Swarms of autonomous drones successfully tested in the wild

published on Thursday, May 05, 2022 at 9:06 p.m.

A dense bamboo forest, China. Suddenly, ten small drones the size of a palm of a hand rise in a buzz.

They fly side by side in the same direction, towards a target a few tens of meters away, avoiding branches, embankments and other obstacles.

In turn, they pass through the narrow spaces between the bamboo stalks.

All this in an entirely autonomous, coordinated way, and on land that they discover in real time.

The experiment, conducted by scientists from Zhejiang University, evokes a scene from science fiction. Their study, published Wednesday in the journal Science Robotics, begins by citing films like “Star Wars”, “Prometheus” or “Blade Runner 2049”.

“The ability to navigate and coordinate swarms of drones in these films has inspired many researchers. Here we are taking a step towards such a future”, write the authors of this work.

These machines, specially designed for the experiment, are equipped with a stereo camera, sensors and an on-board computer. Above all, a specific algorithm has been developed.

Swarms of drones have already been tested in the past, but only in open environments or with known obstacle positions in advance, explained to AFP Enrica Soria, of the Federal Polytechnic School of Lausanne, who has been working on the subject herself for several years.

“This is the first time that a swarm of drones has successfully flown outdoors in an unstructured environment, in nature,” she said, calling the experience “impressive”.

These small flying robots “can determine their environment on their own, map it and then plan their trajectory”, she explains.

– Relief operations –

The applications are multiple.

Since these drones do not rely on any outside infrastructure (like GPS), swarms could be used during natural disasters.

For example, after an earthquake, in order to identify the damage and where to send help. Or in a damaged building where humans cannot venture without danger.

Certainly, it is already possible to use individual drones in such scenarios. But with very limited flight autonomy times, sending swarms would save considerable time.

Another possibility: transporting heavy objects that cannot be lifted by a machine alone.

What about military applications?

Drones are already widely used by the army, and the Pentagon has repeatedly expressed its interest in such swarms, which it is also testing on its own.

“Military research is not shared with the rest of the world,” notes Enrica Soria. “So it’s hard to know what stage of development they are at.”

Could the algorithms developed by the researchers be used by the army? “It’s part of the good and bad sides of having science in open access,” she comments modestly.

– Flocks of birds –

Chinese scientists have carried out several experiments, including flight through the bamboo forest.

In another, the drones were forced to stay in formation. A third test instead had them flying in converging directions, with a human walking in the middle of the area, to prove their ability to avoid each other or a moving person.

“Our work was inspired by birds, which fly smoothly in flocks, even through dense forests,” says Xin Zhou, lead author of the study, in a blog post. The model of insects, with their sudden movements, has instead been avoided.

The challenge, he says, was to reconcile contrary injunctions: light and small machines, but high-performance computing capabilities, and a safe trajectory, without adding flight time…

When will such swarms be widely used?

“We are not that far off,” said Enrica Soria. Tests are still necessary in ultra-dynamic environments, imitating for example cities, where vehicles and passers-by jostle. Regulations will also have to be adopted, which takes time.

But according to her, “in the next few years, we will be able to have very reliable systems”.