Funded PhD / DPhil position AVAILABLE NOW in the Oxford Animal Flight Group

Apply online here.

Title: Flow sensing and load sensing in insect flight with applications to Unmanned Air Systems

Supervisors: Dr G. Taylor & Dr R. Bomphrey

Application deadline: March 2012

Funded PhD project (EU/UK students only)

 

Insects are richly instrumented with both flow sensors and load sensors on the wings, head, and body (Taylor & Krapp, 2007): they provide information which is used to control flight in a way that is quite unlike the conventional methods used in man-made aircraft. Our aim in this project is to investigate how distributed flow sensing and load sensing is used in the flight control of insects, with a view to informing the design of novel control architectures for fixed or flapping-wing Unmanned Air Systems (UAS).

More is known about the flow sensors and load sensors of locusts than in any other flying animal, but we still have little or no understanding of how the information that these sensors obtain is actually used in the stabilization and control of locust flight. Several types of flow sensor and load sensor are known to be important in locust flight control (Taylor & Krapp, 2007). Fields of flow-sensitive hairs with highly directional responses are located on the front of the head, and encounter and sense the oncoming flow. The directional sensitivity of these hairs may allow them to sense changes in angle of attack and sideslip. The antennae are also located on the head, and apparently play a role in forward speed regulation, being sensitive to changes in the speed, rather than direction, of the oncoming airflow. On the wings, there are further arrays of wind-sensitive hairs, which might in principle provide information on boundary layer separation. Finally, distributed strain-sensitive campaniform sensillae on the wings sense the local aerodynamic, elastic and inertial loads, thereby feeding back information that might be used to synchronise, balance and control wing angle of attack and hence force production. The locust therefore makes an excellent model system for studying the uses of distributed flow sensing and load sensing in flight control.

This project will differentiate the functions of each sensor type, and their importance to locust flight control, by modelling the flight stabilization and control system. This will be done by using force measurement and wind tunnel techniques pioneered by the Oxford Animal Flight Group (Taylor & Thomas, 2003; Taylor & Zbikowski, 2005) to parameterize the models, so as to elucidate the function of the different sensors by manipulating them experimentally. These models of stability and control will be developed alongside understanding of the detailed flows that are experienced by the various sensors, using 3D flow measurement techniques that we have also pioneered in Oxford (Bomphrey et al., 2005, 2006a,b; Bomphrey, 2011). These measurements will be used to investigate and explain the distribution and directional sensitivity of the sensors, as well as to identify the precise properties of the flow that they measure.

This project will suit applicants with a background in either biology or engineering with specific interests in any of the following: neurophysiology, flight mechanics, aerodynamics, or unmanned air systems.

Funding Notes:

This DPhil is funded by Dstl under the MoD's National PhD Scheme. This 4-year award provides a maintenance grant at the UK Research Councils minimum stipend (currently £13590 pa) plus an uplift of £1500 pa. University and College tuition fees will be supported by the award at Home/EU level. We aim to appoint a student to begin on 1 April 2012. Applications to begin on 1 October 2012 will also be considered.

To apply please access the online application system at: http://www.ox.ac.uk/admissions/postgraduate_courses/apply . Submit a personal statement rather than a research proposal. Any queries regarding the application procedure please contact graduate.office@zoo.ox.ac.uk.

References:

Bomphrey RJ. 2011. Advances in Animal Flight Aerodynamics Through Flow Measurement. Evolutionary Biology 38(4):1-11.

Bomphrey, R. J., Harding, N. J., Lawson, N. J., Taylor, G. K., & Thomas, A. L. R. (2005). The aerodynamics of Manduca sexta: digital particle image velocimetry of the leading-edge vortex, J. Exp. Biol., 208, 1079–1094.

Bomphrey, R. J., Lawson, N. J., Taylor, G. K., & Thomas, A. L. R. (2006). Application of digital particle image velocimetry to insect aerodynamics: measurement of the leading-edge vortex and near wake of a hawkmoth, Exp. Fluids. 40, 546-554.

Bomphrey, R. J., Lawson, N. J., Taylor, G. K., & Thomas, A. L. R. (2006). Digital particle image velocimetry measurements of the downwash distribution of a desert locust Schistocerca gregaria.

Taylor, G. K. (2007). Modelling the effects of unsteady flow phenomena on flapping flight dynamics— stability & control. In: R. Liebe, ed., Flow phenomena in Nature: a challenge to engineering design, Vol. 1, pp 155-166, WIT Press, Southampton.

Taylor, G. K. & Krapp, H. G. (2007). Sensory systems and flight stability: what do insects measure, and why? Adv. Insect Physiol., 34, 231-316.

Taylor, G. K. & Thomas, A. L. R. (2003). Dynamic flight stability in the desert locust Schistocerca gregaria. J. Exp. Biol. 206, 2803-2829.

Taylor, G. K. & Zbikowski, R. (2005). Nonlinear time-periodic models of the longitudinal flight dynamics of desert locusts Schistocerca gregaria. J. Roy. Soc. Interface 2, 197-221.