气缸压力的时频分析及其在内燃机故障诊断中的应用

Time-Frequency Analysis of Cylinder Pressure and Its Application to Fault Diagnosis for I.C. Engines

对气缸压力进行时．频分析，探讨了气缸压力信号与气阀机构状态之间的关系。对气缸压力信号进行二进小波分解，计算分解后尺度ｌ上信号各频带的能量比，从中提取诊断特征量，从而对气阀机构进行故障诊断。结果表明此方法是可行、有效的。

Cylinder Pressure signal was analyzed in time and frequency domain and the relationship between the cylinder pressure signals and the states of valve were discussed in this paper. Cylinder pressure signal was processed with wavelet analysis. Energy percentage of various frequency bands of the signal on scale I was computed, from which the diagnosis characteristic was extracted to recognize the fault of the valve. The results show that this method is effective and feasible.