An LFT approach to scheduled feedback design with an application to the synthesis of a missile autopilot

Abstract

Traditionally, scheduled controllers are obtained by interpolation of a bank of linear control laws. The strategy adopted here is quite different as the controller is directly designed in scheduled form. The key idea consists of designing the feedback gain as an LFT (Linear Fractional Transformation). For that purpose, the models must be in LFT form. Modal control is well adapted to this kind of design strategy as it suffices to replace matrices by LFTs in algorithms used to compute the feedback gains. The proposed method is illustrated considering a missile autopilot synthesis.