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The NACRE Innovative Evaluation Platform and its Navigation & Control Strategies
ISSN: 0148-7191, e-ISSN: 2688-3627
Published October 18, 2011 by SAE International in United States
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Within the European Integrated Project NACRE (New Aircraft Concept REsearch) led by Airbus, a team of research centers and universities developed a multidisciplinary flying testbed called IEP (Innovative Evaluation Platform). Under the form of a dynamically scaled model of a future civil transport aircraft, its role is to assist engineers during the assessment of flight dynamics characteristics and noise reduction capabilities.
After the feasibility study during which potential scientific and economical benefits of such new test facility have been identified, the team decided to design and manufacture the IEP. Because of the dual aspect of the system (it is a flying unmanned aerial vehicle and a test facility), an extensive requirement analysis has been carried out by the partners in order to identify the necessary operational modes and their associated navigation and control strategies.
The navigation algorithm implemented in the IEP is based on a control geometry around the airplane which is used to sense the target flight path progression in three dimensions. This approach provides a look ahead functionality to increase the control performance without increasing the complexity of the controller architecture. Studies emphasized that the computation of the control geometry combined with a “low cost” controller architecture increases performance and requires a lower computational effort.
In addition to these studies, a robust controller insensitive to modelling errors has been developed. The chosen method has been Incremental Nonlinear Dynamic Inversion. This is a robust extension of the well-known Nonlinear Dynamic Inversion (NDI) technique based on properties of general mechanical systems by feeding back angular acceleration measurements. The controller performance has been evaluated and its robustness properties were verified, demonstrating thus the asset of the approach over NDI techniques.
During the entire IEP project, from conceptual design to taxi tests, partners gathered an important know-how on the development of the flying test facility made of a Modular Flying Platform and a Ground Control Station. Based on this important experience, several paths for future developments of the IEP have been identified.
CitationKittmann, K., Breeman, J., and Schmollgruber, P., "The NACRE Innovative Evaluation Platform and its Navigation & Control Strategies," SAE Technical Paper 2011-01-2632, 2011, https://doi.org/10.4271/2011-01-2632.
- Schmollgruber, P. et al., “An innovative evaluation platform for new aircraft concepts”, The Aeronautical Journal, Volume 114, Number 1157, July 2010
- Schmollgruber, P., Jentink, H. W., Tuinstra, M., “IEP: A Multidisciplinary Flying Testbed for New Aircraft Concepts”, ICAS Congress 2010, France, Nice, Paper 130, September 2010.
- Goraj, Z., Kittmann, K., Voit-Nitschmann, R., Szender, M., “Design and Integration of Flexi Bird - a low cost sub-scale research aircraft for safety and environmental issues”, ICAS Congress 2010, France, Nice, Paper 469, September 2010.
- Kittmann, K., Universität Stuttgart, Integration und Erprobung eines Autopilotensystems in den Versuchsträger TAXI III - Entwicklung einer Simulationsumgebung zur Parametrisierung der Regelkreise des Autopiloten, September 2005
- Sieberling, S., “Design of a robust generic control system using Incremental Nonlinear Dynamic Inversion”, Master's thesis, Delft University of Technology, 2009.
- Smith, P. R., “A Simplified Approach to Nonlinear Dynamic Inversion Based Flight Control,” 1998.
- Bacon, B. J. and Ostroff, A. J., “Reconfigurable Flight Control Using Nonlinear Dynamic Inversion with a Special Accelerometer Implementation,” AIAA Guidance, Navigation, and Control Conference and Exhibit, 2000.
- Williams, J. E. and Vukelich, S. R., The USAF Stability and Control Digital DATCOM, McDonnell Douglas Astronautics Company-St. Louis.
- Drela, M. and Youngren, H., AVL 3.26 User Primer, MIT Aero & Astro, Aerocraft, Inc.
- Mulder, J. A., van der Vaart, J. C., and Mulder, M., Aircraft Responses to Atmospheric turbulence, Lecture Notes ae4-304, Delft University of Technology, 2007.
- Reiner, J., Balas, G.J., and Garrard, W.L., “Flight Control Design Using Robust Dynamic Inversion and Time-scale Separation,” Automatica, Vol. 32, No. 11, 1996, pp. 1493-1504.
- da Costa, R. R., Chu, Q. P., and Mulder, J. A., “Reentry Flight Controller Design Using Nonlinear Dynamic Inversion,” Journal of Spacecraft and Rockets, Vol. 40, No. 1, 2003.