An application of self-tuning controller in the steel industry

When material is fed through a rolling mill, the rolls of the stand should exert a sufficient pressure on the material so as to reduce the thickness of the material by a certain amount while maintaining the interstand tension of the material at the desired level. An adaptive self-tuning controller for the control of a rolling mill is presented. The controller is designed on the basis of a time-series model in which the parameters are estimated recursively on the basis of the available information. The controller gains are determined at each sampling instant so that the outputs follow the desired values as closely as possible. The controller is in the form of a feedback controller, whose gains are calculated online. The basic time-series model which relates the inputs to the outputs of the system, and the controller algorithm are described. Preliminary simulation studies on the resulting system are also presented.