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Robotics Science

Solar-Powered Autonomous Underwater Vehicles 102

sunhou writes "A couple of months ago, researchers tested a solar-powered autonomous underwater vehicle (SAUV) at RPI's Darrin Fresh Water Institute. (More pictures and links to info available at the Autonomous Undersea Systems Institute.) Current autonomous underwater vehicles (AUVs) need to be taken out of the water often to have their batteries recharged. The goal is to have groups of cooperating SAUVs loaded with sensors and networking equipment deployed on long-term monitoring missions. Watch out Sky-Net, here comes Sea-Net! (See also the recent story about The Argo Project.)"
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Solar-Powered Autonomous Underwater Vehicles

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  • by Anonymous Coward on Sunday December 12, 2004 @12:37AM (#11064311)
    That it's dark underwater.
  • by andywebz ( 794668 ) on Sunday December 12, 2004 @12:39AM (#11064317)
    I guess all of their missions and exploration will be very close to the surface. Unless there is some underwater solar energy source I'm unaware of.
    • No one's saying that it has to remain hundreds of feet below the waves at all times. They could easily program the vehicle to surface, recharge itself via solar energy, and go back down again.
      • It is still pretty slow. Even at the surface, solar power isn't very efficient in terms of cost or energy conversion, and below water, it takes a LOT of power to move about. Cheaper than replacing batteries manually? I suppose it would be. It would be good for very long term projects, I suppose.
        • The point of the project is to have autonomous, long-term vehicles, so there wouldn't be anybody around to replace the batteries.
        • If you are only slightly heavier than the surrounding water, and shaped like a wing, then gliding slowly down to depth is not energy intensive.

          When you reach the depth you want, pump the ballast out (or use electrolysis to make gas?) and slowly rise to the surface, again gliding slowly upwards.

          With the yo-yo glider technique, you can cover huge areas.
          • "When you reach the depth you want, pump the ballast out (or use electrolysis to make gas?)" This was covered on /. before: IIRC, the subs pumped oil into a bladder that increased their volume and made them positively bouyant (and vice versea).
          • ... (or use electrolysis to make gas?) ...

            If you use electrolysis on water, then you get a highly explosive gas mixture of Oxygen and Hydrogen.

            To reduce buoyancy you need to either eject the gas. If you use a valve, it could clog and also be a possible ignition source. If you burn it, you it would have to be at a controlled rate, or you sink quickly.

    • by Anonymous Coward
      There is an underwater energy source, but it's not solar. More like thermo. Perhaps they should become hybrids and convert heat into energy.
      • You are correct of course, the temperature difference between the surface and at depth is what OTEC technology is built around. However, I fail to see a good way for a miniature sub to make use of it. OTEC requiers a really, really long pipe extending from the surface to several hundred feet deep and even then doesn't produce much net power).

        But then, I don't have a degree in engineering or thermal dynamics, so maybe I'm missing some finer points. :)
      • This part is a little off topic... As previously thought, plants/animals/etc were thought to be nonexistant in the deeper regions of the earth. But hydrothermal vents have been prevalently discovered with an abundance of life.

        In biology, we see analogy, or the convergence of organism's appendages and structures due to similar environmental pressures. A quick example is the likeness of a sharks fin and a penguins 'fin,' (they are most certainly not homologous structures). With that said, I feel we must em
    • We keep a spare sun under the Atlantic ocean.

      You know, just in case.
    • One of the amazing things about being underwater is that it's not difficult for a submersible not to be underwater anymore. That, combined with the amazing things done with solar cells, batteries, and Ohm's Law for the last twenty years makes me fairly confident that the team's premise is sound.

      Seriously, why is that comment insightful? Will I get modded up the next time an article on solar farms goes up if I question the decision to build the farm in a location where sometimes it's not daytime?
  • All jokes aside (Score:5, Interesting)

    by Icarus1919 ( 802533 ) on Sunday December 12, 2004 @12:40AM (#11064323)
    All jokes aside about it being dark underwater, this is going to be very helpful for research in large bodies of water. They can put a UAV with sensors and movement devices in say the Pacific and monitor the surface areas for long periods of time without ever needing to go back and "fill 'er up". We'll be able to monitor pollution levels, surface temperatures, ocean currents, all sorts of things much more efficiently.
  • Anyone else see that as "Solar-Powered Autonomous Underwear Vehicles"? 'cause, at least for me, that's talking about a spot where the sun don't normally shine...
  • Drug Smugglers (Score:5, Interesting)

    by Anonymous Coward on Sunday December 12, 2004 @12:49AM (#11064349)
    So just how long will it be till Columbian drug smugglers use autonmous vehicles to bring over loads of cocaine? Sounds like an easy way for them to get loads through without worrying about people getting busted if they are caught.
    • Many of the drug dealers probably don't worry about people getting busted, since people are expendable. They worry about losing the drugs, which can still happen with an autonomous vehicle.
    • Or, someone swimming a nuclear bomb undected into a port city.
      • This brings up a good point. A small submersible would be very manuverable, and thus able to follow terrain easily. It would be hard to detect with sonar, and I doubt some of the harbours have radar nice enough to detect this object. Im sure there are ways to detect metal, but it has been obvious in the past week that they are not used, or are ignored. Look at the Oil tanker that hit a peice of scrap pipe. You could equip said submerssible with a nice explosive payload, and detonate it below the SS super d
        • Radar? Underwater? Do you mean active sonar? Yes, there are ways of detecting metal. They are used on anti-sub planes and helicopters (such as the Orion) to detect an otherwise silent submarine (but those will only detect that 300+ foor titanium monster, not the plastic 5- foor minisub) I forget what it is called (been a while since i loaded up my sub sim lately - how many other slashdotters can say they can use the sonar systems on the Akula, Los Angeles, and Seawolf classes, and work a firing solution ou
          • er, how did i type 'foor' twice instead of 'foot'? And why do all my carriage returns get ignored (there is supposed to be 3 breaks in the above comment)?
            • Carriage returns are stripped out. Use the html 'br' or 'p' tags ( replace '' with greater-than and less-than signs. I can't type it that way or else I'd get weird breaks in my post!)
          • One method of sub detection is their magnetic signature. Which is why, periodically, each U.S. sub goes into this big demagnetizaion machine.

            Another way is via thermal signature. Subs with those nice, hot, nuclear reactors tend to leave a trail of slightly warmer water.
    • People are cheaper than autonomous vehicles.
    • The problem with this is that those vehicles would cost a lot of money to create, whereas you can exploit some poor soul by recruiting them to be your drug mule. Cheap, effective, and already mastered. Nice idea, but the need just isn't there.
    • I don't see why they wouldn't use very-low-sitting GPS-guided unmanned boats.
  • Autonomous? (Score:4, Funny)

    by TooMuchEspressoGuy ( 763203 ) on Sunday December 12, 2004 @12:51AM (#11064358)
    "Current autonomous underwater vehicles (AUVs) need to be taken out of the water often to have their batteries recharged."

    Well, then they're not exactly autonomous, are they?

    • Re:Autonomous? (Score:2, Interesting)

      by Council ( 514577 )
      All joking aside, the "autonomous" means it isn't getting controlled constantly by people watching the video feedback, which is usually the case.

      I've built a few subersibles to do lake-bottom surveys in New England that were basically glorified radio-controlled cars, and from what I understand that's basically how the Titanic-exploring bots worked. There's been some absolutely fascinating talk about building an army of small subs like the ones in this story that can survey automatically, giving us -- fina
  • Delivery vehicles (Score:2, Interesting)

    by idolcrash ( 836925 )
    Wouldn't it be possible to collect the solar energy at the surgace, and send the energy through a cable down to the AUV? This assumes that they are already controlled by signals sent through cables, however, and I'm not sure if remote controls are used or what, but it seems a bit more effective (as far as I can tell) then collecting light under the sea (as is implied).

    Of course, then there is the problem of a shark or other large animal running into the cable (hopefully, if it is remote controlled, it will
    • They're "Autonomous Underwater Vehicles." Many of the existing AUV's are preprogrammed and surface later to be recovered by researchers after they have collected their data or need to be recharged. This has the advantage of not having to have a larger vessel up on the surface controlling the vehicle and tying up more resources.
  • Nuclear Energy! (Score:4, Interesting)

    by eln ( 21727 ) on Sunday December 12, 2004 @01:10AM (#11064419)
    I think for long-term underwater exploration, nuclear is the most practical way to go. A nuclear power source can last indefinitely underwater (depending on how much fuel you have) and is not dependent on the weather if and when it does surface.

    • Re:Nuclear Energy! (Score:2, Insightful)

      by koick ( 770435 )
      As a scientist who has used an AUV in the Antarctic, I can assure you we would not want to mess with the bureaucracy/logistics of nuclear power. Some big battery packs and no demands for the vehicle to move fast are all one needs really to collect some very interesting sub-surface data.
    • And you'll buy it for them?
    • Correct me if I'm wrong, but (assuming nothing breaks down) can't all power sources last indefinitely, depending on how much fuel you have? I know my car will run indefinitely, the only limiting factor being how much fuel I have (again, assuming no breakdowns).
  • The really cool auv (Score:5, Interesting)

    by Camel Pilot ( 78781 ) on Sunday December 12, 2004 @01:21AM (#11064466) Homepage Journal
    Imagine an auv that collects its energy from plankton? It is great idea and I would like to patent it but I think there may be some prior art on this idea. :(
    • wasn't there supposed to be some technology by now that would harvest energy from the differential in salinity/temperature between different depths of sea water? Or is that on a larger scale than would be practical with a submersible?
    • It might not be just a good idea, but necessary for long term missions. The thing's going to be covered with slime and barnacles after just a few months. I wonder if they've thought of that.
    • Its patent is currently registered with C Corp, but the patent has been contested in the past by such notaries as Neptune LLC, Jonah Ltd, Pinocchio Inc, and Raffi (he filed in referrence to a blue version which has been reduced to 40-80,000 remaining models world-wide, and the production of which has been mostly halted).
  • Uh-oh (Score:3, Funny)

    by Dekks ( 808541 ) on Sunday December 12, 2004 @01:24AM (#11064479)
    Just don't let captain Murphy get his hands on it...
  • the vehicles probably are set to surface when the battery is low. including calculations on timing such as when to rise up (morning?),

    so YES, they ARE (or might be) autonomous...
  • buoyancy power! (Score:5, Interesting)

    by linoleo ( 718385 ) on Sunday December 12, 2004 @01:54AM (#11064583) Journal
    Why bother with solar panels and propellers? A buoyancy glider [] powered from temperature gradients is far more efficient. And you can use it where the sun don't shine, even off-planet [].
  • I don't see any problem wth it running out of electricity. If it is down too deep to collect any light and is low on energy it could just shift boyancy, go into a low power standby mode, and float to surface.

    When it charges back up, kick into full gear and go kick some more deepwater-glow-in-the-dark-space-robot-extreme godzilla ass or whatever...

    We must harness the power of THE SUN to defeat deepwater-glow-in-the-dark-space-robot-extreme godzilla!!!!!! Uh, shit, I'm a dumbass...

    Anyhow, that seems to mak
    • Anyhow, that seems to make sense to me. . .

      That's because it's both obvious and makes sense.

      I'm a total dumbass, though, so feel free to point and laugh.

      That, too, is both obvious and makes sense. Consider it done.


  • Underwear (Score:1, Redundant)

    by iswm ( 727826 )
    Am I the only one who thought the subject said "Solar-Powered Autonomous Underwear Vehicles"?
  • by wooby ( 786765 ) on Sunday December 12, 2004 @03:38AM (#11064903) Journal

    I can see nerds getting involved in the outdoors once again, bringing a whole new meaning to "phishing" - rigging up Zodiacs with networked fishfinder arrays and catching for themselves the latest in autonomous underwater robot technology.

    Hell, I'd steal one.

    I could slap Linux on it, make its hostname a Douglas Adams character, and brag on a mailing list somewhere.

    • I can see nerds getting involved in the outdoors once again, bringing a whole new meaning to "phishing" - rigging up Zodiacs with networked fishfinder arrays and catching for themselves the latest in autonomous underwater robot technology.

      Hell, I'd steal one.

      Myself, I'm going to wait until the researchers notice the fleet's numbers are increasing without any new deployments. When the original units mysteriously stop communicating with their satellite uplinks, it will be open season on the buggers.

    • It already runs Linux...
  • Shh.. (Score:2, Funny)

    by kristopher ( 723047 )
    It actually runs on the pent up sexual angst of slashdot users.
  • i wonder if it's possible to engineer something that would have them continuously recharge from the movement of the undersea water currents..
  • You know, a good task for a group of Solar-Powered Autonomous Underwater Vehicles would be for them to set out in a search pattern and map/photograph the sea floor in fishing areas (and others?) so that all the crap on the sea floor could be logged, and appropriate ships and/or underwater vehicles could be sent out to clean up (besides any science tasks that could also be completed at same time). I used to do commercial fishing, and we were ALWAYS picking up crap from past fishermen. Lines, nets, anchors

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