Robustness effects of a prefilter in a Smith predictor-based generalised predictive controller

The paper describes how to increase the robustness of the Smith predictor-based generalised predictive controller while maintaining a nominal performance. The design of filters to improve robustness has several advantages: it is much simpler than the normal procedure used in generalised predictive controllers; it allows for better robustness indices than the optimal predictor-based GPC with the same order of filter; and it maintains the same reference to output nominal performance for every choice of filter. To illustrate the properties of the filtered Smith predictor-based generalised predictive controller some examples, taken from recent papers, are presented