A win for drone design: watch this robot fly like a raven

The design, inspired by birds, allows drones to walk, hop, and jump into flight, making more places accessible to autonomous drones without a launcher.

Birds can easily switch between flying and walking. Drawing inspiration from ravens and crows, scientists at EPFL's School of Engineering have created a drone that mimics their movements.

The tiny drone model, weighing only 0.62 kg and named RAVEN (Robotic Avian-inspired Vehicle for multiple Environments), has multifunctional legs that allow it to jump rapidly into flight, walk on the ground, and hop over obstacles and gaps – just like birds do. The robotic legs enable autonomous takeoff in places that traditional drones can't reach, for example dense forests or canopies.

Useful for surveillance and rescue operations

Birds have long captivated scientists' imaginations, and their flight is what inspired the invention of the first airplanes. “Even today’s planes are still quite far from what birds are capable of,” says the Laboratory of Intelligent Systems (LIS) PhD student Won Dong Shin.

“Birds can transition from walking to running to the air and back again, without the aid of a runway or launcher. Engineering platforms for these kinds of movements are still missing in robotics,” he said.

Just like in the body of a real crow, the mechanics of the robot’s legs simulate bird muscles. The lightweight feet, made of two flexible parts, use an elastic joint that helps the drone walk, hop, traverse gaps in terrain, and even jump onto an elevated surface 26 centimeters high.

While this seems intuitive and obvious, it has been a challenging task for engineers working with robots. For example, previous robots designed to walk were too heavy to jump, while robots that could jump did not have feet suitable for walking.

“Translating avian legs and feet into a lightweight robotic system presented us with design, integration, and control problems that birds have solved elegantly over the course of evolution,” said Dario Floreano, a research lead.

Engineers believe that their design can be used in surveillance and disaster relief to assist areas that are hardly reachable with conventional drone technology.

The research paper has been published in the world's most-read scientific journal Nature.

Nature is inspiring robot developers

Nature is playing an increasingly vital role in inspiring robot designs. Researchers at ETH Zurich and the Max Planck Institute for Intelligent Systems claim to have created the first robotic leg, with artificial “electro-hydraulic” muscles that can automatically adapt to different terrain.

​​Caterpillars and origami have inspired scientists at Princeton University and North Carolina State University to create a robot that can move and steer, crawl forward and reverse, or pick up cargo and assemble into a longer unit. This might be a launchpad to create machines that can grow and heal on demand.

Drawing inspiration from a jellyfish collecting stunned prey, a Harvard team of engineers developed a robotic gripper equipped with thin, soft tentacles to handle irregularly shaped or fragile objects.

And researchers in the Netherlands have developed a robot called PigeonBot II, which is equipped with real pigeon feathers. The robot can successfully replicate bird movements, improving robot aerodynamics.