改进的谱相关分析方法及其在故障诊断中的应用

Improved method of spectral correlation density and its applications in fault diagnosis

提出一种基于峭度能量的谱相关分析方法.它利用每个循环频率切片的峭度值来衡量该循环频率的调制能力,并以此作为加权因子进行循环频率的能量累积,最终实现故障特征的有效提取.相对于传统的谱相关分析方法,本文方法降低了信号中多倍频谐波对故障特征频率的干扰,能更清晰准确地提取出故障频率特征.利用传统的谱相关分析方法、本文方法和共振解调三种方法对仿真信号、低速重载试验台的滚动轴承外圈故障信号进行分析,证明了本文方法的有效性.

A new spectral correlation density method based on kurtosis energy is proposed in this article. In the method the kurtosis of every slice along the cyclic frequency axis is calculated and used as the weight coefficient to evaluate the modulation ability of the corresponding cyclic frequency, and then the fault feature is effectively extracted by energy accumulation of the cyclic frequency. Compared with the traditional spectral correlation density （CSD） method, the proposed method has great performance of reduction the influence of multiple-frequency harmonics on the characteristic fault frequency, so the fault feature is extracted more clearly and accurately. Simulation signals and the fault signals from the outer ring of a rolling bearing in a low-speed and heavy-duty test bed have been analyzed by CSD, the proposed method and resonance demodulation. The analysis results prove that the proposed method is effective.