杏吧原创

DRONES could learn a thing or two from the birds and the bees.

If an aerial robot loses a part mid-flight, you would expect it to crash. But it could stay airborne by mimicking fruit flies, which can keep flying even after a catastrophic loss of limb.

To uncover the insects鈥� secret, biologists placed flies with a clipped wing into a wind tunnel and analysed their movements using high-speed cameras. They used this data to run simulations of the flies鈥� wing motion.

They then programmed a robotic fly to mimic the insects with different levels of wing damage, which allowed them to explore movements beyond the range of a real fly鈥檚 normal behaviour. 鈥淲e cannot ask the fly, 鈥榗an you flap your wings a little bit faster or in a different way鈥�,鈥� says at Wageningen University in the Netherlands. 鈥淏ut we can ask that to the robot.鈥�

With a wingspan of 50 centimetres, the robotic fly is larger than a fruit fly, which means the team also had to scale up its movements 鈥� and the 鈥渁ir鈥� it moves in. To keep the same ratio between the size of the wing and the viscosity of the medium around it, they replaced the air with mineral oil. 鈥淚t sounds a bit weird,鈥� says Muijres, but, 鈥渁s a result, the aerodynamics around the wing are the same.鈥�

This means the robot can鈥檛 actually fly 鈥� to do so, it would need air as viscous as mineral oil. However, the lessons gleaned from its oily swims could help other robots with flapping wings overcome damage. Muijres and his team produced an algorithm based on their experiments to help drone developers keep their creations going after an accident (Interface Focus, DOI: ).

It鈥檚 not only fruit flies that have lessons for drones: finding out how bumblebees fly through turbulent skies could improve their stability. 鈥淥ne reason we were interested in bumblebees is they鈥檙e the tankers of the flying insect world,鈥� says at Harvard University. 鈥淭hey鈥檙e pretty incredible flyers in the natural environment.鈥�

By enticing trained bees into a wind tunnel with fake flowers, Crall and his colleagues found that they compensate for higher winds by beating their wings more quickly and at different angles (Interface Focus, DOI: ).

鈥淯nderstanding how insects solve this problem will be very useful for drone design,鈥� says Crall.

Meanwhile, other researchers how stick insects right themselves in the air after a fall, how owls fly silently and how pigeons navigate turbulence to pick up some aerodynamic tricks for flying robots.

Nature can provide clues to improve robotic flight systems, says Stephen Prior at the University of Southampton. But he points out that most commercial drones have fixed or rotary wings rather than fluttering insect-like wings.

This article appeared in print under the headline 鈥淚nsects give flying lessons to drones鈥�