基于数学形态学的振动信号降噪和解调方法研究

摘要

During the fault diagnosis in gearbox, in order to achieve de-noising and demodulation simultaneously in the fault gear vibration signal, two different morphological operators are designed based on the mathematical morphological theory. For different signal processing purpose, the vibration signal can be de-noised and modulated with morphological operators. The procession results of simulated signal and real gear crack fault signal show that the combined operation can filter the impulse and stochastic noises, and improve signal-to-noise ratio, while the difference operation can extract the demodulated impulses in the signal, and reveal impulsion feature in fault signal. The proposed method is simple and fast in computation as only addition and subtraction operators are need. This method can be applied to the singal processing in online diagnosis for gearbox.%在齿轮箱的故障诊断中,为同时实现对齿轮故障信号的降噪和解调,依据数学形态学理论,设计了两种不同的形态运算：形态组合运算和形态差值运算。可根据信号处理的不同目的,实现含噪信号的降噪和调制信号的解调。对仿真信号和实测齿轮裂纹故障信号的分析结果表明：形态组合运算可抑制信号中的脉冲及随机噪声,提高信噪比,实现信号的降噪处理;而形态差值运算可提取信号中的调制脉冲,充分突出故障信号的冲击特征。