Tuesday, November 12, 2013

Tips for specifying a machine vision system

Wearing my “Lean manufacturing” hat, I’d argue that machine vision is little more than a Band-Aid. It patches problems rather than going to root causes and eliminating them. However, in the real world that most of us inhabit, sometimes patching is all you can do. But as with any problem solving, the quality of the outcome is directly related to how well you define what you need to do.

That’s a point made by Greg Hollows of Edmund Optics in “Integrating a Vision System” published in Assembly magazine, September 2013. This intelligent article covers many of the issues that should addressed, and especially the importance of defining requirements. It’s really important that you take the time to do this thoroughly.

One point I’ve seen trip up many vision system installations is long-run part variation. It’s all very well specifying and configuring your system to work with a certain set of products, but many materials exhibit batch-to-batch variation that is often not considered. As Hollows notes in his article, “Changes to the materials used to make the parts can wreak havoc on a vision system’s ability to perform after the changeover.”

There’s no such thing as an easy vision application; they all have challenges, so start by defining carefully what it is your system is supposed to do. Better still, start by reading the article linked above.

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