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Fidelity enhancement of a rotorcraft simulation model through system identification

Published online by Cambridge University Press:  27 January 2016

L. Lu*
Affiliation:
School of Engineering, University of Liverpool, Liverpool, UK

Abstract

High fidelity modelling and simulation are prerequisites for ensuring confidence in decision making during aircraft design and development, including performance and handling qualities, control law developments, aircraft dynamic loads analysis, and the creation of a realistic simulation environment. The techniques of system identification provide a systematic framework for ‘enhancing’ a physics–based simulation model derived from first principles and aircraft design data. In this paper we adopt a frequency domain approach for model enhancement and fidelity improvement of a baseline FLIGHTLAB Bell 412 helicopter model developed at the University of Liverpool. Predictability tests are based on responses to multi–step control inputs. The techniques have been used to generate one, three, and six degree-of-freedom linear models, and their derivatives and predictability are compared to evaluate and augment the fidelity of the FLIGHTLAB model. The enhancement process thus involves augmenting the simulation model based on the identified parameters. The results are reported within the context of the rotorcraft simulation fidelity project, Lifting Standards, involving collaboration with the Flight Research Laboratory (NRC, Ottawa), supported with flight testing on the ASRA research helicopter.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2011 

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References

1. Padfield, G.D. Helicopter Flight Dynamics, Second edition, 2007, Blackwell Science, Oxford, London, UK..Google Scholar
2. Padfield, G.D. (Ed) Applications of system identification in rotorcraft flight dynamics, Vertica, 1989, 13, (3).Google Scholar
3. AGARD, Rotorcraft System Identification, September 1991, AGARD AR 280.Google Scholar
4. Klein, V. and Morelli, E.A. Aircraft system identification: Theory and practice, American Institute of Aeronautics & Astronautics, 2006.Google Scholar
5. Tischler, M.B. and Remple, R.K. Aircraft and rotorcraft system identification: Engineering methods with flight-test examples, 2006, American Institute of Aeronautics & Astronautics.Google Scholar
6. Padfield, G.D. and Du VAL, R.W. Application areas of rotorcraft system identification – Simulation model validation, AGARD LS 178, November 1991.Google Scholar
7. Padfield, G.D. and White, M.D. Measuring simulation fidelity through an adaptive pilot model, Aerospace Sci and Tech, May 2005, 9, pp 400408.Google Scholar
8. Padfield, G.D., Thorne, R., Murray-Smith, D.J., Black, C. and Caldwell, A.E. UK research into system identification for helicopter flight mechanics, Vertica, 1987, 11, (4), pp 665684.Google Scholar
9. Padfield, G.D. SA 330 Puma Identification Results, 1991, Lecture No 10, AGARD Lecture Series No 178: Rotorcraft system identification, AGARD, Neuilly-sur-Seine, France.Google Scholar
10. Anon Handling qualities requirements for military rotorcraft, 2000, US Army Aviation Command, ADS-33E-PRF.Google Scholar
11. Zivan, L. and Tischler, M.B. Development of a full flight envelope helicopter simulation using system identification, J American Helicopter Society, April 2010, 55, pp 115.Google Scholar
12. Drobik, J.S. and Brian, G.J. Application of system identification techniques to the F-111C and PC 9/A aircraft, J Aircr, July 2004, 41, (4), pp 744751.Google Scholar
13. Field, E.J., Rossitto, K.F. and Hodgkinson, J. Flying qualities applications of frequency responses identified from flight data, J Aircr, July 2004, 41, (4), pp 711720.Google Scholar
14. Morelli, E.A., and Klein, V. Application of system identification to aircraft at NASA Langley Research Center, J Aircr, January 2005, 42, (1), pp 1225.Google Scholar
15. Morelli, E.A., Low order equivalent system identification for the Tu-144LL supersonic transport aircraft, J Guidance, Control and Dynamics, March 2003, 26, (2), pp 354362.Google Scholar
16. Grauer, J., Conroy, J., Hubbard, , Humbert, J. and Pines, D. System identification of a miniature helicopter, J Aircr, July 2009, 46, (4), pp 12601269.Google Scholar
17. Bradley, R., Padfield, G.D., Murray-Smith, D.J. and Thomson, D. G. Validation of helicopter mathematical models, Transactions of the Institute of Measurement and Control, 1990, 12, (4), pp 186196.Google Scholar
18. Manimala, B., Walker, D. and Padfield, G.D. Rotorcraft simulation modelling and validation for control law design, Aeronaut J, February 2007, 111, pp 7788.Google Scholar
19. White, M.D., Perfect, P., Padfield, G.D., Gubbels, A.W. and Berryman, A.C. Acceptance testing of a rotorcraft flight simulator for research and teaching: the importance of unified metrics, 2009, 35th European Rotorcraft Forum, Hamburg, Germany.Google Scholar
20. Anon JAR-STD 1H, Helicopter Flight Simulators, April 2001, Joint Aviation Authorities.Google Scholar
21. Anon. AC 120-63 Helicopter simulator qualification, November 1994, Federal Aviation Administration Advisory Circular.Google Scholar
22. Padfield, G.D., Pavel, M.D., Casolaro, D., Roth, G., Hamers, G., and Taghizad, A. Simulation fidelity of real-time helicopter simulation models, 2005, Proceedings American Helicopter Society 61st Annual Forum, Grapevine, TX, USA.Google Scholar
23. Strope, K., Borden, C. and Harding, J. Verification and validation of a UH-60 FLIGHTLAB model in support of the UH-60M Limited UserTest, 2004, Proceedings of American Helicopter Society 60th Annual Forum, Baltimore, MD, USA.Google Scholar
24. Field, E.J., Rossitto, K.F. and Hodgkinson, J. Flying qualities applications of frequency responses identified from flight data, J Aircr, July 2004, 41, (4), pp 711720.Google Scholar