Bird-inspired drone uses legs to walk and jump into the air
68 comments
·January 7, 2025rauljara
type0
> It does beg the question, tho, why we haven’t seen any truly giant bats.
They're mammals, birds have different respiratory system
"Flow-Through Ventilation
Unlike mammals, birds breathe through continuous one-directional flow of air through the respiratory system. We take air in and breathe it out, sort of like the tide moves in and out of a bay. As a result, our breathing system is said to be tidal. Avians have a non-tidal respiratory system, with air flowing more like a running stream."
https://birdfact.com/anatomy-and-physiology/respiratory-syst...
vanderZwan
That's why mammals can't breathe at high altitudes that birds can, but I'm not sure if that affects the body plan much in terms of size. The largest birds are smaller than the largest mammals on land or at sea. Then again, lower oxygen levels compared to the past seems to be a limitation for insect sizes too (who have an even less efficient respiratory system).
I also don't think it's the warmbloodedness. There are giant mammals in general after all.
Perhaps it is because bats form large, dense colonies? There is only so many resources available in any given ecological niche, so then for any species that fills a niche one would expect those resources to be divided either among many small individuals or a few large ones. Bat evolution chose the "big colony" route, which I assume favors smaller individuals.
aziaziazi
> The largest birds are smaller than the largest mammals on land or at sea
With all my respect to you theory I think comparing size of animals should not ignore the medium they moved in: water, land or air. Weight is (loosely but still) related to size. It’s probably not a coincidence the largest mammals lives on water where they need less energy to supper their weight, and it’s not a coïncidents the largest mammals on earth are way bigger that bats.
The biggest bats are ~1.7m which is not so far from biggest albatros (3.7m).
Also consider the biggest bird (Ostriches) can’t fly. Now I’m trying to picture a swimming gigantic bird.
keyle
Nature optimizes. The bigger you get, the more you need to eat. The harder it gets to fly. Fruit bats eat fruits.
Look at the food source and you'll understand the evolution.
vanderZwan
> Fruit bats eat fruits.
The most caloric dense source of nutrition available in nature? I don't see why that is a limitation to body size for a flying animal - quite the opposite!
vanderZwan
Robots and living animals have different limitations and constraints though: compared to separate legs and wings for animals, using one motor with some kind of gearbox to switch output from wings/propellers to legs might have a lower added cost in terms of weight . The legs can stay very skinny. The limitation would be how bulky such a gearbox would be, and how much extra kinetic energy loss it would introduce. At the same time creating functioning wings that can also work as legs sounds like it might be a huge challenge in robotics (unless there's a way to massively simplify it).
Definitely an interesting idea that should be investigated though! :)
(Also, I've seen so many "AI learns to walk" videos that I'm wondering if it could be used to find a design that would work for this task)
DoingIsLearning
Worth pointing out that EPFL's PR release includes a picture of Won Dong Shin (the PhD that actually built it) as opposed to a picture of the lab's director as it sometimes happens in academia.
accurrent
THIS. Ive found good advisors push there students forward, mediocre ones tend to push themselves. Academic robotics is plagued with profs who do "everything".
chinathrow
The article contains an image of him.
DoingIsLearning
I am assuming IEEE is not travelling the world doing investigative journalism, they will have used whatever media was provided by the university.
null
bobim
Yes because otherwise they would have fact checked that there's no lake Geneva.
Modified3019
The initial GIF is a bit lackluster, as it looks like it’s just walking around dragging a tail. The full video posted later in the article is much more impressive.
https://www.youtube.com/watch?v=-8DJ1a3sLIc
The article itself is worth a read too imo, I found the bits about toes for easier balance and jumping to takeoff energy efficiency interesting.
ge96
It's still cute walking around like robots with character
codybontecou
Wow. It really looks like a bird in some of those clips. I know it's still early on but I'm impressed with where we currently are.
litenboll
First thought when reading the title was that it will look very fragile and clumsy when walking (even real birds do) and that was confirmed by the first video. What's the purpose of actually mimicing bird legs and feet? Why not use something more simple like wheels on a board that has a spring for example? I expected the article to justify why, but to me it seems like the big thing was the jumping itself, which does not require complex bird anatomy necessarily. There's probably a good reason that I missed, but this feels like a too direct translation of the bird feature, unless the purpose is specifically to make it look and move like a real bird.
lynguist
> the big thing was the jumping itself, which does not require complex bird anatomy necessarily
No, this is exactly the opposite. The jumping requires exactly this specific anatomy for so many reasons. It stores energy in the joints, it has a specific balance, the jumping works at multiple angles, etc, etc. You can’t do better than that for this specific purpose.
ivell
Wheels need a reasonably flat surface to be efficient. Walking is more efficient than flying for short distances..
numba888
> reasonably flat
comparing to wheel size. one can use bigger light wheels. that would make landing on short runways possible. besides, wheeling is much easier than walking. two wheels balancing and rolling around is not a problem today. but.. without legs it's just an common airplane, nothing to talk about. the best of both? put small motorized wheels instead of flat platforms for feet.
bookofjoe
2 more things that can break/go wrong/stop working resulting in mission failure.
scripturial
Avoiding cheap surveillance technologies seems like a big deal. Although I assume once the government works out what you can do with it, it’ll become illegal pretty quickly. I assume this research will attract DOD grant funding pretty quickly. Students have to eat somehow.
pixxel
Spy drones than mimic birds.
gattr
Makes you wonder what will come first:
- energy-efficient, long-lasting, mechanically optimized robotic "birds"
- good-enough understanding of the avian brain connectome & operation, such that all you need is a bunch of fine wires stuck in it, and a small CPU sending commands (local and remote operation, etc.)
9dev
It’s going to get interesting when the conspiracy theory becomes reality. Imagine the future historians browsing the Reddit archives going like, ”they knew!!“
oefrha
What conspiracy? CIA had spy pigeons among other animals half a century ago, which is public info by now.[1]
They are very proud of it too.
> While many of the animal programs studied by CIA were never deployed operationally—or failed for a variety of technical, logistical, or behavioral reasons—collectively they demonstrate the incredible innovation and creative thinking that has come to characterize everything that our Directorate of Science and Technology does.
[1] https://www.cia.gov/stories/story/natural-spies-animals-in-e...
JKCalhoun
Like the Chinese one?
https://interestingengineering.com/military/chinese-special-...
mapt
Military contractors have been producing teaser videos on the subject for maybe fifteen years now.
Super_Jambo
More likely that sensible mainstream journalists will laugh at people under Govt surveillance because they sound like the reddit conspiracy nuts from their youth...
veunes
It’s like the ultimate bio-inspired stealth tech.
veunes
Maybe there’s a niche application we’re not considering where bird-like movement is crucial?
astrobe_
Naval versions of fighters can use "jump strut" [1]. For instance the Rafale M [2] [3]. I dislike weapons, but those planes are amazing.
[1] https://www.researchgate.net/publication/257410805_Effect_Of...
[2] https://en.wikipedia.org/wiki/Dassault_Rafale#Overview
[3] https://www.alachassebordel.com/post/20-secrets-about-naval-...
mhb
> I dislike weapons
A throwaway comment, but huh?
rob74
> Despite its name, RAVEN is approximately the size of a crow
This phrase first puzzled me, but after some googling I found out that in English "raven" is generally used for bigger crows. Until now I had thought that raven was just a more elegant-sounding synonym for crow. TIL...
EDIT: to my surprise, it's the same in my native German: the bigger ones are called "Raben", the smaller ones "Krähen". TIL²...
xeonmc
Here’s the thing…
pajko
Could this be viable on Mars? Having legs might support a bigger range of terrains than wheels while the flying mode requiring more resources might be used sparingly to overcome bigger elevation changes or to cover a higher distance quicker.
Tough adding legs instead if wheels might introduce balancng issues, the drone could be lowered further to ground level for the time of harsh weather conditions to increase the traction.
cies
If your drone can land on a high spot and save energy by not flying, while using energy to use camera and radio communications, that would be really nice!
Also: the noise a drone makes, gives away it's presence.
rob74
Bonus points for being able to perch on a thin branch, wire etc.
bArray
I think I might be building one of these... This is insanely cool.
Mistletoe
Is there info on how efficient this is compared to a regular drone? I suspect the boring regular drone with four propellers on each corner destroys this.
veunes
I love bio-inspired robotics. It’ll be interesting to see how these evolve. And the drone itself (for me do not know why) looks really cute.
Would love to see a pterosaur / bat version of this drone. Birds use one set of muscles to jump in the air and another to flap their wings, limiting how big they can get. That’s because, if you make your wing muscles bigger, then you need bigger leg muscles to support them, then you need bigger wing muscles to support your legs, etc. pterosaurs and bats have tiny little legs and use their “arm” (wing) muscles to do the initial jump into the air. It’s just one set of muscles that are used for both functions, which is why pterosaurs were able to get so big. It does beg the question, tho, why we haven’t seen any truly giant bats.
This pbs aeons video has a great explanation: https://youtu.be/scAp-fncp64?si=hjeWKGBI7riyjE1M