双谱耦合性质对故障诊断的影响

The Effect of Bispectrum Coupling Property on Fault Diagnosis

为了对双谱的耦合性质进行分析,同时利用三阶累积量和双谱对溢流阀进行故障诊断。由于双谱与三阶累积量相比,可以用来描述二次相位耦合,对比实验结果表明,故障的种类不同,其耦合信息对于这些故障判断的影响也不一样。实验中还通过二维小波在不同的方向上对故障信号和正常信号进行特征提取,然后将这些特征值输入支持向量机进行故障判别,实验结果表明,无论考虑耦合因素与否,这些故障信号在不同的频率部分与其正常状态的区分程度都不一样。

In order to analyze the coupling properties of bispectrum,both bispectrum and three order cumulants were used to diagnose faults.Compared with three order cumulants,bispectrum concludes the quadratic phase coupling information.The comparative experimental results indicate that,when the kinds of faults were different,the impact of coupling information on the results of fault diagnosis became different too.Furthermore,the features of fault signals and normal signals were extracted by 2-D wavelet in different directions,then these features were input into support vector machine to diagnose the faults,and the results show,whether coupling information were included or not,the corrects of diagnosis were different when all these faults were in different frequencies parts.