Flock of small UAVs to track storms

Published 3 December 2007

University of Colorado researchers develop a small UAV — weighing 250 grams and with a wingspan of half a meter; they plan to fly dozens, if not hundreds, of them in swarms for the purpose of early detection of storms; UAVs will eventually be connected to mini submarines

Safety in numbers. There are tests now underway of swarms of miniature airplanes which could someday track hurricanes, helping researchers make better predictions about the storms’ course and strength. Researchers at the University of Colorado at Boulder have developed small unmanned aerial vehicles (UAV) which link up to form an airborne network, allowing the planes to coordinate their behavior independently of a central control. The New Scientist’s Kurt Kleiner reports that the researchers are working on networking autonomous subs the same way. They used short-range radio transceivers to connect five small aircraft, weighing 250 grams each and with a wingspan of half a meter. Each aircraft acts as a node on a network, transmitting its own location and speed, and receiving and passing along the same information from the other aircraft. A simple on-board processor uses the information to adjust the course of each aircraft.

In experiments, reported in a paper presented at the ACM Conference on Embedded Network Sensor Systems, held in Sydney, Australia, earlier in November, the aircraft flew autonomously in formation to different waypoints where they circled while waiting for further instructions. The idea is to make the autonomous aircraft cheaper, more flexible, and more expendable, says Dale Lawrence, an aerospace engineer who worked on the project.

Rather than using a single big, expensive UAV that requires someone on the ground to fly it, the new approach envisions flocks of dozens or even hundreds of small, autonomous aircraft that take general directions from a ground-based controller, but then make many of necessary flying decisions for themselves. One idea is for a flock of such UAVs to use temperature and pressure sensors to arrange themselves within a safe distance of a developing hurricane, or use chemical sensors to map out a hazardous chemical plume. Since the original research, the planes have shrunk down to about 40 grams in weight and 15 centimeters in wingspan, says Kamran Mohseni, who also worked on the project. Early in 2008, the researchers plan to fly ten aircraft together to see how well the networking scheme scales up.

Mohseni is leading the effort to create a similar network with unmanned underwater vehicles. The work is even more challenging, he says, because the submarines will have to communicate using relatively slow, low-bandwidth acoustic waves, since radio waves do not propagate well in water. Mohseni envisions that, eventually, networks of hundreds of underwater vehicles gathering ocean data and transmitting it back to shore. “It’s a major achievement that they actually built the system and made it work,” says Pini Gurfil, an aerospace engineer at the Israel Institute of Technology in Haifa. Other researchers have flown flocks of centrally controlled UAVs before, Gurfil says, but this is the first time that a flock has coordinated its own movements in the air.