Aiming to create drones that are more maneuverable as they fly through the air, researchers at Stanford University turn to birds for inspiration.
A group of researchers from Stanford University's Lentink Lab developed a flying robot that has a wing design that's similar to that of a pigeon.
Getting ready for a world of drones
Dubbed PigeonBot, the drone is able to extend its wings, bend them and move similar to birds. By making drones less rigid and more bird-like, they will be able to maneuver in smaller spaces and to handle more severe winds.
In a future where drones are delivering packages to the masses, being able to navigate through tight spaces and around buildings and trees will be necessary.
"Birds can dynamically alter the shape of their wings during flight," the researchers wrote in one of two studies they published on the matter. "How this is accomplished is poorly understood."
Researchers examine dead pigeons
To determine how pigeons control their wings they studied the wings of dead pigeons. Through their experiments, they learned the angles of the wrist and finger joints impacted the alignment of the feathers used in flight. The angle of the flight feathers dictates the shape of the wing.
"Whenever the skeleton moves, the feathers are redistributed passively through compliance of the elastic connective tissue at the feather base. To prevent the feathers from spreading too far apart, hook-shaped microstructures on adjacent feathers form a directional fastener that locks adjacent feathers," the researchers wrote.
Armed with that knowledge they used real pigeon feathers to build the flying robot. The PigeonBot has 42 degrees of freedom that control the position of 40 elastically connected feathers via four servo-actuated wrist and finger joints.
"Our flight tests demonstrate that the soft feathered wings morph rapidly and robustly under aerodynamic loading. They not only enable wing morphing but also make robot interactions safer, the wing more robust to crashing, and the wing reparable via 'preening," the researchers wrote in another study. "In flight tests, we found that both asymmetric wrist and finger motion can initiate turn maneuvers—evidence that birds may use their fingers to steer in flight."