Machine Vision

To stop the barrel from overflowing

Image-based code reading in a brewery filling process

18.10.2012 -

Beer is sometimes described as liquid bread. This say a great deal about its status in our culture. The popular beverage is produced in large quantities and transported to the end consumers by a wide variety of distribution channels. Beer has been filled into barrels since ancient times. In the modern automated filling process, image-based code readers ensure that high quality standards are complied with.

Consumers must be able to depend on the quality, quantity and compliance with regulations. Because of this, complete tracking of the product by means of codes is of vital importance to producers. In the United Kingdom, the Trading Standard (Weights and Measures Act) sets stringent directives for weights and measures. This ensures that consumers can rely on the stated quantities for their decision to purchase. This Act is therefore an important regulatory instrument. It contains clear specifications regarding the type and method of information, the quantities which may be sold, as well as the units of measurement. When filling beer into returnable metal barrels, the Everards Brewery in the Midlands frequently experienced problems with scanning the bar codes. The ID bar code labels are attached to the new, empty barrels. These are then weighed to determine the tare weight. The bar code is scanned and the tare weight of the new barrel is stored in a database. During the filling process the barrel is transported to a weighing station on a conveyor belt. The barrel is scanned and has to be identified from the database. Then the barrel is re-weighed to calculate the precise quantity of beer with which it has been filled.

Small cause with negative effects

Of course, the barrels have to be re-used on a regular basis. Rough handling of the barrel, during transport or storage can cause considerable damage to the bar codes. Previously, the ID bar codes were detected with a laser scanner. Due to frequent damage to the bar code labels, the scanners only achieved a detection rate of 60 - 65%. This had a negative effect, which could only be remedied by manual intervention.
The process was slowed down and costs were produced. A considerable number of barrels could not be detected precisely enough, which infringed against the Trading Standards. As a laser scanner reads the code along a single line, reading problems occur if the code is aligned at random or at right angles to the reading line. The moving parts of the scanner, such as the mirror are a potential source of faults and limit the life of the system.
Ultimately, the laser scanner did not prove to be adequately efficient and the interaction with the weighing software no longer fulfilled the current requirements. Because of this, Everards looked for a reliable solution, to increase the quality and production flow in this process to a reliable level.

Flexibility and security

Everards took its requirements to the system integrator Fairfield Labels, a supplier of automation solutions and ASP (Automation Solution Provider) from Cognex. They required a system solution with a very high reading rate, which could guarantee compliance with the Trading Standards. In addition, the filling process and weighing of the barrels was to run smoothly and also achieve a considerable added value. Due to their extremely efficient image processing algorithms, image-based Id code readers have a very wide range of functions. With this, they achieve considerably higher reading reliability than laser scanners. This is especially demonstrated when handling impaired or damaged codes. As well as this, image-based systems can also undertake other tasks, can be used more flexibly and can be rapidly adapted to new requirements. This means that an image-based ID reading system rapidly pays for itself.The system solution from Fairfield Labels uses the image-based DataMan 500 ID code reader, which was directly combined with the new weighing software via its integrated interface and controller driver. With its wide field of view, a barrel and its code label can be positioned considerably more flexibly in comparison with a laser scanner.The advanced decoding technology of the code reader guarantees reliable reading, regardless of the alignment of the labels and the varying levels of illumination in the brewery. Even badly printed, damaged, distorted, scratched and blurred codes can be reliably read, even against a confusing background.Parameters such as the aperture, contrast, focus, communication settings etc. can be specified via a simple graphic user interface. With an optional functional extension, both bar codes as well as 2D data-matrix codes can be read simultaneously. The code reader utilises liquid-lens technology and can therefore rapidly focus on the field of view. As it does not contain any moving parts, it is extremely robust, requires no maintenance and has a very long service life.

Contact

Cognex Germany Inc.

Emmy-Noether-Str. 11
76131 Karlsruhe
Germany

+49 721 958 8052

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Digital tools or software can ease your life as a photonics professional by either helping you with your system design or during the manufacturing process or when purchasing components. Check out our compilation:

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