Delay-dependent H-infinity filtering for uncertain time delay nonlinear systems: an LMI approach

The problem of designing a delay-dependent robust H-infinity filter for time delay Takagi-Sugeno fuzzy models is considered. The purpose is to design delay-dependent H-infinity filters ensuring a prescribed H-infinity performance level for the estimation error, irrespective of the uncertainties and the time delays. Sufficient conditions for the existence of a delay-dependent H-infinity filter are given in terms of linear matrix inequalities. Membership functions' (MFs) structural information is incorporated into the delay-dependent filter design to reduce the conservativeness of neglecting this information. It is shown that incorporating MFs' structural information into the filter design does not lead to bilinear matrix inequalities, as in the control design case. Finally, a numerical example is used to illustrate the effectiveness of the proposed design techniques.