Swarm of Robots Learns to Work Together, Without Colliding

In technical speak, the bots are using a set of safe states and barrier certificates to ensure each stays in its own safe set throughout the entire maneuver.

“In everyday speak, we’ve shrunk the size of each robot’s bubble to make it as small as possible,” said Egerstedt, who is also the Julian T. Hightower Chair in the School of Electrical and Computer Engineering. “Our system allows the robots to make the minimum amount of changes to their original behaviors in order to accomplish the task and not smack into each other.”

In a demo with four robots, the lab’s machines approach from four different areas, meet in the middle, circle counterclockwise within inches of each other, then fan out into opposite directions. In another demonstration, eight robots perform the same task, this time circling clockwise before dispersing. Instead of keeping their distance and taking the long way around their neighbors, the robots move very independently wherever they wish.

Avoiding collisions isn’t anything new in robotics. And Google’s self-driving cars are almost crash-free.

“But we haven’t seen thousands of autonomous cars on the road together yet,” Egerstedt said.

“Robots are very conservative — they want to make sure they’re safe. You couldn’t pack the interstate with self-driving cars with today’s technology.”

Egerstedt also said something similar to these algorithms could be used for the next generation of air traffic control. Instead of people directing the flow, planes will be given the authority in airspaces.

“They’ll have to be safer if we plan to pack the airspace more densely.”

The paper about the project, “Multi-objective Compositions for Collision-Free Connectivity Maintenance in Teams of Mobile Robots,” has been accepted at this year’sIEEE Conference on Decision and Control in Las Vegas.

The work is supported in part by the National Science Foundation (grant numbers 1544332 and 1239055). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the sponsors.

Contacts and sources:
By Jason MadererGeorgia Institute of Technology