Measuring pipe diameter by machine vision

Control Engineering magazine has an interesting story on their website about a Cognex VisionPro application, and it’s left me scratching my head.

“Vision-guided robots automate oil tool assembly” (April 19^th, 2012) describes an application where a robot threads a pipe end, then screws on a cap. One of the challenges in this is to deal with various diameters of pipe.

The approach chosen by integrator JMP Engineering is described thus: “A brick red light shines on the pipe at an oblique angle to create a shadow that enables accurate measurement of the pipe diameter.” There’s a picture in the article that shows what the camera sees as a result of this lighting approach. (I’m not copying it here because I don’t want to run afoul of copyright.)

Leaving aside the fact that I think they actually mean a red brick light is used, (“brick red” is hardly an engineering term,) what the lighting does is to make the pipe white in the image, with a semicircular shadow in the bore. I presume that VisionPro analyzes this shadow to determine the diameter, but I’m not exactly sure how.

My guess is there’s some dark blob detection followed by extraction of some key parameter, perhaps the feret diameter, but I’m not sure and frankly, I’m rather intrigued. So please click the link above and read the article, then let me know how you’d approach the diameter measurement task.

Cognex VisionPro upgraded

To tell the truth, this is one of those stories that I save for slow news days, but I think it’s worth a mention. VisionPro is one of the most capable machine vision software products around (and I know that will get the folks at Stemmer Imaging, MVTec and so on just a little bit agitated,) so I think it’s worth your while to stay abreast of the latest developments.

The big change for VisionPro 7.0 seems to be the addition of what Cognex are calling “Inspection Designer.” As the press release points out, this aims to make it easier to develop flaw detection applications. I think what they’re doing is extending the QuickBuild aspects of programming-free development to make it easier for non-programmers to migrate from the InSight smart camera family.

In this regard Cognex seem to following the lead of Matrox and their Design Assistant product. This was sold as a cut-down version of MIL for non-programmers, although my impression is that it’s rather fallen off the radar of late. A quick scan of the Matrox web site shows the only way to get hold of Design Assistant is to buy it bundled with an Iris GT smart camera. That combination makes for a powerful little package but it also keeps Design Assistant from going head-to-head with VisionPro 7.0 in the machine vision marketplace.

I wonder if that’s a smart move?

Cognex publish full year 2010 results

It's hard to know what to say about the results Cognex just reported for 2010. We knew they'd seen a huge turnaround from the dark days of 2008-9 but how many people expected record sales and profit?

As I'm sure many did, I read through the press release looking for details about what they are doing so well, but I struggled to pick up anything significant. Factory Automation is doing well, so we are told, as is Surface Inspection. The most tantalizing hints however seemed to relate to code readers – the Dataman family – and software, by which I presume is meant VisionPro.

There seems to be an implication that Cognex have decided their future lies with vision sensors and reading Datamatrix codes, rather than the higher-end industrial inspection tasks, and that makes sense. I'm sure engineering a robust vision sensor is no easier than developing clever new image processing algorithms, but the market is probably much bigger. In other words, I think I'm detecting a shift in emphasis away from clever engineering and towards marketing and volume.

Who can blame them, if that's where the money is?

Machine vision job in Southern California

An unnamed manufacturer in the growing solar sector is looking for a vision guy or gal with LabVIEW or VisionPro experience. Details are on Dice.

They’re looking for someone to manage projects in areas such as high speed pick and place automation, robotics, assembly quality, manufacturing defects, and incoming material and final assembly inspection. Seems like this goes beyond just developing vision solutions and is more of a project management role. Why, I might even put in an application myself!

Solar bandwagon keeps on rolling

The photovoltaic industry has been one of the few bright spots in what’s been a pretty grim twelve months, so it’s only natural that machine vision companies desperate for sales are pinning the “solar” tag on everything they can.

Cognex is perhaps the most recent company to climb aboard, with the launch of their VisionPro Solar Toolbox. (The link goes to LaserFocusWorld because that’s where I picked up on the story.)

The Cognex press release says, “The new VisionPro® Solar Toolbox includes pre-configured software tools for the most common vision alignment and inspection applications in photovoltaic (PV) solar production.“ I’m not familiar with the particular requirements of the PV industry, but this does sound like old wine in new bottles. VisionPro 6.0 is a pretty comprehensive product, so I struggle to believe that the solar industry has requirements so specialized and unusual that they really need pre-configured software tools.

And to continue in my cynical vein, as a wise man once said, if you see a bandwagon rolling you’ve already missed it.

Upgrades all round

It must be something to do with the season: it seems like everyone is upgrading the machine vision software. First I got an email from Matrox telling me of some new capabilities in their MIL package, then Cognex follow up with version 6.0 of VisionPro.

To the MIL upgrades first: I might be oversimplifying, but the big things to my eyes are the addition of a bead tracking routine and support for 3D imaging. Of themselves they’re not huge advances. Bead tracking is one of those tools that from time to time I wish I had, while the addition of 3D imaging tells us that Matrox believe this is an application area with growth potential.

The VisionPro 6.0 release is a little more exciting. First, they’ve opened it up to images of greater bit depth. In other words, you can now feed it 16-bit images. This makes it possible to work with thermal images and, yes you guessed it, 3D. They’ve also added a line scan calibration tool, which I can see being very useful, (for line scan work, obviously!) And finally, VisionPro now supports 64-bit operating systems. That’s not something most users have been clamoring for, but it does show some forward thinking.

So which product is best? There’s no simple answer but keep checking back because at some point I hope to do a more formal comparison.

Scorpion rumor

I hear that Scorpion are looking to put their 3D software on the Sony smart camera. If true, this will have them going head-to-head with Sick in the industrial 3D camera business.

As I understand things, this will be part of the upcoming release of Scorpion Vision Version 7.2. No word on pricing, although I anticipate something upwards of €6000 for the full camera+software bundle. Scorpion isn’t the cheapest machine vision software package out there, but founder Thor Vollset is working hard to establish his software product as a credible alternative to Cognex VisionPro and Halcon from MVTec.

If you’re looking for a standard machine vision platform you could do a lot worse than to consider this Scandinavian startup.

Vision Guided Robotics Application

VGR is one of the higher profile areas of machine vision these days. Everyone wants to do bin picking applications and if you get along to The Vision Show in Boston I’m sure you’ll find many such demos.

But here’s one that won’t be in Boston. Courtesy of “Observe the Banana” comes this report on VisionPro, Point Grey and Kuka working together to play air hockey. After you’ve watched the video I strongly encourage you to use the link to the Ohio Northern University website that tells just how they did it.

Something free from Cognex?

I noticed today that Cognex are offering a free 30 day trial of their VisionPro software. (Click here for details, but note that VisionPro is not for the novice. It's what we might term 'heavy-duty' vision software.)

So what does this tell us about their state of mind in Natick? Do they fear that their Insight and DVT ranges have achieved maximum market penetration and therefore to get more growth they need to move customers up market? Could sales actually be slipping? Or is there another motive?

The adoption of 1394 and GigE is interesting too. This is going to move Cognex away from their framegrabber range and make them more of a software company. Why would they want to do that? Is software more profitable than hardware? Or are they just facing up to the reality that the framegrabber's day are limited?