基于EEMD及敏感IMF的再制造发动机振动模式研究

为更好提取再制造发动机的振动特征,采用总体平均经验分解模式(Ensemble Empirical Mode Decomposition,EEMD)对信号进行分解,并用于再制造发动机振动模式研究中。在对振动信号分解基础上,利用相关系数计算IMF分量与其原始信号间相关性及原始信号IMF分量敏感因子;利用敏感IMF进行Hilbert变换。研究结果表明,采用EEMD分解算法所得IMF分量能反映再制造发动机的振动特征,基于敏感IMF的边际谱能区分再制造发动机不同部件的振动模式,并将再制造发动机部件分为缸壁、缸盖、曲轴三种振动模式,对提高发动机再制造水平具有重要意义。

Study on vibration mode of remanufactured engine based on EEMD and sensitive IMF

In order to extract the vibration feature of remanufactured engine, the vibration signal is decomposed by ensemble empirical mode decomposition(EEMD), and this method is applied to study vibration mode of remanufactured engine. Based on the decomposition of vibration signal, correlation coefficient is introduced to study the correlation between IMF(Intrinsic Mode Function) components and original signal, and sensitive factors of IMF components are calculated using correlation coefficients. Hilbert transform is made with sensitive IMF components. The study results show that vibration feature of remanufactured engine is include in IMF components decomposed by EEMD, the vibration modes of remanufactured engine can be differentiated by Hilbert-Huang spectrum and marginal spectrum based on sensitive IMF components. According to vibration feature, the vibration state of remanufactured engine is divided into cylinder wall, cylinder cover and crankshaft vibration modes, which are important to improve the remanufacture level of engine.