akiyuky's "NXT-based Vision Guided Brick Sorter"

[Phoxtane]

Here's a video that I came across a while back that I feel is worth sharing:

It's a brick sorter that uses object recognition to classify and sort elements into various cups built by akiyuky, the same mastermind behind some rather ingenious GBC modules.

His blog post at http://legokarakuri.blog91.fc2.com/blog-entry-4.html is the first of two, describing in some more detail how the machine decides where to send the part in question.

The machine appears to work by waiting until the user dumps a load of Lego elements into a bin, setting off the sorting device. A small slab lifts up a smallish selection of elements and dumps them onto the first of two conveyors, which spreads out the elements slightly. The same occurs at the next conveyor, spreading them out even further. The elements are then dropped onto a platform, where a cheap camera detects the presence of a part and stops the conveyor assembly.

At the viewing platform, the part is enclosed in a black box illuminated by a set of LEDs. A scale accurate up to one hundredth of a gram (.01) weighs the element. The camera then sends an image of the part to the control computer, running it through a database made in a program called OpenCV [Open Computer Vision - object recognition software]. After the piece has been identified, a wheel holding one cup for each sorting category rotates the proper receptacle into position and a slide arm dumps it into place.

It's a remarkable piece of machinery, but I myself would probably build it out of wood with sturdy vinyl for the conveyors, and use an Arduino for the control mechanisms. By the time I would have built it myself, I won't have any Lego left to sort!

[timslegos]

Wow that is one pretty neat sorter. A while back i made a sorter too, but not nearly that complicated.

tim

[Phoxtane]

It wouldn't be all that hard to get the parts, either - strip down a couple of old printers and scanners and you should have most of the motors necessary.