基于高阶循环平稳的柴油发动机活塞销振动信号分析

Analysis of Vibration Signals of Piston Pin in Diesel Engine Based on Higher Order Cyclostationarity

分析了柴油发动机活塞销振动信号的高阶循环平稳性,提出了一种基于高阶循环平稳理论提取柴油发动机活塞销磨损故障特征的新方法。利用循环双谱分析活塞销振动信号,考察了振动信号循环双谱图中频率成分的分布情况。定义循环双谱图中幅值的平均累加值与发动机活塞销磨损间隙变化相对应的区域为特征频率平面,提出一种全局搜索策略以搜索特征频率平面。仿真结果及试验结果表明了循环双谱的有效性。利用所述方法在实际活塞销振动信号的循环双谱图中提取的5个特征频率平面内幅值的平均累加值可以作为活塞销磨损故障诊断的特征值。

Higher order cyclostationarity of the vibration signals of the piston pin of a diesel engine was studied,and a novel feature extraction method of diesel engine＇s piston pin＇s wear fault based on the higher order cyclostationarity was proposed herein.Vibration signals of piston pin were analysed with the cyclic bispectrum,the frequency component＇s distribution of the vibration signals in the cyclic bispectrum was studied,and a new global search method was proposed.The cyclic bispectrum characteristic planes whose average modulus values can reflect the wear clearances of the piston pin were found as fault features.The results demonstrate the effectiveness of the cyclic bispectrum method,and 5 cyclic bispectrum planes connecting with the wear clearances of the piston pin are found in the vibration signals＇ cyclic bispectrum and the average modulus values of these planes can be extracted as the feature of the crankshaft bearing wear fault of diesel engine.