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.
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.
There was a recent David Attenborough narrated documentary about a huge cave system in I want to say Vietnam. In the behind the scenes making of short they said drones would not work underground due to some built in programmed restrictions. They had to contact the manufacturer to get the firmware changed to allow it.
That applies to commercial drones. This one has selfmade flight control electronics. 'Selfmade' as in using common of the shelf electronic components, not something locked down like from DJI fi.
The setup is described in the paper if you scroll down. (Experimental) Html-View in the upper right working perfectly without having to download it.
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.
Yeah, but it has to fit down a well. In other words, ideally it would be a maximum of 6 inches in diameter (and significantly less if it's going to be widely useful for solution-mined salt caverns).
The "drilled shaft" is the only entrance, and while those are typically huge by well standards (solution mining needs to circulate water, so you have to have room for nested casings/pipes), they're still dramatically smaller than what's described here. You typically have a "hanging string", which is a suspended pipe within the pipe for injecting water with flow around the outside of it back up the well (either to extract gas or for solution mining). You want something that fits down the inside of that so you don't need to pull the hanging string for a sonar survey. It's a big pipe, but you're not going to fit a literal mini-blimp that's a couple feet long down it.
With that said, I do wonder if these have other mining applications. It's not good for solution mining, but it sounds like it could be useful for remote inspection of dangerous levels of conventional underground mines. Conventional mine shafts and levels have to be big enough for people and equipment to fit in, and this seems reasonably sized for that application.
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.
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.
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.
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.
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].
> 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.
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.
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.
> 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."
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.
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.
> 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.
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.
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.
Does the abstract sound like ChatGPT output to anyone else? Their A and B require a delicate balance of C and D, 'compelling', 'embody a distinct intersection', 'wide array of possibilities'... You don't even need to read past the first few sentences.
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).
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.
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.
There was a recent David Attenborough narrated documentary about a huge cave system in I want to say Vietnam. In the behind the scenes making of short they said drones would not work underground due to some built in programmed restrictions. They had to contact the manufacturer to get the firmware changed to allow it.
Not mentioned here but I believe this is the correct series: https://www.bbc.com/mediacentre/mediapacks/planet-earth-thre...
That applies to commercial drones. This one has selfmade flight control electronics. 'Selfmade' as in using common of the shelf electronic components, not something locked down like from DJI fi.
The setup is described in the paper if you scroll down. (Experimental) Html-View in the upper right working perfectly without having to download it.
Are you sure you're not overlooking the fact that the use case you describe is exactly what was intended by the engineers who designed this airship?
Its portable, and meant to be brought into a cave, for the case where caverns and halls are found, and need to be further explored safely.
> the one time when this would be helpful is when you enter a space with an extremely high ceiling
Yes, that is the intended use case.
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/
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
Whyyyy Facebook?? [facepalm]
If they really want visibility, use an open platform!
Their website has a good few images: https://cavernautes.nxigestatio.org/10-aout.html
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.
Aren't you on FB?
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.
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.
Yeah, but it has to fit down a well. In other words, ideally it would be a maximum of 6 inches in diameter (and significantly less if it's going to be widely useful for solution-mined salt caverns).
The "drilled shaft" is the only entrance, and while those are typically huge by well standards (solution mining needs to circulate water, so you have to have room for nested casings/pipes), they're still dramatically smaller than what's described here. You typically have a "hanging string", which is a suspended pipe within the pipe for injecting water with flow around the outside of it back up the well (either to extract gas or for solution mining). You want something that fits down the inside of that so you don't need to pull the hanging string for a sonar survey. It's a big pipe, but you're not going to fit a literal mini-blimp that's a couple feet long down it.
With that said, I do wonder if these have other mining applications. It's not good for solution mining, but it sounds like it could be useful for remote inspection of dangerous levels of conventional underground mines. Conventional mine shafts and levels have to be big enough for people and equipment to fit in, and this seems reasonably sized for that application.
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.
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.
See https://www.vinerobots.org/ which work like a 触手 (tentacle monster, pronounced shokushu) from an H anime.
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.
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?
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
> 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.
> Thanks to their long-flight endurance, they are suited for long-term missions.
How long can your drone stay in the air?
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.
Running a gas powered drone in a low oxygen environment sounds like a great way to get the next cavers killed by asphyxiation
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.
> 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."
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.
Particularly the multicopter is mass produced, cheap, mature and easy to buy and use.
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.
https://www.xkcd.com/2128/
That’s a good one, and it’s true!
> 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.
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.
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.
Getting closer to the cave scanning drones from Prometheus.
We've basically got those now. https://www.core77.com/posts/133629/A-Throwable-Panoramic-Th...
this seems to come up often on HN!
https://news.ycombinator.com/item?id=41547946
Huh must have seen that and gotten it stuck in my subconsciousness :)
Does the abstract sound like ChatGPT output to anyone else? Their A and B require a delicate balance of C and D, 'compelling', 'embody a distinct intersection', 'wide array of possibilities'... You don't even need to read past the first few sentences.
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).
I thought it was going to be made of cloth that stiffens when current passes through it... :)
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?
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)
Arxiv? More like ar-cave... amirite?
Sorry; It doesn't contribute but I couldn't resist.
Clean out your desk