This paper defines a fuzzy descriptor system by extending the ordinary Taka
gi-Sugeno (T-S) fuzzy model. Several kinds of stability conditions for the
fuzzy descriptor system are derived and represented in terms of linear matr
ix inequalities (LMIs), We illustrate a motivative example of defining the
fuzzy descriptor system instead of the ordinary TS fuzzy model, An LMI desi
gn approach is employed to find stable feedback gains and a common Lyapunov
function. In addition, this paper presents a nonlinear model following con
trol for the fuzzy descriptor system, A new parallel distributed compensati
on, the so-called "twin parallel distributed compensations" (TPDC), to real
ize the nonlinear model following control is proposed, The TPDC fuzzy contr
oller mirrors the structures of the fuzzy descriptor systems that represent
a nonlinear system and a nonlinear reference model. We present a design te
chnique based on the TPDC. All the design conditions are represented in ter
ms of LMIs, The proposed method is a unified approach to nonlinear model fo
llowing control, It contains the regulation and servo control problems as s
pecial cases. Finally, design examples are illustrated to show the utility
of the nonlinear model following control.