Wednesday, October 24, 2007

Inspection systems focus on performance, robustness, and stability



A discussion with Robert Massen, Baumer Inspection


VSD: What systems or services does your company provide? What is the origin of your company?

VSD: What systems or services does your company provide? What is the origin of your company?

Massen: Our company started via a management buyout from a former for-profit institute, which I founded together with the Steinbeis Foundation at the University of Applied Sciences in Konstanz, Germany, around 1982. We have a history of 25 years in machine vision, starting with a large number of industrial customer projects and focusing now on in-line inspection of aesthetic surfaces: multicolored, patterned, and textured products such as laminate floorings, decorated furniture panels, ceramic tile inspection. We design, install, and service worldwide in-line inspection, sorting, and process-monitoring vision systems and are a leader in the field of automated laminate flooring inspection.

VSD: What technologies and components do you use in machine-vision-related applications? How often do you evaluate competing technologies?

Massen: To simulate the very peculiar human perception of decorated multicolored surfaces and at the same time detect physical defects such as scratches, bubbles, bad transparent protection layers, chipped edges, and so forth, we combine multiple camera/ illumination systems into our multisensorial inspection technology, including color linescan cameras with diffuse ultrastable illumination, black-and-white linescan cameras and directed light (4k and 6k, mostly), and spectrally tuned linescan cameras and specific wavelength illumination for the inspection of transparent protective layers.

We prefer Camera Link frame grabbers, possibly with a bit of integrated FPGA preprocessing. We use a PC cluster architecture for achieving the high computing power required for that type of color and texture processing. To be flexible to the ever-changing aesthetic designs of very creative artists, we use almost 100%software-basedimage processing with our own libraries of image-processing algorithms.

Almost half of our staff of 50 employees are software and vision specialists, who do checkout possibly competing technologies. We have a continuing education philosophy, sending our vision specialists to conferences and having some of them working as part-time Ph.D. students.

VSD: How do you evaluate the performance of the few color linescan cameras on the market? Which cameras do you use in your designs?

Massen: A reasonably priced, ruggedized color linsescan camera with high geometric resolution, fast linescan frequency, very low color seams, operating at variable product speeds, and radiometrically stable under severe temperature fluctuations of an industrial production line is still a bit of a dream. We never trust the published technical specifications of the camera manufacturers and even less those communicated by distributors, but we do tests these cameras extensively in our labs. We often discover subtle, but technically important flaws or items missing in the published specs. We always have to do a careful selection of appropriate lenses that are hard to find, both for trilinear and especially for 3CCD prismatic color linescan cameras.

VSD: How do you design your systems for OEM product obsolescence?

Massen: As our systems are highly modular PC-and software-based architectures, we have no problems in adapting to a new generation of motherboards, multicore processors, or new operating systems. We program in a very modular way in standard C/C++, separating software and hardware; so changing to a new camera or frame grabber does not pose any problem. Our customers appreciate this guarantee of long operating life and of a familiar PC and Windows environment, even if arranged as clusters of up to 16 networked PCs.

VSD: In which areas of the industry do you see the most growth? What are users demanding from you in the design of new systems?

Massen: The broad field of nonindustrial vision markets such as security, traffic, and toll control; electronic driver assistance; postal distribution; and logistics will grow at a faster rate than the vision market for machine-vision systems operating in the production line. These systems will use a lot of components, software, and knowledge existing in the machine vision scene. Some established machine-vision companies such as Vitronic (Wiesbaden, Germany; www.vitronic.com) are expanding quickly into these new markets parallel to their ongoing machine-vision activity.

A ColourBrain Laminate Inspection System from Baumer Inspection examines laminated fullboards at a Pergo production facility in Garner, NC, USA. Our customers are using faster and faster running, highly automated, almost unmanned production plants for an evergrowing variety of decorations and for production batches ranging from hundred of thousands to batch size one (such as in automatic kitchen-producing plants).

They ask us to offer them simple-to-use and stable inspection systems for their highly complex inspection tasks. For automatic very-high-speed visual sorting, they need very low overdetection rates (wrongly classifying good products as being bad), fast training for new d├ęcors, and an integrated automatic process-monitoring and quality management system.

VSD: How will OEM components targeted toward machine-vision applications have to change to meet future needs?

Massen: In our specific segment of inspection in production lines, the focus is more on technical performance, robustness, and stability then on price alone. We would appreciate better color linescan cameras operating without false-color seams at wide observation angles to decrease the height of our systems. We would also appreciate the development of cameras that integrate several narrow-spectral-band linescan sensors and fast 3-D sensors in one camera body.

VSD: Could you compare the machine-vision markets in different industry segments in Europe and the rest of the world?

Massen: The European machine market is highly dominated by German companies that produce some 82% of the European turnover. The German machine-vision scene is extremely active, both in the field of application-specific vision systems and also for vision components (cameras, frame grabbers, illumination systems, and software libraries). The specific excellence of the German “Sondermaschinenbau” (specialized highly automated production machinery)is closely related to German machine-vision companies, which has given a definite push to both. A good example of this process is the recent acquisition by the German Weinig Group, a leader in wood-processing machinery, of LuxScan Technologies, a wood scanner company in Luxembourg.

I do see a good and hard-to-copyf uture for similar marriages between advanced production machinery companies and vision companies. At the same time it is astonishing to see German companies such as Basler (Ahrensburg, Germany; www. basler-vc.com) exporting high volumes of cameras produced in high-wage Germany to low-wage China, again a proof that technical excellence and professionalism can compete with low salaries.

VSD: Could you discuss the impact of working with Baumer? What has that meant for your business? How are you now organized?

Massen: The Swiss Baumer Group, a family owned group of some 35 companies with a total of 2000 people, invited MASSEN machine-vision systems as a shareholder in 1992. Baumer was a great help in moving our activity from a more project-based institute activity to a product-based company by focusing on a small number of markets. The 100% integration into the group is therefore not a surprising move but a natural development. The rebranding into Baumer Inspection increases the visibility of Baumer as a unique group of companies producing the total spectrum of noncontact sensors, from classical proximity to vision sensors, intelligent cameras, and application-specific machine-vision systems.

We are a member of the vision technologies business unit of Baumer, which employs some 250 people. This is very broad range of expertise that helps us both in view of vision components and technologies available from the group and as a worldwide machine-vision business supported by the presence of the group´s subsidaries.

ROBERT MASSEN turned a for-profit research institute in image processing into the private MASSEN machine vision systems GmbH, which recently became part of the Baumer Group and was rebranded as Baumer Inspection. Editor in chief Conard Holton spoke with him about integrated system design.