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A High-Resolution Demodulation Algorithm for FBG-FP Static-Strain Sensors Based on the Hilbert Transform and Cross Third-Order Cumulant.

Huang W, Zhen T, Zhang W, Zhang F, Li F - Sensors (Basel) (2015)

Bottom Line: Static strain can be detected by measuring a cross-correlation of reflection spectra from two fiber Bragg gratings (FBGs).The Hilbert transform is proposed for changing the Gaussian distribution of the two FBG-FPs' reflection spectra, and a cross third-order cumulant is used to use the results of the Hilbert transform and get a group of noise-vanished signals which can be used to accurately calculate the wavelength difference of the two FBG-FPs.As a result, a static-strain resolution of 0.9 nε under laboratory environment condition is achieved, showing a higher resolution than the traditional cross-correlation method.

View Article: PubMed Central - PubMed

Affiliation: Optoelectronic System Laboratory, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China. hwzhu@semi.ac.cn.

ABSTRACT
Static strain can be detected by measuring a cross-correlation of reflection spectra from two fiber Bragg gratings (FBGs). However, the static-strain measurement resolution is limited by the dominant Gaussian noise source when using this traditional method. This paper presents a novel static-strain demodulation algorithm for FBG-based Fabry-Perot interferometers (FBG-FPs). The Hilbert transform is proposed for changing the Gaussian distribution of the two FBG-FPs' reflection spectra, and a cross third-order cumulant is used to use the results of the Hilbert transform and get a group of noise-vanished signals which can be used to accurately calculate the wavelength difference of the two FBG-FPs. The benefit by these processes is that Gaussian noise in the spectra can be suppressed completely in theory and a higher resolution can be reached. In order to verify the precision and flexibility of this algorithm, a detailed theory model and a simulation analysis are given, and an experiment is implemented. As a result, a static-strain resolution of 0.9 nε under laboratory environment condition is achieved, showing a higher resolution than the traditional cross-correlation method.

No MeSH data available.


Related in: MedlinePlus

The cross third-order cumulant curves and one-dimensional slice: (a) is the third-order cumulant of X(n); (b) is one-dimensional slice of (a); (c) is the cross third-order cumulant of X(n) and Y(n); (d) is one-dimensional slice of (c).
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sensors-15-09928-f005: The cross third-order cumulant curves and one-dimensional slice: (a) is the third-order cumulant of X(n); (b) is one-dimensional slice of (a); (c) is the cross third-order cumulant of X(n) and Y(n); (d) is one-dimensional slice of (c).

Mentions: For the cross third-order method, the Hilbert transform should be used for changing the Gaussian distribution of the reflection spectra from the two FBG-FPs first. Then the cross third-order cumulant is used to utilize the result of the Hilbert transform and get a group of noise-free signals which can be used to calculate the wavelength difference of the two FBG-FPs. As the theoretical model described, the third-order cumulant of X(n) and it’s one-dimensional slice CXXX(τ), the cross third-order cumulant of X(n) and Y(n) and it’s one-dimensional slice CXYX(τ) are shown in Figure 5. The one-dimensional slices of the third-order cumulants are very smooth, implying that the Gaussian noise is suppressed effectively and the two one-dimensional slices contain the wavelength difference information of the reflection spectra from the two FBG-FPs, so we can calculate the wavelength difference τ by the cross-correlation method in the next step.


A High-Resolution Demodulation Algorithm for FBG-FP Static-Strain Sensors Based on the Hilbert Transform and Cross Third-Order Cumulant.

Huang W, Zhen T, Zhang W, Zhang F, Li F - Sensors (Basel) (2015)

The cross third-order cumulant curves and one-dimensional slice: (a) is the third-order cumulant of X(n); (b) is one-dimensional slice of (a); (c) is the cross third-order cumulant of X(n) and Y(n); (d) is one-dimensional slice of (c).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4482008&req=5

sensors-15-09928-f005: The cross third-order cumulant curves and one-dimensional slice: (a) is the third-order cumulant of X(n); (b) is one-dimensional slice of (a); (c) is the cross third-order cumulant of X(n) and Y(n); (d) is one-dimensional slice of (c).
Mentions: For the cross third-order method, the Hilbert transform should be used for changing the Gaussian distribution of the reflection spectra from the two FBG-FPs first. Then the cross third-order cumulant is used to utilize the result of the Hilbert transform and get a group of noise-free signals which can be used to calculate the wavelength difference of the two FBG-FPs. As the theoretical model described, the third-order cumulant of X(n) and it’s one-dimensional slice CXXX(τ), the cross third-order cumulant of X(n) and Y(n) and it’s one-dimensional slice CXYX(τ) are shown in Figure 5. The one-dimensional slices of the third-order cumulants are very smooth, implying that the Gaussian noise is suppressed effectively and the two one-dimensional slices contain the wavelength difference information of the reflection spectra from the two FBG-FPs, so we can calculate the wavelength difference τ by the cross-correlation method in the next step.

Bottom Line: Static strain can be detected by measuring a cross-correlation of reflection spectra from two fiber Bragg gratings (FBGs).The Hilbert transform is proposed for changing the Gaussian distribution of the two FBG-FPs' reflection spectra, and a cross third-order cumulant is used to use the results of the Hilbert transform and get a group of noise-vanished signals which can be used to accurately calculate the wavelength difference of the two FBG-FPs.As a result, a static-strain resolution of 0.9 nε under laboratory environment condition is achieved, showing a higher resolution than the traditional cross-correlation method.

View Article: PubMed Central - PubMed

Affiliation: Optoelectronic System Laboratory, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China. hwzhu@semi.ac.cn.

ABSTRACT
Static strain can be detected by measuring a cross-correlation of reflection spectra from two fiber Bragg gratings (FBGs). However, the static-strain measurement resolution is limited by the dominant Gaussian noise source when using this traditional method. This paper presents a novel static-strain demodulation algorithm for FBG-based Fabry-Perot interferometers (FBG-FPs). The Hilbert transform is proposed for changing the Gaussian distribution of the two FBG-FPs' reflection spectra, and a cross third-order cumulant is used to use the results of the Hilbert transform and get a group of noise-vanished signals which can be used to accurately calculate the wavelength difference of the two FBG-FPs. The benefit by these processes is that Gaussian noise in the spectra can be suppressed completely in theory and a higher resolution can be reached. In order to verify the precision and flexibility of this algorithm, a detailed theory model and a simulation analysis are given, and an experiment is implemented. As a result, a static-strain resolution of 0.9 nε under laboratory environment condition is achieved, showing a higher resolution than the traditional cross-correlation method.

No MeSH data available.


Related in: MedlinePlus