Thesis defence

Mr Doan LE ANH

Friday 1 March 2019 at 2.00 pm
AIEMN-DOAE amphitheatre on the UPHF Mont-Houy campus

Jury:

• Bruno ALLARD, University Professor, INSA de Lyon / Ampère Laboratory, Lyon (Rapporteur),
• Mr Ramiro GODOY-DIANA, CNRS HDR Research Fellow, ESPCI / PMMH, Paris (Rapporteur)
• Mr André PREUMONT, University Professor, ULB / Active Structures Laboratory, Brussels (Examiner)
• Mrs Guylaine POULIN-VITTRANT, CNRS Research Fellow, INSA-CVL GREMAN, Blois (Examiner)
• Éric CATTAN, University Professor, UPHF / IEMN, Valenciennes (Thesis supervisor)
• Mr Sébastien GRONDEL, University Professor, UPHF / IEMN, Valenciennes (Thesis supervisor)
• Mr Olivier Thomas, University Professor, ENSAM/ LSIS, Lille (Guest)

Summary:

Over the last few decades, the possibility of exploiting the exceptional flight capabilities of insects has prompted a great deal of research into the development of flapping-wing nano-aerial vehicles (NAVs). However, when designing such prototypes, researchers have to analyse a vast range of solutions linked to the wide diversity of flying insects to identify the functionalities and parameters best suited to their needs. In order to alleviate this task, the aim of this work is to develop a tool for examining both the kinematic and energetic behaviour of a nano-air vehicle with flexible resonant wings, and thus to assess its effectiveness.

However, this objective remains extremely difficult to achieve because it concerns very small objects. For this reason, we have chosen first to work on a micro air vehicle (MAV) with flapping wings. The main aim is to validate the modelling tool by systematically comparing the simulations with the experimental results obtained during the actuation of the wings, then during the prototype's take-off and hovering flight. Some of the knowledge and experience acquired can then be used to gain a better understanding of the operation and identify the energy distribution within the NAV.

Although the two vehicles are directly inspired by the kinematics of insect wings, the mechanisms for actuating the artificial wings of the two prototypes are not the same because of the difference in size. Because the NAV is smaller, these wings flap at a higher frequency than those of the MAV, as is the case in nature. As a result, when moving from the MAV to the NAV, the wing actuation mechanism needs to be adapted, and this difference requires a rethink of the design, modelling approach and optimisation process, as well as changes to the manufacturing process. Once these improvements had been made, we obtained simulation results in line with the experimental tests.

The main result of this work is that the two prototypes, the MAV and the NAV, have appropriate kinematics for the wings, resulting in a lift force equivalent to the weight. We have also demonstrated that the MAV is capable of taking off and hovering in a stable manner along the vertical axis. By taking advantage of models based on the Bond Graph language, it is also possible to assess the energy performance of these prototypes as a function of the wing's dynamics. In conclusion, this study contributes to the definition of the essential parameters to be taken into account in the design and energy optimisation of flapping-wing micro- and nano-vehicles.