Robust Modal Damping Control for Active Flutter Suppression

Theis, Julian; Pfifer, Harald; Seiler, Peter

Abstract

Flutter is an unstable oscillation caused by the interaction of aerodynamics and structural dynamics. It is current practice to operate aircraft well below their open-loop flutter speed in a stable flight regime. For future aircraft, weight reduction and aerodynamically efficient high aspect ratio wing design reduce structural stiffness and thus reduce flutter speed. Active control of the flutter phenomena can counter adverse aeroservoelastic effects and allow operation of an aircraft beyond its open-loop flutter speed. This paper presents a systematic robust control design method for active flutter suppression. It extends the standard four block mixed sensitivity formulation by a means to target specific dynamic modes and add damping. This enables a control design to augment damping of critical flutter modes with minimal impact on the rigid-body autopilots. Finally, the design scheme uses a manageably low number of tunable parameters with a clear physical interpretation. Tuning the controller is hence considerably easier than with standard approaches. The method is demonstrated by designing an active flutter suppression controller for a small, flexible unmanned aircraft and verified in simulation.

Citation

Theis, J., Pfifer, H., & Seiler, P. (2020). Robust Modal Damping Control for Active Flutter Suppression. Journal of Guidance, Control, and Dynamics, 43(6), 1056-1068. https://doi.org/10.2514/1.g004846

• Journal Article Type: Article
• Acceptance Date: Jan 20, 2020
• Online Publication Date: Mar 3, 2020
• Publication Date: Jun 1, 2020
• Deposit Date: Apr 11, 2020
• Publicly Available Date: Apr 17, 2020
• Journal: Journal of Guidance, Control, and Dynamics
• Print ISSN: 0731-5090
• Electronic ISSN: 1533-3884
• Publisher: American Institute of Aeronautics and Astronautics
• Peer Reviewed: Peer Reviewed
• Volume: 43
• Issue: 6
• Pages: 1056-1068
• DOI: https://doi.org/10.2514/1.g004846
• Keywords: Control and Systems Engineering; Space and Planetary Science; Electrical and Electronic Engineering; Applied Mathematics; Aerospace Engineering
• Public URL: https://nottingham-repository.worktribe.com/output/3994324
• Publisher URL: https://arc.aiaa.org/doi/abs/10.2514/1.G004846