The VEGA launcher atmospheric control problem: A case for linear parameter‐varying synthesis

• Published in: Journal of the Franklin Institute Vol. 359; no. 2; pp. 899 - 927
• Main Authors: Navarro-Tapia, Diego, Marcos, Andrés, Bennani, Samir
• Format: Journal Article
• Language: English
• Published: Elmsford Elsevier Ltd 01.01.2022; Elsevier Science Ltd
• Subjects: Closed loop systems; Control stability; Control systems design; Controllers; Feedback control systems; H-infinity control; Industrial development; Launchers; Monte Carlo simulation; Nonlinear systems; Parameters; Simulator fidelity; Stability analysis; Synthesis
• ISSN: 0016-0032; 1879-2693; 0016-0032
• DOI: 10.1016/j.jfranklin.2021.07.057

This article presents the design of an atmospheric control system for the VEGA launcher using Linear Parameter-Varying (LPV) synthesis techniques, both non-rate and rate-bounded. Following the Space industry traditional approach, the control problem is first formulated to design a rigid-body controller. Subsequently, it is shown how the launcher control problem can be systematically augmented to obtain the rigid-body controller and bending filters in one single procedure. The resulting LPV controller is analyzed in terms of classical linear stability margins and compared with the VEGA baseline controller via Monte-Carlo analyses using a high-fidelity, nonlinear simulator developed by industry. In addition, the LPV design is benchmarked using extended uncertainty ranges against two other advanced controllers: a structured H∞ and an adaptive augmented design. The results show that the LPV controller provides satisfactory stability margins and excellent performance and robustness characteristics, with the advantage of the design technique offering a systematic and methodological design framework.