ETO Magnetic GmbH, an industrial product manufacturer based in Stockach, Germany uses Cognex In-Sight® vision systems to create a continuous monitoring system for traceability at their facilities in Germany, Poland, China and the United States.
The individual fingerprint
ETO Magnetic is able produce several million defect-free parts for the automotive industry with just a few seconds between steps in the production process. A factor in this success is the continuous monitoring of parts on their way to a finished product, based on intelligent vision systems. Laser-etched and dot peen 2-D codes provide the most important methods for creating an individual fingerprint for quality assurance. Since the introduction of innovative traceability solutions from Cognex, the pseudo-failure rate has been reduced from four percent to almost zero.
Identification with obstacles
Laser-etched codes, as a rule, provide good contrast and can be read reliably, dot peen codes on metal parts present the last generation of code readers with an impossible reading task. During the production process, metal components are thermally and mechanically distorted to the extent that these 2-D codes suffer collateral damage. When stamping the tiny 6x6 mm identification areas in the dot peen process, tool wear can lead to differences in impression depths and angles of the individual marking points. When the last generation of code readers attempted to read these dot peen codes, up to four percent of parts were determined to have unreadable codes. "This rate was clearly too high for us," said Process Planner Klaus Schwanz of ETO Magnetic. "In our manufacturing processes, a product with an unreadable code is treated as a reject. In a plant handling several million parts, our old ID readers were simply not up to scratch. So we looked for a better system and found it from Cognex."
Better with an intelligent solution
It was only when ETO Magnetic began to use In-Sight vision systems on their manufacturing lines that the 2-D dot peen codes could be successfully identified with one hundred percent certainty. "A decisive advantage of the change to the In-Sight vision system is its combination of lighting, camera, ID software, processor and communications interface," said Bruno Halter, Senior Application Engineer at Cognex. An essential contribution was also the know-how of the vision specialist, who eliminated possible problem points in a (literally) illuminating way. For metal surfaces that were, in part, highly reflective and particularly difficult to identify, the developers at ETO Magnetic used flat white lighting. "Earlier, we tried to read dot peen 2-D codes in the same way as printed codes. In particularly difficult cases, reflective behavior of the dot peen codes rendered this method ineffective. To address this challenge, we lit the relevant areas uniformly with white light and were able to recognize the impressions of the dot peen code reliably as black spots," explained Bruno Halter.
A sure thing
The decoding cannot be optimized with additional lighting in every case. In many industrial environments, space limitations often leave room only for the ID reader itself. For this reason, Cognex In-Sight ID readers are equipped with the Cognex IDMax® data matrix code reading software, based on Cognex's leading PatMax® technology. This technology guarantees reliable and stable decoding under the most difficult conditions. A digital, high-speed recognition system, DSP architecture and optimized reader algorithms ensure high reading rates at all times in identification applications with labels and direct marking, even on the fastest production lines.
Quality beyond customers’ expectations
With the comprehensive traceability of parts for the automotive industry, ETO Magnetic goes significantly further than demanded by the company's customers. Most of the 2-D codes are applied solely for internal traceability of the manufacturing processes. In this way, the company can trace every part, however small, in all individual components, down to the delivered load of copper wires for electromagnetic windings. Possible process or material faults are detected early and corrected. Not only satisfied customers but also the management of ETO Magnetic are delighted with their cost-optimized production processes.