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Autonomous excavator constructs a six-metre-high dry-stone wall

ethz.ch

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Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#11

Post by ano-ther »

fnordpiglet wrote: post #6
soperj wrote: post #3

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.

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.

It scans 20-30 (a truckload) before building a section of the wall with them.

Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#12

Post by myegorov »

toomuchtodo wrote: post #9
beachy wrote: post #8

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…

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…

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.

Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#14

Post by toomuchtodo »

myegorov wrote: post #12
toomuchtodo wrote: post #9

Earlier quoted context omitted.

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…

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.

Appreciate this. Where can we read more on this engineering? All citations are welcome, I am fascinated by this engineering domain.

Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#15

Post by yk »

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.

Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#16

Post by abduhl »

toomuchtodo wrote: post #9
beachy wrote: post #8

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…

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…

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.

Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#17

Post by seabrookmx »

toomuchtodo wrote: post #9
beachy wrote: post #8

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…

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…

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.

Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#19

Post by foota »

fnordpiglet wrote: post #6
soperj wrote: post #3

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.

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.

I'm getting some light towers of hanoi vibes

Re: Autonomous excavator constructs a six-metre-high dry-stone wall

#20

Post by ExMachina73 »

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.
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