基于短时AR谱分析的柴油机气阀漏气的故障诊断

Fault diagnosis of diesel valve leakage based on short-time AR spectrum analysis

通过对传统的短时Fourier变换进行改造,在短时Fourier变换的计算中利用自回归(AR)谱估计代替离散Fourier变换(DFT),得到了一种基于AR谱估计的短时AR谱分析方法.短时AR谱分析方法能够较好地给出柴油机缸盖振动信号的时频分布表示,提高了气阀漏气故障诊断的准确性.

In the calculation of STFT, discrete Fourier transform （DFT） is replaced by autoregressite （AR） spectrum estimation, and a new method based on AR spectrum estimation is gained, namely short-time AR spectrum analysis. The method is applied to fault diagnosis of valt,e in leakage, and the results show that it can give a better time-frequency distribution expression of signals and improve,eracity of the diagnosis.