Abstract: A method which can be used to analyze and separate the vibration signals of diesel engine is presented. The vibration signals contain a great deal of information about the engine’s fault state whose fault characteristic parameters are hard to obtain for the complex mechanical movement and operating conditions. To use this information, a fourth order blind identification (FOBI) model that estimate the separation matrix by independent component analysis is established. This FOBI method is implemented to diesel engine vibration to separate the different signals, the results show that signals of different characteristics can be separated perfectly. This method can be used as the pre-processing step to obtain the fault characteristic parameters.

Key words: Vibration and wave, diesel engine, FOBI, fault diagnosis

摘要： 针对柴油机振动信号特征参数的识别提取比较困难，本文运用四阶盲识别的方法分析研究柴油机的振动信号。把基于FOBI(四阶盲识别)算法的盲源分离方法引入到柴油机振动信号的处理中，建立仿真模型对该算法进行验证，并对一组采用北京东方所振动测试仪器在柴油机上实测的振动信号进行分离实验，分离结果表明不同特征的振动信号可以被分离，且最大限度地保留了源振动信号的信息，该算法可以作为柴油机振动信号的预处理方法。

关键词: 振动与波, 柴油机, FOBI算法, 故障诊断