Oct. 28 (UPI) -- Penguins occupy ecosystems increasingly vulnerable to climate change. Tracking their abundance and distribution is vital to the project of tracking global warming's ecological effects -- but counting penguins is difficult work.
To make the task of tallying the size of penguin colonies a bit easier, researchers recruited the assistance of not one robot, but a whole swarm of bots.
"The idea actually grew out of a conversation at my sister-in-law's wedding," Mac Schwager, an assistant professor of aeronautics and astronautics at Stanford University, told UPI in an email. "I met our co-author Annie Schmidt at the wedding, and learned that she studies penguin populations in Antarctica, and one of their key challenges was counting the penguins."
"I told her I worked with autonomous groups of drones that could be used to take images for counting the penguins," Schwager said. "At that point, it was clear that we had a great research synergy."
Researchers typically use a single drone to conduct aerial surveys of penguin colonies, but the process is slow and requires a lot of time, effort and skill from the drone pilot.
In collaboration with Schmidt and her team of biologists, Schwager and Stanford grad student Kunal Shah programmed a swarm of drones to autonomously survey penguin colonies.
The team of scientists described their novel solution in a new paper published Wednesday in the journal Science Robotics.
"Our main technical innovation is our path planning algorithm, the computer program that decides where each drone should go and when," Schwager said. "Existing methods typically plan paths like a lawnmower, or a vacuum cleaner, going back and forth over the survey area."
"It turns out, other paths can be much more effect, in the sense that they can take the same images while requiring less back-tracking, and while making sure that the drone is close enough to the base camp to make it back safely with the remaining battery life."
Previously, it took scientists three days to survey Antarctic penguin colonies using a solitary, hand-piloted drone. The robot swarm programmed by Schwager and his colleagues completed surveys in just two to three hours.
Time is precious in Antarctica, where animals are often on the move and weather can quickly take a turn for the worse. But speed isn't the swarm's only advantage. The self-piloted robots also offer reliability.
"If one drone fails, the other drones can take up the slack and still finish the survey," Schwager said.
For now, Schwager's swarm of drones only take pictures. The counting is done back at base after the survey has been completed and the photographs downloaded onto computers. But in the future, Schwager said the drones could use artificial intelligence to count penguins as they go.
Schwager has previously programmed robotic swarms to track the movement of people and cars on the ground in order to analyze pedestrian and vehicular traffic patterns, and he thinks similar algorithms could be adopted to track animal movements.
"The system could also be used to survey forests and other landscapes for wildfire risk, a problem that is very close to home right now for us at Stanford," he said. "We could also use the drones to survey construction sites, mining sites, agricultural fields, to assess damage after a natural disaster, or to help find lost hikers."
Biologists and study co-authors Schmidt and Grant Ballard are currently testing the drone aerial survey system in Antarctica. Meanwhile, Schwager and his colleagues at Stanford continue to make tweaks to the system to help the drones make better in-flight decisions and avoid collisions with birds or drones that have gone astray.
"We are passionate about using teams of autonomous drones to help us to understand and take care of the natural environment around us," Schwager said.