  In this paper, a dynamic antiwindup compensator design is proposed which
augments the main controller and guarantees robust performance in the event of
input saturation. This is a two stage process in which first a robust optimal
controller is designed for an uncertain linear system which guarantees the
internal stability of the closed loop system and provides robust performance in
the absence of input saturation. Then a minimax linear quadratic Gaussian (LQG)
compensator is designed to guarantee the performance in certain domain of
attraction, in the presence of input saturation. This antiwindup augmentation
only comes into action when plant is subject to input saturation. In order to
illustrate the effectiveness of this approach, the proposed method is applied
to a tracking control problem for an air-breathing hypersonic flight vehicle
(AHFV).
