A non-circular arc roll gap model for control applications in steel rolling mills

This contribution presents a mathematical model for cold rolling mills suited for the control purpose. Founded on physical considerations, particular emphasis is laid on the modelling of the roll gap, including a detailed description of the elastic work roll deformations. Typically, non-circular arc roll gap models involve significant computational effort. Thus, a key objective of this paper is to propose a model which is applicable for control due to clearly reduced computational cost. This roll gap model is combined with the dynamics of the mill stand and the bridle rolls in the entry and the exit section. By virtue of the flatness property of the entire model, the nonlinear control design for the mill is addressed by applying the flatness based control theory