描述了关于气路滑油泄漏故障监测的探索性研究,利用静电感应技术首次实现了对该类故障的在线监测,获取了实测的故障信号。采用自适应提升小波方法得到了第102阶段(正常状态)和第106阶段(故障状态)的2层细节信号、逼近信号,经过对比分析发现二者在细节信号最大幅值以及局部波形上存在着较大差异;根据统计分析方法及Hilbert方法提取了静电信号(电压信号)时域特征参数、频域特征,并将静电信号(电压信号)转化为电荷信号后进一步提取出活动率水平、正(负)事件率等参数,总结了可用于气路滑油泄漏故障判别的故障特征。研究结果表明利用静电感应技术可以实现在线监测发动机气路滑油泄漏故障,该研究是基于静电感应的气路状态监测及故障诊断技术的重要组成部分,并为实现仪器产品化奠定了基础。
This paper describes the exploratory research about monitoring the fault of lubricating oil leakage in gas path. It is the first time to monitor this kind fault using electrostatic induction technology and obtain the actually measured fault signal. The two layer detailed signals and approximation signals are obtained using adaptive lifting wavelet method in the 102nd stage (normal state) and 106th stage (fault state). Through comparative analysis,it is found that the signals in the two stages have large differences both in detailed signal maximum amplitude and local waveform. The characteristic parameters of the electrostatic signal ( voltage signal) in time and frequency domains are extracted using statistical analysis and Hilbert methods; and the electrostatic signal is transformed into charge signal, then some parameters for charge signal like active level, positive (negative) event rate are calculated. The fault characteristies that can be used for fault diagnosis of lubricating oil leakage in gas path are summarized. The study result shows that the electrostatic induction technology can be used to realize the online monitoring of lubricating oil leakage in turbojet engine gas path,which is an essential part of state monitoring and fault diagnosis based electrostatic induction technology for turbojet engine gas path, and lays a foundation for the commercialization of the instrument.