Drones from the air can do some amazing feats. They can hover almost still for extended periods of time and perform high-speed dovetails. Drones are not as good at landing as birds. Birds have evolved over millions of years to be able to transform almost any object into a perching spot. This includes a telephone wire, a sign, and a branch.Blue Birds in Michigan Drones are limited to landing on flat surfaces.
Researchers spent many years studying
how birds land gracefully on a variety of objects and natural surfaces in order to develop more flexible flying drones. Even though birds can land on different surfaces, the landing strategy of these birds is the same regardless.
Researchers recently attempted to reproduce the avian landing strategy using a quadcopter equipped with a 3D-printed structure mimicking the grasping functions for bird feet and legs. These results were published in Science Robotics.
SNAG: A bird-like drone
The drone, which looked like a bird, was called SNAG (stylized nature-inspired aerial grasper). Why is it called “stereotyped?” The drone, just like birds, is programmed to perform the same landing sequence regardless of the surface it will be perched on. Researchers outlined SNAG’s bird-inspired landing sequence.
SNAG’s feet and legs were inspired by the peregrine Falcon, a bird that was once common in North America. This bird was chosen by the researchers for its “eye-catching grasp ability.” SNAG’s claws can be used to grab, carry, and catch prey-like objects, such as small bean bags, tennis balls, and other small items.
Researchers wrote that SNAG’s claw geometry
was sharp enough to engage with surface imperfections, but not too sharp. The claws can deform compliant surfaces, without getting stuck. “SNAG uses elastic bands inspired by birds to release its grip. The toe joints are covered with elastic bands that passively extend the claws and toes. This happens when the foot motor relaxes.
Every Thursday, a new email arrives in your inboxResearchers also tried different bird toe arrangements to determine which one was most effective. The results showed that perching doesn’t create an evolutionary selection pressure that can explain arboreal toe diversity.
The study did not only reveal the complexity
of avian evolution and perching strategies, but it was also a key aspect of the research. The practical aspect of drones flying like birds is power conservation.
The drones can land on many objects so they don’t need to stay put while carrying out tasks like environmental monitoring, search and rescue or site inspection. Why Do Birds Suddenly Appear Researchers concluded that improvements could be made for future bird-like drones by building systems that are more capable of selecting sufficient perching areas.