2003 Volume 43 Issue 10 Pages 1562-1571
The focus in this work is on linear model identification of a Steckel hot rolling mill process on a point during the acceleration phase of the process. It furthermore focuses on the controller design based on the linear models and on controller implementation on a non-linear simulator of this process. The linear models are identified for different cases simulated with and without gauge meter compensation and controlled tensions as part of the simulator. The system identification is accompanied by a heuristic justification of the data obtained. A diagonal PID/PI controller as well as MIMO H∞ controllers, of which the designs are based on the linear models, are implemented on the simulator. From the system identification data for the different linear models it could be seen that gauge meter compensation successfully counteracts the adverse effect of mill stretch and eliminates oscillations in exit gauge, which result from tension oscillations. Simulations of the different controllers in closed loop with the non-linear plant simulator show that good control can be achieved by controllers of which the designs are based on linear diagonal models. One of these controllers, a diagonal H∞ controller, tested on a non-linear simulator which incorporated gauge meter compensation and inner loop tension control, was found to be the most suited for a switching control system.
