A QFT Procedure for Generating Design Frequencies and Bounds of Guaranteed Accuracy

In this paper, a QFT procedure is presented to systematically determine the following (i) the set of design frequency intervals from a given design frequency range, (ii) the controller bounds of prescribed accuracy at each design frequency interval, and (iii) the controller phase intervals for efficient bound generation at each design frequency interval. The procedure is given for the robust gain-phase margin specifications, based on several new results derived in the paper in the interval analysis framework. The procedure is demonstrated on a significant practical problem concerning the longitudinal motion of an aircraft.