Internal Model Controller to Attenuate Periodic Disturbance of a First-Order Time-Delay System

A controller design based on the internal model control principle is introduced as an alternative to the repetitive control structure to attenuate the periodic disturbance. Such a disturbance phenomenon is observed for example in hot rolling mills due to roll eccentricity and is considered here as a motivation example. The emphasis is on the analytic design of the filter and on the time-delay parameter within the controller. By these two components, the controller action is tuned to achieve a zero gain and synchronized time shift to compensate completely the periodic disturbance. The overall procedure is validated by simulations on a model identified from real process data.