The traceability of individual products is proving difficult in times of strongly interlinked chains for production and global supply. For high-priced components, the industry now uses RFID labels, data matrix codes or even chemical markers for identification purposes. Yet seamless traceability of the production history also makes sense for low-cost products, because even a single connector, worth only a few cents, may impair the performance and durability of a complex and costly end product. More cost-effective “tracking & tracing” solutions are in demand for small, price-sensitive components such as electrical plug connectors or spark plugs. Often it is technically unfeasible or simply too expensive to use labels or special markings in such cases.
Fraunhofer IPM has developed a tracking system for mass produced parts that enables individual authentication. The technology is based on the fact that many semi-finished goods or components have an individually distinct microscopic surface or interwoven color structure. An industrial camera takes high-resolution images of selected areas on the component’s surface. The specific structural pattern captured by the image and the way in which they are positioned relative to each other is used to generate a numerical identification code, which is then stored in a database together with other process and measurement data. This entire process can be repeated to identify the component at a later date. If there is a match for a code, the component in question is unequivocally identified.
The label-free tracking procedure has been designed for a wide range of materials from smooth plastics to aluminum, cast iron to varnished surfaces. The stochastic ‘finger print’ can be filtered out of the detected surface image at second intervals even with batch sizes of some 1000 parts. This enables the allocation of component data at production speed. As no additional markers or IDs have to be affixed to the product for this purpose, this system is forgery-proof and, due to the absence of quantity-related costs, it also makes economic sense to implement it for mass produced products.
For more information: www.ipm.fraunhofer.de