Cognex OCR technology meeting product regulations in toughest environments
Croatia-based INFO d.o.o.a distributor of Videojet, manufacturer of industrial coding, printing and marking products has developed a date printing and checking solution for global building materials company.
The Challenge:
Factory floors where 25 and 50 kg bags of cement are produced are extremely challenging environments. Sometimes paper bags are accidentally torn apart and cement dust fills the environment. Another problem is that bags are stained with cement from the outside.
Very often the bag position on the conveyer is not perfect and distance between ink-jet printer head and bag is not consistent. The difference in size, quality and position of the printed characters is significant. In addition, the lighting and contrast are very inconsistent – if the bag has a thin cement layer on the surface where the characters are printed, the contrast is very low and this creates a noisy background for the vision system.
Customer requirement:
The cement manufacturing line is a very rough production environment and date printing was not always successful and some bags went to the market without the required documentation. INFO’s customer also needed to comply with new Croatian legal regulations calling for a printed production date on the side of each cement bag they produce in order to control quality and product counterfeiting.
The Integration:
INFO deployed the robust Cognex In-Sight® 5100 vision system with its Optical Character Recognition (OCR) tool and this has proven to be the most suitable technology for the job. Dust in the atmosphere had little impact on images acquired by vision system as it features powerful lighting and good camera lens protection. Any challenge associated with variable positions of characters was handled by pattern algorithm and OCR tool.
For inspection results monitoring, In-Sight is connected to the VisionView® 700 operator interface panel so that the operators can monitor the process. The In-Sight is also connected to the PLC over MODBUS TCP. In this network, In-Sight sends the decoded characters to the PLC and the PLC then compares them with characters in the database.
Web: www.cognex.com
