MULTIVARIABLE CONTROLLER-DESIGN FOR A HOT-ROLLING MILL

This paper describes a controller design for a hot rolling mill, The m ain purpose of the algorithm is to improve the control of the cross-wi dth thickness profile of the plates, This is obtained by designing a c ontroller which wakes independent thickness control possible at the tw o sides of the rolling mill. This is obtained by first linearizing the positioning systems using feedback linearization and then using linea r quadratic eigenspace design on the linearized multivariable system. Integral control is included to ensure zero stationary thickness error , The design is done using derived dynamical multivariable models, To ensure that the design is stable, the stability of the system is inves tigated using the small gain theorem, The performance of the controlle r is evaluated using models estimated from data from the hob plate mil l at The Danish Steel Works Ltd.