Signal detection and fault diagnosis based on wavelet transform

The theory of wavelet transform is introduced. The time frequency localization features of the wavelet transform and the signal wavelet transform and the signal wavelet decomposition algorithm based on the multi resolution analysis are analyzed. The signal local singularities during the wavelet transform are studied according to the propagation features of the fault signal modulus maximums during the wavelet transform on the different scales, and by use of the signal wavelet decomposition algorithm. The rolling bearings of 308 type vibration acceleration fault signal is decomposed.The fault characteristic signal on time domain is positioned and the results are given. The fault characteristic frequency is f =46.88 Hz. The results show that the wavelet transform is an efficient method to inspect online and fault diagnosis for the rolling bearings.