关键词: 故障诊断, 小波变换, 液压泵

Abstract: The time-frequency localization features of the wavelet transform and the signal wavelet decomposition-reconstruction algorithm based on the multi-resolution analysis are analyzed. The signal local singularities under the wavelet transform are studied. According to the propagation features of modulus maximums of the fault signal and the noise under the wavelet transform different on the scales, and by use of the signal wavelet decomposition-reconstruction algorithm, the pump shell vibration acceleration signal is decomposed, denoised, and reconstructed. The signal-to-noise of the monitored signal improved greatly. The fault characteristic signal on time domain is positioned. The fault characteristic frequency is picked up.

Key words: Fault diagnosis, Hydraulic pump, Wavelet transform