15 ms·

Hybrid Aerial Underwater Drone – Bachelor Project [video]

66 points by nhma 9mo ago

https://www.energy.aau.dk/aau-drone-can-both-fly-and-dive-underwater-n145124 https://www.energy.aau.dk/aau-drone-can-both-fly-and-dive-un...

bestouff 9mo ago
The manhunt from a drone becomes more of a nightmare.
- deleted 9mo ago
  [deleted]
- trhway 9mo ago
  in some sense it isn't nightnmare, it is already a reality, just non-uniformly distributed. Sounds like you just haven't watched hours of footage from Ukraine. The drones there - in the 10-30km zone from the frontline - are onmnipresent like birds, just the birds of the killing-humans-on-sight kind (and with IR cameras it is 24x7, at night it is even more effective as you don't see it coming, only hear a slight buzz of the props, while the drone sees a warm human even better at night, like a kind of a flying rattlesnake :). Unprepared NK soldiers in Ukraine facing drones first time https://youtu.be/9BQKfSHqRDk?t=117 https://youtu.be/9BQKfSHqRDk?t=117
idiotsecant 9mo ago
Variable pitch! Waterproof! This thing is awesome. Surely there is different tuning when it's in water vs when it's not, right? How do you detect the transition? Motor currents? This is a really neat project!
- nhma 9mo ago
  In their report (https://gitlab.com/hybrid-drone/paper https://gitlab.com/hybrid-drone/paper) the authors mention that they implemented one controller for flying and another for diving. The transition seems to be initiated manually, but they propose a few ways of automatic detection and transition.
thatoneengineer 9mo ago
Obligatory: https://xkcd.com/2128/ https://xkcd.com/2128/ Or for the more cynical, replace "search and rescue" with "military covert ops".
Stevvo 9mo ago
SciFi becomes reality.
ch4s3 9mo ago
It's interesting how simple this looks, off the shelf parts, and 3D printed components. I'm almost surprised this doesn't already exist after looking at it.
- alexpotato 9mo ago
  If this what can be done with off the shelf parts and 3D printing, imagine what DARPA and the like have been doing for the past 20 years. Makes the UFO/UAP stories about "it transitioned from the water to the air and back to the water!!" seem way more plausible.
  - ch4s3 9mo ago
    > imagine what DARPA and the like have been doing for the past 20 years. People always say this, but anyone I know who's ever worked in one of these companies that contracts for the DoD or DARPA always complains about how behind the market government tech is. Obviously private industry isn't producing competitors to the F35, but for less complicated kit the government doesn't seem to be doing anything super sophisticated. In fact a bunch of people I knew who went to Iraq bought supplemental gear on the private market.
    - engineer_22 9mo ago
      > In fact a bunch of people I knew who went to Iraq bought supplemental gear on the private market. Like, photography gear?
      - ch4s3 9mo ago
        No, like armor and rifle optics.
        engineer_22 9mo ago
        Oh, the people you're talking about were deployed military personnel?
wumms 9mo ago
I suppose that pool is the ~max RF range under water? Is prop pitch mandatory for underwater use?
stoev 9mo ago
Any ideas how the signal is transmitted once the drone is underwater? Typical RC transmitters run 2.4 GHz. Some systems use 700 MHz. The former wouldn't penetrate at all, the latter might penetrate to a shallow depth, but I think that what's shown in the video is deep enough that the signal would get attenuated. There doesn't seem to be a tether and the drone doesn't seem to have any computer vision capabilities to fly itself whilst under water. I wonder how they solved this.
- echoangle 9mo ago
  IMU that determines rotation rates and acceleration without vision. A drone can fly and hold attitude with some accuracy without any outside help, it doesn’t need cameras or outside control. Only GPS to counteract drifting but that can be neglected in the very short term.
- nhma 9mo ago
  As far as I can tell from their report (https://gitlab.com/hybrid-drone/paper https://gitlab.com/hybrid-drone/paper), the authors did not consider underwater RF transmissions in their prototype design and simply use standard COTS components typically used for DIY UAVs.
hermitcrab 9mo ago
Very impressive. I assume that underwater propulsion uses a lot more energy per meter moved?
- trhway 9mo ago
  that is the thing here. While the project is cool, the drone's underwater drag is very high, while typical such drone of that size is foldable, and thus one can fold it (even if a bit, Star Wars X-wing style) to decrease drag and use say only one or two motors with much greater efficiency as result. Though high speed drone like this https://www.youtube.com/watch?v=7PTsHDFMams https://www.youtube.com/watch?v=7PTsHDFMams may be ok without collapsing.
- phire 9mo ago
  But you use spend much less energy fighting gravity. I’d expect it to have more range underwater than a typical quadcoter has through air. And much longer “flight” time. But I doubt it gains enough to compete with a fixed wing drone using the same battery.
  - hermitcrab 9mo ago
    >I’d expect it to have more range underwater than a typical quadcoter has through air. I would expect the opposite, with the higher drag being much more of an issue than gravity. But I would be interested to hear a definitive answer.
hermitcrab 9mo ago
Maybe you will be able to use these to defend Greenland?
petermcneeley 9mo ago
As an undergrad project this is rather impressive. But those motors do not look very water resistant. We all know that that shape and those blades are not very efficient in the water. And as others mention the RF signal probably cuts out at a few meters (probably worse in salt water).
- jbay808 9mo ago
  Definitely impressive as a proof of concept. A lot of the other problems can be solved with iteration. There are some IP67-rated drone motors meant to both fly and run underwater (available from Westmag for example). There might be less that can be done about the underwater drag, but if it doesn't need to go long distances underwater that's not as much of a problem. For the RF signal, it can either run autonomously underwater, or use a fibre-optic umbilical, or even convert from an umbilical to wireless when it takes to the air.
OhioMan2943 9mo ago
Getting closer to the well documented amphibious UAP drone I guess..
tantalor 9mo ago
> Hybrid drones offer great potential in many industries due to their ability to operate in air and water. "Hybrid" usually means a combination of features from two different things. For instance, a car with electric & internal combustion engines. But here they are using "hybrid" to mean a combination of capabilities. That's different than features. Also, "hybrid done" already has a meaning: https://en.wikipedia.org/wiki/Hybrid_drone https://en.wikipedia.org/wiki/Hybrid_drone
- stinkbeetle 9mo ago
  Looks to me like it is a hybrid of an underwater drone thing and an aerial drone thing, and that you have a good opportunity to expand that wiki page to include the other meanings of the term.
  - DonHopkins 9mo ago
    [flagged]

66 points by nhma 9mo ago

https://www.energy.aau.dk/aau-drone-can-both-fly-and-dive-underwater-n145124 https://www.energy.aau.dk/aau-drone-can-both-fly-and-dive-un...

bestouff 9mo ago

The manhunt from a drone becomes more of a nightmare.

deleted 9mo ago
[deleted]
trhway 9mo ago
in some sense it isn't nightnmare, it is already a reality, just non-uniformly distributed. Sounds like you just haven't watched hours of footage from Ukraine. The drones there - in the 10-30km zone from the frontline - are onmnipresent like birds, just the birds of the killing-humans-on-sight kind (and with IR cameras it is 24x7, at night it is even more effective as you don't see it coming, only hear a slight buzz of the props, while the drone sees a warm human even better at night, like a kind of a flying rattlesnake :). Unprepared NK soldiers in Ukraine facing drones first time https://youtu.be/9BQKfSHqRDk?t=117 https://youtu.be/9BQKfSHqRDk?t=117

idiotsecant 9mo ago

Variable pitch! Waterproof! This thing is awesome. Surely there is different tuning when it's in water vs when it's not, right? How do you detect the transition? Motor currents? This is a really neat project!

nhma 9mo ago
In their report (https://gitlab.com/hybrid-drone/paper https://gitlab.com/hybrid-drone/paper) the authors mention that they implemented one controller for flying and another for diving. The transition seems to be initiated manually, but they propose a few ways of automatic detection and transition.

thatoneengineer 9mo ago

Obligatory: https://xkcd.com/2128/ https://xkcd.com/2128/ Or for the more cynical, replace "search and rescue" with "military covert ops".

Stevvo 9mo ago

SciFi becomes reality.

ch4s3 9mo ago

It's interesting how simple this looks, off the shelf parts, and 3D printed components. I'm almost surprised this doesn't already exist after looking at it.

alexpotato 9mo ago
If this what can be done with off the shelf parts and 3D printing, imagine what DARPA and the like have been doing for the past 20 years. Makes the UFO/UAP stories about "it transitioned from the water to the air and back to the water!!" seem way more plausible.
- ch4s3 9mo ago
  > imagine what DARPA and the like have been doing for the past 20 years. People always say this, but anyone I know who's ever worked in one of these companies that contracts for the DoD or DARPA always complains about how behind the market government tech is. Obviously private industry isn't producing competitors to the F35, but for less complicated kit the government doesn't seem to be doing anything super sophisticated. In fact a bunch of people I knew who went to Iraq bought supplemental gear on the private market.
  - engineer_22 9mo ago
    > In fact a bunch of people I knew who went to Iraq bought supplemental gear on the private market. Like, photography gear?
    - ch4s3 9mo ago
      No, like armor and rifle optics.
      - engineer_22 9mo ago
        Oh, the people you're talking about were deployed military personnel?

wumms 9mo ago

I suppose that pool is the ~max RF range under water? Is prop pitch mandatory for underwater use?

stoev 9mo ago

Any ideas how the signal is transmitted once the drone is underwater? Typical RC transmitters run 2.4 GHz. Some systems use 700 MHz. The former wouldn't penetrate at all, the latter might penetrate to a shallow depth, but I think that what's shown in the video is deep enough that the signal would get attenuated. There doesn't seem to be a tether and the drone doesn't seem to have any computer vision capabilities to fly itself whilst under water. I wonder how they solved this.

echoangle 9mo ago
IMU that determines rotation rates and acceleration without vision. A drone can fly and hold attitude with some accuracy without any outside help, it doesn’t need cameras or outside control. Only GPS to counteract drifting but that can be neglected in the very short term.
nhma 9mo ago
As far as I can tell from their report (https://gitlab.com/hybrid-drone/paper https://gitlab.com/hybrid-drone/paper), the authors did not consider underwater RF transmissions in their prototype design and simply use standard COTS components typically used for DIY UAVs.

hermitcrab 9mo ago

Very impressive. I assume that underwater propulsion uses a lot more energy per meter moved?

trhway 9mo ago
that is the thing here. While the project is cool, the drone's underwater drag is very high, while typical such drone of that size is foldable, and thus one can fold it (even if a bit, Star Wars X-wing style) to decrease drag and use say only one or two motors with much greater efficiency as result. Though high speed drone like this https://www.youtube.com/watch?v=7PTsHDFMams https://www.youtube.com/watch?v=7PTsHDFMams may be ok without collapsing.
phire 9mo ago
But you use spend much less energy fighting gravity. I’d expect it to have more range underwater than a typical quadcoter has through air. And much longer “flight” time. But I doubt it gains enough to compete with a fixed wing drone using the same battery.
- hermitcrab 9mo ago
  >I’d expect it to have more range underwater than a typical quadcoter has through air. I would expect the opposite, with the higher drag being much more of an issue than gravity. But I would be interested to hear a definitive answer.

hermitcrab 9mo ago

Maybe you will be able to use these to defend Greenland?

petermcneeley 9mo ago

As an undergrad project this is rather impressive. But those motors do not look very water resistant. We all know that that shape and those blades are not very efficient in the water. And as others mention the RF signal probably cuts out at a few meters (probably worse in salt water).

jbay808 9mo ago
Definitely impressive as a proof of concept. A lot of the other problems can be solved with iteration. There are some IP67-rated drone motors meant to both fly and run underwater (available from Westmag for example). There might be less that can be done about the underwater drag, but if it doesn't need to go long distances underwater that's not as much of a problem. For the RF signal, it can either run autonomously underwater, or use a fibre-optic umbilical, or even convert from an umbilical to wireless when it takes to the air.

OhioMan2943 9mo ago

Getting closer to the well documented amphibious UAP drone I guess..

tantalor 9mo ago

> Hybrid drones offer great potential in many industries due to their ability to operate in air and water. "Hybrid" usually means a combination of features from two different things. For instance, a car with electric & internal combustion engines. But here they are using "hybrid" to mean a combination of capabilities. That's different than features. Also, "hybrid done" already has a meaning: https://en.wikipedia.org/wiki/Hybrid_drone https://en.wikipedia.org/wiki/Hybrid_drone

stinkbeetle 9mo ago
Looks to me like it is a hybrid of an underwater drone thing and an aerial drone thing, and that you have a good opportunity to expand that wiki page to include the other meanings of the term.
- DonHopkins 9mo ago
  [flagged]