Virtual Top Hats Allow Swarming Robots to Fly in Tight Formation
In a first, Georgia Institute of Technology researchers have created a team of free-flying robots that obeys the two rules of the air: don’t collide or undercut each other. They’ve also built autonomous blimps that recognize hand gestures and detect faces.
The five swarm robotic quad-copters, created by researchers at the Georgia Institute of Technology in the US, zip back and forth in formation, then change their behaviours based on user commands. The trick is to manoeuvre without smacking into each other or flying underneath another machine, researchers said.
If a robot cuts into the airstream of a higher flying quad-copter, the lower machine must quickly recover from the turbulent air or risk falling out of the sky. “Ground robots have had built-in safety ‘bubbles’ around them for a long time to avoid crashing,” said Magnus Egerstedt, professor at Georgia Tech.
“As the number of robots and the complexity of the task increases, it becomes increasingly difficult to design one single controller that simultaneously achieves multiple objectives, e.g., forming shapes, collision avoidance, and connectivity maintenance.”
“Our quad-copters must also include a cylindrical ‘do not touch’ area to avoid messing up the airflow for each other. They’re basically wearing virtual top hats,” said Egerstedt. As long as the machines avoid flying in the two-foot space below their neighbour, they can swarm freely without a problem. That typically means they dart around each other rather than going low. “We figured out the smallest amount of modifications a quad-copter must make to its planned path to achieve the new formation,” said Li Wang, PhD student at Georgia Tech.
“Mathematically, that’s what a programmer wants – the smallest deviations from an original flight plan,” Wang said.
“Our skies will become more congested with autonomous machines, whether they’re used for deliveries, agriculture or search and rescue,” said Egerstedt. “It’s not possible for one person to control dozens or hundreds of robots at a time. That’s why we need machines to figure it out themselves,” he said.