- Multi-layered verification systems are crucial to ensure defective components are properly identified and completely removed from production lines.
- PLCs should check communication between cameras, software and sensors to prevent data processing bottlenecks that could cause parts to go uninspected.
- Failure mode analysis during design is essential to identify potential error sources, such as incomplete removal of defective parts or sensor malfunctions, before systems go into production.
Just a few years ago, humans were largely responsible for quality control. However, due to fatigue during long and late shifts, differences in the level of experience of individual employees or other circumstances, they often represented a source of error themselves.
By integrating in-line inspection systems for 100% inspection, manufacturers have been able to free up employees for other tasks requiring human oversight while maintaining product and inspection quality at a consistent level.
But who checks whether the machine itself is becoming a source of error?
Inspection process reliability
To ensure that the individual inspection systems and sensors fulfill their tasks as required and that no part leaves the line untested, manufacturing companies need a strategy to verify the testing and safety of the process. This requires that interactions between individual components and inspection steps must be precisely defined, as well as the consequences if one of the process steps fails.
An inline inspection example of series-produced components using the Kistler KVC 621 SE optical quality inspection system illustrates what such a concept might look like.
This compact testing system for punched metal components can perform an optical inspection of up to 4,000 parts per minute to check for dimensional accuracy and surface defects such as scratches or dents. Up to three integrated camera stations take pictures of the test part enabling the KiVision image processing software to handle the evaluation and ensure that every part is inspected, even at high cycle rates.
The built-in camera stations and software for image processing are connected by the programmable logic controller (PLC), which initiates the individual steps such as recording of the test piece, data transfer and evaluation by the image processing software. It also checks the communication between the individual components. The camera, for example, sends the signal to the PLC when an image has been taken and transmits the image to the image processing software.
