爆破振动信号的HHT时频能量谱分析

The HHT time-frequency power spectrum analysis of the blasting vibration signal

采用希尔伯特-黄变换对爆破振动信号进行时频能量谱分析。经验模态分解中采用了极值点对称延拓消除端点效应,采用分段三次Hemite保形插值算法插值拟合消除欠包络现象以及筛分终止局部准则;对于传统HHT计算瞬时频率的负峰问题采用了标准化和直接正交法解决。采用了LabView平台实现,提高了计算效率和实用性。

The short-time Fourier transform can not meet the different requirements of the high and low frequency changes of signal and the wavelet transform can be limited by the wavelet base we select. Therefore, we use HHT to analyse Che blasting vibration signal through the time-frequency power spectrum. In the EMD, we use the symmetric extending of extreme point to eliminate the effect of endpoint. We use the piecewise cubic Hermite interpolating to eliminate the phenomenon due to the envelope, and adopt the local criterion of sifting termination. For the problem of negative peak in cal- culating the instantaneous frequency in the traditional Hilbert transform, we adopt the normalized Hilbert and the direct quadrature method to solve. In all the HHT analysis, we use the LabView plat- form to achieve which can improve computing efficiency and practicality, and we prove that HHT is useful for the analysis of the blasting vibration signal.