基于第二代小波和EMD的解调方法及其应用研究

COMPOSITE FAULT DIAGNOSIS METHOD BASED ON SECOND GENERATION OF WAVELET AND EMD

针对复合故障中滚动轴承微弱冲击性故障特征难于提取的问题,提出基于第二代小波和EMD的解调方法,进行复合故障的耦合特征分离和轴承损伤性故障微弱信号的特征提取研究。该方法首先应用第二代小波分解与重构原始信号,针对分解与重构出的高频段信号进行经验模式分解(Empirical Mode Decomposition,EMD),得到若干个本征模函数(Intrinsic Mode Functions,IMFs),然后针对本征模函数中的高频成分进行Hilbert包络解调,准确提取高频调制故障特征。仿真及实验结果表明该方法的有效性和实用性。

Aiming at difficulty of weak impactive roller bearing fault feature extraction of composite faults,a demodulation method based on the second generation wavelet and the empirical mode decomposition(EMD) is proposed to separate the coupling features of a composite fault and to extract the fault feature of a roller bearing.Firstly original signals are decomposed and reconstructed by using the second generation wavelet.Then the high-frequency signal from decomposition and reconstruction of original signals is analyzed using EMD,several Intrinsic Mode Functions(IMFs) are obtained.Then the high-frequency components of IMFs are analyzed by Hilbert envelop demodulation,the modulate fault feature is extracted exactly.Simulation and experiment analysis results indicate the validity and the practicability of the method proposed here.