Smart robustness based on the fuzziness of uncertainties

The parameter uncertainties of the plant are considered as a fuzzy set. Designing the closed-loop control robustly, the controller parameters are selected referring to the membership function of the uncertainty and on the condition of guaranteed stability in the region of possible parameter uncertainties. For the sake of convenience, the design process is mapped to the space of the uncertain plant parameters although center-of-gravity defuzzification concerns the closed-loop parameters. The control problems are oriented on minimum disturbance feedforward under norm restriction of the controller matrix.