Study on denoising of continuous spectrum on-line monitoring signal of water quality with micro-reagents based on HHT

Abstract

A continuous spectrum water quality on-line monitoring signal processing method based on Hilbert-Huang transform (HHT) is proposed in this paper, which combines the micro-reagent water quality on-line monitoring technology of sequential injection. The modulation signal and spectrum curve of each intrinsic mode function (IMF) component of the original spectrum signal were obtained by empirical mode decomposition (EMD). The water sample data of different concentrations in the continuous spectrum on-line monitoring system was analyzed by the HHT model. The noise signal was excavated to realize the noise reduction processing, and the reconstruction of the continuous spectrum signal was realized after the noise reduction processing was completed. The research results show that this method can effectively reduce the noise of continuous spectrum signals according to different signal-to-noise characteristics of continuous spectrum, and has convenient use, fast processing speed, and high resolution in the time-frequency domain, which effectively improves the stability and accuracy of the micro-reagent continuous spectrum water quality on-line monitoring system.

References

[1] HarvieA J, DemelloJ C, et al.. Optical determination of flow-rate and flow-uniformity in segmented flows[J]. Chemical engineering journal, 2020, 394: 124908

[2] YinM Q, HuX F, SunY N, et al.. Broad-spectrum detection of zeranol and its analogues by a colloidal gold-based lateral flow immunochromatographic assay in milk[J]. Food chemistry, 2020, 321: 126697

[3] HanB, ZhangY N, WangX, et al.. Non-contact flow rate detection of component in mixed gas using spectrum absorption theory[J]. Optical fiber technology, 2018, 45: 167-172

[4] ZhangR R, MaS, ErdalS, et al.. Hilbert-Huang transform analysis of dynamic and earthquake motion recordings[J]. Journal of engineering mechanics, 2003, 129(8):861-875

[5] WuZ H, HuangN E. A study of the characteristics of white noise using the empirical mode decomposition method[J]. The royal society, 2004, 460: 1597-1611

[6] ZhaoY, ZhangH W. Displacement measurement method based on laser self-mixing interference in the presence of speckle[J]. Chinese optics letters, 2020, 18(5):051201

[7] HuangN E, ZhengS, LongS R. A new view of non-linear water waves—Hilbert spectrum[J]. Annual review of fluid mechanics, 1999, 31: 417-457

[8] HuangN E, ZhengS, LongS R, et al.. The empirical mode decomposition and Hilbert spectrum for non-linear and nonstationary time series analysis[J]. The royal society, 1998, 454: 903-995

[9] ChenH K, WangT F, WuS S, et al.. Research on separation and enhancement of speech micro-vibration from macro motion[J]. Optoelectronics letters, 2020, 16(06):462-466

[10] LupieriG, ContentoG. Numerical simulations of 2-D steady and unsteady breaking waves[J]. Ocean engineering, 2015, 106: 298-316

[11] FanG, ZhangJ J, FuX, et al.. Dynamic failure mode and energy-based identification method for a counter-bedding rock slope with weak intercalated layers[J]. Journal of mountain science, 2016, 13(12):2111-2123

[12] PengJ. Hilbert-Huang transform (HHT) based analysis of signal characteristics of vortex flowmeter in oscillatory flow[J]. Flow measurement & instrumentation, 2012, 26(4):37-45

[13] PengJ, FangM. Response of a dual triangulate bluff body vortex flowmeter to oscillatory flow[J]. Flow measurement and instrumentation, 2014, 35: 16-27

[14] WangX P, HuangS X, KangC, et al.. Integration of wavelet denoising and HHT applied to the analysis of bridge dynamic characteristics[J]. Applied sciences, 2020, 10(10):3605

[15] YangY J, WangZ Y, YangX P, et al.. Signal processing of fluorescent optical fiber temperature measurement based on Hilbert-Huang transform[J]. Advanced materials research, 2014, 1052: 447-453

[16] ZhangX J, HuoY, WanD S. Improved EMD based on piecewise cubic Hermite interpolation and mirror extension[J]. Chinese journal of electronics, 2020, 29(05):899-905

[17] YangK M, WangG P, FuP J, et al.. A model on extracting the pollution information of heavy metal copper ion based on the soil spectra analyzed by HHT in time-frequency[J]. Spectroscopy and spectral analysis, 2018, 38(2):564(in Chinese)

[18] LiW, WangL M, ChangL, et al.. Sequential injection-continuous spectroscopy based multi-parameter method for water quality analysis[J]. Spectroscopy and spectral analysis, 2021, 41(02): 612-617

[19] DongZ K, SongY R, XuR Q, et al.. Broadband spectrum generation with compact Yb-doped fiber laser by intra-cavity cascaded Raman scattering[J]. Chinese optics letters, 2017, 15(07):80-83

[20] ZhuX B. A novel FBG velocimeter with wind speed and temperature synchronous measurement[J]. Optoelectronics letters, 2018, 14(04):276-279