Robustness filter design for the Simplified Filtered Smith Predictor with disturbance rejection

This paper presents a method for designing the robustness filter in the Simplified Filtered Smith Predictor control scheme in discrete time. The proposed design simultaneously considers process uncertainty and disturbance attenuation problems in the robustness filter synthesis. The novelty of the method consists of evaluating the robust stability condition by linear matrix inequalities to design the robustness filter parameters assuring the closed-loop stability in the presence of process model uncertainty and closed-loop regulation considering the process-specified disturbances. A numerical example considers first-order systems with time delay and illustrates the advantages of the proposed method.