University studies drone swarms to clean up oil spills

Just as thousands of ants converge to follow the most direct path from their colony to their food and back, a swarm of inexpensive drones could quickly map an offshore oil spill.

A research project at the University at Buffalo’s School of Engineering and Applied Sciences is studying how a swarm of unmanned aircraft systems (UAS) could use mathematical formula to mimic nature to accomplish tasks.

“Nature may not proactively use mathematics, nor does it have foresight. It behaves in ways driven by feedback, implicit drive for adaptation, and a certain degree of apparent randomness,” said Souma Chowdhury, assistant professor of mechanical and aerospace engineering. “But we can look at what kind of mathematical principles define that behavior. Once we have that, we can use it to solve very complex problems.”

Chowdhury is pioneering a way to program a team of drones to quickly map an oil spill. His computational efforts, in a paper which he co-authored with students Zachary Ball and Philip Odonkor, were presented in January at the American Institute of Aeronautics and Astronautics’ Science and Technology Forum.

The study, called “A Swarm-Intelligence Approach to Oil Spill Mapping using Unmanned Aerial Vehicles,” optimized and simulated a five-drone swarm that can map a spill more than half a mile wide in nine minutes.

The research team had to overcome the lack of communication bandwidth typical of a flying ad hoc network and the short battery life of off-the-shelf drones. Following the principles partly inspired by the dynamics of a flock of birds, Chowdhury devised a method for the drones to quickly record whether they are over water, oil or the edge of the spill.

In addition, the drones assume that the space around the oil they have spotted is also oil, although that is recorded as less than certain. This simple information is shared with the other drones in the swarm, as opposed to sharing actual images or video, which would require too much bandwidth.

“Communication is the foundation of any swarm,” Chowdhury said.

As the drones move from point to point over the spill, they avoid going over space that other drones have already covered. Thus, with five drones making observations every five seconds, the size of the spill can be determined quickly.

The drones also fly to their base on a boat, when their batteries get low. The drones that replace them on the search already have the information from all the other drones, enabling them to avoid previously mapped locations.

“The thematic focus of my lab is developing computational design approaches that take inspiration from nature,” Chowdhury said.