振动信号的时域和频域分析是设备诊断技术中行之有效的方法。国内外应用振动分析方法对小型或单缸发动机故障诊断的研究也取得了一定的成果。而大型发动机由于缸数增加，结构更为复杂、振源多、信号混叠，在小型和单缸发动机上取得的研究结果，不能直接用于大型发动机诊断。有? Time-domain and frequency-domain analysis of vibration signals is an effective method for diagnosing equipment. Domestic and international application of vibration analysis method for small or single cylinder engine fault diagnosis research has also made some achievements. The large engine due to the increase in the number of cylinders, the structure is more complex, vibration source, signal aliasing, the results obtained in small and single cylinder engine, can not be directly used for large engine diagnosis. Have?