Robust multivariable control for hot strip mills

A multivariable regulator for a hot strip mill is developed which is robust ly stable for changes to the mill modulus while still providing high strip thickness accuracy. This is in contrast to the conventional automatic gauge control which has to trade of nominal performance to provide robust stabil ity. The performance and stability off the multivariable H-infinity control ler and the conventional controller are analysed and the benefits of the mu ltivariable controller is demonstrated using a nonlinear simulation.