Blog

This drone can land on a branch, just like a bird

Image: William Roderick CC-BY-NC-ND

Have you ever watched a bird landing in a tree? Somehow, they manage to stop flying, grab on to a branch and balance all at once. Now, thanks to a team of researchers from Stanford University in the United States, there’s a robot that can do the same!

To start off, the team recorded parrots landing on a range of perches. “What surprised us was that they did the same aerial manoeuvres, no matter what surfaces they were landing on,” says researcher William Roderick. “They let the feet handle the variability and complexity of the surface texture itself.”

It took years of work, and 20 different designs, to nail this perfect landing. The robot can land on all kinds of logs and branches, and then take off again! It can also catch thrown objects out of the air, a bit like a hawk catching a smaller bird.

The robot doesn’t just behave like a bird, it also looks like a bird! It has a 3D printed structure like a bird’s bones, motors that act as muscles, and it has tendons too. It’s attached to a quadcopter drone to help it fly.

At landing time, a sensor called an accelerometer tells the robot when to grasp. Each foot is spring-loaded and closes within 50 milliseconds of hitting a branch. Once it has a good grip, the robot begins to balance. Motors bend the robot at the hip joints until it is perfectly balanced on the branch.

Why make such a robot? Drones are useful for exploring the environment, but they can only fly for a short time before they run out of batteries. A drone that can perch is able to keep an eye on the local environment for longer before it needs to go home. Plus, a flying drone is loud, but while perched it’s silent and sneaky. That way it’s much easier to spot endangered animals minding their own business!

If you’re after more science news for kids, subscribe to Double Helix magazine!