Optimal Feedforward Filter Design for Flying Gauge Changes of a Continuous Cold Mill

02 Sep 2011

Camile WJ Hol, Marc de Boer, Vincent Beentjes; Tata Steel RD&T IJmuiden, The Netherlands
Mike Price; Tata Steel Port Talbot Works, Wales
Steven Sujoto; Accenture, Amsterdam, The Netherlands
Carsten W. Scherer; SRC SimTech Chair Mathematical Systems Theory, University of Stuttgart, Germany
Anton A.J. van der Weiden; Delft University of Technology, Delft, The Netherlands

In a continuous cold mill subsequent hot rolled strips are welded together before rolling. The transition from strip A to strip B is called the Flying Gauge Change (FGC). Exit thickness errors and large strip tension variations occur if the actuators are not adjusted well during the transition. In this paper the model-based design of the FGC controller that minimizes off-gauge length and tension variations is presented. This is done through nonlinear local optimization of a cost function, that represents the economic cost of tension variations and off-gauge as accurately as possible. Simulation results show that the resulting controller reduces off-gauge and tension variations signicantly, even if variation in friction and slip are taken into
account.

Paper presented at IFAC (International Federation of Automatic Control) 18th World Congress, Milan, Italy, August 28 - September 2, 2011