EEMD改进算法在异步电机轴承故障诊断中的应用

Application of an improved EEMD method in bearing fault diagnosis of induction motors

  • 摘要:
      目的  为了克服传统的集成经验模态分解(EEMD)方法凭经验选取参数(集成次数及白噪声幅值系数)的弊端,同时降低该方法的计算时间成本,提出一种快速集成经验模态分解(FEEMD)方法来提取特征频率。
      方法  通过改变添加白噪声的分布密度,得到不同的信号包络线。进一步通过求解移动均值滤波器最优的搜索窗口宽度来实现寻找最优的包络线,从而避免EEMD方法凭经验选择参数的缺陷。同时,在信号中的异常分量分解出来后,对剩余分量进行经验模态分解(EMD),从而进一步节省计算成本。最后,将该方法与Hilbert包络解调技术相结合应用到对异步电机轴承内环故障特征频率诊断中,并与传统的EEMD方法进行比较。
      结果  结果表明,FEEMD方法能够更高效地完成对故障频率的提取。
      结论  FEEMD方法可克服传统EEMD方法凭经验选取参数的弊端并缩短计算时间,有效应用在轴承故障频率的提取试验中。

     

    Abstract:
      Objective  In order to overcome the disadvantages of the traditional ensemble empirical mode decomposition (EEMD) method in selecting parameters (integration time and white noise amplitude coefficient) based on experience, and reduce the cost of calculation time, a fast ensemble empirical mode decomposition (FEEMD) method is used to extract the characteristic frequency.
      Method  By changing the distribution density of the added white noise, different signal envelopes can be obtained. Furthermore, we can identify the optimal envelope by finding the optimal search window width of the moving mean filter, thereby avoiding the defect of EEMD selecting parameters by experience. At the same time, after the abnormal component in the signal is decomposed, the residual component can be decomposed by EMD to further save the calculation time cost. Finally, the method is combined with Hilbert envelope demodulation technology and applied to the fault characteristic frequency diagnosis of the bearing inner ring of an asynchronous motor.
      Results  As the results show, compared with the traditional EEMD method, FEEMD can extract the fault frequency more efficiently.
      Conclusion  FEEMD overcomes the disadvantages of the traditional EEMD method in selecting parameters based on experience and shortens the calculation time. As such, it can be effectively applied in bearing fault frequency extraction experiments.

     

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