Dynamical model of the lateral strip motion in a tandem hot rolling mill

Abstract

Laterally asymmetric rolling conditions can cause a lateral motion (snaking) of the strip in flat rolling. This lateral motion can deteriorate the product quality due to contact with plant components or lead to collisions and, consequently, downtimes of the plant. A model-based snaking controller can ensure safe plant operation and consistent product quality. This paper presents a control-orientated mathematical model of the lateral strip motion. It can serve as a basis for observer and control design because of its low-dimensional and computationally inexpensive structure and low effort required for parameterization. The proposed model is based on first principles. Unknown or uncertain parameters are estimated by solving tailored optimization problems. The model is then validated by measurements from an industrial plant. This validation confirms the model's high accuracy and the small computational effort.