Robustness augmentation of an aircraft pitch rate controller

A robustness augmentation algorithm for fixed architecture controllers is proposed in this paper. It is based upon the theory of guardian maps and seeks to improve the robustness of an initial pole placement within a region of the complex plane. An initial controller satisfying some pole confinement constraints on a nominal model is robustified to still ensure performance on some uncertain models. The procedure is successfully applied to augment the robustness of an initial pitch rate controller of a Challenger 604 aircraft submitted to mass and center of gravity variations.