Vision system monitors more than 60,000 short circuit bridges

The company WMK - Teltow GmbH, part of the Schempp + Decker Präzisionsteile GmbH Berlin, Germany, produces short circuit bridges for electronic systems in cars to close electric circuits and to make sure, that no airbag opens while working on the car electricity. In close cooperation with itec GmbH and aviCOM GmbH, Omron developed an inspection system for short circuit bridges and applied it successfully to the production. Main part of this technology is a vision system from Omron.

This concept of automation makes production frequencies of only 60 ms possible

The constructional and electrical completion of the test machines, consisting of a winding off and winding up station for the endlessly manufactured contact elements and integrated test equipment with two vision sensors, took place on the basis of Omron PLC and driving technology and a user terminal for optimal human-machine communication.

The multipurpose inspection system has integrated PLC and servo technologies, which make it possible to adapt the system to different production situations with different quantities and rates and also an exact positioning of the objects in short time. Although the quantity and the rates of the materials that need to be wound off or up vary considerably, on the basis of the PLC, servo technology and four frequency converters in connection with the vision sensor an inspection time of 60 ms was realized.

Assuring a maximum error rate of 0, 0005%

Because of the requirements in the field of security, a very high quality is needed, when manufacturing these elements. So we had the task to build a system with test equipment that would fulfill a high quality requirement of less than five defective parts per one million parts.

High production rate made possible

All relevant adjustments can be done with the user interface, also activating the vision sensor. The full inspection of the short circuit bridges, within the scope of the continuity of the production is a very complex process with high requirements on the performance and the ability for applications in industries of the vision sensor.

To guarantee constant inspection conditions of the highly shining contact bridges we used a special ring light to make a diffuse reflective light possible.

To guarantee full quality of the punched contact bridges, the following inspection processes use the vision sensor:

• Surface inspection (Surface Detect, Binary Area).
• Dimensional accuracy inspection (Edge Position and numeric processing of the coordinates).
• Check of completeness of all punched elements (Grey Search, Precision Search).

After a successfully completed test phase the employment for other high precision parts can be designated.