Why is a solution for acoustic quality assessment shown at a trade fair booth entirely devoted to optical measurement and testing methods and industrial image processing? “It totally makes sense”, says Judith Liebetrau, project manager at Fraunhofer IDMT. “The solution we developed adds perfectly to the overall portfolio of Fraunhofer’s visual production monitoring tools. In cases in which optical measuring and testing devices reach their limits, because the optical sensors cannot be placed closely enough to the machine to be monitored, or because the component to be monitored has already been installed in a larger product, our solution for acoustic quality assessment can be the perfect alternative«.

Integrating optical and acoustical sensors offers the chance to develop entirely new methods for measuring, analyzing, and testing. The assessment of processes, conditions, and events becomes more reliable, as more data can be captured for being analyzed and evaluated. An important advantage of the sound based method is that it requires no direct contact with machines or components to be assessed. Instead, the solution uses microphones to capture airborne sound. After clearing the recorded acoustic signal from environmental noise (the purer the signal, the better irregularities in the quality of products or the condition of machines can be detected), the signal is evaluated against a reference data model the solution has been trained with.

The new solution can be applied in various contexts. It can be used, for example, to assess the material quality of components prior to production, or to conduct acoustic functionality checks during assembly. Furthermore, the solution can be used for post-production assessment purposes, such as for end-of-line tests in product quality inspection.

To allow secure processing, transfer, and storage of measured data, Fraunhofer IDMT offers appropriate validation and encryption technologies, ensuring that data is not corrupted (intentionally or unintentionally) and that sensitive data may be accessed by authorized people and machines only.

To promote the concept of sensor data fusion, Fraunhofer IDMT is currently looking for further collaboration partners both from the research community and from business.

If you are interested in novel ways of integrated acoustical and optical monitoring of processes and conditions in industrial applications, please stop by the Fraunhofer Vision Alliance booth (# 6302) in hall 6, and get to know Fraunhofer IDMT’s new method for airborne sound based quality assessment.