Predictive profile control for a hot strip mill

This paper discusses the control of the strip profile in a three stand hot strip mill. The demand for higher quality requires a control system with high accuracy and fast response. Inherent transport delays in this process motivates the design of the controller to have a predictive capability. Due to the physical limitations of the actuators the measurements of the strip profile are filtered to ensure the control actions will be feasible. The tuning and robustness of a predictive controller and a PID controller is demonstrated in the frequency domain. The interactions of the profile control with the other mill control systems are discussed. Other salient points of this method including easy installation in existing mills with appropriate actuators, without any modifications.