Abstract
A portable vibration meter with an accelerometer is usually used for vibration diagnosis of rotating machinery. The measuring operation near the rotating machinery is essential and it is not necessarily safe. In order to alleviate this problem, we develop handheld vibration measurement equipment using a laser displacement meter. For the developed handheld vibration measurement equipment, the measured vibration data contain non-stationary fluctuation due to handheld and non-contact measurement. Non-stationary fluctuation is difficult to remove using Fourier transform. In this paper, we propose a method for removing non-stationary fluctuation from the measured vibration data based on wavelet transform. To accurately identify non-stationary fluctuation, we determine a proper scaling function and a proper reconstruction level in the multi-resolution analysis using wavelet transform. The effectiveness of the method proposed is verified through simulation and experiment using the handheld vibration measurement equipment developed.
