内燃机缸盖振动信号的特性与诊断应用研究

研究了内燃机缸盖振动信号的时域、频域和循环波动特性，揭示了它的非平稳时变特点，提出抽区间采样分析与参数平均相结合的振动诊断方法，并给出在气门间隙异常和气门漏气故障诊断中的应用实例

The Characteristic Analysis of Vibration Signal Measured on Engine Cylinder Head and Its Applications to Fault Diagnosis

The characteristics of the time domain, frequency domain and cycle by cycle variation of the vibration signal measured on the cylinder head in an internal combustion engine are analyzed, revealing its essentially non stationary and time varying properties. Both of the time domain and frequency domain characteristics during a working cycle provide a powerful tool for fault diagnosis, while the cyclic variation seems to be an obstacle for signature extraction. Based on such analyses, a simple technique for engine diagnosis is proposed. Only a special partition of the vibration signal within each working cycle is sampled and analyzed. The diagnostic signatures are extracted from each partition but averaged among lots of cycles. The applications of this technique to the diagnosis of some typical engine faults are presented.