Robust Flare Control Design Using Structured H∞ Synthesis: a Civilian Aircraft Landing Challenge

this paper addresses the flare design of a civilian aircraft within the benchmark proposed by ONERA and AIRBUS to enhance the robustness and capabilities of autoland control systems. The flare segment must perform soft landings within a desired range of touchdown points on the runway in the presence of parametric uncertainties, strong wind turbulence and ground effects. In this paper, a structured H∞ approach based on the standard H∞ formulation is explored for the vertical speed controller. In addition, some strategies to improve the robustness of the autoland control system against some critical parameters are described. Finally, the longitudinal performance and robustness of the control system are examined through nonlinear nominal simulations and Monte-Carlo analysis.