基于EMD-DCS的滚动轴承伪故障特征识别方法

EMD-DCS based pseudo-fault feature identification method for rolling bearings

伪故障特征是健康零部件振动信号中具有的故障特征,伪故障特征是由系统内故障零部件引起的。由于滚动轴承伪故障特征与故障特征具有相似性,针对转子-轴承系统中滚动轴承伪故障特征识别问题,提出一种基于经验模式分解(Empirical Mode Decomposition,EMD)和循环平稳度(Degree of Cyclostationarity,DCS)的伪故障特征识别方法。利用滚动轴承健康信号和伪故障信号对比分析基于单通道伪故障信号进行滚动轴承故障诊断的技术难点;建立了考虑滚动轴承打滑率的转子-轴承系统动力学模型;利用时频分析方法和循环平稳分析方法对滚动轴承伪故障特征进行分析;给出了基于EMD-DCS的滚动轴承伪故障特征识别流程;在滚动轴承故障模拟实验台上开展了滚动轴承伪故障特征识别实验。实验结果表明:基于EMD-DCS的滚动轴承伪故障信号识别方法可以有效区分滚动轴承故障特征与伪故障特征。该研究工作对于提高滚动轴承故障诊断准确率、保障设备安全运行具有理论意义和实际应用价值。

Pseudo-fault feature is the fault feature included in the vibration signals of healthy parts,which is caused by the faulty parts in the system.In the paper,a pseudo-fault feature recognition method based on empirical mode decomposition(EMD)and degree of cyclostationary(DCS)was proposed to identify the pseudo-fault feature of a rotor bearing system.The technical difficulties of rolling bearing fault diagnosis based on the single-channel pseudo-fault signal were analyzed by comparing the healthy and pseudo-fault signals of the rolling bearing.A dynamic model of the rotor-bearing system considering the rolling bearing slipping rate was established.The pseudo-fault feature of the rolling bearing was analyzed by the time-frequency method and the cyclic stationary method.The feature identification process of the rolling bearing pseudo-fault based on EMD-DCS was presented.An experiment of feature identification was carried out by using a rolling bearing fault simulator.The experimental results show that the EMD-DCS based method can effectively distinguish pseudo-fault features of rolling bearings from fault features.The research in the paper has theoretical significance and practical application value to ensure the equipment operation safety.