Adaptive Incremental Nonlinear Dynamic Inversion Flight Control for Consistent Handling Qualities

Adaptive Incremental Nonlinear Dynamic Inversion Flight Control for Consistent Handling Qualities

Smit, B. (Student TU Delft)
Pollack, T.S.C. (TU Delft Control & Simulation)
van Kampen, E. (TU Delft Control & Simulation)

2022

Control augmentation systems based on Incremental Nonlinear Dynamic Inversion (INDI) are able to provide high-performance nonlinear control without a holistic model. Considering an angular rate control law for a fixed-wing aircraft, only a control effectiveness (CE) model and angular acceleration measurement feedback is required. Despite enhanced robustness against parametric model mismatches due to reduced model dependency, the performance of INDI-based control laws can still vary due to inaccurate CE models. This paper confirms that longitudinal centre of gravity (CG) shifts and CE uncertainty result in varying handling qualities and stability (HQ\&S) characteristics. An adaptive solution using Least-Mean-Square (LMS) based parameter estimation is investigated to address these variations. The results demonstrate that online CE model correction result in reduced HQ\&S variation. However, it was found that some flight conditions together with adverse CG shifts could lead to violation of the time-scale separation assumption that underlies the adaptive control law design. As this assumption is inherent to the INDI control design itself as well, online CE model correction is only partly able to resolve the resulting performance variations.

http://resolver.tudelft.nl/uuid:d10a6b18-a90d-4936-999d-9c23a9a13f40

https://doi.org/10.2514/6.2022-1394

978-1-62410-631-6

AIAA SCITECH 2022 Forum

AIAA SCITECH 2022 Forum, 2022-01-03 → 2022-01-07, virtual event

AIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2022

Institutional Repository

conference paper

© 2022 B. Smit, T.S.C. Pollack, E. van Kampen