Abstract: Shape, thickness and tension control interact each other intensively in wide strip tandem cold rolling process, which leads to reduction of the control system’s performance. In order to improve control precision of tandem cold rolling process, decoupling design to realize decoupling control is a quite effective method, which is based on the building and analysis of comprehensive coupling model for tandem cold mill. First, rolling theory is used to systematically analyze various influencing factors of shape control, thickness control and tension control in the rolling process. Then, the comprehensive coupling model for tandem cold mill is built with consideration of the dynamic characteristics of inner ring, so as to quantitatively describe the coupling relations among roll gap, roll bending force, roll speed, outlet thickness, outlet crown, and inlet/outlet tensions. At last, based on the Matlab/Simulink tools, this coupling model is used to carry out simulation analysis of the coupling characteristics of the last stand of some tandem cold mill, and the necessity of its decoupling control is pointed out.

Key words: Complex coupling model, Coupling characteristic, Decoupling control, Tandem cold mill