To improve drones, researchers study flying insects

Unmanned aircraft, known as drones, used by amateurs, researchers and industry to take aerial images and perform other tasks, are gaining in popularity and size. But this miniaturization, which produced drones that fit in the palm of someone, began to run up against the laws of physics.

Rotating rotor blades like those of a helicopter can only be reduced too much before the friction of the air exceeds the lifting force, which causes overheating and the failure of small engines. This is why engineers, eager to develop tiny UAVs that may one day monitor pipelines to detect leaks or even rush among the flowers to help pollinate crops, are increasingly interested in the fly of insects hovering.

Nature has suggested what scientists are beginning to understand in theory: "flapping wings can be reduced almost indefinitely" while producing a sufficient lift force, said Mark Jankauski, Assistant Professor in the Department of Mechanical and Industrial Engineering of Norm Asbjornson College of Engineering.

But creating artificial versions of the intricate designs of insects is another matter. Indeed, according to Jankauski, specialist in the field, the precise mechanics of flapping wings remains poorly understood.

Now, with a $ 370,000 three-year grant from the National Science Foundation, Jankauski is leading a project to map flapping flight physics in a variety of ways, including more efficient analytical models that can significantly simplify the flight process. wing design.

"There is still a lot of work to be done before (flapping wings) is a viable technology for an application," said Jankauski. "It's a starting point."

Jankauski's partner on the project, Erick Johnson, an assistant professor of mechanical engineering at the MSU, specializes in computer models that simulate how structures such as wings interact with fluids, including air. The behavior of the flapping wings is extremely complex, he said.

"My models take days or weeks to run" on an average computer, Johnson said. In comparison, the models developed by the researchers will be "almost instantaneous," he said, adding that "it's a fascinating field."

To do this, it will be necessary to find approximations for the complex equations that would otherwise be solved by computer models. To do this, Jankauski and Johnson will make detailed measurements of flapping wings.

In their lab, researchers have a device that can accurately bend the wing replicas to create detailed geometric maps of how the wings respond to different forces. They will also experiment with other test benches that replicate and measure flying insects flapping their wings, according to Jankauski.

Ultimately, the new models could allow designers to consider thousands of possible wing designs and quickly obtain information on solutions that would best lift and maneuver tiny UAVs. The models could also be used to help control the flight of drones by calculating, for example, the necessary pitch of the wing or the speed of flapping, according to Jankauski.

The project will also contribute to an expanding scientific field that explores the extraordinary characteristics of biological thieves more generally. "There is an absolute wealth of knowledge about the world through the study of insects and how they interact with their environment," said Jankauski.