This flying robot needs a hug

Instead of looking for a runway, researchers have built an unmanned aerial vehicle (UAV) that can land by clipping trees or poles and wrapping its grippy wings around them to avoid falling. It’s an unconventional method, but it could make it easier to place surveillance or inspection equipment in areas that are hard to reach.

The UAV, which designers at the Intelligent Systems Laboratory at the Swiss Federal Institute of Technology (EPFL) named Parkhug, is another robot designed to emulate behavior seen in nature: bats and owls fly using their wings and climb or perch on trees.

The Parkhug robot is designed with dual-purpose wings that remain rigid and extendable, allowing the UAV to fly, but also become flexible when the tension wire is released.

As described in a paper recently published in the journal NatureWeighing just 550 grams, this lightweight UAV has an “upturned nose design” that allows it to reorient itself vertically when it begins to fall after a crash. The impact of the crash also releases the tension wire, allowing the UAV’s spring-loaded wings to wrap around the structure and stay on it most of the time.

Even after adding fishing hooks to the outside of the wings to improve grip, the Parkhug UAV only successfully attached itself to a tree or pole 73 percent of the time. And it was during those tests that the UAV made impact after a short, gentle glide.

The unique approach of reusing the wings for a safe landing eliminates the need for an additional landing mechanism. This will make the UAV lighter, potentially expanding its payload capacity, and how far it can fly before hitting a tree.

A higher success rate will be needed before the UAV can be equipped with expensive equipment such as sensors or cameras. The researchers also plan to expand the UAV’s capabilities with avionics and control surfaces since in its current form it is merely a manually launched glider without any steering capabilities. They also want to find a way to make it take off on its own and fly back into the sky on its own.