The 19-inch computers offer plenty of space for individual customization.

© Heitec

Highly integrated and compact industrial computers in a wide variety of formats are enjoying great popularity. Based on the architecture of standard PCs, they are more robust than these and meet the demanding requirements of many industrial applications, such as stable operation at elevated temperatures, shock and vibration resistance, resistance to contamination and moisture. The ability to expand the computers with additional PCI(e) cards, usually developed by the customer, and to have an almost unlimited selection of high-performance components such as processors, mainboards, graphics cards, power supplies and cabling available continues to make industrial PCs highly attractive - even in the 19-inch format. Due to the large variety of components, a suitable industrial PC can be realized depending on requirements, even with a limited budget. The industrial components are mostly characterized by compatibility with international standards, high long-term availability, simple expandability and comprehensive support, which is an advantage in view of complex certification cycles. They therefore offer the best conditions for scalability, upgradeability and configurability for different product variants. Replacing subcomponents, increasing performance, adapting to new technologies or making necessary adjustments are relatively easy to implement. If the requirements of the target application change, the system solution can grow with them. As their advantages are obvious, the computers are no longer only used in classic industrial areas, but also form a stable basis for the digital factory and their area of application is diverse, as the following example illustrates.

Use in test systems

Heitec supplies its sister company Heitec PTS - a provider of industrial X-ray technology for cast aluminum wheels - with 19-inch industrial PCs for use in controlling the fully automated wheel inspection systems 'HeiDetect Wheel Robot'. The cooperation with the Fraunhofer Institute, the resulting image evaluation software 'ISAR' and a degradation-free detector enable an almost pseudo-error-free evaluation of the results including stable image quality. Paired with an integrated industrial robot, the flexible system achieves very high throughput rates and is therefore ideally suited for inline operation in mass production.

As this system is subject to constant further development in terms of throughput times and data quality, the demands on the industrial PC used are increasing accordingly. The computers to be supplied for each new generation are therefore always equipped with high-performance components in order to keep cycle times low or reduce them during volume production.

But it's not just throughput times that are changing - the technology on which the applications are based, which has been under development for more than a decade, is also advancing into ever more areas: Computed tomography (CT), traditionally known from medical technology, is being used in its industrial form for inspection tasks. In the automotive industry, it has so far been used to inspect individual parts such as wheels, steering knuckles or wheel carriers. Recently, however, this technology has also been used for quality assurance in the measurement of entire objects - such as in prototype development for body testing.

In another 'Heitec PTS' solution, four moving robots with cameras directly on the production line use X-ray sensors to create a three-dimensional image of the entire vehicle and generate thousands of cross-sectional images. A 3D data model is created from this data and the resulting individual images, which makes any deviation from the CAD model visible. The accuracy of the 3D measurement is in the 100 μm range, which is roughly equivalent to detecting details in the dimension of a human hair. This allows vehicle structures to be analyzed precisely and weld seams, adhesions or the condition of the bodywork to be checked before and after painting. If a fault is identified, the systems stop so that the fault can be rectified immediately and production can then restart.

The innovation combines X-ray technology, plant engineering, robotics, measurement technology, image processing and computer expertise in an unprecedented way. It is the result of several years of development work with extensive test measurements as well as complex data processing and a dedicated software program that generates the detailed images. By processing large amounts of data, it is able to capture the many different patterns, combine data parts and finally evaluate the findings automatically. The possibilities are almost limitless: The aim is to create a kind of artificial intelligence that filters out relevant data, decides for itself which methodology to use and includes robots that access various self-adapting sensors. And in the middle of it all are up to ten robust and powerful 19-inch industrial PCs that control the fully automated processes and provide the performance for the complex and data-intensive image processing and evaluation.

The IPC requirements

The rear view of the industrial PC can also be equipped with different interfaces depending on the application.

© Heitec

In terms of technology, a cost-optimized 19-inch industrial PC housing was chosen for the system solution, whose compact, robust structure is ideally suited to the application and software requirements. The industrial PC, preconfigured by Heitec according to the customer's specifications, evaluates the individual X-ray images using a very powerful Nvidia graphics card and other high-performance components. This allows the images to be evaluated almost in real time and significantly reduces cycle times during mass production. However, some adaptations to the hardware were still necessary in this case: For example, the customer wanted additional interface cards with which to communicate with the system. Despite the maximum performance target, the aim was to design everything as cost-effectively as possible. A standard solution was therefore already advantageous in this respect due to its quick and uncomplicated adaptability to the requirements catalog. For example, the front and rear can be equipped with different panels for USB ports, connectors or LEDs and, if required, larger CPU cooling units can be connected using optimized drives. In order to fit exactly into the control cabinet, the 19-inch industrial computers had to be reduced in depth to 380 mm with a height of 4U, and at the same time the space requirements of the measurement cards had to be taken into account.

An industrial mainboard with a high-performance Xeon processor with eight processor cores provides the required computing power. The additional specific graphics card for the extended temperature range and with long-term availability is combined with the server CPU and mainboard. To meet the high demand for storage space and data security and to prevent data loss in the event of defects, several hard disks are used in a RAID array (Redundant Array of Independent Disks), which are designed for continuous use and have been made less sensitive to shocks and vibrations through the use of vibration dampers and shock absorbers.

Better ventilation is achieved, among other things, by a special mounting of the Nvidia Quadro P2000 graphics card with 5 GB. In order to avoid hotspots in the closed case with the large amount of data processing, the air from the fan is drawn into the inside of the case through the built-in filter mat. The resulting overpressure allows the warm air to escape through the perforated plates at the front and rear. The filter mat is easily accessible and replaceable from the front and has the additional effect of preventing the ingress of dust and other contaminants. This efficient method of thermal management was validated prior to delivery by thermal simulation and full load tests under real environmental conditions.

The ATX power supplies, designed for higher industrial temperature ranges, are dimensioned for an optimum operating point with sufficient reserves - their output is set twice as high as the normal operating state of the system, as their highest efficiency is achieved at 50% of the maximum output. The system is controlled via real-time capable Profinet and partially via a COM interface. The computers are connected to each other and to the factory network via Ethernet. The housing was also designed to be EMC-tight in order to minimize the risk during approval and also during operation.

In a complex application such as the one described, reliably functioning housing technology based on an industrial PC is an important element in the overall system. Here, a modular system concept forms a future-proof basis for future adaptations and updates.

Author:
Stephan Leng is in product management in the Electronics division at Heitec.