基于改进Hilbert-Huang变换的管路环向裂纹故障诊断研究

Fault Diagnosis of Circumferential Crack in Pipeline Based on Improved Hilbert-Huang Transform

在制造、加工、装配以及服役过程中,航空液压管路可能存在平面型缺陷。在适航载荷作用下,这些缺陷会萌生裂纹并发生扩展,最终导致管路破裂和油液泄漏。为了在管路产生微裂纹时对其进行故障诊断,采用了自行搭建的航空液压管路模态试验平台和测控系统,对存在环向裂纹航空液压管路的振动信号进行了采集和预处理。而在对管路振动信号进行分解时,由于经验模态分解(Empirical Mode Decomposition,EMD)算法存在模态混叠问题难以获得准确的本征模态函数(Intrinsic Mode Functions,IMF)。为提高信号处理精度,提出一种基于自适应噪声完备经验模态分解(Complete Ensemble Empirical Mode Decomposition with Adaptive Noise,CEEMDAN)和Hilbert变换理论相结合的改进Hilbert-Huang变换方法对航空液压管路环向裂纹进行故障诊断。研究结果表明,该方法能够更准确地诊断航空液压管路的环向裂纹故障。

In the process of manufacturing,processing,assembly and service,aircraft hydraulic pipelines may have planar defects.Under the action of seaworthy load,these defects will crack and expand,and eventually lead to pipe rupture and oil leakage.In order to diagnose the micro-crack in the pipeline,a self-built modal test platform and measurement and control system were used to collect and pre-process the vibration signals of the aviation hydraulic pipeline with circumferential cracks.However,in the process of Decomposition of pipeline vibration signals,it is difficult to obtain accurate intrinsic mode functions(IMF)due to the Mode aliasing problem of empirical mode decomposition(EMD)algorithm.In order to improve signal processing accuracy,an improved Hilbert-Huang transform method based on complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN)and Hilbert transform theory is proposed to diagnose the ring crack of aviation hydraulic pipeline.The results show that this method can diagnose the circumferential crack fault of aviation hydraulic pipeline more accurately.