Vibration Signal Analysis of Water Seal Blasting Based on Wavelet Threshold Denoising and HHT Transformation

Table 4

Energy of each IMF layer before and after noise reduction for four charge structures.

IMF component	Conventional charge structure		Water interval charge at both ends		Water interval charge at the orifice		Water interval charge at the hole bottom
	Original signal (cm^2/s^2)	Denoised signal (cm^2/s^2)	Original signal (cm^2/s^2)	Denoised signal (cm^2/s^2)	Original signal (cm^2/s^2)	Denoised signal (cm^2/s^2)	Original signal (cm^2/s^2)	Denoised signal (cm^2/s^2)
1	117.55	61.74	1046.48	152.46	549.43	44.20	101.6183		87.79
2	616.57	453.23	2791.32	2733.52	1410.10	1560.04	709.31983		1081.49
3	1200.64	1244.93	266.96	572.90	283.00	487.04	359.94249		312.52
4	49.73	149.61	54.62	366.70	44.94	212.24	31.25765		50.60
5	24.64	20.68	9.27	173.26	10.52	11.07	23.62858		11.98
6	10.37	17.79	1.68	19.99	8.52	4.07	3.12566		4.95
7	11.53	10.74	5.65	5.88	5.92	1.69	1.99501		0.41
8	10.42	10.97	3.08	4.60	1.13	1.25	2.81837		0.99
9	16.40	22.90	0.06	2.88	1.77	0.14	0.32634		1.36