[HN Gopher] Autonomous excavator constructs a six-metre-high dry...
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Autonomous excavator constructs a six-metre-high dry-stone wall
Author : belter
Score : 517 points
Date : 2023-11-24 22:07 UTC (1 days ago)
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(TXT) w3m dump (ethz.ch)
| toomuchtodo wrote:
| https://www.science.org/doi/10.1126/scirobotics.abp9758
|
| https://youtu.be/P7wmotyKgXc
| soperj wrote:
| Considering it scans all the rocks, you'd think it would be able
| to fit the rocks together better. I don't expect a Incan wall,
| but I think it would be able to construct a tighter fitting wall
| if it were programmed to care.
| fnordpiglet wrote:
| It could perhaps if it had all rocks available up front to scan
| and plan the entire wall with. But it retrieves one rock at a
| time and can only place on the top row somewhere. Given the
| geometries are random I wouldn't expect it to reliably have
| tight fits given how it's sampling and placing.
| ano-ther wrote:
| It scans 20-30 (a truckload) before building a section of the
| wall with them.
| mlhpdx wrote:
| Exactly as I do as a human when I build such walls (several
| of them in my life). It's a very difficult spatial problem
| to fit the stones into a pretty, stable structure. No doubt
| something large memories and detailed spatial search on a
| computer could help with. That doesn't seem to have
| happened in this example, though. That wall is horrendously
| ugly.
| highstep wrote:
| Not only ugly, but unstable and sketchy. I wouldn't go
| near that wall.
| foota wrote:
| I'm getting some light towers of hanoi vibes
| ur-whale wrote:
| In other words, it's using a greedy algorithm
| soperj wrote:
| Even then, if you make one long row, you have hundreds of
| available spots to place it, with at least 6 sides to decide
| on which orientation to place the stone. If there are no good
| spots currently, it could place the stone down next to the
| pile and go collect another stone until a better spot
| materialized.
| fnordpiglet wrote:
| No, I was wrong. It has a collection of 30 or so rocks per
| section and optimizes their placement in the entire
| section. I'll still posit the randomness of the geometry
| requires more rocks than that to find a smooth fitting, and
| I imagine human wall makers select rocks up front with
| similar geometries before even beginning out of thousands
| of rocks then optimizes their placement during construction
| in a similar but less preside way than the machine.
|
| If you watch the video closer than I did you will see it
| plans each stone for optimal stability and placement.
| defrost wrote:
| An Incan wall is much "easier" (airqoted qualifier).
|
| There's much effort required to square up stone and shape
| faces, a lot of drilling, wedges, and precision chisel
| finishing.
|
| However, once it comes to the stacking it's been reduced to a
| bricklaying exercise (already solved for robots and posted to
| HN).
|
| Traditional drywall evolved from field clearing, stacking rocks
| to get them out of the way and to reduce wind across exposed
| otherwise rocky _potential_ fields.
|
| Stacking and balancing "as they come" or with relative minimal
| look ahead | reshuffle queuing is a tougher proposition; this
| is impressive work.
| soperj wrote:
| I'm not saying that it's not impressive. I'm just saying that
| I feel like considering that it doesn't have the human
| limitations of it being hard to remember every facet of the
| rocks, that it could do better job still!
| Qwertious wrote:
| Some Incan walls are regular bricks, but others are just
| slightly-dressed boulders used for drywall polygonal masonry.
| They're an interesting compromise - some dressing for
| flexibility, but not so much that you have to throw half the
| boulder away.
| progne wrote:
| I was once on a mountain top composed almost entirely of rocks
| like these. I'd like to give a sand castle artist this excavator
| and ask them to turn it into a fairy tale.
| mkoubaa wrote:
| Anyone under the age of 20 is a Minecraft artist already
| abraae wrote:
| This seems like game changing technology. There are a heap of
| such walls around here, some built long ago by Dalmation
| immigrants (and some allegedly by German POWs). It's quite labour
| intensive and highly skilled to create them.
|
| We have some on our property, used to retain the hillside after
| land slips. They were built with an excavator by a gnarly old guy
| who was unbelievably skilled.
|
| One thing I wonder is whether these are safe. These things
| terrify the shit out of me, as one toppling rock of that size
| could instantly kill a child.
|
| Walls built by human operators of sufficient skill are safe (I
| know, I went around and tried to wobble every single rock to make
| sure). But are these built to the same level?
| toomuchtodo wrote:
| You could potentially shotcrete (spray it with concrete to
| reinforce) the wall after the robotic excavator is done if
| you're concerned about stability. I can't speak to whether you
| can highly automate this as well, but it seems possible with
| current state robotics with human operators.
|
| https://en.wikipedia.org/wiki/Shotcrete
|
| https://www.geostabilization.com/technology/shotcrete-robot/
|
| https://dawinvehicles.en.made-in-china.com/product/jBMnaOKdL...
| myegorov wrote:
| The ability of a dry stack retaining wall to shift and
| breathe is a feature, not a bug. For stone walls that require
| added reinforcement against lateral loads, look into tiebacks
| or geogrid reinforcement.
| toomuchtodo wrote:
| Appreciate this. Where can we read more on this
| engineering? All citations are welcome, I am fascinated by
| this engineering domain.
| gerdesj wrote:
| There are Civil Engineers here (I only studied it at Uni
| - I ended up in IT!)
|
| When you deploy a structure like a retaining wall you
| want to try and ensure that the materials you use will
| retain their properties as long as possible and if part
| of it fails, it should not case the whole structure to
| fail. Add additional design requirements as you like eg
| colour and texture but always think about function first
| or you will regret it later!
|
| In a garden setting, you will want to consider: gabions,
| drystone walling and "sleepers" (large lumps of wood -
| like railway sleepers).
|
| Some quick material thoughts: Wood is prone to rotting,
| so ensure it is treated and well drained. Drystone
| walling can be prone to collapse unless it is allowed to
| drain properly and plants/weeds should be removed. It
| should be slanted at around 5 degrees from vertical to
| resist collapse. Gabions made of galvanized steel wire
| are extremely strong and resistant to pretty much
| anything. Devon Popples are an ideal filling for gabions
| and make a phenomenal structure.
|
| I built a deck part way down in my garden. It is about 5m
| wide and sticks out about 1.8m. Behind it is a sleeper
| retaining wall which is about 1.8m high. I angled it back
| by about 2 degrees from vertical. I laid it on a concrete
| strip to spread the load and gravel base and back filled
| with quite a lot of scrap brick and rubbish for drainage.
| I used some 2m x 10mm stainless steel threaded rods
| embedded into the conc base to ensure horizontal
| stability (horizontal shear). I used 180mm, No. 10
| passivated screws to keep the wall together whilst I
| built it and back filled.
|
| "Where can we read more on this engineering"
|
| It's everywhere but you will have to deal with local
| conditions. I am not convinced you are what you claim.
| saalweachter wrote:
| Another quick tip: resist the urge to stack your stones
| long-ways parallel to the course of wall. Instead, put
| the longest dimension perpendicular to the wall.
|
| This makes it much harder for the wall to fall outward as
| it shifts.
| lapsed_pacifist wrote:
| The 5 rules of dry stone:
|
| https://thestonetrust.org/5rules/
| rpmisms wrote:
| > I am not convinced you are what you claim.
|
| Knowing where to look without colleagues or steeping in
| the field is difficult. When teaching people to code, I
| often run into the same issue: assuming people are good
| at googling, or know what Stack Overflow is.
| toomuchtodo wrote:
| I am very good at googling and other online resource
| discovery, but that is no replacement for a knowledgable
| practitioner pointing you towards known good, high
| quality online resources. You don't know what you don't
| know. "Unknown unknowns."
|
| I will even pay subject matter experts when necessary to
| bootstrap the research and autodidact process. There is
| no speed limit when learning, but rails and direction
| have value until you have enough foundation in a domain.
| I will absolutely let someone teach if they're willing to
| set me on the right path, one of the reasons this forum
| is so valuable: highly knowledgeable people willing to
| bestow knowledge for free. And asking is mostly free
| (assuming you are polite and receptive).
| rpmisms wrote:
| An ounce of prevention is worth a pound of cure, or in
| this case, an ounce of experience is worth a pound of
| research.
|
| Also: _Wisdom. It is the difference between knowledge and
| experience._ -Data, _Star Trek_
| myegorov wrote:
| This would be discussed in an introduction to soil
| mechanics and foundation design (Braja Das's textbooks
| used to be the standard reference in the US when I was a
| student 15+ years ago) but I'm afraid they're too dry for
| anyone outside the profession. I'm not aware of an author
| who can animate civ eng subjects for the adult with the
| talent of David Macaulay. But I can point you to a few
| "engineering gems" that might pique your interest if you
| like this sort of stuff: prestressed and post-tensioned
| concrete (the work of Freyssinet, see Billington's
| books), readings from John Ochsendorf's class on historic
| structures in https://ocw.mit.edu/courses/4-448-analysis-
| of-historic-struc..., bicycle wheel as prestressed
| structure (the same principle used in some tension-
| compression stadium roof structures): http://www-
| civ.eng.cam.ac.uk/cjb/papers/p20.pdf
| FabHK wrote:
| One further book that might be of interest (though only
| tangentially related) is _Structures: Or Why Things Don
| 't Fall Down_ by J. E. Gordon.
| lapsed_pacifist wrote:
| Look at the Dry Stone Wall Association of Great Britain,
| or The Stone Trust in the United States. These
| organizations still teach traditional methods of dry
| stone walling which cover a lot of these techniques.
| Probiotic6081 wrote:
| Or make the walls squiggly ~~~ for extra structural
| integrity
| abduhl wrote:
| Shotcrete is regularly applied via robot in mining. The
| problem with shotcrete in open cell designs such as this is
| overspray and plugging of the large voids.
|
| Gabion baskets are likely a better idea if you have stability
| problems and want to do a similar kind of automation.
| seabrookmx wrote:
| This defeats the purpose a little bit though because the
| environmental benefit is to _not_ use concrete, as producing
| it has very high CO2 output.
|
| They use shotcrete a lot here in BC where cliffs are close to
| the road, but usually when it's soil or more loose material.
| Any rock structures (natural or man made) are typically left
| bare.
| dventimi wrote:
| Perhaps concrete in construction and demolition waste could
| be used.
|
| https://www.bigrentz.com/blog/construction-waste-statistics
| gerdesj wrote:
| "You could potentially shotcrete"
|
| You could stop water draining through the retaining wall and
| turn it into a dam, which will not end well.
|
| My back garden/yard has a 40m drop to a lawn. The levels are
| managed by dry stone walls. Soil here is heavy clay with
| really heavy clay sub soil, so efficient drainage is
| imperative.
|
| As well as drystone walls, consider gabions which can form
| phenomenally tough retaining walls. You can plant on them too
| rather than having to weed drystone walls. Gabions are much
| more resistant to plants forcing joints apart than drystone
| walls.
| toomuchtodo wrote:
| You would still need humans to erect the gabions though,
| no? Trying to understand the best optimization use case for
| this product and best fit final results. Please excuse my
| knowledge gaps! I'm am trying to fill those gaps.
| gerdesj wrote:
| What problem are you trying to fix?
| toomuchtodo wrote:
| Reduction in human labor for building these types of
| structures. The world is getting old fast, but
| infrastructure is still required, both new and
| maintenance of what exists today. Also, job assistance
| that reduces the toll on humans in this industry. This
| prevents treating the human as a consumable when the
| automation can be human driven, increasing quality of
| life and potential career longevity (if desired).
|
| Not replacing humans, to be clear, but helping them build
| better with less effort. Thank you for indulging me. I
| hope to eventually leave tech to build things that are
| needed that are built to last (I too am getting old
| fast).
| jacquesm wrote:
| You can fill gabions that have been pre-made by using a
| mini excavator. Or you can do it by hand but that's
| pretty labor intensive, unless you like wheelbarrows and
| buckets I would advise against it. Personal experience
| and all that ;)
|
| The important thing with gabion is to realize that they
| still need careful planning, anchoring, leveling and
| possibly a foundation to ensure that they aren't going to
| shift over time.
| throw0101b wrote:
| > _You could stop water draining through the retaining wall
| and turn it into a dam, which will not end well._
|
| Which is why gravel backfill with a perforated pipe at the
| base (that drains to day light) is specified by many/most
| building codes.
| schiffern wrote:
| So what you're saying is we made a problem for ourselves,
| and then we hacked on additional cost (and plastic) to
| fix it?
|
| I'm starting to see the advantages of this dry stone wall
| technique.
| throw0101b wrote:
| A 'sealed' retaining wall where the stones are
| interlocked or even glued/mortared together would
| probably have a higher load capacity than one made
| dry/unadhered. Or someone could simply like the aesthetic
| of a more 'filled in' wall, regardless of practical
| considerations.
| rootusrootus wrote:
| Eh, the perforated pipe technique can efficiently collect
| the water and move it somewhere else entirely. It's nice
| that dry stone can just let water fall through, but then
| it just runs out at the base. Which might be fine, but
| you might still want a french drain anyway.
| scythe wrote:
| I don't understand. You don't need to fully coat the wall
| with shotcrete in order to stabilize the rocks. There could
| still be holes.
| coryrc wrote:
| If the wall is going to move a little shotcrete ain't going
| to stop it.
| abduhl wrote:
| I'd disagree with this. The general rule in mining is "six
| inches of shotcrete will hold up the world."
| landemva wrote:
| The shotcrete I have been around was sprayed onto hogwire
| (already on the rock) and then bolted. It was not just coated
| onto existing rock as if it was a cake icing.
| hutzlibu wrote:
| One of the ideas of this project is, to NOT use concrete, to
| not have CO2 emmisions.
|
| And depending on the "skill" of the robot and its algorithms,
| it could be very stable. I know that quite some ancient
| buildings in south america are put together just with stones
| put together(with precision and shaping of stones). They
| survived earthquakes and are still standing. So if enough
| stones of various shapes are avaiable - you won't need
| concrete. The weight and friction will hold them together.
| mauvehaus wrote:
| Visiting Scotland, I was told that the apparent lack of
| stability is what keeps the sheep from pushing against the dry
| stone walls there.
|
| Apocryphal or true? No idea. It's intriguing to think that
| sheep have a sense for stable construction, and that people
| have learned to deceive it.
| daxfohl wrote:
| They had no problem escaping through them in Clarkson's Farm.
| kbenson wrote:
| I really enjoyed that show, but I have no confidence that
| production assistants weren't gallavanting about at night
| acting as gremlins.
|
| Clarkson is first and foremost an entertainer, and I'm sure
| he'd agree with that assessment.
| chaboud wrote:
| Clarkson is the sort of guy who would have both friend
| and foe knocking over his walls just to mess with him.
|
| Nonetheless, sheep farming can be incredibly difficult,
| and sheep love to assert just enough independence to be
| annoying.
| 123pie123 wrote:
| the adjoining farm next to our backgarden had sheep that
| was obsessed with getting into my backgarden - no idea
| why. they would jump over the 5ft wall with barb on the
| top.
|
| When we complained he move the sheep to another field,
| they escaped that field and entered our back garden
| through a totaly different way - through our front
| garden. eating loads of our plants - I can understand the
| pain Clarkson went through (made up or not)
| lapsed_pacifist wrote:
| Not true. A well built fieldstone wall is massive, we
| estimate around .5T per linear yard when we build one to 4ft.
| with cope stones. Sheep will not knock it over, but cattle
| can. For that reason, through-stones are allowed to protrude
| a few inches on normal pasture wall for sheep, but you should
| make them flush on walls for cattle because the cows will try
| to use the protrusions to scratch themselves and could knock
| the wall over.
|
| A well built wall doesn't appear unstable. One of the tests
| is whether or not you can see any daylight through the wall,
| and the wall should easily support the weight of several
| people leaning against it.
| yk wrote:
| First they are coming for the medival castle builders, then they
| come for the renaissance painters.
|
| In all seriousness though, that's a pretty nice feat of robotics.
| The excavator has to work with stones that are not standardized
| and has to understand how they interact, my intuition is that
| that is a lot harder than building a regular brick wall.
| Oarch wrote:
| The Fabricate conference has always been great for research like
| this
| ExMachina73 wrote:
| Perhaps in hundreds of years they'll be able to deploy AI robots
| to poorer regions of the world to build basic utilities, mine
| resources, and even whole cities from nothing. Or have them
| depoloyed to current cities constantly repairing and optimizing
| infrastructure.
| HPsquared wrote:
| Factorio style.
| dublinben wrote:
| If there's one thing that lower income countries have an excess
| of, it's people to perform labor. There's a reason why you
| don't see countries (e.g. China) introducing more automation
| until they rise to a certain income level.
| TulliusCicero wrote:
| Generally you're right, but also
|
| a) You may not have skilled labor easily available for a
| niche like constructing a dry stone wall out of giant rocks,
| and
|
| b) sometimes employing that labor via local firms can result
| in corruption issues.
| trebligdivad wrote:
| Damn, that must have been fun to debug and test!
| fernly wrote:
| ETH Zurich[1, 2] is fairly famous as an engineering school.
| Somehow in my mind it is linked with computer scientist Edsger
| Dijkstra[3], but according to the Wiki he was never based there.
|
| [1] https://en.wikipedia.org/wiki/ETH_Zurich [2]
| https://ethz.ch/en.html [3]
| https://en.wikipedia.org/wiki/Edsger_W._Dijkstra
| hollerith wrote:
| Dijkstra was close to Niklaus Wirth, who _was_ based there.
| ur-whale wrote:
| ETHZ is quite famous indeed.
|
| Einstein, among others, studied there [1]
|
| [1] https://ethz.ch/en/the-eth-zurich/global/events/digitaler-
| ei...
| mahkeiro wrote:
| Indeed, 22 Nobel Prizes have been awarded to researchers who
| have or had a connection with ETHZ.
| Animats wrote:
| Nice. Heavy equipment with many degrees of freedom is hard for
| humans to control. Some operators are really good, but not all of
| them.
|
| A backhoe hooked up to a virtual reality input arm with force
| feedback was built several decades ago. The operator could feel
| obstructions, and dig out the dirt around a pipe by feel. Never
| became a product, though. Probably too early.
| zyxin wrote:
| Do operators currently need to manually control every movement
| of the arm? I always assumed that such heavy equipment uses
| inverse kinematics to help the operator.
| s1artibartfast wrote:
| It is usually one lever per hydraulic cylinder.
|
| The human brain already automates the kinematics.
|
| There isn't much upside to automation and a lot of downside
| because of the diverse instructions required.
| landemva wrote:
| Often a lever, or joystick motion, per function. And site
| plans can be input to bulldozers and excavators, and with
| precision sensing they do cool things like preventing
| operator from digging below grade. Those 'sticking pipe' in
| trenches, and those putting in landfill cells rave about it
| because it avoids rework. The old guys don't need it, but
| they are aging out of the workforce.
|
| https://www.komatsu.eu/en/Komatsu-Intelligent-Machine-
| Contro...
| Animats wrote:
| Here's a modern piece of heavy equipment, a Ponsse tree
| harvester, with the operator showing how the machine is
| used.[1] One big joystick for each hand, and a lot of
| buttons on each joystick. The operator is guiding the
| beast, but once it grabs onto a tree, there's some
| automation to cut the tree into preset lengths. Notice how
| fluid the movements of the machine are.
|
| It's nowhere near autonomous, but it's several times faster
| than total manual control would be.
|
| [1] https://www.youtube.com/watch?v=OlvByJeAfv0
| dboreham wrote:
| > It is usually one lever per hydraulic cylinder.
|
| Not so much these days, but the general idea is correct.
|
| Usually there are joysticks (one per hand) that provide
| control over one movement per axis. So for example the
| right hand joystick on a mini-excavator usually controls
| bucket curl (left/right) and boom movement (forward/back).
| Left hand does boom up/down and rotate left/right. There's
| an ISO standard for this UI. Old school tractor-loader-
| backhoe machines (what people in the US call "a backhoe")
| had one lever per cylinder, so more complicated to control
| and more levers. An old-style motor grader is the extreme
| example of lever confusion[1].
|
| Operation of heavy machines relies (still) on the brain's
| capability to virtualize the movement of the machine in
| terms of the body's limbs. That's why you need some time
| training to become proficient. After a few hours you just
| think "I want the bucket over there" and your hands make
| the necessary movements without thinking.
|
| There's already lots of automation available on high-end
| machines such as use of GPS to control cut/fill operations
| with bulldozers, and laser-transit-based automated dig
| depth control for excavators.
|
| [1] https://www.cat.com/en_US/articles/for-owners/the-
| basics-of-...
| myself248 wrote:
| There's no IK because sometimes the operator needs to be very
| specific about where the "elbow" or "shoulder" ends up, to
| avoid hitting some other object. So they have manual control
| over everything.
|
| If you're going to automate the kinematics, then you either
| need a manual override mode (which the operators will be
| unskilled with since it's seldom-used), or you need sensors
| and rules for the machine to know where it's not supposed to
| be (clearances around wires, other structures, etc) and that
| needs to be better than human operators currently do.
|
| Those are theoretically possible, sure, but a valve-per-
| cylinder is really stinkin' reliable.
| h2odragon wrote:
| The force feedback would be yet another layer of tetchy stuff
| to keep running in a really harsh environment.
|
| I've know backhoe operators who _strongly_ preferred older
| equipment, when its too new the pins are too tight and they
| have no "slop" to work with. That slop is what they're using
| for sensory input, if you watch them. With attention and
| experience that's real time feedback.
|
| The _whole machine_ is the force feedback mechanism. You 're
| not just sitting there in a comfy chair pulling levers, you're
| on top of a collection of systems all singing their own song in
| response to the varying loads placed on them.
| londons_explore wrote:
| > The force feedback would be yet another layer of tetchy
| stuff to keep running in a really harsh environment.
|
| Luckily, hydraulics offer a very easy way to do force
| feedback: Just measure the post-valve cylinder pressure.
|
| That means you can have all your wiring and sensors in the
| cab far away from the dirt and rain. Makes force feedback
| pretty easy and cheap.
| gfodor wrote:
| This is the kind of thing computer science academics dream about
| ur-whale wrote:
| Minecraft IRL
| WhitneyLand wrote:
| - Wouldn't this type of wall normally be built using heavy
| machinery without laborers lifting and placing heavy rocks?
|
| - A heavy machinery operator would no longer be needed, but
| wouldn't you need 1 or more people to operate and manage the
| robot as well as verify the solution?
|
| It's a really cool direction for construction but I wonder what
| the net/net cost savings would really be in the near future
| anyway.
| maxglute wrote:
| There's probably a lot of savings to be had by lifting safety
| rules. Cram more machines to do more work on site and finish
| faster.
| abraae wrote:
| I think this is great tech, but maybe not for those reasons.
| On any safe site, people are already very cautious and
| working well back from the excavator. Some teams have a
| protocol where you have to make eye contact with the digger
| driver before you can go anywhere within the sweep of its
| arm.
| maxglute wrote:
| But without the excavator operator, can you not cram more
| autonomous excavators to get more work done? Seems like
| sufficiently good sensors would allow them to work in each
| others safety zones for parallel work.
| bluGill wrote:
| Probably not as the soil they ig needs to go someplace.
| That means dump trucks will still be the majority of the
| site.
| logtempo wrote:
| I don't like wars, but being able to build a wall out of some
| broken concrete blocks without it being man handled is a good
| feature I believe.
|
| Also being able to build during a long period of time (during
| the night for example) make the job less exhausting.
|
| Also one could think of it as an assistant: put some augmented
| reality display, and let the machine showing to the operator
| where to put the rock.
|
| Or help for building records: you keep the operator part, but
| you record the scans and position and weights during
| construction phase, so you can eventually run simulation later
| to know how the wall will change over time etc.
| Eumenes wrote:
| Graham Hancock BTFO
| vondur wrote:
| The Romans could have used this to keep those pesky Germans out!
| Daub wrote:
| Having made a few dry stone walls I can attest to the merit of
| this achievement. Judging where rocks are to be placed, and in
| what orientation is a zen art.
|
| Anecdotally... I once tried to get wild flowers to grow on a
| stone wall. Every year we would seed the wall, only for the seeds
| to fall out or be eaten by birds. On inspiration, my boss filled
| a few shotgun cartridges up with seeds and fired them at the
| wall. Perfect result! The following year it was covered in
| flowers.
| 93po wrote:
| Now this is gardening I can get behind
| chaboud wrote:
| Well please don't stand in front of it...
| schiffern wrote:
| Not only is this a technical marvel, but it has potential
| construction physics implications.
|
| In simple terms, currently we expend energy to fragment rock,
| and then we expend additional energy (as concrete) to glue it
| back together. We do all this to re-arrange rocks into a shape
| (and strength) we want, and most importantly to do it _cheap_.
|
| Suddenly, an alternative just got a lot cheaper.
|
| Clearly this isn't fully baked yet (and it's hardly a drop-in
| replacement for reinforced/pretensioned/cantilevered/etc) but
| for things like heavy infrastructure and civil engineering this
| might offer a way to achieve fundamental thermodynamic
| improvements.
|
| Excited to see where this technology goes.
| samtho wrote:
| The problem with dry stone construction is that you cannot
| determine the performance characteristics required for, say,
| a building foundation. Not all boulders are created equal,
| but a professional concrete pour, mixed and installed to the
| manufacturer's specification is going to have a guaranteed
| maximum strength- something random boulders will not have.
|
| What we can do is create our own concrete mix using Portland
| cement (the "glue") and locally sourced materials to bulk it
| up such as gravel, aggregates, sand, etc.
| schiffern wrote:
| So the question becomes, how do existing concrete
| manufacturers determine whether locally sourced materials
| ("random rocks") are suitable?
|
| In traditional dry stone construction, strength of each
| rock is determined by sound and by sight. It seems crazy,
| but nowadays this should be feasible with a neural net. If
| you want to get fancy (or achieve high reliability) add
| ultrasound in the grippers or other sensor modalities.
|
| Or... you target a market other than building foundations?
| :) I suspect different groups could pursue both paths.
| beambot wrote:
| > how do existing concrete manufacturers determine
| whether locally sourced materials ("random rocks") are
| suitable?
|
| They test individual samples from each pour on a
| calibrated press. For large buildings and critical pours,
| they'll keep & test multiple samples that undergo
| accelerated aging to make sure they're up to spec for the
| anticipated lifetime of the building (or until the
| concrete fully stabilizes over a few months / years).
| diroussel wrote:
| So could catagorization of local stone based on acoustic
| and visual indicators, combined with random sampling and
| strength testing provide the assurance needed that a wall
| will have the required structural properties?
| crotchfire wrote:
| The point is that the concrete manufacturers pulverize
| and homogenize the aggregate. This makes random sampling
| acceptable.
|
| If you haven't pulverized and mixed the inputs, a random
| sample is merely a random sample. It isn't meaningful
| unless it comes from a high-entropy source.
| diroussel wrote:
| So are you saying we couldn't estimate the structural
| properties of autonomous built dry walls from local
| stone? Or that the error bars would be unacceptably
| large? Or just that this approach would only work with
| certain stone in certain locations?
| SiempreViernes wrote:
| I think the problem is more that you cannot at all
| guarantee a specific performance of the structure ahead
| of time, because you can't know what the properties of
| the local rocks will be before you are on site and have
| measured them all.
| londons_explore wrote:
| Geotechnical engineering is all about taking samples and
| using wide enough safety margins. And in the vast
| majority of cases, the end result is a building that
| doesn't fall down.
|
| Sure, you might have been _really_ unlucky that all your
| test samples of soil and rock were really strong granite,
| but the exact spot you put the main structural pile,
| unknown to you, was all mud and silt... But the chances
| are so vanishingly unlikely we accept it.
| berkes wrote:
| Doesn't that apply to wood too? Yet we use wood to build
| houses almost everywhere.
| _tom_ wrote:
| The interesting thing here is you can feasibly measure
| them all.
|
| Not ahead of time, but as you build.
| nabla9 wrote:
| _A Deep Learning Based Method for the Non-Destructive
| Measuring of Rock Strength through Hammering Sound_ Appl.
| Sci. 2019, 9(17), 3484;
| https://doi.org/10.3390/app9173484
|
| Acoustic inverse problems are solved routinely in
| seismology and exploration geophysics. Seeing trough a
| rock the cracks and internal structure using acoustics
| seems solvable.
| galaxyLogic wrote:
| Why not do a stones-wall like in the article, but add
| cement as glue between the rocks?
| actionfromafar wrote:
| The wall will then dam up water or crack instead of
| shifting slightly, I read in another comment.
| jelliclesfarm wrote:
| I did this for a landscaping project because I was not
| confident enough that it will stay ..lasted ten plus
| years and then it started cracking. I am now left with
| unsightly gray blotches and worried the rest might
| tumble..
|
| It was/is gorgeous..I did three sections ..mostly for
| three very large kidney shaped raised beds..moss has
| grown over the stone and I also tried sticking thyme and
| mint in some of the suitable gaps..
|
| I guess it's diff if it's enclosed and filled with soil.
| I wish i had the confidence and skill to attempt an
| actual wall.
|
| I used to drive past a house here where the guy took like
| three years to complete a 80 ft long dry wall and he
| planted all kinds of beautiful flowering plants ..it was
| stunning and when it was done, the flowers and fruit
| trees popped up with their colours too ..it took forever
| but he didn't care..you could tell that it was a labour
| of love and he was really enjoying it.
| Daub wrote:
| That is what I assumed when I first started drywalling.
| However, in the wild, I can't see such a solution
| working. Unlike the walls of a house, walls bedded on
| soil move all the time. In the ever-moving domain of the
| Welsh hillsides, cement glue would crack within a year.
|
| Ideally, drystone walls are composed of two skins. The
| way the stones are arranged tends these skins to each
| incline inwards slightly. In this way, the wall as a
| whole acquires cohesion through physics.
| alistairSH wrote:
| Several reasons... Primarily, because the ground
| underneath shifts overtime, particularly in area, subject
| to a freeze and fall cycle. But you also have to solve
| for water flow - if you build a solid stone wall with
| concrete, you also need to add drainage on the backside
| of the wall. With dry, stacked stone, you can often get
| away without a complex drainage solution
| koolba wrote:
| > Not all boulders are created equal, but a professional
| concrete pour, mixed and installed to the manufacturer's
| specification is going to have a guaranteed maximum
| strength- something random boulders will not have.
|
| Random boulders surely have some guaranteed _maximum_
| strength. Now _minimum_ strength is the real problem.
| hedora wrote:
| Modern concrete only lasts a hundred years or so. Stone
| walls last much longer when correctly constructed.
|
| Presumably the placement algorithm understands compression
| strength of the local rocks, soil heaving, etc.
|
| So, software addresses the initial problems you describe at
| construction, and geology/materials solve the problem of
| needing to inspect it every decade or so, and replace it in
| 50-100 years.
| worik wrote:
| With concrete you have outsourced, not solved, that problem
|
| There's a lot of drystone walls here, in Aotearoa, but not
| of buildings.
|
| There is a related technique for buildings, building from
| rubble, using lime morter.
|
| I live in a building partly built that way
| legulere wrote:
| It's more difficult but still possible. Mountain passes in
| Switzerland are often built on dry walls
| ReptileMan wrote:
| Tensile strength will be a problem. Compression will be
| solved eventually, the tetris part also. But if there are to
| be tensile or twisting loads - there will be trouble.
| londons_explore wrote:
| Add steel/fiberglass tension rods and you can trade off
| compressive for tensile strength.
| klyrs wrote:
| So... reinforced concrete.
| rewmie wrote:
| > Not only is this a technical marvel, but it has potential
| construction physics implications.
|
| I don't think this is true. Gabion walls are already widely
| used, particularly in geotechnical structures, and masonry
| structures have been around for literally thousands of years.
|
| The reason modern building technologies such as
| concrete/steel/composite structures replaced these techniques
| is that they are far safer, easier to maintain, far more
| space-efficient and and impose far fewer architectural
| constraints.
|
| Automating this process helps drive down the cost, but cost
| is one of many factors and not a critical one.
|
| > Suddenly, an alternative just got a lot cheaper.
|
| Not really. This article just showcases a way to automate the
| construction of a particular wall type. This by no means
| implies these walls are now competitive.
|
| Other than aesthetics, I don't see how it's possible to even
| conceive standard techniques such as gabion walls being
| replaced by dry-stone walls. The cost of building a gabion
| wall is literally the cost of a metal mesh and filling it
| with rocks. Gabion walls are even used by armed forces as
| rapid-deployment defensive walls in the form of Hesco
| bastions.
|
| https://en.wikipedia.org/wiki/Hesco_bastion
| DigiDigiorno wrote:
| I'm surprised the seeds would survive the heat and pressure of
| a shotgun cartridge blast that contained enough gun powder to
| embed them in a wall
| bob1029 wrote:
| Seeds are incredibly resilient in many cases. Also, shotgun
| shells come in a range of power level and configuration.
| Something like birdshot replaced with seeds would make sense
| to me.
| adammarples wrote:
| It sounds like judging where rocks are to be placed is a simple
| optimization algorithm
| Obscurity4340 wrote:
| Didn't they do that in The Grinch?
| ascorbic wrote:
| For future walls, try a Cornish hedge. Despite the name, these
| are actually dry stone walls with an earth core. Mature ones
| are normally covered in wildflowers. Here's how they're made.
| http://www.cornishhedges.co.uk/PDF/building.pdf
| lapsed_pacifist wrote:
| This isn't really a proper wall though, it's a single thickness
| stack. I don't think it could handle any lateral force at all
| without toppling. If this machine could build a double skin
| wall with batter, wall heads, and hearting throughout the
| center, I'd be really impressed!
| londons_explore wrote:
| I suspect all those things are just fairly minor software
| changes...
| Matumio wrote:
| This is the way you use a gun. What a flowery blossoming place
| this world would be. Reminds me of
| https://en.wikipedia.org/wiki/Swords_to_ploughshares
| m463 wrote:
| > my boss filled a few shotgun cartridges up with seeds and
| fired them at the wall.
|
| A friend of mind had a hill in his yard, and hired a guy that
| knew the local seed mix to hydroseed it. It went well.
|
| https://en.wikipedia.org/wiki/Hydroseeding
|
| Can't figure a good word would be for what your boss did. It's
| not quite pyroseeding...
| klyrs wrote:
| Ballistic broadcasting?
| nopinsight wrote:
| Nice achievement!
|
| With upcoming multimodal foundation models, there will be many
| more robots with increasing capabilities soon. The world of
| robotics will look very different just in the next 5 years.
|
| Some announcements:
|
| China's plan: "...China aims to be ready to mass-produce
| humanoids by 2025." https://www.therobotreport.com/china-plans-
| to-mass-produce-h...
|
| Tesla Robot: "...it would be low cost and available to the public
| sometime between 2025 and 2027. "
| https://builtin.com/robotics/tesla-robot
| tsimionescu wrote:
| You should take both of those announcements with a huge dollop
| of salt. Even the article you shared is extremely skeptical of
| the actual progress of Tesla's robot. And Chinese press
| releases should really not be read into too much - they are
| often much more for internal signalling then information.
|
| Either way, there are companies which are much farther along
| than those - Boston Dynamics has a series of extremely
| impressive robots. They are still very far away from being a
| consumer technology. The kinds of physical power required to
| achieve the movements makes them extremely dangerous to be
| around on any malfunction or glitch, and they are very heavy
| machinery. Even animals and other humans, which are far more
| advanced in terms of their ability to control their movements,
| sometimes accidentally hurt others (stepping on your toes,
| turning around and hitting you when they didn't know you're
| there, etc.). Imagine a several hundred kilo machine stepping
| on your toes with its full weight just because it mis-estimated
| your movements.
| nopinsight wrote:
| > Imagine a several hundred kilo machine stepping on your
| toes with its full weight just because it mis-estimated your
| movements.
|
| "Specifications. Tesla Bot is planned to measure 5 ft 8 in
| (173 cm) tall and weigh 125 lb (57 kg)."
| https://en.wikipedia.org/wiki/Optimus_(robot)
|
| I'm aware that Tesla tends to be over-optimistic in its
| timeline regarding AI and robotics. I do not endorse the
| estimates without question and yes, some other companies
| might have made more progress than they did. The citations
| were meant as examples of the development in the domain. (And
| Boston Dynamics doesn't seem to plan a consumer launch of a
| humanoid robot any time soon, so I didn't cite them.)
|
| What made me more optimistic these days are recent progress
| in multimodal large foundation models which allow robots to
| perform much better, esp on manual manipulation. See demo
| from Sep 2023 here: https://www.youtube.com/watch?v=D2vj0WcvH
| 5c&t=18s&ab_channel...
| tsimionescu wrote:
| Oops, I significantly exaggerated the weight, thanks for
| finding that.
|
| Still, 60kg is no laughing matter.
|
| Also, isn't the fact that companies which are way further
| along in developing robot capabilities are _not_ thinking
| about wide-scale commercialization decent evidence for it
| not being viable yet?
| 082349872349872 wrote:
| For those both unfamiliar with Menzi Muck walking excavators and
| having a little boy's love of construction equipment, there are
| plenty of videos online of non-autonomous skilled operators with
| fancy moves...
| BobaFloutist wrote:
| I wonder how many decades before someone hooks this up to a
| webcam and lets people play minecraft in real life.
| digitalsushi wrote:
| As someone who works in insurance, I advise you not to wait
| amelgares wrote:
| This is the kind of equipment that you do not want a rogue AI
| getting in control of.
| nextworddev wrote:
| Most likely these come with periodic OS updates... which is an
| attack vector
| rendaw wrote:
| I'm surprised centimeter precision is sufficient. I'd have
| thought millimeter precision or so would be required. It feels
| like 1cm could accumulate to a gap or could spell the difference
| between stable points contacting and not.
| RichieAHB wrote:
| IIUC cm precision should be fine if the algorithms looking for
| stable placement accounts for that cm (and reality id imagine
| it'd account for less precision than that). If a placement
| needs sub cm precision the algorithm would just discard that
| option.
|
| Additionally there shouldn't be any accumulation in a specific
| direction. Any accumulated gaps would be accounted for when
| placing the next rock and rectified to within a cm.
| hliyan wrote:
| With this type of advancement, we may finally be ready to tackle
| the biggest challenge for domestic robots since domestic robot
| were envisioned: ironing and folding clothes.
| PaulDavisThe1st wrote:
| You have forgotten the first task of the day: buttering fresh
| toast.
| downboots wrote:
| Similarly, envision a solar sintering bot operating in the desert
| 1-6 wrote:
| I wish there were more companies in the US that can look at
| problem and solve it to a great deal of technical complexity. It
| seems like we're too focused on large and shiny objects.
| lnsru wrote:
| Robotics is expensive. One needs a team of software developer,
| electronics engineer and mechanical engineer to develop
| something. 3 people over 3 years with expensive hardware and
| couple millions $ for MVP needed. How many google ads for an
| app could one buy for this sum?
| sschueller wrote:
| That is what public funded universities and research is for.
| Many claim projects like CERN is a waste of money but this is
| where many new ideas and tech comes from as a side effect of
| trying to solve problems that arise while trying to build a
| bigger and more powerful accelerator.
| lnsru wrote:
| I have a problem with public funded universities and
| research in Germany. I really don't like how professors own
| companies where everything comes from PhD students' work.
| Basically they transfer state/grant money into personal
| pockets via paid work hours. Though I don't know how this
| works in Switzerland. Another day I saw a long list of CERN
| technologies that I can license from them and they were not
| for free.
| wg0 wrote:
| Jaw dropping. There's too much engineering work involved.
| Interfacing with vehicle and tons of sensors. Software.
|
| Would be best if some entity quickly moves towards
| commercialization/packaging of this solution.
| unglaublich wrote:
| These folks have a spin-off called 'Gravis Robotics', pretty
| interesting stuff going on. Their promotional video contains
| technical details as well:
|
| https://www.youtube.com/watch?v=yiTIXAAulzI
|
| https://gravisrobotics.com/
| aristophenes wrote:
| The photo of the wall in the article is obviously digitally
| altered, just to the left of the person walking. The rocks change
| into uniform smooth grey, and it doesn't match the reflection in
| the water. Is it supposed to be the digital plan of the wall vs
| the real thing?
| rkangel wrote:
| It absolutely matches the reflection in the water - you can see
| the hard hat of the person and the colour transition.
|
| The change in colour will be the result of a change in source
| of boulder. The whole point is that they are "recycling".
| evilaubergine wrote:
| where were the wireframe mesh rocks sourced from?
| dryrocks wrote:
| The excavator creates a mesh of each stone by scanning it
| "in hand", and updates the settled positions of them as it
| builds. The left side of the image is the 3D digital twin
| model that is maintained by the system, captured from the
| same perspective to show how it matches the real wall.
| TomWhitwell wrote:
| Yes, I think it's an artistic interpretation of a digital model
| of the stones - how the autonomous system sees them.
| 7734128 wrote:
| If you zoom in you can see that it's a polygon like mesh. It's
| certainly supposed to be how the rocks are represented in the
| system.
| jvidalv wrote:
| Just wanted to share that in my country (Spain) and more
| concretely in my area (rural part of Catalonia) we have a
| building technique called "Pedra Seca" literal translation is
| "Dry Stone". It basically involves building stuff with just
| rocks, nothing more. It's still in use mostly in agricultural
| fields.
|
| Here are a few examples:
|
| https://dd9de8c7b7.cbaul-cdnwnd.com/b5fbcf0e77b7b72ef95acd62...
|
| https://static1.ara.cat/clip/98e3619e-8dd2-4c0b-828c-254a62e...
|
| The google search:
|
| https://www.google.com/search?client=safari&sca_esv=58408328...
| adhesive_wombat wrote:
| Dry stone walling is also very common in the UK. It's a complex
| and now expensive skill, but a properly-built (this bit is key)
| wall will stay put for well over a hundred years because the
| rocks can shift a little rather then cracking the structure as
| temperatures change and water drains right out of them.
|
| It's also very locally distinctive because the shape of the
| stones and therefore the wall layout and texture depends on the
| stones you naturally have nearby.
|
| https://en.wikipedia.org/wiki/Dry_stone#/media/File%3ADry_st...
| fullspectrumdev wrote:
| Very common in rural Ireland, and having such a wall repaired
| or made is either going to cost you nothing or a LOT of
| money.
| HPsquared wrote:
| As with many of the best things in life, they are either
| free or very expensive.
| _a_a_a_ wrote:
| Sex? :)
|
| (edit: no, that was not an offer, sorry)
| adhesive_wombat wrote:
| It's the opposite really, because you're trying to get
| your rocks on, not off.
| imp0cat wrote:
| It's very common in Croatia, too.
| arbuge wrote:
| And Malta: https://www.google.com/search?q=malta+rubble+wall
|
| There they are called rubble walls ("hajt tas-sejjieh" in
| Maltese).
|
| Seems pretty common in Mediterranean countries.
| imp0cat wrote:
| Thank you, there is a great explainer in those search
| results: https://environmentalmalta.com/wp-
| content/uploads/2019/12/IR...
| Biganon wrote:
| In Switzerland as well. "Mur en pierre seche".
| simon_acca wrote:
| I recently witnessed something similar dating back to pre-Inca
| times in the archeological city of Quilmes:
| https://drive.google.com/drive/folders/1-6DnSeACUPUUskeJJIuB...
|
| We have them in Italy too btw, search for "muretti a secco".
| kinow wrote:
| Interesting! I am living in Catalonia now, but in Barcelona. I
| haven't seen (or paid attention) to a wall like that. Will pay
| more attention and try to find some nearby. Thanks!
| jlevers wrote:
| I rode through a huge area filled with these sorts of walls
| somewhere wayyy down a dirt road in rural central Mexico, sorta
| near Zacatecas. It looked like it was once a vineyard, or
| something like that...I'd never seen walls that looked this way
| before. Really beautiful. I had no idea that it was originally
| a European thing.
| protomolecule wrote:
| Looks safe.
| buro9 wrote:
| This is incredible because the vast majority of what it takes to
| build roads, rail tracks, docks, and such infrastructure is all
| in the clearing and relandscaping of land. It doesn't have to be
| perfect in terms of aesthetics or seals, but it has to be very
| stable and able to take the thin layer of road surface, rails,
| concrete on top and the weight that they'd carry.
|
| To be able to automate the landscaping is to massively reduce the
| cost of infrastructure projects in terms of labour and materials,
| but also likely the time to deliver them too.
| dryrocks wrote:
| For those looking for a more technical overview of the process,
| the overview video of the research paper is available here:
| https://www.youtube.com/watch?v=TxpE5yryCTU
| Obscurity4340 wrote:
| Stonewaller-3000
| rob wrote:
| Farmers in New England would have loved this. Miles and miles of
| stone walls just hidden in forests/woods.
| nuc1e0n wrote:
| Show it still standing in a year and I'll be more impressed.
| gnarlouse wrote:
| Imagine if the Spartans had this at the battle of Thermopylae
| hardlianotion wrote:
| This will revolutionise Yorkshire.
| moffkalast wrote:
| One might call it a... Deus Ex Cavator.
| bufferout wrote:
| For comparison, a 15th generation Japanese stonemason master
| doing it by eye: https://youtu.be/f9wGOXXoCuY
| crtified wrote:
| I assume (but don't know) that this method of construction would
| be less viable in more seismically-active parts of the world.
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