H∞ design of future flight control systems

The H^∞ design technique outlined is used to develop flight control laws for a control configured vehicle. The dynamics of the vehicle, including the effects of structural dynamics, are modeled. The aircraft model used in this study is the advanced supersonic transport (AST). It is a linear eighth-order longitudinal system consisting of two rigid body modes (the short period and the phugoid) and two structural flexibility modes (the first and second fuselage bending modes). Model reduction techniques are employed, resulting in a control system design model which retains only the significant modes. A linear controller is then designed according to specified closed-loop performance requirements. Sensitivity and complementary sensitivity response specifications are used to generate the frequency response weightings used in synthesizing the H^∞ controller