谐波小波及其时频剖面图在旋转机械诊断中的应用

分析了谐波小波的定义、特点，以及用谐波小波时频图、等高线图表示谐波波分解结果的方法。分析结果表明，这两种方法虽然可以直观表示信号的时频能量分布以及无噪声信号中的微弱奇异成分，但当信号中存在噪声时，用这些方法将难以检测信号的奇异性，因而它们在工程实际中几乎是没有用的。提出了谐波小波时频剖面图（Ｔｉｍｅ－Ｆｆｒｅｑｕｅｎｃｙ Ｐｒｏｆｉｌｅ Ｐｌｏｔ，即ＴＦＰＰ）方法，利用该方法可以检测含噪声信号的微

Application of Harmonic Wavelet and Its Time-Frequency Profile Plot to Diagnosis of Rotating Machinery

Harmonic wavelet definition and characteristics are introduced. In harmonic wavelet analysis, wavelet time frequency map and contour plot are ususlly used to show the harmonic wavelet decompositon. They can illustrate the distribution of signal energy over time frequency directly, furthermore, identify weak singularity in a pure signal clearly. When the signal possesses noise, these two methods become ineffective on identifying singularity, so they are almost useless in practice. A new method, wavelet time frequency profile plot (TFPP) is proposed, which can suppress the effect of noise and recognise weak singularity. With TFPP, vibration data of a key rotating machine in an oil refinery are analysed. After synthesizing fast Fourier transform, singular feature of the signal is extracted and weak fault is diagnosed successfully.