Modellbasierte Dicken- und Ebenheitsregelung in Grobblechwalzwerken (Model-based Control of Thickness and Flatness in Heavy Plate Mills)

This paper deals with the thickness and flatness control problem in heavy plate mills. After a short description of the industrial plant the first part of the paper is concerned with a new control strategy for the improvement of the thickness homogeneity over the plate length. This model–based concept takes into account valuable information from previous passes which, together with accurate mathematical models of the deformation process, can be used to calculate a disturbance feedforward as an add–on to the existing thickness controller. In the second part a control strategy for the flatness of the plate–ends is derived. In this context, the so–called ski–effect, which results from asymmetries during the rolling process, is investigated in more detail. Thereby, the control concept is based on a model for asymmetrical rolling, which in combination with an improved speed controller of the drive train is used to avoid the occurrence of such ski–ends.