基于局部特征尺度分解与瞬时频率谱的齿轮故障诊断

Gear Fault Diagnosis Based on Local Characteristic-scale Decomposition and Instantaneous Frequency Spectrum

摘要:

齿轮故障振动信号具有非平稳、非线性特征,且可视为多个调幅-调频分量的叠加,单个调幅-调频分量的瞬时频率蕴含了齿轮的故障特征；为了将信号准确分解、获得单分量的瞬时频率,进而根据瞬时频率谱进行齿轮故障诊断,提出了局部特征尺度分解与瞬时频率谱相结合的故障诊断方法；该方法首先对齿轮振动信号运用局部特征尺度分解,得到若干个瞬时频率有物理意义的内禀尺度分量,然后分别应用希尔伯特变换技术求取每个分量的瞬时频率,并对瞬时频率进行傅里叶变换得到瞬时频率谱,最后根据瞬时频率谱进行故障诊断；对齿轮断齿故障实验数据进行了方法有效性分析,分析结果表明:该方法不仅能够准确诊断出齿轮箱故障情况,还能定位发生故障的齿轮,该方法可有效地应用于齿轮故障诊断。

Abstract:

The vibration signal of fault gear is characterized by non-stationary and non-linear, and can be regarded as the superposition of some amplitude-modulation components and frequency-modulation components. The instantaneous frequency of a single component contains the fault characteristics of gear. In order to decompose the signal accurately and obtain the instantaneous frequency of a single component, a fault diagnosis method based on the local characteristic-scale decomposition (LCD) and the instantaneous frequency spectrum was proposed. Firstly,the original vibration signal was disposed by LCD, and the intrinsic mode components (ISC) whose instantaneous frequency have physical meaning were obtained.Secondly, each instantaneous frequency of ISC was computed by Hilbert transform (HT), and the instantaneous frequency spectrum was got by means of Fourier transform (FT). At last the instantaneous frequency spectrums were acquired to fault diagnosis. The fault data of gear broken teeth was analyzed. The analysis results show that the method can diagnose the fault of gear box, and locate the fault. The method can be applied to gear fault diagnosis effectively.