【摘要】 介绍了经验模态分解(EMD)方法的基本原理和实现过程,并应用该方法对柴油机气缸盖上面采集到的非线性非稳态复杂信号进行了分解,获得了线性稳态的本征模函数(IMF)信号。每个本征模函数信号包含了比较单一的故障特征,对其进行功率谱密度分析最终找到了产生剧烈振动的激振源激振频率。分析、判断激振的频率可以知道产生剧烈振动的最终原因为燃烧不良。现场拆装发动机缸盖部分发现喷油孔严重烧损,验证了结论的正确性。更多还原

【Abstract】 The elementary principle and realizing course of the empirical mode decomposition(EMD) method was introduced.The non-linear and unstable signal that was collected from the upper of cylinder head was decomposed and the intrinsic model function(IMF) signals were acquired.The intrinsic model function signals including rich fault characteristics were analyzed with the power spectral density method and the motivating frequency of the vibration source was acquired.It is also known that the reason of severe vibration is the bad combustion in the cylinder by analyzing the motivating frequency.It was found that the injection hole was seriously damaged after the engine was decomposed.This phenomenon verified the result.更多还原