为了基于航空发动机整机机匣振动信号实现中介轴承复合故障的有效识别,从信号的复杂性角度出发,利用图谱中的拉普拉斯能量(Laplace Energy,LE)指标对信号的复杂性进行描述,提出了将固有时间尺度分解(Intrinsic Time Scale Decom-position,ITD)与LE指标相结合的故障诊断方法.为实现复合故障的有效分离,基于ITD算法对某型航空发动机整机机匣振动加速度信号进行分解,并对分解后获得的固有旋转分量(Proper Rotation Components,PRCs)基于奇异值差分谱进行降噪.然后利用LE指标对分量信号进行筛选,对筛选后的信号进行重构,最后根据重构信号的平方解调谱,对实际航空发动机中介轴承的复合故障进行识别.结果表明:所提出的方法,可以基于航空发动机的整机机匣振动信号,准确有效地提取出中介轴承复合故障的特征频率,实现中介轴承复合故障类型的有效识别.
Compound Faults Identification of Whole Aero-Engine Intermediate Bearing Based on ITD-LE Index
In order to realize the effective identification of the compound fault of the intermediate bearing based on the vibration signal of the aero-engine casing,from the perspective of the complexity of the signal,the Laplace energy( LE) index in the spectrum is used to de-scribe the complexity of the signal.A fault diagnosis method combining intrinsic time scale decomposition( ITD) and LE index is pro-posed.In order to realize the effective separation of compound faults,the vibration acceleration signal of an aero-engine casing is decom-posed based on the ITD algorithm,and the proper rotation components( PRCs) obtained after decomposition are denoised based on the singular value difference spectrum.Then,the LE index is used to filter the component signals,and the filtered signals are reconstructed.Finally,according to the square demodulation spectrum of the reconstructed signal,the identification of the composite fault of the actual aeroengine intershaft bearing is carried out.The results show that the method proposed can accurately and effectively extract the charac-teristic frequency of the composite fault of the intermediate bearing based on the vibration signal of the whole casing of the aero engine,and realize the effective identification of the composite fault type of the intermediate bearing.
ITDcasing vibration signalLaplace energy indexcompound faultsintershaft bearing
万方数据
维普
