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Increasing persistence of UAVs and MAVs through thermal soaring

Published online by Cambridge University Press:  03 February 2016

I. D. Cowling ,
S. Willcox ,
Y. Patel ,
P. Smith  and
M. Roberts
I. D. Cowling
Affiliation:
[email protected], Blue Bear Systems Research, Clapham, Bedfordshire, UK
M. Roberts
Affiliation:
Cambridge Unmanned Ltd, Sandy, Bedfordshire, UK
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Abstract

This work looks to harness atmospheric energy through thermal soaring to optimise the flight persistence of Micro Air Vehicles (MAVs) and Unmanned Air Vehicles (UAVs). There are two key challenges when considering thermal soaring, the first being the locating of thermals and the second being the extraction of the maximum potential energy from the thermals. Thermal location is by no means an exact science with experienced glider pilots needing to consider many factors to improve the probability of encountering a thermal. As thermals are caused by the uneven heating of the Earth’s surface it is, however, possible to predict likely thermal locations. With the application of a suitable guidance algorithm which considers these ‘hot spots’ it is possible to increase the likelihood of encountering a thermal. Once a thermal is found it is important to attempt to extract the maximum energy from the thermal. To do this the vehicle needs to move quickly to the centre of the thermal. There are many potential techniques for thermal centring, some of which appear to be entirely contradictory to each other, the crucial factor determining the success of such a technique has been found to be the response time of the onboard sensors. This paper considers the many aspects of thermal soaring such as locating thermals, thermal detection and thermal centring. Five different thermal models are presented which are used to demonstrate the thermal centring techniques. Finally a commercial glider simulation package is used to demonstrate the control architecture and simulate a fully autonomous flight.

Type
Research Article
Information
The Aeronautical Journal , Volume 113 , Issue 1145 , July 2009 , pp. 479 - 489
Copyright
Copyright © Royal Aeronautical Society 2009 

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References

1. Allen, M., Guidance and control of an autonomous soaring UAV, NASA Dryden Flight Research Centre, USA.Google Scholar
2. Allen, M., Updraft model for development of autonomous soaring uninhabited air vehicles, AIAA 2006-1510.Google Scholar
3. Piggott, D., Beginning Gliding, 3rd ed, A & C Black, London, UK.Google Scholar
4. Piggott, D., Gliding, A Handbook on Soaring Flight, 8th ed, A & C Black, London, UK.Google Scholar
5. Reichman, H., Cross Country Soaring, Soaring Society of America, Hobbs, New Mexico, USA.Google Scholar
6. Bradbury, T., Meteorology and Flight, 3rd ed, A & C Black London.Google Scholar
7. Telford, J., Cionvective plumes in a convective field, J Atmospheric Sciences, 22, (3), pp 347–357.Google Scholar
8. Cowling, I., Yakimenko, O., Whidborne, J. and Cooke, A., A prototype of an autonomous controller for a quadrotor UAV, Proc European Contr Conf, 2007, Kos, Greece, July 2007.Google Scholar
9. Cowling, I.D., Towards Autonomy of a Quadrotor UAV, PhD Thesis. Cranfield University, Cranfield, UK, 2009.Google Scholar
10. Irvine, R., Brown, A., Vosper, S., Rooney, G., Devenish, B., Hook, M. and Sparks, E., Autonomous Soaring Project Phase 2, Proc SEAS DTC, Annual Technical Conference, Edinburgh, Scotland, UK, 2007.Google Scholar
11. Condor, The competition soaring simulator, http://www.condorsoaring.com. 2009.Google Scholar