A novel non-fragile output feedback controller design for uncertain Takagi-Sugeno fuzzy systems

Abstract

The paper is concerned with non-fragile control design via output feedback controller for uncertain fuzzy systems. In control design for physical systems, there are chances that malfunction in actuator happens and an exact value of the control input may not be applied. Hence, controller gain variations as well as uncertainty in the system parameters should be considered in the control design. For an uncertain fuzzy system, a design method of a non-fragile output feedback controller is proposed by introducing a new class of non-parallel distributed compensators(non-PDCs) where the integrals of the membership functions are involved. Non-PDC is a generalized controller of PDC, which is a traditional controller for fuzzy systems. A non-PDC non-fragile output feedback controller for uncertain fuzzy systems is obtained from new fuzzy multiple Lyapunov functions and its control design conditions are given in terms of a set of linear matrix inequalities(LMIs), which are easily numerically solvable. The descriptor system approach, which leads to relaxation in controller design conditions, is also employed. Finally, a numerical example is given to illustrate our nonlinear control design and to show the effectiveness over other existing results.