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How do you deal with parts that are stuck together? I actually noticed one in your demo video, and was curious. This seems like it would be very difficult to

• jacquesm 10y ago
  They have a category all by themselves, get taken apart after the first run and then simply made to go through again in the next batch. The neural net is surprisingly good at classifying 'mess' as a category!
  • kolinko 10y ago
    I wonder if you could make a simple mechanism to split apart the easier parts...
    • jacquesm 10y ago
      I suspect that's a harder problem than anything I've done so far.
      • monk_e_boy 10y ago
        Does it make your finger hurt splitting the parts? Mine ache after about 10 minutes of playing with lego
        • jacquesm 10y ago
          I have a whole bag of tricks for that.
          • EGreg 10y ago
            Care to share? :)
            • jacquesm 10y ago
              Lego makes two 'removal' tools, those are handy, then, I have a very sharp naked 4" blade that will take care of the hardest cases, baseplates will flex the tiniest bit and that will usually give you enough space to flip the top part off. Finally, a regular plate pushed at a 45 degree angle into the space between two other plates will separate the two without damage to any of the parts if you do it 'just so'. Adapt as needed :)
        • PhasmaFelis 10y ago
          You need a brick separator! At least two, if possible. http://www.bricksabillion.com/tools/the-brick-separator/ http://www.bricksabillion.com/tools/the-brick-separator/
    • itbeho 10y ago
      Perhaps subject them to a near vacuum state? Pressure differential of trapped air in pieces might pop them apart.
      • moron4hire 10y ago
        From experience, Lego are nowhere near water-tight, say nothing about air-tight. The air between the pieces will leak out before you can build a high enough vacuum to pop them apart. I suspect this is by design: air-tight connections probably create enough of an internal vacuum that doesn't come apart with hand-force.
        • robotresearcher 10y ago
          If the push-in joints were air-tight they would be harder to put together as you would be pressurizing the air in each connection. Then the internal pressure would be working against the friction fit to pop them apart again.
        • mattkrause 10y ago
          Really? I made a mould out of Lego (to make Lego-shaped gummy candies) and with a thin coating of vaseline on the outside, it was indeed water-tight (and silicone-goop-tight too).
          • moron4hire 10y ago
            Vaseline would count as a liquid gasket, in this case. It's really going to completely change the conditions.
            • mattkrause 10y ago
              I think there were there were beads of water on the outside of the mould, but it was much closer to water-tight than I had imagined, even without the vaseline. They're astonishingly well made for a children's toy.
  • mikeash 10y ago
    That's a nice solution. I'm reminded of a short video I watched on the Lego factory. One segment of it discussed the machine that put the minifigs' heads on their bodies. There's a big hopper of bodies that get drawn up onto a belt and then a camera makes sure each body is facing the right direction before putting the head on. What do they do with bodies that are facing backwards? Is there a little side channel that flips them around? Nope, they just get tossed back into the hopper to try again. It's effectively random which way they'll be facing when they get picked up, so they'll eventually get through. I thought that was a nice illustration of keeping things simple and taking advantage of processes you already have, and seems similar in spirit to this.
    • jacquesm 10y ago
      That's exactly what I love about this whole project. It's an endless series of seemingly simple puzzles. Then you start solving them and they turn out to be much more complicated than you thought. Until you hit the solution and then it's simple again.
      • mikeash 10y ago
        Sounds about right. Thanks for sharing it!
    • bonzini 10y ago
      And because it's effectively a coin toss, the average number of passes through the machine is just 2! Just a remark from a Lego nerd: it's attaching arms to bodies, not heads. The neck has a stripe on the front, so that is where the camera looks at to determine which side is facing up.
      • jacquesm 10y ago
        Somewhere there is a part that has cycled forever ;)
        • mikeash 10y ago
  • developer2 10y ago
    Are "mess" and "unknown" the same bin? I would expect that they get grouped together as a "human intervention" bin. It would be very surprising if you went so far as to train the neural net to recognize pieces stuck together as something different than an unrecognized piece.
    • jacquesm 10y ago
      Yes. Well, the net is trained to see them different for later (I have some more nifty ideas) but they are grouped together when sorting.
  • Splines 10y ago
    What about pieces that, put together, equal another larger piece? Say, a few "flat" pieces of the same color to make a larger 1 unit tall brick? Can you see the seams on these?
    • jacquesm 10y ago
      No, it would miserably fail at that unless I fed a whole bunch of such composites in and tried to teach it the difference between the two. Even then I'm not sure if it would work but it doesn't happen often enough to be a problem.