It's a bird, it's a plane, it's a ... feathered drone?
There is much to learn from the natural world when it comes to robotics, and there may be no better exponents of this than the folks in the Laboratory for Intelligent Systems (LIS) at Switzerland's École Polytechnique Fédérale de Lausanne. For their latest bio-inspired project, the scientists have crafted a drone with a feathered, shape-shifting wingspan that allows it to fly fast, turn sharply and endure strong winds. Kind of like a bird.
Scientists often turn to the animal kingdom to overcome robotics challenges, and lately we are seeing how this approach can benefit unmanned flying machines. A beetle-inspired drone with wings that snap open and a turtle-inspired drone that uses its wings to crawl across land are a couple of recent examples, both the handiwork of LIS, and now the team has tapped the masters of flight to come up with a new kind of drone design.
Birds are able to fly so efficiently because they can adjust the shape of their wings, down to individual feathers, depending on the task at hand. This has been closely studied by aerospace engineers with a view to developing shapeshifting wings for larger, low-energy aircraft, and now the LIS team has found it might have something to offer drone flight, too.
The scientists set out to build a drone that could adjust the configuration of its wings to fly between obstacles, make sharp turns and also stand up in strong winds. This meant building a mechanism that allowed it to retract large artificial feathers fixed to its outer wing, kind of like one of those folding handheld fans. The fake feathers are made from fiberglass and a thin layer of nylon, while the wing is made from composite materials designed to maximize strength and keep weight to a minimum.
With the wings fully extended, the drone can fly "very aggressively," the researchers say. When faced with strong winds, it can retract the wings to become more streamlined. And by changing the wingspan and the surface area, the drone can make turns without the need for a ailerons (the flaps you see on an airplane wing when you peer out the window).
The researchers say the drone could find applications in urban environments at low altitudes, where winds are known to change quickly. You can see it in the air and hear from the researchers in the video below.
The research was published in the journal Interface Focus.