Pedro V M Simplicio

Structured Singular-Value Analysis of the Vega Launcher in Atmospheric Flight

Using the structured singular value μ, an independent control law assessment is presented for the Vega launcher thrust vector control system. A systematic uncertainty modeling and analysis process is illustrated to retrieve and structure driving perturbation combinations affecting competing control system design requirements. It is demonstrated how μ analysis not only complements and generalizes classical frequency-domain stability assessments but also how it applies naturally as a performance indicator to manage the requirements tradeoff space. The proposed methodology is shown to be reliable and computationally more efficient than widespread verification and validation techniques that rely on random sampling via Monte–Carlo analysis. Although not meant as a replacement of these traditional approaches, μ analysis effectively complements and enhances the verification and validation tasks by guiding the analyst toward worst-case convergence over the uncertain parameter search space. The attitude dynamics i...

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

Abstract 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.