H ∞ control synthesis of switched discrete-time fuzzy systems via hybrid approach

Because switched system with nonlinear subsystems shows great difficulties in controller design by conventional methodologies, the fuzzy logic theory, which has been proven to be a practical and effective way to deal with the analysis and synthesis problems for complex nonlinear systems, is applied to design a class of hybrid fuzzy H∞ controller for switched discrete-time fuzzy system in this paper. On a basis of one step prediction of switching signal, a hybrid parallel distributed compensation (PDC) control strategy is proposed, which includes two necessary parts: the state feedback controllers for subsystems and the update feedback controllers for switching instants. In both arbitrary and dwell-time switching cases investigated, it is proved that the hybrid PDC controller contains less conservativeness than conventional switched PDC controller. Numerical examples are given to illustrate the effectiveness and advantages of the proposed approach.