Fastener presence verification

The inspection point

The most expensive assembly error is a missing screw that surfaces in the customer's hands rather than at the end of the line. The hard part is not counting: it is telling a half-seated screw from a seated one, because from above both are present. Since the part shifts a little every time, a check that looks at fixed coordinates produces false results.

How it runs on the line

The unit looks at the exit of the assembly station. Assembly and missing-part mode is trained on complete, correctly assembled parts, so a missing fastener and a proud head both come out as deviation. The result reaches the PLC as pass/fail and the part is stopped before it moves to the next station.

• OK

• NOK