H∞ filtering for fuzzy systems with immeasurable premise variables: An uncertain system approach

This paper discusses a design of stable filters with H-infinity disturbance attenuation of Takagi-Sugeno fuzzy systems with immeasurable premise variables. When we consider the filter design of Takagi-Sugeno fuzzy systems, the selection of premise variables plays an important role. If the premise variable is the state of the system, then a fuzzy system describes a wide class of nonlinear systems. In this case, however. a filter design of fuzzy systems based on parallel distributed compensator idea is infeasible. To avoid such a difficulty, we consider the premise variables uncertainties. Then we consider a robust H-infinity filtering problem for such an uncertain system. A solution of the problem is given in terms of linear matrix inequalities (LMIs). Some numerical examples are given to illustrate our theory. (C) 2008 Elsevier B.V. All rights reserved.