Why bird-like drones can help with saving energy

Humans may have been able to create technology to realize their age-old dream of flying long ago. But there is still a lot to learn from the avian masters of the skies. At a university in the Netherlands, researchers are exploring ways for drones to mimic how birds "hover" in the wind to reduce the energy needed to stay aloft. It might look unassuming, like a basic small model plane. But the drone hovering in the wind tunnel at Delft University in the Netherlands is mimicking energy-saving behavior that can be observed in birds when they soar using thermals which are warm currents of air. “We tried to mimic the birds' flight behavior,” explains Sunyou Hwang, a Ph.D. student leading the project. “For example, kestrels do so-called wind hovering when they are hunting, so they stay in the air without flapping their wings. Then they don't use that much energy because they don't flap their wings.” But while birds have an intuitive understanding of the wind, "teaching" a drone to simulate this skill is less straightforward. The researchers could also program the drone to autonomously find a new soaring spot when the wind field changes during the flight. “We didn't use prior knowledge of the wind field, so this MAV (Micro Air Vehicle) didn’t know what kind of wind field we have, and it has to find that feasible position by itself,” says Sunyou Hwang. Bart Remes, who collaborates on the research and mentors Hwang’s Ph.D. work, says that observing birds' behavior meant that "we know that it is possible" – but that prior to the experiments they did not know how great the efficiency savings might be or what the optimal position was. And while the researchers focus on “fundamental research, so we don't know what the application will be," Remes says the knowledge gained could be useful for a range of projects and applications in the future. Their work has yet to be peer-reviewed and the team is just one group of researchers looking to the natural world to improve man-made aircraft. This article was provided by The Associated Press.