Video motion amplification vs. operating deflection shapes for machinery diagnosis
AbstractOperating Deflection Shape (ODS) has been an important tool in visualizing the vibration of a machine and its system, including piping networks. The input for ODS is the phase-linked signal set from a group of accelerometers, moved over often hundreds of test points. The data is superimposed onto a CAD model, and then scaled-up vibration motion is animated at frequencies of interest. This process is time-consuming and therefore expensive each time it is applied by experts, and is error-prone. An alternative method has been developed that is based on evaluation of high resolution/ high speed videos. The method provides information equivalent to a high-sensor-count ODS, by treating each pixel as an accelerometer, using the pixel’s light intensity modulation to translate information embedded in the video into vibration motion able to be observed and interpreted by human investigators.
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