Fixed-order piecewise-affine output feedback controller for fuzzy-affine-model-based nonlinear systems with time-varying delay

Abstract

As the most frequently applied intelligent control scheme, fuzzy logic control (FLC) has drawn substantial interests from both academic and industrial applications [1]–[2][3]. The appeal of the FLC methodologies is that FLC has been recognized to be of conceptual simplicity and effectiveness to control many highly complex nonlinear processes or even nonanalytic systems. Among different model-based FLC schemes, the protocol on the basis of T-S fuzzy models, is especially appropriate to the model-based nonlinear control. The procedure of this approach is firstly to employ T-S fuzzy model to represent or approximate the nonlinear plant. Essentially, the T-S fuzzy systems are characterized by a group of fuzzy IF-THEN rules exhibiting local input-output features of a nonlinear plant. With the connection of these subsystems via fuzzy membership functions, the overall fuzzy model is then yielded to describe the global dynamical behaviors. Furthermore, based upon this fuzzy model, together with taking full advantage of the strength of modern linear control theory, the control analysis and design were carried out via Lyapunov-function-based approaches. Correspondingly, the systematic stability analysis and controller synthesis issues of fuzzy systems have been addressed.