High-Speed Camera based Experimental Modal Analysis for Dynamic Testing of an Automotive Coil Spring

<div class="section abstract"><div class="htmlview paragraph">Experimental modal analysis (EMA) is a measurement technique to assess the dynamical properties of mechanical components and systems in various phases their life cycle, e.g. for design, end-of-line testing health monitoring. The most common EMA uses accelerometers, which provide high frequency acceleration measurements at few discrete locations. However, attached accelerometers may alter mass damping multiple tests are required obtain spatially dense information. To overcome these issues, this paper we use high-speed cameras video processing algorithms. In fact, as contact-less sensors do not modify dynamics system under test. Furthermore, full-field displacement data, allowing transfer functions with single excitation, reduces experiment duration. On downside, camera suitable relatively low-frequency applications only require optical contrast on component surface. While previous based research was focused flat, plate-like components, demonstrate methodology 3D automotive coil spring. We stereo vision setup measure field, employing Lucas-Kanade flow feature tracker. Thereby, make local averaging noise reduction. As able capture static information geometry obtained addition parameters. This allows intuitive visualization results. For spring investigation field up 140 <i>Hz</i> an estimated accuracy range micrometer. results compared accelerometer highlighting advantages EMA. investigate sensitivity respect excitation environmental conditions discuss two alternative markers enhance image contrast.</div></div>