Method for analysis of fractal characteristic of rotating machinery bump-scrape acoustic emission signal

The invention relates to a method for analyzing the fractal property of a rubbing sound emission signal in a rotary machine. The invention comprises the following technical proposal that: an AE signal is extracted from an AE sensor of a friction point; the AE signal which is superimposed with white Gaussian noise and nonstationary noise is sampled, quantized and subframed; data comprising noise in each frame is equally divided into short-time frame data segments with the length of m; a fractal dimension value of each short-time frame data segment is calculated by a fractal dimension algorithm based on waveform; the data with a serial number bang in the middle is selected as the output of a median filtered wave. The method solves the disadvantages that the prior method has very large calculation amount, low precision of Katz dimension and large fluctuation of short-time frame fractal dimension curve. Under the environment of strong noise, with the method, logarithm wavelength dimension has the stronger capacity of distinguishing the noise from the AE signal than the Katz dimension and box dimension; the logarithm waveform dimension of an AE signal frame is closer to the fractal dimension of a pure AE signal than the Katz dimension and the box dimension, thereby effectively detecting and reflecting the occurrence of an AE rubbing event, having high precision and reducing the calculation amount.