几种信号去噪方法在爆破振动信号中的应用分析

摘要

The signal de-noising principle of the wavelet threshold method, EMD and EEMD are mainly pro-posed. Three methods were used to denoise the blasting seismic signals under open-pit blasting. The compara-tive analysis of the oscillogram of denoising, signal-to-noise ratio and the root mean square error detection show that the difference of denoising effect are produced by the wavelet threshold denoising method for differ-ent signal source. The value of signal-to-noise ratio and the root mean square error have big volatility. There-fore, the method is unstable in the process of blasting vibration signal denoising. The signal denoising effect by EMD and EEMD methods are compared with the wavelet threshold method, which shows their adaptability in signal analysis. The EEMD can eliminate modal aliasing phenomenon generated by the decomposing signal through EMD. As a result, EEMD denoising method can achieve higher signal-to-noise ratio and smaller root mean square error compared with EMD denoising method, so the effect of denoising through EEMD is much better than EMD. But the EEMD also has the disadvantage of too long computation time.%介绍了小波阈值法、EMD以及EEMD的信号去噪原理，并采用3种方法分别对露天爆破开采下所获得的爆破地震波信号进行去噪处理。对比分析去噪后波形图、信噪比以及均方根误差，发现小波阈值去噪法对于不同信号源去噪时效果各不相同，其信噪比与均方根误差值波动幅度大，说明小波阈值法在爆破振动信号去噪中具有不稳定性。与小波阈值法相比，EMD与EEMD对信号去噪效果稳定，体现了它们在信号分析中的自适应性。与EMD去噪法相比，EEMD能消除EMD分解信号时所产生的模态混叠现象；EEMD去噪法能够获得更高的信噪比以及更小的均方根误差值，去噪效果要明显好于EMD法，缺点在于计算时间太长。