基于DBO-VMD滤波的煤岩爆破电磁信号时-频特征研究

Research on time-frequency characteristics of electromagnetic signals from coal and rock blasting based on DBO-VMD filtering

  • 摘要: 首先提出了DBO-VMD的信号分解方法,得到了VMD参数优化的最佳适应度函数包络熵,该函数可迅速锁定最优参数组合,避免模态混叠现象,分解效果优于EMD;提出了基于经验法的中心频率准则降噪方法,并证实了该方法降噪性能在信噪比表现上优于EMD 约2倍;发现煤岩破裂期的偏度大于0、峭度介于0.9-4.6,脉冲指标介于3.7-6.1,频段在20 kHz以下,主破裂事件发生时信号能量最大,最强分量频道在10 kHz以下,并随着频道上升信号分量幅值迅速下降,非破裂期的低能脉冲则集中于0-4 kHz频段,信号整体频段处于甚低频。

     

    Abstract: The conventional vibration monitoring of mining and blasting operations is easily affected by the surrounding environment or monitoring system, which affects the monitoring effect. This paper proposes a blasting monitoring method based on electromagnetic signals and studies the time-frequency characteristics of blasting electromagnetic signals. Firstly, the signal decomposition method of DBO-VMD was proposed, and the optimal fitness function envelope entropy for VMD parameter optimization was obtained. This function can quickly lock the optimal parameter combination, avoid mode mixing phenomenon, and the decomposition effect is better than EMD; a denoising method based on the central frequency criterion was proposed to filter out high-frequency and low-energy components, and it was confirmed that the denoising performance of this method is more than 2 times better than EMD in terms of signal-to-noise ratio performance; it is found that the skewness is greater than 0, the kurtosis is between 0.9-4.6, the pulse index is between 3.7-6.1, and the frequency band is below 20 kHz, the signal energy is the largest when the main rupture event occurs, and the strongest component channel is below 10 kHz, and the amplitude of the signal component decreases rapidly with the rise of the channel, while the low-energy pulses in the non-rupture period are concentrated in the 0-4 kHz frequency band, and the overall frequency band of the signal is at very low frequency.

     

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