The application of predictive control to steel annealing

This paper discusses the application of predictive control techniques to a continuous annealing line at Swedish Steel (SSAB Tunnplat, Borlange, Sweden). All the predictive control technology used in this application was developed and implemented using the advanced control package, Connoisseur. The application necessitated the use of multiple linear models through the normal operating range( which is highly non-linear). The paper describes the methods used to develop these models using the on-line adaptive features of the Connoisseur package. The on-line adaptor has made it possible to develop and maintain these models with a minimum of effort. The resultant control schemes operating from Connoisseur have fully automated the annealing line throughout the normal range of operation and released the operator from extensive "hands-on" operation. The main benefit returned by this application has been the automation of the annealing line, which has allowed further developments to proceed in a controlled manner (ie. operator influence minimised).