摘要:
为有效抑制爆破振动信号中的噪声干扰,提出一种基于高斯变异多元宇宙优化算法(GMVO)优化变分模态分解(VMD)的降噪方法。该方法利用高斯变异策略增强多元宇宙优化算法的全局搜索与局部开发能力,以最小包络熵为适应度函数,自适应寻优VMD的惩罚因子α与模态数K;进而对含噪信号进行VMD分解,联合多尺度排列熵与方差贡献率为判据,设定双阈值筛选有效本征模态函数(IMF)分量并重构信号,实现噪声抑制。以爆破振动预测模型构建纯净仿真信号,在此基础上分别加入信噪比为3、5、7、10、15dB的高斯白噪声进行降噪验证。结果表明,高斯变异MVO-VMD在信噪比、均方根误差、相关系数及光滑度四项指标上均优于MVO-VMD、小波阈值、EMD-MPE及EEMD-MPE四种经典方法,且在强噪声环境下鲁棒性指数均高于0.8。某地下矿山实测信号的降噪应用表明,高斯变异MVO-VMD能有效抑制高频噪声并校正基线漂移,掏槽孔与周边孔降噪后信号光滑度指标分别低于0.0009和0.0035;在与四种经典方法的对比中,所提方法在光滑度指标、能量比及频谱相似度上均表现出更优的综合性能,验证了其在实际工程中的有效性与适用性。
Abstract:
To effectively suppress noise interference in blasting vibration signals, a denoising method combining Gaussian mutation multi‑verse optimizer (GMVO) and variational mode decomposition (VMD) was proposed. In this method, a Gaussian mutation strategy was introduced into the standard multi‑verse optimizer to improve its global exploration and local exploitation capabilities by adding normally distributed perturbations to individuals after wormhole transmission. The enhanced GMVO was then employed to adaptively determine the optimal VMD parameters, i.e., the penalty factor alpha and the number of modes K, using the minimum envelope entropy as the fitness function. The optimization process aimed at minimizing the envelope entropy, which reflects the complexity of the signal envelope and indicates better decomposition performance. With the optimized parameters, the noisy signal was decomposed via VMD into a series of intrinsic mode functions (IMFs). To distinguish noise‑dominant components from effective ones, multi‑scale permutation entropy (MPE) and variance contribution rate were calculated for each IMF. MPE quantifies the complexity of time series at multiple scales, with noise‑dominated components generally exhibiting higher entropy values. A dual‑threshold criterion was established: IMFs with MPE values exceeding 0.6 or variance contribution rates below 1% were rejected as noise or invalid modes. The retained IMFs were reconstructed to obtain the denoised signal.For validation, a clean blasting vibration signal was simulated using a prediction model previously developed, which incorporates modulated white noise and a Gamma envelope to faithfully reproduce the nonstationary characteristics of real blasting vibrations. Gaussian white noise at different signal‑to‑noise ratios (SNR) of 3, 5, 7, 10, and 15 dB was added to generate noisy signals. The denoising experiments demonstrated that the GMVO‑VMD method outperformed MVO‑VMD, wavelet thresholding, empirical mode decomposition with MPE (EMD‑MPE), and ensemble EMD‑MPE (EEMD‑MPE) in terms of SNR, root mean square error (RMSE), correlation coefficient, and smoothness index. The robustness indices remained above 0.8 even under strong noise interference. Application to field blasting vibration signals from an underground mine showed that the method effectively suppressed high‑frequency noise and corrected baseline drift, with smoothness indices below 0.0009 for cut holes and 0.0035 for perimeter holes. Compared with the four classical methods, the proposed approach exhibits superior overall performance in smoothness, energy ratio, and spectral similarity, confirming its effectiveness and applicability in practical engineering.