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CEAS EuroGNC 2024

Design and Flight Testing of a Feedback-Linearising Control Law for a Large Flight Envelope on a Sub-Scale Airliner
Daniel Pusztai PhD Student, University of Bristol, School of Civil, Aerospace & Design Engineering, BS8 1TR, Bristol, United Kingdom.
Mark H. Lowenberg Professor of Flight Dynamics, University of Bristol, School of Civil, Aerospace & Design Engineering, BS81TR, Bristol, United Kingdom.
Simon A. Neild Professor of Nonlinear Structural Dynamics, University of Bristol, School of Civil, Aerospace & Design Engineering, BS8 1TR, Bristol, United Kingdom.
Abstract:
A new flight control law for transport aircraft to improve performance beyond the normal flight envelope is presented. It consists of a longitudinal, lateral, and directional control and stability augmentation system and has three main features: 1) Feedback linearisation to cancel the effects of the aircraft's nonlinear aerodynamics; 2) Proportional-integral-derivative control with gain scheduling to improve the overall system dynamics and facilitate command tracking; 3) Command shaping functions with feedforward paths to achieve good handling qualities. Flight envelope protection is achieved by limiting the pilot's control inputs depending on the airspeed and vehicle configuration. The control law was implemented and test-flown on a remotely-piloted 3.7% scale model of NASA's Generic T-Tail Transport aircraft configuration. Flight tests are compared to simulation studies to evaluate the robustness of the developed controllers. The results include lateral-directional control during stalled flight, angle of attack limitation during slow level flight, and a single engine failure scenario with automatic yaw coordination. Some results are also compared to the unaugmented system and a simple linear roll/yaw damper to prove the benefits of a nonlinear control law.
Keywords: flight control law; feedback linearisation; flight envelope protection; transport aircraft; flight testing
 View PDF CEAS-GNC-2024-069


Daniel Pusztai, Mark H. Lowenberg, Simon A. Neild: Design and Flight Testing of a Feedback-Linearising Control Law for a Large Flight Envelope on a Sub-Scale Airliner. Proceedings of the 2024 CEAS EuroGNC conference. Bristol, UK. June 2024. CEAS-GNC-2024-069.
BibTeX entry:

@Incollection{CEAS-GNC-2024-069,
    author = {Pusztai, Daniel and Lowenberg, Mark H. and Neild, Simon A.},
    title = {Design and Flight Testing of a Feedback-Linearising Control Law for a Large Flight Envelope on a Sub-Scale Airliner},
    booktitle = {Proceedings of the 2024 {CEAS EuroGNC} conference},
    address = {Bristol, UK},
    month = jun,
    year = {2024},
    note = {CEAS-GNC-2024-069}
}