双相干谱与双谱在物流故障诊断中的性质对比

The Comparison of Bicoherence Spectrum and Bispectrum in Fault Diagnosis

在物流设备故障描述方面,双谱和相干谱具备较多的相似之处,但就设备故障所表现出的非线性和非对称等特征,双相干谱因其可以对二次相位的耦合程度进行定量估算,因此有效综合了上述二者的优势.为了体现这种区别,在减压阀故障诊断实验中,对特定的故障信号和正常信号同时采用双谱和双相干谱进行故障判别.实验结果表明,在所采用的实验数据中,双相干谱的诊断结果要好于双谱的诊断结果.

Bicoherence spectrum and bispectrum have many same performance,but in showing the nonsymmetric and nonlinear features of mechanical faults,bispectrum has deficiency.The bicoherence spectrum can quantitatively estimate square phase coupling degree,can overcome this problem in some extent.In order to reflect the difference in fault diagnosis experiment of pressure reducing valve,the specific fault signals and normal signals were diagnosed by using bispectrum and bicoherence spectrum simultaneously.The experimental results show that the diagnosis results of bicoherence spectrum is better than bispectrum.