國立虎尾科技大學 |

Noise Analysis and Reduction in a Fiber-Grating-Based Acoustic Emission Detection System.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Noise Analysis and Reduction in a Fiber-Grating-Based Acoustic Emission Detection System./
Author:	Hu, Lingling.
Description:	1 online resource (121 pages)
Notes:	Source: Dissertation Abstracts International, Volume: 78-09(E), Section: B.
Subject:	Electrical engineering. -
Online resource:	click for full text (PQDT)
ISBN:	9781369718911

Noise Analysis and Reduction in a Fiber-Grating-Based Acoustic Emission Detection System.
Hu, Lingling.

Noise Analysis and Reduction in a Fiber-Grating-Based Acoustic Emission Detection System. - 1 online resource (121 pages)

Source: Dissertation Abstracts International, Volume: 78-09(E), Section: B.

Thesis (Ph.D.)--The University of Nebraska - Lincoln, 2017.

Includes bibliographical references

Detailed and systematic noise analysis and novel noise reduction methods in fiber-grating-based acoustic emission (AE) detection system are presented in this dissertation. The goal of this work is to provide solutions for the detection of small acoustic emission signals, which is of great interest in practical applications.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2018

Mode of access: World Wide Web

ISBN: 9781369718911Subjects--Topical Terms:

596380
Electrical engineering.
Index Terms--Genre/Form:

554714
Electronic books.

Noise Analysis and Reduction in a Fiber-Grating-Based Acoustic Emission Detection System.
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100 1 $a Hu, Lingling. $3 1148518
245 1 0 $a Noise Analysis and Reduction in a Fiber-Grating-Based Acoustic Emission Detection System.
264 0 $c 2017
300 $a 1 online resource (121 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Dissertation Abstracts International, Volume: 78-09(E), Section: B.
500 $a Adviser: Ming Han.
502 $a Thesis (Ph.D.)--The University of Nebraska - Lincoln, 2017.
504 $a Includes bibliographical references
520 $a Detailed and systematic noise analysis and novel noise reduction methods in fiber-grating-based acoustic emission (AE) detection system are presented in this dissertation. The goal of this work is to provide solutions for the detection of small acoustic emission signals, which is of great interest in practical applications.
520 $a A cost-effective way for interrogation in an AE detection system using fiber Bragg gratings (FBGs) as sensors is to convert the AE-introduced wavelength shift to intensity variations of a laser whose wavelength is set on the slope of the grating's reflection spectrum. Disturbance in such a sensing system, including the wavelength shift introduced by the components inside the system, and the response of the system to external perturbations are discussed herein.
520 $a The small, cost-efficient distributed feedback (DFB) laser diode is an attractive light source for the sensing system. However, it is also a main contributor of noise. The output wavelength of the DFB laser diode results from the interplay between the injected current and the temperature of the semiconductor junction. The low frequency drift of the laser wavelength caused by thermal and mechanical disturbance can be controlled by using a feedback control system. However, the high frequency wavelength fluctuations caused by the spontaneous emission broadens the laser linewidth and can be converted into large frequency noise by using a frequency discriminator, such as piFBGs.
520 $a To improve the SNR of the system in a cost-effective way, a noise reduction method using two types of reference channels is proposed. Using a matched piFBG as a reference, which works at the same operating point as the piFBG sensor and is isolated from AE signals, the noise from the light source can be completely subtracted from the sensing signals. The reference channel is improved for use in the environment with a large thermal gradient and mechanical fluctuations by interferometers, which have large detection bandwidth. A novel data processing method was developed for each type of reference to efficiently subtract the laser intensity and frequency noise from the sensor signals. It has been demonstrated that the SNR can be improved more than 20 dB by using the proposed noise reduction methods.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2018
538 $a Mode of access: World Wide Web
650 4 $a Electrical engineering. $3 596380
655 7 $a Electronic books. $2 local $3 554714
690 $a 0544
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a The University of Nebraska - Lincoln. $b Electrical Engineering. $3 1148519
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10272532 $z click for full text (PQDT)