Automated rope knot tying machine

[JerinG]

Does anyone know for an application of automated rope knot tying? I'm thinking about an application for hop trellis twining. It is currently done manually, but I think the potential is there. There was some work done in the past, but I think that this is too complicated for a farming application:
A Robotic Knot-Tying Platform for High-Trellis Hop Twining

I was researching about common applications for knot tying in farming and found this:
The CLAAS knotter
It is a simpler knot than it is for hop trellis application that uses clove hitch knot, so the challenge is greater. I will appreciate any help about what is already done in this area of automated rope tying and I'm willing to discuss any other ideas that could be potentialy applicable.

 

[3DDave]

That's a fun device (the embedded video failed for me, so here's a direct CLAAS knotter video link from that page:

https://www.youtube.com/watch?v=AEgPs1wGBRs&feature=youtu.be)

I recall an article by the late Bob Pease about tying tobacco plants and how quickly he could do it. Same deal, clove hitch at the top, but a larks foot at the plant. Tobacco doesn't twine so they manually had to wrap the plants around the string as they grew to keep the from falling over.

"What’s All This Knot Stuff, Anyhow? (Part 4)" 07.09.09 Electronic Design; there's a PDF, "Bob Pease Lab Notes Part 7.pdf" you can search for (Google returns a link, all 2000 characters of gobbledegook which I won't paste; do a search with typedf)

This is an interesting knot-tying robot, the necktie robot, "Why knot"

https://www.youtube.com/watch?v=c0atClPSTx8

 

[hydtools]

Something like a rebar tying tool?

https://www.maxusacorp.com/rebar_tying_tools/

Ted

 

[JerinG]

Interesting proposals. First necktie robot is great, but again too sophisticated for farming equipment, I think.

Rebar tying tool is also great (video), but you can't push a rope like you can push a wire. Rope materials used in hop trellis are described here. Some metal wire is used, but is being replaced slowly with natural materials.

Currently this is done like so and so.

 

[tbuelna]

Here is a more recent (2015) public access paper on the subject.

https://www.researchgate.net/public...twining_robot_for_high_trellis_hop_production

 

[IRstuff]

Seems to me that trying to replicate the manual operation isn't necessarily the right answer.
> why is the knotting operation even a requirement?

In cases like this, one should go back to the operational requirements, presumably, something like:
> Each plant shall have a thin, lightweight, vertical structure that it can grow on and climb to a maximum height of 7.5 meters
> The vertical structure shall support the weight of the growing hop and its own weight and stay vertical within 10 degrees
> The vertical structure shall be easily removable from any overhead support required to maintain verticality

So, doesn't have to be a twine, and doesn't necessarily have to be tied in-situ. Unclear whether the twine is supposed to be reusable, but one option would be to have premade loops in the trellis and use small carabiners to clip the vertical twines to the loops.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[JerinG]

IRstuff, you are correct. I was aplying this logic sometime ago. But... There is always a but .

The clove hitch knots are used because the rope needs to be secure on horizontal steel wire. In the case of strong winds rope moves left to right and hop field becomes a mess and it is also a possibility of rope failure. Germans use barbed wire and a simpler knot, because barbed wire prevents vertcial rope moving on the wire.

I was thinking about an option of clamping elements that would secure the rope to steel wire and they would break when the hop is harvested. This is done in a way, that a machine on a tractor cuts the rope near the ground and then pulls the rope with the plant down. The rope breaks on top, where it was knotted. This can be seen in one of the videos I posted in my last post. The only thing is that these clamping elements need to be degradable, because otherwise we will have fields full of plastics, which is a no no in these times. It is strong wish that all plastic ropes will be replaced with natural materials. But these natural materials need to degrade in a short amount of time but not in one season, because they don't fulfill the function. Plastic ropes also make a lot of problems with other machinery used in the field. They twine on all sort of plows, they get into bearings, etc. A lot of it stays in the ground and makes trouble for a long time.

 

[FACS]

This makes me think of fishing knots, fishing nets, and trot lines.

https://www.youtube.com/watch?v=NblQFmSYVnE

Maybe this will spur some thought.

Why knot tie the knots first- make an assembly - and then put them up? It seems if they can make a gigantic fishing net you should be able to do this.

 

[Strong]

My first thought combining knot tying with farming was a hay baler:
Search: hay baler twine knotter troubleshooting

https://www.bing.com/search?q=hay+b...2ERsfehGPEYYPXh2vipnb3fooI5SiggmWzq3P&plvar=0

Any help?
Walt

 

[JerinG]

Hey FACS, thanks for this info. I will check it out. But I still need to get that preasembled knot around a steel line that is 6 m high and then tighten it.

Hey Strong, I'm also very optimistic about this hay baler machines. One mechanics that is very close to what I want, but still needs a lt of work to do the job I want. I will check the information on your link.

I will show you what a hay field looks like right after it's been harvest. As you can see there is a lot of vertical plastic rope residue. On the last photo you can see how the plants are growing. Steel wire that is used for holding vertical ropes is supported prependiculary every few meters. So If one tends to design a machine that will follow the line, it needs to move away when it arrives to that perpendicular line.

 

[dhengr]

JerinG:
So, we are going to get rid of two fairly talented guys (farm workers), who can each tie two knots, one with each hand, at the same time, on the same horiz. overhead wire. And, replace them with two guys who don’t got to know nothing, or have any talent, but they can hold up two 15lb. machines, at only $700 each, over their heads, for hours at a time, hooked up to a compressor, or an electric generator on a trailer, which needs to be serviced regularly, maybe just a really long extension cord in each row. Sounds like a bad deal for everyone involved, except the guy who sells the knot tying machines, which didn’t seem to be needed in the first place.

 

[SnTMan]

Yeah, you don't want to go around automating mindless tasks

Having said that, the guy tying a knot with each hand is pretty amazing.

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[JerinG]

dhengr, what kind of talent are you talking about? It is just repeated hand task and most of people who are not too clumsy will get the hang of it in some time. It happened a lot in history. One example of such "talented" people is all that was connected with horse transport before cars took over the world. And numerous other examples. And you must know that most of this work is done by cheap labour force that comes here every year when there is a lot of work to do in short amount of time and then shipped back. People from our country don't do that kind of work no more or maybe less then they used to.

Second argument is somewhat different and I didn't think about it until I was also talking to people from hop growing instutition here and they said that it is only a matter of time when there will be an accident with a platform that is used by people when they are knoting the ropes. Saftey inspectors are looking "through one eye only" now, so that every year the ropes can be tied. But things can change quickly when there something will go wrong.

But yes, I agree with your observation that people are scared of automation, because there is less potential mindless work to do. But I'm not that worried. A lot of things still need to be done by humans and robots or simple automated machines will not be able to do the job so quickly and in such quality as humans can. Just go and ask Elon Musk. He misjudged the robots ability to do very complex tasks that people can do with almost no thinking, like car wiring and connectors. These kind of tasks are still not defined enough, so that a robot could to a good and fast job.