Abstract
Takagi-Sugeno fuzzy system can describe a wide class of nonlinear systems, and is widely used in many engineering fields. Recently, system analysis and control design for nonlinear systems based fuzzy system approach have been active. This paper is concerned with robust observer for sampled-data fuzzy systems. The system is usually modelled as a continuous-time fuzzy system, while the observation is taken at discrete instants. First it is shown that the error system which stems from an original fuzzy system and a sampled-data observer becomes a time-delay systems. Sufficient conditions for the error system to be asymptotically stable are given in terms of linear matrix inequalities (LMIs). We derive such conditions via descriptor system representation under the assumption that sampling-time is not greater than some prescribed number. Based on the conditions, we propose an observer design for a fuzzy system and then extend to a robust observer for the same class of systems. Numerical examples are given to illustrate our sampled-data observer.
