Analysis and design of a stable fuzzy control system

In this paper, a systematic guideline is introduced to design a stable fuzzy controller for a class of nonlinear dynamic systems. Based on the Lyapunov synthesis approach, we construct the fuzzy controller such that it can assure the prespecified output accuracy of a control system. The output of the resulting controller can actually be divided into two parts. One is used to assign the poles of the control system to desired locations and the other is used to guarantee the stability of the whole control system. A detailed stability analysis is carried out and the result shows that the trajectories of the control system will converge to a bounded ball, whose size is;determined by a boundary layer. Finally, the proposed fuzzy controller is applied to control a chaotic system. (C) 1998 Elsevier Science B.V. All rights reserved.