The use of vibro-acoustics measurements during manufacturing testing as an approach for detecting defects has been steadily gaining acceptance in the automotive industry. Several studies performed by Hughes and others have demonstrated that signature analysis of vibro-acoustic spectra can be a sensitive measure of product quality.
However, the implementation of a vibro-acoustic test system in a production environment is not always straightforward. Additionally, test system implementation and support requires knowledge in instrumentation, signal processing, spectral analysis, and statistical analysis. The latter skill is especially important in the development and maintenance of templates that provide pass/fail criteria. Template generation has been recognized as an engineering intensive process.
This article discusses an approach to developing a robust vibro-acoustic manufacturing test, issues typically encountered, and some selected case studies. The studies discussed are typical for the automotive industry. For the purposes of this paper, the term “noise” monitoring is assumed to be either an acoustic or vibration measurement.