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 t...

https://www.engadget.com/2017/05/15/...s-drone-crash/