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...
Autonomous excavator constructs a six-metre-high dry-stone wall
61–70 of 190 posts
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#62I wonder how many decades before someone hooks this up to a webcam and lets people play minecraft in real life.
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#63Earlier quoted context omitted.
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 wi…
> 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.
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).
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#64This 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…
If the wall is going to move a little shotcrete ain't going to stop it.
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#65Earlier quoted context omitted.
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.
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.
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...
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#66This 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 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.
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#67Earlier 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…
If the wall is going to move a little shotcrete ain't going to stop it.
I’d disagree with this. The general rule in mining is “six inches of shotcrete will hold up the world.”
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#68Earlier quoted context omitted.
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.
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
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#69Earlier quoted context omitted.
Appreciate this. Where can we read more on this engineering? All citations are welcome, I am fascinated by this engineering domain.
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…
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.
Re: Autonomous excavator constructs a six-metre-high dry-stone wall
#70Considering 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.
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 acro…
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.