When we look at how everyone’s favorite flying dinosaurs get around, we can see that although they use their wings a lot too, their legs are at least as important. Even waddling or hopping about somewhat ungainly on legs is more energy efficient than short flights, and taking off from the ground is helped by jumping into the air with a powerful leap from one’s legs. Based on this reasoning, a team of researchers set out to give flying drones their own bird-inspired legs, with their findings published in Nature (preprint on ArXiv).
The prototype RAVEN (Robotic Avian-inspired Vehicle for multiple ENvironments) drone is capable of hopping, walking, jumping onto an obstacle and jumping for take-off. This allows the drone to get into the optimal position for take-off and store energy in its legs to give it a boost when it takes to the skies. As it turned out, having passive & flexible toes here was essential for stability when waddling around, while jumping tests showed that the RAVEN’s legs provided well over 90% of the required take-off speed.
During take-off experiments the drone was able to jump to an altitude of about 0.4 meters, which allows it to clear ground-based obstacles and makes any kind of ‘runway’ unnecessary. Much like with our avian dinosaur friends the laws of physics dictate that there are strong scaling limits, which is why a raven can use this technique, but a swan or similar still requires a bit of runway instead of jumping elegantly into the air for near-vertical take-off. For smaller flying drones this approach would however absolutely seem to have legs.
So the takeaway is…
…we need to bioengineer stronger legs onto larger birds?
My JATO project isn’t working well.
The birds panic after ignition, and I have been unsuccessful at training them to reload their spent rockets.
My experiments don’t fare much better. I’m failing to find the sweet spot for safe takeoff. My JATOs either set the birds on fire or rip off their legs. :( Maybe I should try launching ostritches.
But the post experiment snacks are amazing!
Looks uncannilly bird-like, as if he’d motion-captured a bird’s movements.
Wait until they’ll start pooping.
Ejects a tiny lipo before takeoff, seems reasonable.
Only if it’s complety spent.
Cute, interesting, but no actual utility
you may say that now, but you’ll change your tune once a whole mob of these drones drops down from the skies, hops over, and starts viciously kicking you in the shins.
seriously, though, I wouldn’t be so quick to dismiss the idea. It’s certainly a niche application, but if you need the long-distance efficiency of a small fixed-wing drone, but also need to take off, land, and maneuver on terrain too rough for wheels, this seems like a promising start.
Though based on the limited demos I’m guessing they haven’t mastered the “landing” part or any sort of truly autonomous walking.
(also.. if you combined this with a flapping-wing ornithopter design, it seems like the sort of thing that would seriously appeal to spy agencies. Though the “utility” might just be in attracting government funding…)
The legs and associated motors, etc are excess payload robbing baggage after they’re aloft. Hand tossed launches and soft “crash” landings or net catches for small devices are much more efficient. For large drones it ain’t gonna work at all. But as I said, cute and an interesting engineering exercise and maybe cool toy.
This was my thought. If you need something small that goes and lands in a tree or on a windowledge and eavesdrops/films, this is probably what it would look like.