Study On Thickness Automatic Control System Of Tandem Mill

The accuracy of sheet gauge is one of two major quality control guidelines. It is especially important to increase the sheet quality in the fierce competition of in and abroad market economy. The gauge control is one of the two key technologies in the field of sheet rolling and it is developing fast with the development of electronics technology.This paper is the innovation of an imported used five-tandem mill. The main innovation work is to innovate the screw-down type and the control of rolling. In the condition of non-manufacturing housing structure, the original electrical screw-down mechanism is replace by a long-stroke cylinder and the gauge automation control system is applied into rolling adjustment. The full-digital DC drive system is applied in the control system. High-speed VME digital control system HIPAC is applied into the first-class automation control; the mathematical model is set up for the secondary rolling process. This paper describes the principle of sheet gauge, the main constitute of automation system including hardware and software structure, some main functions of first class automation system and the application of gauge control system in the cold mill.In the application of automation gauge control, in this paper some new achievements in the field of modern control theory, electronics and computer are applied. Meanwhile, forward-feedback AGC, feedback control AGC, tension control, tension feedback control and monitoring ATC system are applied. The main character of this control is to set the sheet gauge calculated by bounce formula as practice gauge which is compared with the setting gauge or lock gauge. The difference is the gauge difference value and is regulated by screw-down system. In such a way, the character of this system is increased and avoids the influence of such factors as roll wearing, roll heat expansion and so on. Therefore, it can greatly increase the accuracy of sheet gauge.This paper analyses detailed introduction of the design way for tension automation control ATC, gauge automation control, L2 class software in the modification of AGC, explains the principles of control functions and how the AGC meets with the requirement of cold mill production.