[HN Gopher] A rigid but foldable indoor airship aerial system fo...
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       A rigid but foldable indoor airship aerial system for cave
       exploration
        
       Author : PaulHoule
       Score  : 59 points
       Date   : 2024-09-20 05:41 UTC (17 hours ago)
        
 (HTM) web link (arxiv.org)
 (TXT) w3m dump (arxiv.org)
        
       | progbits wrote:
       | Getting closer to the cave scanning drones from Prometheus.
        
         | ceejayoz wrote:
         | We've basically got those now.
         | https://www.core77.com/posts/133629/A-Throwable-Panoramic-Th...
        
         | finnh wrote:
         | this seems to come up often on HN!
         | 
         | https://news.ycombinator.com/item?id=41547946
        
       | gertrunde wrote:
       | I'm not normally a big fan of facebook etc... but there are a
       | selection of photographs of this device here:
       | 
       | https://www.facebook.com/nxigestatio/
        
         | fractallyte wrote:
         | Whyyyy Facebook?? [facepalm]
         | 
         | If they really want visibility, use an open platform!
        
           | cuSetanta wrote:
           | Their website has a good few images:
           | https://cavernautes.nxigestatio.org/10-aout.html
        
             | redundantly wrote:
             | Those images are better than the ones they have on
             | Facebook. I don't know why they picked such hazy pictures
             | that make it hard to see the machine.
        
           | sgt wrote:
           | Aren't you on FB?
        
         | notjulianjaynes wrote:
         | Yes, I'm sure this article is interesting but only photos of
         | this strange device will satisfy me. Thanks.
         | 
         | Edit: concurring with the person complaining about Facebook
         | which I cannot access
        
       | ricc wrote:
       | I thought it was going to be made of cloth that stiffens when
       | current passes through it... :)
        
         | hedora wrote:
         | I thought you were going to mention concrete canvas, which
         | stiffens into a semipermanent (10 year) structure when wet:
         | 
         | https://www.concretecanvas.com/us/cc-shelters/
         | 
         | Bring your own cave?
        
       | aaron695 wrote:
       | The 10 hour Cavernautes video is here -
       | https://www.youtube.com/watch?v=a9LNriDuivA
       | 
       | Moving on, you can fly in a blimp by yourself in a cave here -
       | https://www.manawa.com/en-GB/activity/france/uzes/unusual-ac...
       | (Tom Scott did this in an aircraft hanger)
        
       | krisoft wrote:
       | But like... why? What does an indoor airship get us which we
       | couldn't do before "for cave exploration"? It sounds like they
       | needed to map out the cave in detail before they could even
       | design the airship. So there aren't even any pretence of
       | "exploration". The airship is not big enough to carry people, nor
       | does it have manipulators to take samples.
       | 
       | That leaves us with the "an artistic manifestation". Which is
       | cool. It is a neat art project I guess. But then that is not
       | "cave exploration". It is a temporary inflatable art installation
       | inside a cave.
       | 
       | Am I missing something here?
        
         | rozab wrote:
         | https://www.xkcd.com/2128/
        
           | tamimio wrote:
           | That's a good one, and it's true!
        
         | m4rtink wrote:
         | Caves are dark, wet, slippery and might not even contain
         | breathable atmosphere in some cases & could get flooded in
         | minutes, with deadly results.
         | 
         | Having a foldable flying drone you could use to scout for you
         | could help a lot when exploring caves.
         | 
         | As for the cave scanning - I think that is mainly so they can
         | set their design constraints & later the bot can take over,
         | possibly including SLAM[0]. There are already designs like that
         | that have been tested in unexplored flooded caves[1].
         | 
         | [0]
         | https://en.wikipedia.org/wiki/Simultaneous_localization_and_...
         | [1] https://en.wikipedia.org/wiki/DEPTHX
        
           | krisoft wrote:
           | > Having a foldable flying drone you could use to scout for
           | you could help a lot when exploring caves.
           | 
           | I agree with that. But is this the right form for it?
           | Airships are bulky. Caves are obstructed. A smaller flying
           | drone, like some form of a multicopter would be my choice if
           | I want to maximise the chances that it fits the cave.
        
             | lesuorac wrote:
             | > Thanks to their long-flight endurance, they are suited
             | for long-term missions.
             | 
             | How long can your drone stay in the air?
        
               | Retric wrote:
               | They cap out at several hours for gas powered drones or
               | ~1h of flying time for batteries.
               | 
               | But it's unlikely for you to actually need endurance
               | because you're not getting signal that far through a cave
               | without repeaters or a long cable. A bigger deal is being
               | able to go underwater or fit through tiny openings.
        
               | ceph_ wrote:
               | Running a gas powered drone in a low oxygen environment
               | sounds like a great way to get the next cavers killed by
               | asphyxiation
        
               | Retric wrote:
               | Most gas powered drones don't actually use much fuel and
               | thus their oxygen use is limited. At the extreme end a 20
               | pound drone might use the same oxygen per minute as ~5
               | people and you're not going to stay in the same place for
               | that long vs people going through rough terrain. If
               | anything adding gas sensors would more than make up for
               | such issues.
               | 
               | Personally I'd be more concerned with explosive gas
               | mixtures, but that's not an issue in most cave systems.
        
               | lesuorac wrote:
               | > But it's unlikely for you to actually need endurance
               | because you're not getting signal that far through a cave
               | without repeaters or a long cable.
               | 
               | I mean you could let it roam on it's own and report back
               | no? But even if you had to be in the same area as it, it
               | then lets you go for even longer. Like some people sleep
               | in these caves and bag in/out a bunch of supplies so
               | needing to carry less batteries would be nice I assume.
               | 
               | > A bigger deal is being able to go underwater or fit
               | through tiny openings.
               | 
               | That's in the abstract as well: "Our design strengthens
               | the robot while granting the ability to access narrow
               | spaces by folding the structure - up to a volume
               | expansion ratio of 19.8."
        
               | m4rtink wrote:
               | Talked to some local cave explorers once (Czech Republic
               | has huge karst cave systems) and they mentioned they
               | often hang from a rope on wet cave walls with power tools
               | and rubber boots when making new parts of caves
               | accessible, so they can press further to new parts.
               | 
               | A floating lightning drone could be useful for that. :)
               | 
               | You could combine this with inflatable light technology &
               | the gas bag itself could be a source of illumination.
        
             | PaulHoule wrote:
             | Particularly the multicopter is mass produced, cheap,
             | mature and easy to buy and use.
        
           | zeroping wrote:
           | Many caves are not particularly wet , slippery, or prone to
           | flooding. Only a few have issues with a lack of airflow. I
           | understand the interest in robotic exploration for some
           | specifically risky caves, but I don't like this
           | generalization that implies all caves are too dangerous for
           | humans to enter.
        
         | ballenf wrote:
         | > 5 Use case: cave exploration as an artistic manifestation
         | 
         | I guess that's their answer, where calling it art is kind of a
         | sophisticated way of saying "because it's cool". Also, the cave
         | in question is close to them and somewhat recently discovered.
         | 
         | Since even a moderate breeze would make this uncontrollable in
         | open atmosphere, it seems like a cave is one of the only places
         | this airship can be used. And even then many caves have strong
         | drafts that could totally disrupt use.
        
         | reginald78 wrote:
         | I watch a lot of videos of caving and cave diving disasters.
         | I've often thought how useful something like this would be for
         | rescue operations, especially since a number of the stories
         | feature the rescuers dying as well.
        
       | YeGoblynQueenne wrote:
       | That's a cool idea but I don't think it's er gonna fly. They
       | should have gone for a flexible craft with a long, articulated
       | body - like a snake. All those long, winding passages. The
       | upright balloon can pass through them, but it can't deal with
       | long _and_ low passages. A snake-like one could.
        
         | fasa99 wrote:
         | So the snak character build is +5 for narrow entries but is
         | nerfed when the exit is a hole in the ceiling of a larger
         | cavern, an area where the ballon is +8. Ultimately what we need
         | is a hybrid build between ballon and snak, an inflatable snak
         | ballon if you will, should be +3 on both. The second win is
         | that snak motility can be driven by controlled focal
         | inflation/deflation cycles.
        
         | PaulHoule wrote:
         | See https://www.vinerobots.org/ which work like a Hong Shou
         | (tentacle monster, pronounced _shokushu_ ) from an H anime.
        
         | swagasaurus-rex wrote:
         | Looking at the pictures below, it does look like they need
         | something more narrow for realistic cave use, but they probably
         | will need greater lift than what they get with their current
         | low surface area shape.
        
       | ksymph wrote:
       | I asked my friend who is in the cave search and rescue squad
       | their thoughts, to paraphrase:
       | 
       | It's cool, but they don't see what problem it solves.
        
         | limaoscarjuliet wrote:
         | Friend of mine is in business of storing natural gas in salt
         | caverns (https://www.eia.gov/naturalgas/storage/basics/). They
         | do scan these by dropping a sonar in a drilled shaft, but this
         | approach has limitations. Using a moving scanning airship might
         | be helpful.
        
       | idlephysicist wrote:
       | Fair play to them, it's a detailed paper. But I'm not sure that
       | this would have much practicality in other caves. The terrain
       | just changes too quickly (most of the time).
        
       | peppertree wrote:
       | The idea is cool but none of the design decisions made sense. Why
       | would you need carbon fiber struts. Airship that size doesn't
       | have to deal with pressure changes there was no reason to be semi
       | rigid. Where do you attach the sensor payload. Anywhere above the
       | very bottom is going to be unstable with the vertical design. But
       | that's also the worst place for vision & lidar sensors.
        
       | krunck wrote:
       | Good idea..for huge caves. I've been caving for 30+ years and I
       | can tell you that a skilled and well equipped human will be able
       | to explore more than one of these airships. Sometimes passages
       | are obstructed by ceiling collapses. ( after water drains from
       | the cave due to the lowering of the base level rock will fall off
       | the ceiling due to the loss in buoyancy). Sometimes one needs to
       | move a few rocks to get by. Sometimes you just need to squeeze
       | and contort to get through. Sometimes you need you dig a bit of
       | sediment because it fills a passage to the point of preventing
       | preventing access.
       | 
       | Having said all that, the one time when this would be helpful is
       | when you enter a space with an extremely high ceiling. One can
       | bolt up the wall see see what's there. But the better/easier way
       | is to use a drone to do recon first.
        
         | frontiersummit wrote:
         | My caving experience is less than yours, but I want to echo
         | what you say. The average person envisions spacious tourist
         | caves, not belly-crawling 800 yards through muddy gravel which
         | has been more my experience with wild caves in the American
         | Midwest. Gear gets shredded in caves worse than maybe any other
         | environment, and slows you down like nothing else.
        
       | mead5432 wrote:
       | Arxiv? More like ar-cave... amirite?
       | 
       | Sorry; It doesn't contribute but I couldn't resist.
        
         | ribs wrote:
         | Clean out your desk
        
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