Study Of Thickness Control Strategy For Single Stand Reversible Cold Rolling Mill

The gauge accuracy and flatness are two key quality targets in strip production. At present, huge advancements have been derived with the development of rolling theory, control theory and artificial intelligence theory and with their application in the rolling process. However,it is still one of researching hotspot problem in strip gauge control field that single stand invertible strip mill adopts special control technology and achieves high level control accuracy.The aim of this study is researching the theory and application of gauge control on the study of Tangshan Steel Corporation 1,650mm invertible cold strip mill . After the systemic and general study of gauge control system, it provides the way to the higher accuracy research and provides the theory references.The improved method of hydraulic pressure screw-down system and the achievement of servovalve linear control are studied and analyzed. The dynamic models of hydraulic pressure screw-down system and describes simulation studies on the influences of the variations of some system parameters on the rolled thickness and the dynamic properties of the system. The results are identical with theory and operating condition in practice. The results show that the model is simple and beneficial to analyzing the influences of the processing factors on the thickness accuracy.The transfer functions of both closed loop and opened loop are got from experiments. And the application patterns of BISRA AGC are studied and analyzed. It is deduced that BISRA AGC doesn't dispel itself disturb, but also blow up it. The main problem of gauge closed loop system is adaptive problem of adjuster parameters control.Finally this paper analyzes the effect principle how roller eccentricity affect strip gauge. Two of basic types of roll eccentricity are discussed and the characteristic, cause and measurement of roll eccentricity were included, then illustrated how roll eccentricity influence strip gauge. A new method of roller eccentricity is deeply researched, avoided the traditional method, attributing to carrying out directly by digital programs.