Virtual 'top hats' ensure swarming drones won't crash

Drone swarms can be used for lots of things, like creating holograms, putting on a Superbowl halftime show or collecting military intelligence. One of the problems with a bunch of quadcopters executing maneuvers in close proximity, however, is that they can crash when they touch or fly under each other. Researchers at the Georgia Institute of Technology have found a way to avoid both issues by creating a virtual bumper area around each copter so that they don't accidentally touch. They've also ensured that each copter has a little "top hat" of space above it so it won't go underneath another drone and get caught up in its airflow. Ph.D. student Li Wang figured out that the top hat must be as tall as five times the diameter from one rotor to another by flying drones atop one another.