FUZZY SCHEDULING OF REGIONAL QFT CONTROLLERS

A novel optimization-based controller synthesis method is developed fo r nonlinear dynamic systems with structured parametric uncertainty. Fu zzy logic is used to smoothly schedule independently designed regional robust controllers over the plant's operational envelope. These linea r controllers are synthesized using established conventional control d esign techniques, e.g., quantitative feedback theory. The resulting fu ll envelope nonlinear dynamic controller handles complex dynamic syste ms which cannot otherwise be addressed by simple fuzzy logic control ( FLC). An analytical representation of the membership functions of FLC allows the optimization to chose the location parameters of the region al controllers. The scheduled controller's valid region of operation i s maximized, thus efficiently achieving full envelope operation, while guaranteeing pre-specified tracking performance. (C) 1997 by John Wil ey & Sons, Ltd.