A simplied approach for generating frequency domain bounds for QFT designs

Abstract

(QFT) design methodology for multiple feedback controllers can be difficult and tedious. The procedure involves uncoupling the system into a series of single input-single output (SISO) designs. This, at times, requires the designer to make unnecessary assumptions as well as to purposely use overly conservative constraints. Contained in this thesis is a methodology proposed for generating bounds that eliminate the need for this uncoupling. The new method uses an objective function subjected to constraints provided by the specifications to simultaneously generate bounds on all feedback controllers. The proposed method is easier to both learn and apply and it can produce controllers that have much lower bandwidths than those generated with the conventional method. Though the basics of QFT remains unchanged, the new method significantly improves the technique.