Product number, manufacturing date, and index are pressed into the surface of the railroad bearing. Since the characters are on a dial, if an individual character doesn't properly roll to the next character a duplicate serial number can be generated of the character is not fully formed.
The product was rolled until a laser sensor located the first character. A Cognex InSight line scan camera imaged the full length of the string and a pattern match was performed on each character.
Due to the variance in surface finish and impression depth (as the character die wore down), multiple images over the whole production were collected and a composite image for each character was generated. The composite image of the character was used to generate the pattern classifier.
After the bearing raceway has been machined to a sized blank, the possibility exists that the surface may have underfills, pitting, or other blemishes. Such non-conformances need to be removed and repaired before the additional value is added to the product.
The product is placed into an encoder roller system via an overhead robotic system and is imaged with a line scan camera. If variations in the surface finish are detected, the product is moved to a secondary inspection area, other wise it is moved onto the next step in the process.