Robust Steering Control of Hot Strip Mill

In this paper, a robust steering control is proposed as a means to guarantee the stability of a hot strip finishing mill and improve its performances. The aim of the rolling process is to obtain a metal strip which is uniform and at the desired thickness. The lateral movement of the strip may reduce the quality of the product and damage the rolls. Hence, this displacement must be limited to improve process reliability. Since a hot strip mill treats products with very heterogeneous characteristics, a significant database was created and divided into different families of products. A method for reducing the numerical complexity of the problem exploiting the relation between the different product parameters is also presented. This method yields a convex stabilisation problem. Hence, for each family, a different robust controller is designed. Simulation and experimental results concerning the ArcelorMittal hot strip mill of Eisenhüttenstadt are presented.