An innovative new approach to building safer, more efficient small unmanned aerial vehicles is taking a cue from nature.
Anticipating worsening turbulence due to environmental concerns in the coming years, engineers studying the unmatched hovering ability of kestrels hope to reverse engineer the secrets of their exceptional flight capabilities to help assemble better future drones.
Smaller drones, known as sUAVs, have a range of different applications that include delivery services, photography, and more. However, wind conditions can often cause turbulence that either grounds them temporarily or, when caught off guard, can lead to their destruction.
Now, a team of researchers has published their findings in the Journal of the Royal Society Interface, which details an ongoing collaboration between RMIT University and the University of Bristol that seeks to overcome such issues by building drones that operate more like some of nature’s best flyers.
Specifically, the nankeen kestrel is an avian species whose amazing prowess while flying during adverse conditions still confounds researchers. To unravel the secrets of their flight, the researchers used motion capture technologies made possible in RMIT’s special Industrial Wind Tunnel facility, one of the largest such facilities anywhere on the Australian continent.
“Birds don’t rely on a single response to wind gusts,” according to RMIT researcher Matt Penn. “They constantly adjust their wings and tails to stay balanced, while the natural flexibility of their feathers and joints helps absorb sudden changes in airflow.”
“They can also sense disruptions very quickly, which allows them to respond almost instantly and maintain control,” added Penn, one of the team members who co-led the studies into how birds can cope with turbulence.
According to Penn and his colleagues, these birds possess a range of unique strategies that help them overcome the dangers of turbulence, which help them navigate under conditions that would cause most sUAVs to come tumbling from the sky.
To attempt to understand what makes kestrels such adept fliers, the team created a robotic replica to mimic some of their key flight movements and characteristics, which allowed the team to unravel some of the secrets to how these incredible birds perform.
“By creating a robot replica, we were able to measure how specific movements were contributing to steadiness in flight,” said Dr Mario Martinez Groves-Raines, a researcher now with the Royal Veterinary College in London, adding that precision measurements of kestrel flight that normally could not be achieved in nature were possible using the team’s robotic version.
“We uncovered several unique techniques behind the kestrel’s impressive stability,” Groves-Raines said. “Many of these techniques have the potential to improve [the] manoeuvrability of small aircraft, which encounter similar challenges to kestrels.”
“This research shows what’s possible when engineers look to nature for solutions,” added RMIT senior researcher Associate Professor Abdulghani Mohamed.
“Our findings open new pathways for designing aircraft that can better handle turbulence.”
Going forward, the researchers say they hope to apply their findings toward the construction of novel sUAVs, which can help future drones operate safely and more efficiently, much like their agile avian forebears.
Ultimately, similar engineering in the coming years may have applications that extend well beyond just drone flight, and could also help to ensure safe operations for much larger aircraft.
The team reported their findings in a pair of new studies, ‘Bridging the Gap: A Review of Gust Mitigation in Birds and Small UAVs’, and ‘Stability and control benefits of coupled wing and tail morphing in kestrel wind-hovering flight explored using a robot replica’, both of which were published in the Journal of The Royal Society Interface.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.