基于瞬时转速和双谱的内燃机故障诊断研究

首先对双谱分析和瞬时转速信号的特点进行分析，测量6135柴油机在正常、轻微故障和严重故障三种状态下的瞬时转速，分别计算其双谱，得到了具有明显区别的双谱幅值图；通过计算双谱对角切片，可以容易且有效地识别故障的存在；进一步分析双谱相位信息，可以确定单缸断油时的故障缸位置。根据瞬时转速的双谱特征进行故障诊断，故障特征明显，诊断效果良好。

Research on Fault Diagnosis for Internal Combustion Engines Using Transient Rotate Speed and Bispectrum

In this paper, the characteristics of bispectrum and transient speed signal were analyzed. Transient speed was measured at a 6135 diesel engine in three operating status: they are the status of normal, slight fault and severe fault. The respective bispectrum of speed signal at different statues were calculated. The amplitude figures showed the remarkable difference, and the bispectrum diagonal slice can be used to find the fault case easily and effectively. Moreover, through analyzing the information of bispectrum phase, the fault cylinder position can be pointed out in misfire fault. The results showed that bispecturm was an effective method for fault diagnosis based on the transient speed, and this can offer a new method in the fault diagnosis of internal combustion engines.