Machine vision wizards love to play with high-end, PC-based vision software; products like Halcon, MIL and Common Vision Blox bring them out in goosebumps. But a growing number of basic machine vision tasks – typically the presence/absence applications– can be implemented fairly quickly performed on vision sensors.
A vision sensor, for those unfamiliar with the term, is a compact camera with built-in processing functions. Think of it as a low end smart camera or a smart photoelectric sensor. They’re configured over an ethernet connection, then run all day long, outputting pass and fail results (hopefully at the right time!)
Cognex have offered their Checker vision sensor family for some years. These tended to have low resolution but ran at high frame rates, which I found useful for some applications. More recently they’ve added pixels but that has reduced the framerate, which may or may not be a good thing.
And now Keyence have a competitive product, the IV series of vision sensors. These are compact, provide VGA-level resolution, and can be ordered with autofocus. (I don’t have any info on frame rates.) Pricing is competitive with Cognex – in the sub $2,000 range – and while I haven’t tested the software, I suspect it’s pretty robust and easy to use.
Sensors like these are a great way of implementing simple checks, and they’re so inexpensive that you can use two or three before coming close to the price of a smart camera. They may not be super-sexy but they get the job done.
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2 comments:
Has anyone tried this out yet? How does it compare with the Checkers?
Keyence is slower (typically 30ms - 150 ms processing time depending on # of tools and brightness), but the contrast is better because of better optics (colored, auto focus and auto brightness). Checker is faster and has more functions, but the contrast is not as good (black & white image and hard to keep it focused with manual adjustment).
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