Fuzzy based sliding manifolds for identification of a class of nonlinear systems

A variable-structure based fuzzy-logic identifier (VSFI) is introduced to model a class of black-box nonlinear systems. The proposed identifier adopts a serial-parallel structure and, unlike most fuzzy identifiers, does not require measurements of all the system's states. Based on output measurements, the system states are estimated using a high gain observer. It is shown that the proposed VSFI is stable provided that the system identified is stable. Furthermore, we show that the estimator state-errors converge exponentially to an arbitrarily small ball. Simulation results illustrates that the identification scheme proposed might serve as a potential candidate for nonlinear system identification.