Wednesday, July 21, 2010

Vision sensor application

Vision sensors, such as the Checker from Cognex, don’t seem to get the respect they deserve. I think they’re terrific tools, if used in the right application. The problem lies in knowing when they are the best tool to use.

To help, here’s an interesting application story I stumbled across on the Cognex web site: “Vision Sensors Error-Proof Oil Cap Assembly.”

In this case, the selling points for the Checker were use of ladder logic for easy integration and low cost. There’s no mention of the high frame rate capability, which I consider one of the most interesting features of the sensor.

Why do I like the high frame rate? Go back and read “In praise of high frame rates” (6/28/10) for a reminder.

1 comment:

John Salls said...

I agree the vision sensors are fantastic tools for the right application. I guess the way I view them is as visual prox switches. If you are looking for the presence or absence of something and you can see it visually but can't sense it with some other method (thru beam, capacitive, ultrasonic, etc.), Vision sensors are perfect. Their only negative is most vision applications tend to grow into something else and Vision Sensors can't grow very far. For example, you might start off just trying to detect the presence of an oil cap. The vision sensor does a great job of that. Then you want to measure how well the cap is seated. You may or may not be able to add that feature with a Vision Sensor. But if you application is well defined and you can prevent vision creep or are willing to upgrade should it occur, they are fantastic!!!