MISE & Agrave; DAY
WASHINGTON | A team of engineers from the prestigious American University of Stanford have created robotic grippers that can be attached to drones, transforming the latter into robotic birds capable of grabbing objects or perching on various surfaces.
These new capabilities could allow flying robots to save their batteries instead of having to stand still – for example during operations to search for survivors – or help biologists to take samples more easily in the forest .
“We want to be able to land anywhere, which is why it's exciting from an engineering and robotics point of view,” co-author David Lentink told AFP. of an article about this innovation published Wednesday in the journal Science Robotics.
As often in robotics, this project was inspired by animal behavior – in this case the way birds arise and cling to branches – to overcome technical difficulties.
But imitating these birds, which millions of years of evolution allow to cling to branches of different sizes or shapes, sometimes covered with lichen or made slippery by the rain, is no easy task.
To this end, the Stanford team used high-speed cameras to study how small parrots land on perches varying in size and material: wood, foam, sandpaper and Teflon.
The poles were also fitted with sensors that recorded the force with which the birds landed and took off again.
Scientists found that while the landing motion was the same in each situation, parrots used their legs to adjust to the variations encountered.
More specifically, birds wrap their talons around their perch and also use pads that are both soft and pleated to ensure good adhesion.
To be able to support a small drone with four propellers, the scientists designed their clamps from the model of peregrine falcon legs.
The structure, made with a 3D printer, includes motors and fishing line as muscles and tendons.
The mechanism takes 20 milliseconds to hang on, and an accelerometer then tells the robot that the landing process is complete.
An algorithm finally allows the mechanical bird to keep its balance on the branch.
< p> The robot bird managed to catch objects that were thrown at it, such as balls tennis, and land in real conditions in the forests of the northwestern United States.