Patent ID: 7933742

Claim:
An abnormality diagnosing method for sound or vibration for analyzing sound or vibration that appears at an evaluation point set up in a target space containing a plurality of sound sources or vibration sources, and thereby diagnosing the presence or absence of abnormality occurring in the sound source or vibration source, comprising: a preliminary step of extracting abnormal waveform signals individually from a detection result of sound or vibration acquired in advance at the evaluation point at the time of occurrence of abnormality in each of the plurality of sound sources or vibration sources; a first step of extracting an evaluation waveform signal serving as an analysis target from a detection result of sound or vibration at the evaluation point; a second step of performing Hanning window processing, Fourier transformation, normalization processing, and Hilbert transformation on the evaluation waveform signal extracted at said first step, and thereby deriving a real signal mother wavelet of complex type; a third step of performing wavelet transformation on each of the abnormal waveform signals extracted at said preliminary step by using the real signal mother wavelet derived at said second step, and thereby calculating a correlation value of each abnormal waveform signal with the real signal mother wavelet; a fourth step of comparing the correlation value calculated at said third step with a predetermined criterion, and thereby determining the presence or absence of abnormality in each of the plurality of sound sources or vibration sources; and a fifth step of displaying the correlation values calculated by the third step on a same time axis on a display section, wherein the real signal mother wavelet derived at the second step has a start point and an end point at zeros, and an average over the domain of the real signal mother wavelet is zero while the function is bounded, and wherein the third step of performing the wavelet transformation includes obtaining an inner product between a transform function to which each of the abnormal waveform signals is applied and the real signal mother wavelet.