Research contract worth $100,000 draws 16 hopefuls to micro air vehicle competition

Open-source software, the foam-like material Depron and tiny infrared attitude controllers were common design elements among the 16 teams competing at the first US-European Micro Aerial Vehicle (MAV) Technology Demonstration and Assessment event, held in Garmisch-Partenkirchen, Germany last week.

Chasing the chance to secure a research contract worth up to $100,000, the teams ranged from individuals and university teams up to companies working for the UK Ministry of Defence. MAV contestants included fixed-wing designs with double tailbooms and oval lifting bodies through to miniature multiple-rotor helicopters and flapping-wing concepts, such as that proposed by the University of Delft (Flight International, 13-20 September).

“With Depron, we can use a hot wire to cut out and rapidly prototype a new configuration for flight testing,” says Bedfordshire, UK-based MoD contractor Blue Bear Systems Research director Dr Phill Smith, whose team has designed a delta-wing MAV.

Paparazzi, an open-source autonomous flight software package, was being used by four of the 16 teams for their fixed-wing aircraft. It was originally developed by researchers at France’s Ecole Nationale de l’Aviation Civile, whose competition entry is a flying oval wing design. This team and a number of others with similar aircraft used an infrared sensor to determine the temperature difference between the ground and the sky for attitude control. All the designs had small-, medium- or high-resolution colour video cameras to transmit pictures and many had global positioning system chips for waypoint navigation.


Dinosaurs to inspire design

Flight experts expect the earliest realisation of micro air vehicles (MAV) to involve sailplane-type configurations with control surface features copied from the dinosaur species pterosaur. The sailplane configuration is viewed as more stable and lighter, an important requirement for MAVs that have to carry sensor payloads. The pterosaurs had such a wing – a thin membrane that stretched from their wing spar bone to their legs. They also had a flap wing at the front, attached to a bone called the pteroid, which pointed downwards.

In tests, the flap wing, which stretches from the pteroid’s tip back to the spar bone, has given a lot of extra lift. “A sail-type wing for simplicity, maybe with a turbulator and flap wing [would be good],” says the UK’s University of Cambridge professor of animal mechanics Charles Ellington.

Source: Flight International