Dynamic characteristics of cold rolling mill and strip based on flatness and thickness control in rolling process

The dynamic model of cold rolling mill based on strip flatness and thickness integrated control was proposed, containing the following sub-models: the rolling process model, the dynamic model of rolls along axial direction, and the compensation model. Based on the rule of volume flow rate, the dynamic rolling process model was built. The work roll and backup roll were taken as elastic continuous bodies, the effect of shear and moment of inertia were taken into consideration, and then the dynamic model of rolls was built. The two models were coupled together, and the dynamic model of rolling mill was built. In the dynamic model, the thermal expansion of the rolls, the wear of the rolls and other related parameters can not be considered. In order to compensate the dynamic model, the coupled static model of rolls and strip was applied. Then, according to the inner relationship of these models, the dynamic model and the compensation model were coupled, and the dynamic model of rolling mill based on the strip flatness and thickness integrated control was built. The dynamic simulation of the rolling process was made, and the dynamic thickness and the dynamic flatness information were obtained. This model not only provides a theory basis for the virtual rolling, but also provides a platform for the application of advanced control theory.