Kicking the tires

The Institute for Automobile Technique Dresden (IAD) at the Technical University of Dresden (TUD), Germany operates a certified test stand for tire and car body analysis. Analytik & Messtechnik Chemnitz (AMC), Germany replaced the old PLC-based system with proprietary controllers with a modern system based on PXI and LabVIEW from National Instruments. The test stand is used to inspect static and dynamic properties of car tires (shown in Figure 1, courtesy of IAD, Technical University of Dresden, Germany). Force and momentum are recorded using a six-axis wheel hub. Rotating speeds equivalent to a road speed up to 300 km per hour (187.5 miles per hour) can be tested. Parameters such as camber and skew have to be measured at such high speeds because there is no speed limit on German high-ways (Autobahn). All German car manufacturers limit their cars elec-tronically to a maximum road speed of 250 km per hour (156 miles per hour).

Upgrades and enhancements are readily made because the test stand, controlled by three cooperating pro-grams, is scalable and modular. For performance reasons the Programmed Automation Controller (PAC) hardware is configured from CompactPCI/PXI modules. The LabVIEW Real-Time Software controls safe and real-time operation of the test stand. This includes controlling powerful electrical motors for the rotating drums that simulate the road. The rotating tires are dynamically pressed with different amounts of force onto the simulated rotating road to test such factors as car weight and bumpy road conditions. Hydraulic pistons tilt the wheels for testing under different camber and skew. Each individually changeable axis is controlled by its own thread in the software. I/Os are shared variables for fast, efficient modular data exchange using the Technical Data Management Streaming (TDMS) protocol to transfer and save descriptive information along with bulk measurement data. Tire temperatures and dynamic suspension parameters are also monitored and analyzed by LabVIEW in real time. The test stand is operated via an Ethernet connection. Analysis is completed using DIAdem software from National Instruments.

Figure 1 (click graphic to zoom)

Dresden is the capital of the Free State of Saxony within the Federal Republic of Germany. It is a world heritage city under United Nations Educational, Scientific and Cultural Organization (UNESCO) rules. Shortly after Gottlieb Daimler and Carl Benz invented the automobile in the late 1880s a car industry developed in Saxony. Several car companies merged into what is now the Auto Union Company. Today all their models are traded under the name Audi. The predecessor of the IAD was estab- lished under the direction of Court Councilor Professor Hermann Scheit in 1903. It provided analytical services of automobile mechanics, tires, and engines to industry and for the Technical University of Dresden. As a result, the IAD has more than 100 years of experience in auto-mobile technology, as an historic photo of a tire test stand (Figure 2, courtesy of the IAD, Technical University of Dresden) shows.

European events

Analytica 2008, the world’s leading inter-national trade fair for the laboratory sector was held April 1-4 in Munich, Germany. At this trade fair there were not only analy-tical instruments on display, but also com- puter systems for auto-mated and in-depth analysis of organic and inorganic chemical, life science, and physical laboratory probes. The PC-based or industrial computer systems also manage Laboratory Information Management Systems (LIMS). The 32,500 visitors (not including exhibitors) analyzed what 1,032 exhibitors had to demonstrate. Analytica can be compared with Pittcon, the largest laboratory science event in the United States, which was held one month earlier, March 3-6, 2008 in New Orleans. It had about the same number of exhibitors (1,100) but fewer visitors, 19,500, including 8,800 exhibitor attendees). Pittcon claimed visitors from 85 countries. About one third of the Analytica visitors were from 111 countries. Analytica organizers claim that 98.5 percent of the visitors were professional people, no tire kickers. Messe Muenchen International (MMI) and the organizers of Analytica also manage Analytica events in China, India, and Vietnam.

For more information, contact Hermann at:
hstrass@opensystems-publishing.com