Metrology and Quality Assurance in Industry 4.0
Industry 4.0 and the Industrial Internet of Things (IIoT) are two terms that tend to appear together when the topic turns to the future of manufacturing. This is because the two concepts are closely linked: the increased interconnectivity that comes with the IIoT is a key component of the smart factories of Industry 4.0.
As a result, advancements in IIoT technology are rapidly making Industry 4.0 a reality, and the ensuing paradigm shift will have a profound impact on every aspect of the manufacturing sector, from machine tools to metrology.
Gisela Lanza has a unique perspective on the IIoT, Industry 4.0 and the new role of metrology for quality assurance they engender. For four years, she worked simultaneously as the first incumbent of the shared professorship of Global Production Engineering and Quality at the Karlsruhe Institute of Technology (KIT), and at Daimler AG in strategic planning.
How is Industry 4.0 influencing quality assurance and metrology?
Thanks to the increasingly important influence of sensor technology, we will definitely be able to collect much more measured data, and thus improve our detection of causal connections. I would even venture the hypothesis that in the future we will be recording 100 percent of all important measured values. 100 percent testing means that quality data (i.e., all critical parameters) will no longer be acquired by random sampling, but rather through 100 percent coverage. This signifies a radical change in quality control, because now we can get much closer to the tolerance limits.
What will the quality control of the future look like, in your opinion?
One example here might be a revival of pairing strategies, which production people often hate because of the complicated mathematical approach and the logistical outlay involved. Here, components with different quality features are used in pairs, to jointly provide the functions of an assembly with very high tolerance requirements. Pairing strategies are an obvious option if not every component produced is able to meet the specified tolerances.
One example here is the injectors used in engines, which have to work with an operating pressure that may reach 3,000 bar in the future. Rigorous deployment of inline metrology will enable even more intelligent, component-specific pairings to be used in conjunction with dynamic modification of production parameters, which will open up many new options.
So will data be increasingly acquired inside the production line?
Yes. There’s an ongoing trend toward more inline metrology, or even toward process-integrated measuring instruments, permitting minimized control loops.
Measurements are no longer taken in a separate measuring room, but directly in the production process. This is increasing the demand for metrology applied in a modularised mode in plants and production lines, while standard measuring instruments are becoming less sought after.
Metrology is turning into a project business, in which the customized application is the crucial competitive factor.
On the subject of sensor integration: Can a machine tool be converted into a measuring machine?
This goal has been around for some time, and it continues to be a very exciting task. But there are still numerous challenges involved, such as high costs and interference factors from the production process such as temperature or dirt.
What’s more, typical metal-cutting parts often require a very high degree of measuring accuracy. Users also want an independent metrological framework, which ideally enables measurements to be taken in parallel to machining – this is known as concurrent measurement. Measuring with the machine tool, however, is already standard procedure for high-precision products. One example here is the production of diesel injectors at Bosch.
