used the above control algorithm to simulate the automatic gauge control on a three-stand continuous rolling mill. A random interference from the mill and strip is added to the system, simulation results show that the AGC syetem can effectively solve various types of disturbances, and has strong robustness,fast response capability and high steady-state accuracy through the coordination of GM-AGC,FF-AGC and MN-AGC.