H∞H∞ control for switched fuzzy systems via dynamic output feedback: Hybrid and switched approaches

Fuzzy T–S model has been proven to be a practical and effective way to deal with the analysis and synthesis problems for complex nonlinear systems. As for switched nonlinear system, describing its subsystems as fuzzy T–S models, namely switched fuzzy system, naturally is an alternative method to conventional control approaches. In this paper, the H∞H∞ control problem for a class of switched fuzzy systems is addressed. Hybrid and switched design approaches are proposed with different availability of switching signal information at switching instant. The hybrid control strategy includes two parts: fuzzy controllers for subsystems and state updating controller at switching instant, and the switched control strategy contains the controllers for subsystems. It is demonstrated that the conservativeness is reduced by introducing the state updating behavior but its cost is an online prediction of switching signal. Numerical examples are given to illustrate the effectiveness of proposed approaches and compare the conservativeness of two approaches.

► Stability and H∞H∞ performance for switched fuzzy system are studied.
► Two control strategies, namely hybrid and switched control, are presented.
► Conservativeness is reduced by introducing the state updating in hybrid control.