A design method of type-1 servo systems by multiobjective fuzzy satisficing approach using genetic algorithms

This paper discusses a control system design with various specifications in both the time-domain and the frequency-domain. First, a control system design is formulated as a multiobjective optimization problem, and it is transformed a fuzzy satisficing problem by introducing aspiration levels and unsatisfying functions. It is solved by a Genetic Algorithm (GA) interactively. Then, the proposed method is applied to the design of the two-degree-of-freedom LQI servo system with the virtual command signal. The effectiveness of the proposed method is demonstrated by a numerical example, which has an undesirable undershoot.