基于双脉冲特征的滚动轴承缺陷尺寸估计方法

Defect size estimation of rolling bearings based on double impulses characteristic method

根据提取的滚动轴承特征信号实现对故障缺陷尺寸的准确估计,提出了一种基于双脉冲特征的滚动轴承缺陷尺寸估计方法.采用AR模型对采集到的振动信号进行预白化处理,对预白化处理后的信号进行VMD分解,得到一系列固有模态函数.根据峭度值和互信息最大,分别选取包含有阶跃成分与冲击成分的分量,并采用平方包络增强信号的特征.根据双脉冲特征,确定滚动体进入和退出缺陷时所对应的时间,提出了故障轴承的缺陷尺寸估计方法.研究了转速和缺陷尺寸对该方法精度的影响,分析了造成误差的原因.通过实验验证该提取方法的有效性,经过估计得到的缺陷尺寸误差在5%以内,验证了该缺陷尺寸估计方法具有较高的精度.

A defect size estimation method based on double impulses feature is proposed in this paper for rolling bearing. This method realizes accurate estimation of fault defect size according to extracted feature signals of the rolling bearing. Collected vibration signals are pre-whitened by an AR model, and the pre-whited signals are decomposed into a series of Intrinsic Mode Functions (IMFs) by Variational Mode Decomposed (VMD). According to the kurtosis value and the mutual information being the largest, the step component and the impact component are extracted respectively. Then, the square envelope is applied to enhance characteristics of the signals. According to double impulses characteristics, the corresponding time when the rolling element enters or exits the defect is determined hereby, and the defect size estimation method of the fault bearing is put forward as a result. This paper also shows the influence of rotational speed and defect size on accuracy of above method, and analyzes possible causes of errors. The effectiveness of the proposed extraction method has been verified by experiments. The error of estimated defect size is less than 5%. It is verified that the defect size estimation method has higher accuracy.