Heater wrote:Sounds like a fun project.
The poster did not list any technical experience with any technology, nor suggested any mechanical or optical approach, so while it may be an afternoon for someone who is an expert in all of the technologies, for a beginner I would say it will take a few weeks. It's tricky and requires expertise in multiple areas (mechanical separation, optical recognition) that have nothing to do with each other. The poster did not mention access to any technology other than a raspberry pi. It might be a few weeks before they even receive all the parts they would use.
By the way, with your setup, if there is recognition of colors, then mechanical ability to separate one color at a time is sufficient, because you can simply repeat the whole set up. Mixed -> Red, meaning the servo will separate out only reds, then change the code and change the separated-bin from the red one to a green one, and repeat mixed->green, separating out all the greens, and so forth. Likewise both false positives and false negatives are okay: suppose that when separating the reds from the mixed, 20% of the reds are not identified (stay in the mix, false negative) and 10% are mistaken decisions or the servo activates the wrong piece (a different color makes it into the red.) He can simply run through the mixed bag multiple times, so that he gets all the reds.
He could then modify the code for a "Quality assurance" mode that goes through the Red mix as input and rejects anything that isn't red.
Please note that this is factory-like level of automation, and in every way an extremely difficult project.
Assuming that the machine takes 10 seconds to separate a bead through the vibration setup, the machine would take 30 hours per color (per run) to go through the poster's mentioned bag of 11,000. (Obviously on the first run, there will be fewer beads in subsequent runs if colors are repeated). So it's very slow. if we reduce 10 seconds to 1 second, it will take 3 hours to go through a bag of 11,000 beads.
I think the fact that one bag of beads has 11,000 inside was missed when suggesting servo action. It's one of the main reasons that I mentioned puffs of air. That's just a huge number of beads.
Heater wrote:There we go. Job done in an afternoon !
An afternoon if you're 'buying", a month if you're "selling"
. I defy you to build this by tomorrow
By the way I wonder whether it would be possible to attract the things with static electricity, since they're plastic, and somehow attract them to one of several bins located around the stream. Does anyone know:
-> Is there a circuit that can quickly create or discharge a static electricity field?
-> Could this be powered by PWM?
-> Would it be sufficient, and safe, for sorting plastic beads?
-> Will it be safe and not shock anyone
This is just a blue-sky idea but I'm curious. Certainly easier than building a puff-of-air generator. It would be nice to be able to sort a stream of plastic beads just as they fall. Any physicists/electrical engineers in the house?
Though I would again emphasize that this is an extremely difficult project.