基于加窗和EEMD的船用柴油机拉缸故障诊断

Fault Diagnosis of Marine Diesel Engine Scuffing Based on Windowing and EEMD

船用柴油机发生拉缸故障时,其振动信号较为复杂,而且伴有较强的背景噪声,经验模态分解(Empirical Mode Decomposition,EMD)无法有效地诊断出柴油机拉缸故障,为此采用加窗和集合经验模态分解(Ensemble Empirical Mode Decomposition,EEMD)的方法。以6-135柴油机为研究对象,测取典型工况下机体表面的加速度信号,根据柴油机的结构和配气相位分布,分析确定加速度信号的加窗位置,再将加窗后的信号进行EEMD处理,计算前3阶模态分量的能量值并对重构信号进行频谱分析。结果表明:基于加窗和EEMD的方法可以更加精确有效地实现柴油机拉缸故障的诊断。

When the marine diesel engine has a scuffing,its vibration signal is more complicated,and it is accompanied by strong background noise. The EMD cannot effectively diagnose the diesel scuffing. Therefore,the windowing and EEMD will be using. Taking the 6-135 diesel engine as the research object,the acceleration signal on the surface of the machine body under typical working conditions is measured. According to the structure of the diesel engine and the phase distribution of the gas distribution,the windowing position of the acceleration signal is analyzed and determined,and then the signal after windowing is processed by EEMD. The energy value of the first 3rd order modal components is calculated and the analysis of the reconstructed signal are analyzed. The results show that the method based on windowing and EEMD can realize the diagnosis of diesel scuffing more accurately and effectively.