Until now, in the field of robotics, there was a dichotomy that drones designed for walking were too heavy to jump (even less to fly) and drones, specialized in flight, were very limited in their construction to be capable of to even take a few steps. The arrival of RAVEN, a drone that runs to take off, has changed that.
A team led by Dario Floreano, from the Laboratory of Intelligent Systems (LIS) from the Federal Polytechnic School of Lausanne (EPFL)is responsible for RAVEN (acronym for Bird-Inspired Robotic Vehicle for Multiple Environments). Designed after perching birds such as crows and rooks that frequently switch between air and landthe multifunctional robotic legs allow it to take off autonomously in environments previously inaccessible to winged drones.
“Birds were the inspiration for airplanes in the first place, and the Wright brothers made this dream come true, but even today’s airplanes are still a long way from what birds are capable of – explains Won Dong Shin, one of those responsible for RAVEN, in a statement -. Birds can go from walking to running, to midair, and back again, without the aid of a track or launcher. In robotics there was still a lack of engineering platforms for this type of movements”.
RAVEN’s design is objective to maximize gait diversity and minimize mass. Inspired by the proportions of bird legs, Shin designed a set of custom, multifunctional avian legs for a fixed-wing drone. It used a combination of mathematical models, computer simulations and experimental iterations to achieve an optimal balance between the complexity of the legs and the total weight of the drone (0.62 kg).
The resulting leg keeps heavier components close to the “body”, while a combinationeithern of springs and motors imitates the powerful tendons and morbird scles. The lightweight bird-inspired feet composed of two articulated structures take advantage of a joint.eithern thetoPassive static that supports various postures for walking, jumping and jumping.
“Fit the legs and feet of birds to a lightweight robotic system presented us with design problemsintegration and control that birds have resolved elegantly throughout evolution – adds Floreano -. “This led us to not only devise the most multi-modal winged drone to date, but also shed light on the energy efficiency of jumping to take off in both birds and drones.” The process has been published in Nature.
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The results offer a lightweight design for winged drones that They can move over rugged terrain and take off from restricted locations without human intervention. These capabilities enable the use of such drones in inspection, disaster mitigation and delivery in confined areas.
“Bird wings are the equivalent of the front legs of terrestrial quadrupeds, but little is known about leg-wing coordination in birds, let alone drones. These results represent only a first step towards a better understanding of the design and control principles of multimodal flying animalsand its translation into agile and energy-efficient drones,” Floreano concludes.