A team of engineers from the prestigious American Stanford University have developed automatic clips that can be attached to drones to turn them into robotic birds capable of grabbing objects or resting on different surfaces.
These new capabilities would allow flying robots to conserve battery consumption rather than having to stand still, for example during searches for survivors, or help biologists more easily sample in forests.
“We want to be able to land anywhere, so that’s exciting from an engineering and robotics point of view,” said David Lintink, co-author of the Science Robotics article about the innovation on Wednesday.
As is often the case with robotics, the project was inspired by animal behavior – in this case the way flights land and cling to tree branches – in order to overcome technical difficulties. But imitating these birds, which millions of years of evolution have allowed them to cling to branches of different sizes or shapes that are sometimes covered with lichen or cause slippage due to rain, is no easy task.
To this end, the Stanford team used high-speed cameras to study how baby parrots land on perches of varying size and materials: wood, foam, sandpaper and Teflon. Sensors are also placed on the branches that record the force with which the birds land and take off again.
The scientists noted that while the landing motion was the same in each position, the parrots used their legs to adapt to the differences they encountered.
More specifically, birds wrap their claws around the site on which they perch, and use soft, folded pads to ensure good adhesion.
To give it the ability to withstand a small drone with four propellers, the scientists designed the clamps based on the model of the legs of a peregrine falcon.
The 3D-printed skeleton includes motors and fishing line for use as muscles and tendons.
It takes 20 milliseconds to attach the clamps, and then the accelerometer tells the robot that the landing is complete.
Finally, the algorithm allows the mechanical bird to maintain its balance on a tree branch.
The robot was able to grab objects that were thrown at it, such as tennis balls, and land in real conditions in the forests of the northwest United States.