Virtual equivalent system and stability criteria for discrete-time T-S model based fuzzy control systems

The stability of T-S model based fuzzy control systems for discrete, linear time-invariant plant and nonlinear time varying plant is analyzed with the help of virtual equivalent system concept and methodology. The main results developed in this paper indicate that the stability of the fuzzy control systems depends on the following conditions: First, the local model set covers the uncertainty of the plant; Second, the normalized membership function identifies the true model(s) of the plant; Third, each local controller stabilizes its corresponding local model.