Vision Systems

Can anyone offer some opinions on the different Vision systems available?

Banner And Cognex seem to be the bigger ones I've seen.

I want to inspect syringes to make sure the plastic cap is properly clicked on the end. The cap might be missing, or not clicked on all the way.

Talking to an applications engineer for Banner, he was suggesting the P4 GEO unit.

I am completely new to this, but somehow I am thinking the Edge unit is more appropriate. It seems that the way to detect a partially installed cap is to measure the distance from the edge of the cap to the edge of the bottom of the barrel. Thus an edge analysis.

There is a Banner iVu, with a built in display with touch screen. I tend to think that that is a good failure point, and if the built in screen is down inside the machine, hard to see. There is a remote screen option, for about $500 more.

I tried find more on-line description of the functions of the Banner, to understand the EDGE,Blob, etc. tools.


Are there other brands/models I should look into?

From working with both systems, without a doubt go with Cognex. The Banner is a low-cost system with very limited functionality, I don't think it would make you happy, I know it didn't for us and we were doing a really simple application. This has been a couple years ago and I'm sure Banner has improved them, but Cognex is the cat's meow for vision. You'll be much happier with it. We have 50+ Cognex and they are very reliable units. I think we still have one old 2000 system running (circa 2002 or so) that we've not upgraded yet, because there is no real need for it.
The Cognex has all kinds of tools in the software that make your life easy and very reliable for vision for an application like you describe.
They aren't cheap, I'll grant that, but we wouldn't buy anything else now. We are actually using the line-scan versions to inspect parts for defects. You would be surprised at what you can do with them.

What is the physical distance difference between one that is snapped on and one that is not and min/max of the part sizes? This will determine the resolution and lens you need.
The most important part of vision inspection is the lighting, DO NOT SKIMP ON THE LIGHTING -- YOU WILL REGRET IT!
Lighting is also not cheap.
You can holler at me if you need more info....I think you have my number.

I've never used them, but Keyence has vision sensors too. And all their other sensor stuff is very good, I use a lot of it. They'll bring it out and demo it for you at your shop, too. Worth a shot

Another vote for careful attention to the lighting, optics and resolution.
I would think you would be best off with a Cognex unit although I haven't used one of their boxes for quite a while so I'm not familiar with their current tools. They are defiantly "King of the hill" in on-line machine vision.

I'm hoping these are plastic tubes. Imaging a reliable edge on translucent plastic is bad enough, glass tubes can be a real pain.

Blob tools are a little more tolerant of things like a parting line or small bit of flashing on the cap.
There is nothing you can do with a blob tool that you can't do with a set of edge tools. You just may have to take more points and do your own blob math or averaging.

In addition to Tony's questions I would ask, Is the part stationary or moving and how much time do you have.
Could you post a pic of the parts?

Bob

My experience with Keyence is they extremely proud, price wise. Nearly double on most things I quote compared to other companies we deal with (Banner, Balluff, Turck). Have not priced vision from them, so I can't comment on it specifically.

The parts (both caps and barrels) are milky white plastic. They are rotating on an eight station indexer, 3 per second.
The indexer has a 270 degree cam, (90 degrees dwell) so they are approximately stationary for 1/12 of a second. That seems like a lot of time, inspection wise.

There are six different products that the machine must handle.

Since these are pre-fill syringes, they want to ensure that the cap is in place and fully seated. The next step in the operation is to fill them with medicated goo. then push in the plungers and pack and ship.

I was in Chicago at Pack Expo this week. One of the engineers from Banner was telling me that back lighting would be the best. I have to think hard about how to do that... The indexer is only 10" diameter where the syringe barrels are sitting. There are eight sets of linear bearings and sixteen air cylinders behind them. The barrels ride up and down on the linear bearings as part of the assembly process.
So, getting back light diffusers tucked in there and not interfere with the carriages and tooling riding up and down will be quite a trick. Maybe sideways lighting..
But the lighting will be a key factor to making it work.

I can find some pretty cheap, and current Banner units. That seemed like a possibility to at least learn a bit about the technology. There was bunch on a site for $150 each.. Banners website has a download for software updates.

Asking the application guy about a used unit is not so cool, they Only want to sell the new unit, for around $1600 - $2300. And the guy I can ask the questions is the guy that sells me a new unit.........

I see a few Cognex model 100 Checkers on Ebay, but all the literature I see only refers to the model 200 Checkers.

Unless, until one gets a little bit familiar with all the different models it can be a hard decision which one to get and play with.

I don't know if this is an option or not - but you might be able to do this inspection with a linear displacement sensor. We have tested a number of laser gauging products (mostly Keyence) and have been able to get +/-0.0005" repeatability with good tooling and get within 0.005" with hardly any effort at all.

Sensor reaction times can be as fast as 50 usec so you could scan the part multiple times in your dwell period. The scanned spot is small however and your target would have to be of decent size depending on the accuracy of your indexer. . . (by decent size, i am thinking at least 0.030 - 0.050 inches in diameter)

Keyence did a demo of an optical micrometer where I work recently. It was neat, and they (with our engineer) set it up to work in the exact application it might be used. It also had some gating/focus options, so even if the part was close or far from the sensor, it would measure the individual feature on the surface of the part.

Keyence doesn't come cheap, though they might discount you if they think you will buy regularly, and they seem more than happy to help test a couple solutions or research material--measuring system compatibility. I guess they want to sell something...

We buy a lot of sensors - the Keyence sensor stuff is reasonable for what you get. We replaced a set of Allen Bradley send-receive photo-eyes that detect rolls of toilet paper as they go through a smart conveyor with a Keyence send-receive unit for less $$. They Keyence sensor used a laser source that could see through the "tails" that had become unwound on the rolls.

And as mentioned above - the Keyence sales engineers are Johnny on the spot with a big suitcase full of demo units and fixtures to help you proto-type your app and then will loan parts to you to do further testing.

All that said - if you have a true vision application - Cognex is hard to beat.

Motion,
Thanks for the lead. Distance measurement might not work here. At least it is not obvious it would. Some of the syringe barrels have a long tip, and the cap goes over the tip. It might be a real trick to line everything up to know if you were measuring the cap, or the tip of the barrel.

Also, there are six different types of product going through the machine, of quite different shapes and lengths, It might be a bit if frustration for the setup tech to re-align the measurement gizmo for the different caps/barrels. In one case it might have to try to see the cap from the side or the bottom depending on the shape and size and resultant strategy.

It looks like something for another future application.

The hope is the visual system can recognize the barrel and the cap, and understand the (correct/incorrect) relationship with them.

I use some Keyence 2d laser scanners and was just playing with a few of their vision products yesterday. I was pretty impressed with the functionality. As far as the pricing, all Keyence stuff seems to be in the format of two sensors feeding one controller. So, if you need a single sensor/camera, it's pricey. If you need two, it's reasonable. The third is expensive and the fourth is reasonable again.

I'm not claiming that they are better or worse than Cognex, but they are definitely competing.