Birds have been inspiring drones for years, but the hummingbird is particularly agile – its ability to hover and make sharp turns could teach drones a thing or two. Now researchers at Purdue University have managed to do just that, building a hummingbird-inspired drone and teaching it to fly using algorithms trained on the birds' natural flight patterns.
While previous attempts at robotic hummingbirds were larger than life, slow and human-controlled, the Purdue drone is close to the same size as the real thing. It has a wingspan of 17 cm (6.7 in), and weighs as much as the average adult hummingbird – a svelte 12 g (0.4 oz). Plus, it can lift more than twice its own weight, up to 27 g (0.95 oz). It's all wrapped up in a 3D-printed body that sports wings made of carbon fiber and membranes, which flap at frequencies of up to 40 Hz.
Most importantly, it can fly like a hummingbird. That's more impressive than it sounds for a robot – these unassuming little birds can pull off some of the most insane aerial stunts known to bird-kind, including hovering and turning 180 degrees in 0.2 seconds flat.
The researchers observed these kinds of maneuvers in living hummingbirds and built algorithms out of them, then compiled the lot into a realistic computer simulation of hummingbird behavior. This is then used to teach the robots to take flight.
While hummingbird-inspired drones won't necessarily be the fastest or farthest fliers, their improved maneuverability and relatively small size means they could move through spaces that other robots can't fit into. The researchers use the example of sending the drone into a collapsed building after a disaster, to help look for survivors or assess damage.
Interestingly, the robot has no cameras and so it can't see just yet, but through an electrical sense of touch and AI algorithms that can analyze those touches, it could navigate in the dark just fine.
"The robot can essentially create a map without seeing its surroundings," says Xinyan Deng, lead researcher on the study. "This could be helpful in a situation when the robot might be searching for victims in a dark place – and it means one less sensor to add when we do give the robot the ability to see."
Before more sensors can be added to the robot, however, the team says that its lifting power needs a boost. Cameras, GPS and other sensors could be useful in future versions, and batteries would allow it to fly free – in its current form, the robot has to remain tethered to an energy source.
Other advantages include the fact that the robot can effectively fly silently, and can handle turbulence with ease. The team also developed a version that's more on the scale of insects, weighing just 1 gram (0.04 oz).
The research is due to be presented next week through three papers at the IEEE International Conference on Robotics and Automation in Montreal. The team demonstrates the robots in the video below.
Source: Purdue University
