A vehicle transmission consists of around 300,000 parts. Its main components - for example the differential, input and output gear, carrier, clutch, transmission housing, valve body and housing - are tracked throughout the entire production process. In addition, the main components on the engine must be monitored throughout the entire production and distribution process. To estimate the size: an engine consists of around 200,000 parts - including pistons, cylinder head, engine block, camshaft and crankshaft.

KIA Motors' traceability program reads the 2D data matrix codes on the components to determine whether the correct part is present. The system then stores manufacturing information such as production date and model number on the server for full traceability.

KIA Motors installed Cognex readers at each mounting point of the transmission and engine components, which capture and read the codes and, thanks to the direct Ethernet connection, transmit them to the PLC without an additional transmission device.

© Cognex Germany

The barcode reader previously used led to frequent stops of the production machines due to code reading errors. It was operated manually, making it difficult to keep to the production cycle - with negative effects on both work performance and production output. At the same time, there was a risk of using the wrong parts if a code was misread, causing production errors. As the parts of the 6-speed gearboxes are also very small, the Data Matrix codes on this line proved to be particularly difficult. And last but not least, KIA Motors reduced the marking size from 10 mm × 10 mm to 5 mm × 5 mm. This also affected the marking quality.

Faced with these challenges, KIA Motors switched to Cognex barcode readers on its 6-speed transmission production line. The result is read rates of 99%. The readers feature patented algorithms that enable read rates of 99% and higher, even in the most challenging DPM and label-based ID applications.

Patented algorithm

The car components from KIA Motors are assembled with an anti-rust oil spray. Ergo, one of the challenges for the reader is to eliminate errors due to traces of oil on the code. The devices also have to ignore the fact that the 2D data matrix codes are stained or damaged due to dirt or scratches, even though they have been washed and kept clean. And last but not least, the codes are very small due to the reduced marking size and exhibit strong deviations in marking quality. However, the '2DMax+' code reading algorithm from Cognex is unaffected by this: The 2D code reading software is based on the company's pattern matching technology. Regardless of the cause, it can cope with a wide range of quality losses in two-dimensional DPM codes or printed codes, even if critical parts are missing. The software is able to read data matrix codes even with missing finder patterns or timing/clocking patterns. It locates and reads underexposed and overexposed Data Matrix codes without the need for multiple read attempts, improving throughput, speed and overall reliability.

As Cognex barcode readers are also Ethernet-connectable, they can be integrated directly into the factory network and enable direct communication with the PLC without a transmission device.

Stationary barcode readers were installed to check the quality of the laser markings on the production line. KIA Motors installed the 'In-Sight 5110' reader from Cognex at each assembly point of the transmission and engine components. The car manufacturer also opted for the 'In-Sight Micro 1110' in tight, narrow places. A portable reader was installed as a backup system

Author:
Janina Guptill is a Marcom Specialist at Cognex Germany in Karlsruhe.