This bird-inspired drone is more energy efficient and proficient at complex flight maneuvers

Alfonso Maruccia

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Artificial Flight: Modern drones have become pretty advanced, but they are very energy-inefficient. European researchers decided to take inspiration from birds to develop a new type of drone that could consume less power and mimic its real-life counterpart's complex movements.

Researchers at the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland developed a Robotic Avian-inspired Vehicle for Multiple Environments (RAVEN) by adding hind limbs to a fixed-wing design. The final result is a drone that takes off quicker than a traditional model and performs complex maneuvers that mimic real birds.

The researchers note that birds inspired the invention of airplanes, but even modern planes are far from perfect flying machines. A bird can quickly go from walking to flying into the air and back again instantly. It does not need a runway or a launcher. Engineers have yet to reproduce this kind of biological versatility in artificial designs.

The RAVEN study aims to maximize "gait diversity" while minimizing mass. The bird-inspired multifunctional legs allow the drone to rapidly take off and fly, walk on the ground, and hop over small obstacles. The researchers compared RAVEN to a real raven to display the drone's capabilities.

Taking off with a jump can "substantially" contribute to the initial flight speed and is more energy efficient than the legless design of traditional drones. The EPFL researchers developed the perfect robotic legs using mathematical models, computer simulations, and experimental iterations.

The project's final result is an optimal balance between the artificial limbs' mechanical complexity and the RAVEN drone's overall weight (0.62kg). The hind limbs keep heavier components close to the drone's main body, while springs and motors mimic a bird's powerful tendons and muscles.

Evolution and biology solved the flight problem ages ago with birds, but the researchers had to work hard to try and emulate the same versatility in a drone design. The study suggests that RAVEN's multifunctional robot legs can expand deployment opportunities compared to traditional fixed-wing aircraft. Thanks to their ability to autonomously take off, the new drones could operate in complex terrains and other hazardous conditions to get their job done.

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The researchers note that birds inspired the invention of airplanes, but even modern planes are far from perfect flying machines. A bird can quickly go from walking to flying into the air and back again instantly. It does not need a runway or a launcher. Engineers have yet to reproduce this kind of biological versatility in artificial designs.
Somebody tell these "researchers", not to get so full of themselves. Also remind them that bird bones are hollow. Take a moment to inform that there is such a spec as "wing Loading".

For comparison:

The Osprey (Pandion halleatus )

Here are the wingspan and weight measurements for an osprey:
  • Wingspan: 4.5–6 ft (1.67 m)
  • Weight: 4 lbs (1.4 kg) It can lift maybe 40% of it's body weight

  • A rough estimate of its wing loading, (without dinner in claw) 1 Lb per Sq ft.

  • The WWII F-4U "Corsait"

  • The F4U Corsair has a wing area of 314 sq ft and a wing loading of appx. 26 Lbs, per Sq. ft.

  • The F-15C has a wing loading of 73. Lbs. sq ft. (Yikes). And hence the need for 2 mile long runways. That bird won't hop.

 
Somebody tell these "researchers", not to get so full of themselves. Also remind them that bird bones are hollow. Take a moment to inform that there is such a spec as "wing Loading".

For comparison:

The Osprey (Pandion halleatus )

Here are the wingspan and weight measurements for an osprey:
  • Wingspan: 4.5–6 ft (1.67 m)
  • Weight: 4 lbs (1.4 kg) It can lift maybe 40% of it's body weight

  • A rough estimate of its wing loading, (without dinner in claw) 1 Lb per Sq ft.

  • The WWII F-4U "Corsait"

  • The F4U Corsair has a wing area of 314 sq ft and a wing loading of appx. 26 Lbs, per Sq. ft.

  • The F-15C has a wing loading of 73. Lbs. sq ft. (Yikes). And hence the need for 2 mile long runways. That bird won't hop.

I don't think the plan was to replace fighter jets with these... they are mini-DRONES... those don't tend to weigh more than a few pounds either...
 
I don't think the plan was to replace fighter jets with these... they are mini-DRONES... those don't tend to weigh more than a few pounds either...
My "objection", was the point where these researchers really think they are onto something. A lighter wing loading contributes to a shorter takeoff run by way of dropping the stall speed_period. Specifically, when taking off off the ground, wing flapping ties into "ground effect", as much as Bernulian fluid dynamics

So, what's being called a "breakthrough" here, is really, no such thing. It's merely an adaptive implementation of the already known.

Birds are instinctive masters of variable geometry wing configuration. One extreme example is the peregrine falcon, that basically "retracts" its wings to attain chase speeds of perhaps 200 Mph in a dive. The rearmost feathers on most to all birds wings act as landing flaps. So, they go from a flat bottom airfoil in soaring, to a highly under cambered configuration (higher lift), for takeoff and landing. We "cheat" with flaps and leading edge extensions to modify the lift, drag, and stall profile.

Ignoring the rotating props, we come closest to mimicking bird flight with the V-22 "Osprey". Hm, I wonder why they call it that.

As to whether I'm indulging in "semantics", or am making a valid point, isn't mine to judge.
 
This what I call creativity and innovation from the human's mind, although that idea is already captured from our nature.

This reminds who the Boss is!

creativity pyramid:
......../.\
..../........\
.. /.Nature.\
./Human mind\
/ .......AI .........\
 
It's cool how they’re taking inspiration from birds to make drones more efficient. Adding legs for quick takeoffs and better movement sounds like a game-changer, especially for tricky environments.
 
It's cool how they’re taking inspiration from birds to make drones more efficient. Adding legs for quick takeoffs and better movement sounds like a game-changer, especially for tricky environments.
So basically, what you're saying is that after innumerable configurations, strategies, and choices of propulsion systems we've gone through to achieve sustainable flight, is that birds had it right all along? Wasn't that a given?

OK, I think this whole project was a write-off, that covered up the egregious amount they overpaid the dancer/hooker in the Bat Woman costume. Whose, (BTW), wing flapping moves in her dance routine, provided the "true impenus", for the project. Although, I'm sure it was one of those, "you had to be there", (and intoxicated) moments, to understand the true gravity** of her inspirational movements.

** See what I did there?
 
After feeding a local dove some sunflower seeds for months, I was lucky one day during last summer to see it stretch its wings and tail in different configurations. I noticed it has a grid like structure with it's feathers - it looked absolutely amazing like something out of a Leonardo Da Vinci drawing from the 22nd century. It's ability to take off and land so accurately was amazing even in the most difficult spots. Our flight technology is so f*cking primitive compared to birds. What we need to do is work on having more moving, more flexible parts, not just ailerons.
 
After feeding a local dove some sunflower seeds for months, I was lucky one day during last summer to see it stretch its wings and tail in different configurations. I noticed it has a grid like structure with it's feathers - it looked absolutely amazing like something out of a Leonardo Da Vinci drawing from the 22nd century. It's ability to take off and land so accurately was amazing even in the most difficult spots. Our flight technology is so f*cking primitive compared to birds. What we need to do is work on having more moving, more flexible parts, not just ailerons.


Drogonflies are the holy grail for aircraft, and what the Onrithopter's in Dune are based on them. Nothing in the bird or insect world has the amazing abilities of the dragonfly
 
After feeding a local dove some sunflower seeds for months, I was lucky one day during last summer to see it stretch its wings and tail in different configurations. I noticed it has a grid like structure with it's feathers - it looked absolutely amazing like something out of a Leonardo Da Vinci drawing from the 22nd century. It's ability to take off and land so accurately was amazing even in the most difficult spots. Our flight technology is so f*cking primitive compared to birds. What we need to do is work on having more moving, more flexible parts, not just ailerons.
You're at once completely correct, and entirely wrong, about human needs and aspirations in terms of flight capability, versus that of bird's practical needs.

At one time, in the "far distant past", (maybe 50 years ago?), calling someone a, "bird brain", was a fairly stout insult. Since then, we've discovered, or rather taken into account, just how exceptional those bird brains are at performing the functions of a flight computer, particularly in terms of low speed control surface configuration, and geolocation.

Humans habitually measure an animal species potential intelligence in terms of comparing brain to body size and weight. Recent insights have concluded that "bird brains", have considerably more densely packed neurons, which throws the entire theory into chaos.

FWIW, humans do employ, "compound flight controls". We even name therm. For example, "elvons", (elevator and aileron), and "ruddervators" (differential aileron) to control direction in the horizontal plane of travel. We have finally gotten around to successfully eliminating vertical stabilizers. Witness the B-2 "Spirit". But only through massive advances in flight control computers. Birds have had what is essentially, "fly by wire", down pat for millions of years.

That's where the similarity ends. Human's "needs" in terms of flight regime and envelope are vastly different. In terms of wing loading, birds are more comparable to a Piper "Cub", or gliders in that respect, than they are to an airliner or an F-16. Trust me, feathers would have no place on an SR-71. You would have baked chicken in a matter of seconds, nor would the craft in any way be able to attain mach 3.

Interestingly enough, some modern fighter jets can somewhat emulate an avian landing protocol, in what is known as a "high alpha pass". You yank the nose up to a 70+ degree angle of attack, and apply vast amounts of power. The thrust to weight ratio has to be at, or very close to 1:1 to pull this off.

Here's a fun fact; during WWII, bomber squadrons used carrier pigeons to carry intelligence information back to HQ. You tossed the birds out of the plane in paper bags. By the time the bag ripped apart, the birds had (hopefully), slowed to a flying speed where they wouldn't be harmed.

I'll stop now, as we're already well past "TL:DR" status.
 
@captaincranky I completely agree that a birds requirement for flight is very different to humans needs. Regardless our flight tech is still fairly primitive. Obviously our main requirements are for transporting people/cargo from a-b efficiently and effectively. Having aircraft use less space for landing and takeoff would be a start.
 
Drogonflies are the holy grail for aircraft, and what the Onrithopter's in Dune are based on them. Nothing in the bird or insect world has the amazing abilities of the dragonfly

Do you refer to a darting ability? Some insects I've watched can move at truly rapid speeds from a stationary position.
 
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