Cross Standard Form for generalized inverse problem: application to lateral flight control of a highly flexible aircraft

Abstract

This paper introduces the Cross Standard Form (CSF) which can be considered as a generalization of the LQ inverse problem to the H2 and H infinity inverse problems. The CSF allows to formulate a standard problem on which an initial compensator can be obtained by H infinity or H2 synthesis. The definition of the CSF is based on the possibility to construct equivalent observer-based realization of a given compensator. From the robust control application point of view, the general idea is to apply the CSF to a first compensator satisfying nominal performances to initialize a H infinity procedure in order to handle frequency-domain or parametric robustness specifications. These state observer based tools are then applied to design lateral flight control of a highly flexible aircraft.