Stability Conditions for Fuzzy Control Systems with Fuzzy Feedback Gains

This paper presents the stability analysis of fuzzy-model-based control systems. A fuzzy controller with fuzzy feedback gains is proposed to control a nonlinear system represented by the T-S fuzzy model. The fuzzy feedback gains effectively enhance the nonlinearity of the fuzzy controller to strengthen the stabilization ability. To facilitate the stability analysis and reduce the computational demand, the fuzzy controller is separated from the fuzzy model by a particular system representation during analysis. Consequently, the number of stability conditions can be reduced to ease the finding of the solution. Two cases of fuzzy controller design, namely the fuzzy controller employs the same and different membership functions as those of the fuzzy plant model, are considered for various applications. Simulation examples are given to illustrate the merits of the proposed approach.