Irish author Jonathan Swift knew that "vision is the art of seeing the invisible." This vision also drives the image processing specialist Isra Vision. True to the motto "The More You See," a well designed modular industrial image processing system has been made available. The system includes high-quality components such as colour line scan cameras, lighting systems, software modules and PC plug-in cards, which come together to form powerful, complete systems that meet the demands of each particular application. Not only does this guarantee a 100 % quality control, but it also makes an important contribution to production optimisation, which can be seen in the example of can inspection.

The Success Story of Cans

In 1933, George Newman, manager of the Gottfried Krueger brewery, was about to make a comeback: prohibition, which had been in effect since 1920, was repealed in the USA. In order to boost business, Newman wanted to produce a beer that is easy to transport. Then, a heaven-sent product came from a canned food manufacturer: cans with an inner coating that prevented the contents from adopting a metallic flavor. Already in 1935, Krueger sold 300 million cans. Today, the yearly production of beverage cans has reached 200 billion worldwide – without a doubt an innovative idea that has caught on.

The industrial image processing systems that reliably perform quality inspections during manufacturing are equally innovative. These days, no production plant can afford to rely only on sample inspections. Seamless surveillance is in demand. The emerging field of industrial image processing is therefore only in its early stages: four out of five corporations wish to use image processing systems in their production.At the top of their wish lists are flexible systems that can be adapted to the constantly changing requirements in production.

The ready-to-use and flexible image processing systems from Isra Vision are designed to fit the particular sector in which they will be used. The inspection systems from the manufacturer in Darmstadt, Germany, detect every defect quickly, automatically and with 100% reliability.

Inspecting 50 Cans per Second

Particularly high demands on image processing systems are made by the modern process for manufacturing cans and caps for the food and beverage industry, with its complex production lines. The cans are checked at high conveyor belt speeds of 240 m/min for holes and cracks on the rim, as well as interior defects and contamination.

The 100 % quality control of the cylindrical metallic packaging is performed by Isra's Can Expert product family. The system is capable of inspecting more than 50 coated steel or aluminum cans per second. The individual test stations distributed throughout the production area are configured to detect defects that have never before been detected, due to a significantly higher camera resolution. The system also allows products to be traced while they pass through the modules.

However, this is only one example of a great many applications that can be realised with Isra image processing systems. In addition to can and packaging manufacturing, there are, for instance, applications in the automotive industry, the sectors of glass, print, film and foil, plastics, logistics, mechanical, engineering, non-wovens and paper.

Flexible Product Building Blocks

Each image processing system for the wide range of applications is based on modular product building blocks consisting of high-quality individual components, such as high resolution colour line scan and matrix cameras, PCI and PMC image processing boards and readyto- use software modules. The key components are derived from the manufacturer’s own development and manufacture.

The optical stations are particularly sophisticated – specially designed for the particular application. For instance, the Total Can Inspection (TCI) station is responsible for the interior inspection of the cans. This module reliably detects bright and dark contaminations as well as flaws in the finishing and deformations with sizes as small as 0.2 mm x 0.2 mm. Three high resolution matrix cameras with overlapping image areas ensure that a significantly higher degree of coverage of the inspected areas of the interior of the can is achieved than is possible with other systems on the market. As a result of their high pixel frequency, the cameras are suited for high speed operations. A novel lighting system with specifically designed strobe LED arrangements forms the foundation for more accurate results.

The optical station WIM of the Can Expert System reads the bodymaker number, often hardly visible to the naked eye, from the bottom of the can. This number allows defects to be systematically traced. In this way, the user receives feedback on the optimisation of his manufacturing processes.

High speed algorithms specifically designed for this purpose, which incorporate plenty of industry-specific knowhow, are used by the software modules. The tools perform – depending on the application – code identification, optical character recognition, processing of diameter, distance, angle and contour measurements, and also identification, verification, colour image processing and position detection. In can inspection, the software algorithms ensure an extremely low false reject rate.

All of the different modules can be operated at one integrated station. The flexible user interface provides extensive information on the inspections via its system overviews and live captures. All measurement results for the individual measuring stations are assigned by the host computer and stored in a database for further assessment. This means that it is possible to instantly call up the overall results and, for example, statistics as a live trend. The soft PLC in the host computer assumes the task of tracing products over the entire process.

The industrial PCs at the individual stations communicate with each other via high-speed Ethernet TCP/IP. This also enables trouble-free forwarding of information, for example to the plant director’s computer. The core of the particular image processing station is located in the industrial PC. This core consists of special image processing cards, which provide the necessary intelligence for the various tasks of image processing.

A highlight among these boards is the Smash Web Processor – high-performance hardware which has been designed for high speed surface inspection applications. This module for sophisticated and fully digital image processing solutions in real time performs the data pre-processing onboard.

A Complete Solution, Tailored to the Application

All modules are a part of the modular “vision kit” and from these building blocks, complete solutions are tailored to the respective application. The modular structure of the system allows the users to use modules selected according to their quality strategy and upgrade the system as needed later.

Compared to similar solutions on the market, Isra systems offer an extended performance spectrum with a higher degree of accuracy and higher measurement resolution. The users can ensure flawless production with our image processing systems and avoid producing waste. Their advantages are noticeable wherever high speed processing and high quality is expected.

Holger Hofmann Isra Vision Systems AG Tel. +49-(0)721-5603 0 hhofmann@isravision.com www.isravision.com