Robot Visual Inspection

Samuel_Bouchard

Some customers asked us how to do robotic visual inspection. It is not possible with our camera, which is dedicated at vision guided pick & place. Who has done inspection in the past? @yuvarajoo can you explain how you did it in the video below? 

Sebastien

@Samuel_Bouchard
Turns out you can do some visual inspection with your Robotiq camera, but only part detection visual inspection as explained by @Catherine_Bernier
 in this post

matthewd92

I have done vision based inspection in the past using Cognex. The way it works is you will build a vision program that has the features that you want to inspect. Often you will use a feature on the part to orient the inspection frame of reference to the actual part orientation. This allows for the part to move slightly and still the vision system to locate the part. Then it's just a matter of adding various tools to the program for measuring the features you are interested in. The really great thing about vision inspection is it's extremely fast. We used to measure about 10 different features on the parts we made at a rate of more than 90 per minute and we could decide whether a part was good or bad and reject or accept accordingly. We had trap doors in the part chute that would open on rejected parts. Under the trap door would be a light curtain that we used to verify that the rejected part exited the chute. Then the door would close and the machine would continue. All of this was happening as we were making parts at around 94 per minute. 

We we also used vision to inspect ink jet printing on stainless steel strip moving at roughly 1000 feet per minute. The camera would read the message that was printed about every 8" and then either accept the lettering or spray a reject mark onto the band that the machine would use to reject the bad section of band. 

Cognex, Microscan, Sensopart, Keyence and others all make vision inspection systems. Prices can vary from $2000 to close to $10000 or possibly more depending on what you need to do exactly what you are trying to accomplish. Lighting is extremely important and can be a little like black magic. 

I'm sure there are other pros that can chime in on this as well. 

Samuel_Bouchard

Here is an interesting one from Microscan and Axis New England @Ryan_Weaver.

Ryan_Weaver

@Samuel_Bouchard  - this was a combination of 5 small vision applications, consisting of:

• 1D barcode read
• 2D datamatrix read
• Presence/absence detection
• 2 Pattern recognition tools

The applications themselves were programmed and ran on the smart camera, then were called via software triggers over TCP/IP from the robot.  The TCP/IP interfacing was a little clunky, but it worked reliably once it was configured.  It certainly would have been nice to have a smooth UR+ tie-in for the camera.