基于希尔伯特-黄变换周期平稳类微弱故障信号检测

在希尔伯特黄变换可以将振动信号分解为有限的模式函数的基础上,针对周期平稳类微弱故障信号难以检测到的问题,对信号进行经验模式分解,然后对本征模式函数进行希尔伯特变换;接着通过希尔伯特谱对多频信号中的弱信号和仿真齿轮裂纹弱故障信号分析,得出多频信号中弱信号成分和其时间分布以及调相频率;最后分析滚动轴承损伤弱故障,从希尔伯特谱中可以分析时频和振动量的分布情况,进而提取故障特征,分析出故障;表明希尔伯特谱对周期平稳类微弱故障信号具有一定的分析能力.

Detection of weak fault signal about cyclostationary by Hilbert-Huang transform

Hilbert-Huang transform(HHT) can decompose the vibration signal as numbered mode functions.For solving the difficulty in detecting of weak fault signal about cyclostationary,a method is given.First,the signal is decomposed by the empirical mode decomposition(EMD) method.Secondly,the intrinsic mode function is dealt with by the Hilbert transform.Finally,the Hilbert spectrum is shown.The weak singularity signal in time domain and the simulation fault signal of gear flaw are presented.And the distribution of the weak signal component and the frequency of the phase modulation can be obtained from the Hilbert spectrum.Finally,the signal of the defect of rolling element bearing is analyzed by the Hilbert spectrum.The distribution of the time,frequency and the amplitude is shown by the Hilbert spectrum.Then the characterics of the weak fault signal is detected.The results demonstrate that the method is useful for detecting of weak fault signal about cyclostationary.