A challenge. Finding the length of a potato strip

mp91 said:

I am also from the potato world. I remember seeing a post you made a little while ago about high speed cameras and food and I thought to myself I have probably worked on your equipment in the past.

Did you work on equipment by Kiremko or KEY or Tomra? They seem to be the big three (in Aus anyway) and I have worked with them all. My answer to the length is like other smart arses... get a strip sorter and it will tell you!

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I was once asked if I wanted to do a Simco Ramic optical sorter training course in Oregon, I'm in Perth, western Australia. Sure, would love to.
When they contacted Simco Ramic to arrange course was told would have to do it at one of our sites in Australia as they couldnt even find a model as old as ours were , even on their scrap heap.
Even the model we had that ran on basicly a 286 computer was capable of measuring a 1mm fault on a potato chip at 100ft/sec.
Amazing tech watching a camera pick up a blemish and blow only that chip off 6 inches later.
We replaced it years ago with a Key tech Raptor I think it was.

Simco Ramic was a competitor. I think they have been out of business for a long time now. At least I haven't heard about them for a long time.


I can't believe 100ft/sec. Maybe per minute. If the camera can do a frame rate of 1000 FPS then at 100ft/sec the resolution would be 0.1 ft which is not good.


Our scanner scans strips moving at about 400 ft/min with a resolution of about 1/40 of an inch. The big advantage we have is the ability to cut out the defects precisely due to our advanced motion control.

I would have thought that vision would be an obvious solution to this problem.
Not only can it detect the size of the potato chip, but also if there are chips that have turned bad or have other defects.

I know of a Danish company that specializes in exactly that, using vison to remove defects and outliers, only not potato chips but for the wooden sticks used in ice cream popsicles.
edit: And they do it by looking at the wooden sticks falling down in a continous stream, just like the example with the potato chips.

You are probably right Peter. 100 ft/min does sound about it.
Was over 20 years ago I worked on that vision system.
We had a upgrade of the production line about 10 years ago and a new Key Optyx laser vision system was installed to replace the Simco. That is amazing tech sorting in size, shading and colour and then eject only that chip.
Understand the tech was originally developed to sort logs for sawing.

janner_10 said:

I assume now with scan times what they are, you could get away with just one sensor and recording the time it is on for, thus determining the length.

I'm guessing the speed of the fry / chip falling doesn't fluctuate too much depending on it's weight.

What an interesting project that must of been though.

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With hardware interrupt for rising and falling edges,worth testing.

JesperMP said:

I would have thought that vision would be an obvious solution to this problem.
Not only can it detect the size of the potato chip, but also if there are chips that have turned bad or have other defects.

I know of a Danish company that specializes in exactly that, using vision to remove defects and outliers, only not potato chips but for the wooden sticks used in ice cream popsicles.
edit: And they do it by looking at the wooden sticks falling down in a continuous stream, just like the example with the potato chips.

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There should be only potatoes. Other material shouldn't make it that far. The potatoes are steamed, then rolled in an abrasive chamber the rubs the skins off. The potatoes are shot by a water cannon through a metal grid that cuts the whole potato into strips. The strips are then scanned for defects. This is probably done by a KEY scanner but there are others. The defect scanner is cheaper and can scan a high volume of strips than what a defect removal machine can do. 90% of the strips are usually OK and don't need to go to the defect removal machine. We make the defect removal scanner and cutters. If everything is right then our scanners only need to scan the 10% of the total flow that has defects on them. One thing we do is monitor the ratio of good strips to strips with defects. Sometimes the KEY scanners are set to be too sensitive so we get good strips thrown in with the bad ones. A big advantage we have over KEY is that we can cut on either side of the defect as shown in the video above. The KEY machines cut in 5/8 inch chunks so a 1/16 inch defect still must lose 5/8 of an inch of strip. This is a loss that our machines don't have. This difference results in our technology paying for the machine in a few months.

We cannot sell these machines except to the potato manufacturer that paid for the development.

Peter Nachtwey said:

I don't know anything about Kiremko or Tomra, Key is a competitor.

We are actually the outside R&D for the major potato processing company. This potato processing company actually owns the technology since they funded all the development. I don't know of any installations outside the US. I am not involved with the development of the potato scanning, grading and defect removal any more. There are other people that do that. I am mostly involved in motion control.

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Ah that's cool. We had 5 KEY sorters including one of the defect removal unit. Super cool tech. Always gets new people to the factory excited and suprised how much tech goes into making hundreds of tonnes of fries a day.

35 years ago the potatoes would go down a conveyor with about 10 women on each side. They would look at the potatoes going by and if they looked bad they would cut out the bad part with a knife. In the summer time it was hot and steamy. It had to be a miserable job.

The KEY defect removal units use a wheel with slots where the knives stick through when needed. The problem with this is that the knives could only cut every 5/8 inches. Sometime a knife would cut in the middle of a defect so the knife before and the knife after also had to cut to get the whole defect. This meant that 1 1/8 inches of strip would be lost just to cut out a small 1/2 inch defect.

You should see modern sawmills.

mp91 said:

Ah that's cool. We had 5 KEY sorters including one of the defect removal unit. Super cool tech. Always gets new people to the factory excited and suprised how much tech goes into making hundreds of tonnes of fries a day.

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You dont work at Tingalpa by any chance.

Peter Nachtwey said:

35 years ago the potatoes would go down a conveyor with about 10 women on each side. They would look at the potatoes going by and if they looked bad they would cut out the bad part with a knife. In the summer time it was hot and steamy. It had to be a miserable job.

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That was how it was done at the plant where I used to work 3 years ago.
Potatoes after peeling passed over a conveyer of rolling section and operators would look for bruising or green spots and cut off by pieces by hand.
It was a miserable job.

sparksy@gage said:

You dont work at Tingalpa by any chance.

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Nope - I am out of the potato world now. Used to work at a big plant down in Tassie