That video makes me realize that we're still in the earliest days of drone warfare.
Imagine the ability to soar on thermals for hours, it would greatly change reconnaissance and loitering strike drones. A flock of strike eagle drones all turning towards your convoy's position would be a terrifying thing to see. I don't know how you'd be able to attack such a flock effectively if they scatter when sensing and incoming missile or shell. Perhaps an air battle of the future will look like 2 flocks of birds crashing into each other?
I wonder if a hummingbird drone would be more energy efficient than a quadcopter?
But I regularly watch Red-Tailed hawks, around these parts, and they not only change the way they flap their wings, they drastically alter the surface area of their wings; dependent upon the type of flying they are doing. Sort of like ailerons, on airplanes.
For example, when they are "on a mission," going from "here," to "there," they trim their wings, so they are narrow and smooth. They almost look like gulls, in flight.
However, when they are hunting, which involves slow, flapless, soaring, they spread out all their feathers, so their wings have a great deal of surface area.
The aerodynamics of flapping aren't actually very well understood, so one of the reasons is just a platform for applied experiments. The reason you would want such a platform is because bird fight is potentially more energy efficient than anything humans have developed (as seems to be the case with so many naturally evolved mechanisms).
I think the answer would be "what birds do is quiet and efficeent, we should do that!"
But really it's probably just like robotic hands - we just don't have small powerful/precise robotic muscles and we won't do a good job. So I think we're not going to completely emulate a bird soon.
evolution produces end results that are worthwhile fully understanding at the very least, i imagine hovering around on updrafts is pretty energy efficient off the top of my head too
My brother bought a flapping drone/remote controlled bird for my son's birthday many years ago. AirHogs Firewing it was called. I had no idea such things existed. I think they weren't a great success.
Not a precision instrument by any means - it had a bias to fly to one side, and the box included weighted stickers to address this issue. And also, it's a miracle that we didn't break it. But the technology to do this as a toy has clearly been around for a while.
There are plenty of flying objects more energy efficient than quadcopters. Quadcopters are actually very inefficient. They brute force flying using thrust and with enough thrust anything will fly.
The big advantage they have is maneuverability and mechanical simplicity. Quadcopters can move in any direction and can hover in place. Quadcopters do not need control surfaces or variable pitch props. All they need is 4 motors with 4 basic props and everything is done electronically in software.
Yes. Birds themselves are super efficient. If you ever see a red kite staying stationary in a breeze by only wiggling some feathers here and now you can see that for yourself.
You can also look at the distance flown by certain bird species. The current recorded longest continous bird flight is that of a bar-tailed godwit which has flown from Alaska to Tasmania. It was flying for 11 days nonstop, a journey of 8,425 miles (13,560 km).[1]
These birds weigh approximatelly 290g. Quadrocopters in the same weight range fly for half an hour to maybe an hour? And the godwit fits into this weight budget the energy storage, propulsion, navigation, landing gear, and facilities to reproduce, and facilities to extract energy from stuff found in nature. If any roboticist could mimic this flying feat with any flying machine in the same weight category they would be pretty pleased with themselves.
In short, there is plenty of reason to suspect it is possible to make more energy efficient flying machines than what we have currently.
Paper: https://doi.org/10.1109/TRO.2022.3189812