Self-adaptive failure diagnosis method of rotary mechanical component based on continuous wavelet transformation

Abstract

The invention relates to a self-adaptive failure diagnosis method of a rotary mechanical component based on continuous wavelet transformation. The method comprises the following steps of: 1, performing zero-mean preprocessing on an acquired discrete initial vibration signal to obtain a preprocessed signal from which a direct-current component is eliminated; 2, performing continuous wavelet transformation on the preprocessed signal obtained in the step 1 to obtain a wavelet coefficient which corresponds to each scale parameter; 3, calculating the kurtosis of the wavelet coefficient which corresponds to each scale parameter in the step 2 respectively; 4, searching for a wavelet scale parameter which corresponds to large kurtosis in the wavelet scale parameter obtained in the step 3 with a self-adaptive algorithm to configure an optimal analysis signal; and 5, performing envelope demodulation on the optimal analysis signal obtained in the step 4 to obtain an envelope signal. The method has the beneficial effects that: the accuracy of failure diagnosis is increased, and the method is particularly suitable for failure diagnosis of mechanical parts with impact damages.

Description

technical field [0001] The invention relates to the technical field of mechanical fault diagnosis, in particular to the fault diagnosis technology for rotating mechanical parts (such as bearings or gears, etc.). Background technique [0002] When local faults (such as spalling, pitting, cracks, etc.) occur in rotating mechanical parts (such as rolling bearings), their vibration signals are usually accompanied by shocks. Resonance occurs to generate a high-frequency vibration signal. Therefore, through the analysis of the high-frequency vibration signal, the fault diagnosis of the bearing can be effectively carried out, and the interference of the low-frequency noise is also eliminated. For a long time in the past, high-frequency resonance demodulation technology (also known as envelope demodulation technology) has become an effective method for fault diagnosis of rotating machinery parts, which can accurately obtain the fault characteristic frequency of rotating machinery p...

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Problems solved by technology

[0004] The purpose of the present invention is to solve the problem that the center frequency of the band-pass filter is difficult to determine in the existing high-frequency resonance demodulation technology, and proposes an adaptive fault diagnosis method for rotating mechanical parts based on continuous wavelet transform, which is especially suitable for Fault Diagnosis of Impact Damaged Rotating Machinery Components

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