Improvement in Control of the Tandem Hot Strip Mill

Our previous work has shown that the use of the state-dependent Riccati equation (SDRE) technique as a basis for the development of a suitable controller for the tandem hot metal rolling process has resulted in significant improvements in performance. However the method of setting the controller parameters was left as a part of future efforts. In this paper we show that improvements in the implementation of the SDRE method provides a method of easily setting initial control parameters and then making automatic adjustments to the controller as the strip is processed through the mill. This eliminates the need for an on-line solution of the state dependent Riccati equation or the need for lookup tables to make controller settings. These improvements greatly simplify the design and implementation of the controller and also make the SDRE technique even more attractive in the control of many similar complex industrial processes.