Engineering: Bird-like drones take a sharp turn

A winged drone that can turn sharply like a bird to avoid obstacles in dense urban and forest environments is presented in a paper published in Communications Engineering.

Although winged drones are aerodynamically and energetically more efficient fliers than those powered by multiple propellers, winged drones need more space in order to turn, which limits their use in dense environments, such as cities.

To improve the turning performance of winged drones, Dario Floreano and colleagues designed a bird-inspired drone. The drone, which is made of fibre-reinforced plastics, has a maximum wingspan of 1.5 metres and weighs 711 grams. It has two wings and a tail that are similar in appearance to those of a bird, has artificial feathers, and can be folded and tilted. The authors performed wind tunnel and flight tests to assess the impact of wing and tail movements on the speed at which the drone can roll and the area it needs to turn. They found that tilting each wing at different angles enables the drone to roll more than four times faster than when the wings are tilted at similar angles but one is extended and the other is tucked in. By extending the wings and tail outwards, the authors found that the drone is able to turn with a radius of 4.9 metres, compared to a turn radius of 12.1 metres when the wings and tail are tucked in. This indicates that the drone is capable of performing sharp turns, which could enable it to fly in cluttered environments.

The authors suggest that their findings could aid the development of new winged drones capable of flying long distances through both open and dense environments.