Design of fixed-structure controllers with frequency-domain criteria: a multiobjective optimisation approach

An optimisation-based iterative design of fixed-structure controllers with frequency-domain criteria is presented. An interactive multiobjective optimisation procedure is presented, which is based on a direct shaping of the frequency responses, without the need to construct explicit weighting filters. At each iteration, a constrained optimisation problem is formulated in such a way that successive improvements of the design to meet the designer´s specifications are achieved. For computational efficiency, time-domain expressions consisting of linear matrix equations are used to characterise the frequency responses.