[EDIT] Adding some useful quotes from the radio interview and cleaned up the facts
[EDIT] The homepage for the company is at [3]
A similar, though much larger, machine for sorting oysters was invented in Australia a few years back (around 2006 by the look of it).
I can't find any specific web presence for the machine itself, but I managed to dig up an interview with the inventor [1] and the episode of 'Inventions from the Shed' I originally saw it in [2].
The basic premise, from memory, is to feed oysters into a chute via a conveyor belt. The oysters are funnelled so that they drop in front of a series of cameras set at different angles, which use shape recognition to match the oyster with one of a few grades of oyster.
[We built] a scanning detector that would take four images of the oyster as it fell--just falling under gravity and passing through four separate scanners at 45 degrees to each other, produces four separate images.
We take the four images and they're processed through a dedicated microprocessor and the algorithms that we use are fairly sophisticated, because they have to react very fast. And, yes, we produce in a sense a volumetric calculation
The machine then chooses which bin to route the oyster to by rotating a directing piece at the bottom of the drop.
Directly below the scanning system we use a server motor which is effectively the same as you would use in industrial robot and it has a slide that is re-positioned for each oyster, and is stationary as the oyster is diverted from the direct fall down into an exit tube. That server motor rotates and is in its new position within about .03 of a second.
The machine ends up being quite fast, with around a week's worth of work done in less than a day. The accuracy, at 98%, is also impressive.
We have had one machine operating in excess of ten a second. We've limited it for this particular production machine to a theoretical maximum throughput of one eight of a second. It works out when an oyster grower is putting them through at an average of probably three to four a second [which is] about a thousand dozen an hour, between 800 and 1,000 dozen an hour
Some diagrams showing what the machine looks like are at [4].
The main differences between this mechanism and the skittle machine is the extremely quick sorting necessitated by the application (sorting large amounts of oysters that was previously done by hand) and the reliance on shape matching rather than colour. I wonder how hard it would be to make a machine that sorts skittles in a similar way, that is by dropping them down a chute, analysing and directing them before they reach the bottom rather than the somewhat slower method evident in the demonstrated machine.
[EDIT] The homepage for the company is at [3]
A similar, though much larger, machine for sorting oysters was invented in Australia a few years back (around 2006 by the look of it).
I can't find any specific web presence for the machine itself, but I managed to dig up an interview with the inventor [1] and the episode of 'Inventions from the Shed' I originally saw it in [2].
The basic premise, from memory, is to feed oysters into a chute via a conveyor belt. The oysters are funnelled so that they drop in front of a series of cameras set at different angles, which use shape recognition to match the oyster with one of a few grades of oyster.
[We built] a scanning detector that would take four images of the oyster as it fell--just falling under gravity and passing through four separate scanners at 45 degrees to each other, produces four separate images.
We take the four images and they're processed through a dedicated microprocessor and the algorithms that we use are fairly sophisticated, because they have to react very fast. And, yes, we produce in a sense a volumetric calculation
The machine then chooses which bin to route the oyster to by rotating a directing piece at the bottom of the drop.
Directly below the scanning system we use a server motor which is effectively the same as you would use in industrial robot and it has a slide that is re-positioned for each oyster, and is stationary as the oyster is diverted from the direct fall down into an exit tube. That server motor rotates and is in its new position within about .03 of a second.
The machine ends up being quite fast, with around a week's worth of work done in less than a day. The accuracy, at 98%, is also impressive.
We have had one machine operating in excess of ten a second. We've limited it for this particular production machine to a theoretical maximum throughput of one eight of a second. It works out when an oyster grower is putting them through at an average of probably three to four a second [which is] about a thousand dozen an hour, between 800 and 1,000 dozen an hour
Some diagrams showing what the machine looks like are at [4].
The main differences between this mechanism and the skittle machine is the extremely quick sorting necessitated by the application (sorting large amounts of oysters that was previously done by hand) and the reliance on shape matching rather than colour. I wonder how hard it would be to make a machine that sorts skittles in a similar way, that is by dropping them down a chute, analysing and directing them before they reach the bottom rather than the somewhat slower method evident in the demonstrated machine.
[1] radio interview - http://www.radioaustralia.net.au/international/radio/onairhi...
[2] video - http://www.dailymotion.com/video/xmdk44_inventions-from-the-...
[3] homepage - http://www.oystek.com.au/
[4] drawings
grader - http://www.oystek.com.au/images/grader_line.jpg
top down view - http://www.oystek.com.au/images/grader_line2.JPG
complete setup - http://www.oystek.com.au/images/grader_line3.JPG