一种基于改进阶次包络谱的滚动轴承故障诊断算法

摘要

针对变转速工况下滚动轴承故障特征的提取问题，提出了一种基于滤波定阶理论的改进阶次包络谱分析方法。该方法在包络解调后，先对信号进行低通滤波，在确定计算阶次跟踪（COT）的重采样频率并进行重采样后，再对重采样后的包络曲线进行离散傅里叶变换得到阶次包络谱。通过仿真信号和实验数据对该算法进行验证，结果表明：该算法适用于变转速工况的轴承故障诊断，和传统阶次包络谱算法相比，该算法为角域重采样中重采样率的设置提供了一种方法，可以有效避免阶次混叠现象和降低重采样率。%To extract fault characteristics of rolling bearings under variable speed conditions,an improved order envelope spectrum algorithm was proposed based on the method to use low-pass filter to limit frequency and order.The envelope signals were obtained after the original vibration signals were filtered with a low-pass filter,then the re-sampling frequency of COT(computed order tracking)was determined and the filtered envelope signals were re-sampled.Finally, the improved order envelope spectrum was obtained using the absolute values of the discrete Fourier transformation of the re-sampled envelope signals.The results showed that the proposed algorithm provides a method to evaluate the re-sampling rate,the method reduces the re-sampling rate and avoids the order aliasing compared with the traditional order envelope spectrum algorithm.