Data demodulation method for polarization maintaining fiber stress sensing
A polarization-maintaining optical fiber and stress sensing technology, applied in the field of optical measurement, can solve the problems of local lack of self-adaptation of signals, unsuitable for nonlinear noise and signal structure with sudden changes, and inability to replace, etc., to increase the recognition ability, The effect of improving sensitivity and accurate measurement results
Inactive Publication Date: 2012-02-22
TIANJIN UNIV
View PDF4 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
When the useful information of the signal and the frequency bands of the noise do not overlap, Fourier smoothing can achieve better results. However, setting a specific cutoff frequency is not suitable for nonlinear noise and signal structures with sudden changes.
In wavelet transform, once the wavelet base is selected, it cannot be replaced in the whole process of decomposition and reconstruction, and there is no local adaptability to the signal
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment 1
[0040] figure 1 is a flow chart of the data demodulation algorithm for polarization-maintaining optical fiber stress sensing; figure 2 Is the hardware structure of the present invention, wherein, 1 is an SLD light source, 2 is a polarizer, 3 is a polarization maintaining fiber, 4 is a collimator lens, 5 is a turntable, 6 is a Glan prism, 7 is a beam splitter, 8 is Static arm, 9 is a moving arm, 10 is a converging lens, 11 is a stepper motor, 12 is an acquisition card, and 13 is a computer.
[0041] Principle and working process of the inventive method are as follows:
[0042] The white light interference polarization coupling distributed polarization maintaining fiber stress sensing test system is based on the principle of polarization maintaining fiber polarization coupling. It uses external disturbances to cause polarization coupling in the polarization-maintaining fiber, and obtains the position and size of the disturbance point through Michelson interferometer demodulat...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention discloses a data demodulation method for polarization maintaining fiber stress sensing. The method comprises the following steps of: acquiring an interference signal by using a polarization maintaining fiber stress sensing test system to acquire photovoltage data; pre-processing the photovoltage data, averaging every n points to acquire new photovoltage data, and data volume; decomposing a photovoltage data signal into an intrinsic mode function (IMF) component and an allowance by an experimental mode method; finding out a basic component and identifying a small coupling point; reconstructing coupling intensity of a signal, and calculating the stress magnitude through intensity of each coupling point so as to realize the distributed detection of a system; and calculating indexes which can show the system test accuracy, such as a signal-to-noise ratio and the like. The method can effectively improve the signal-to-noise ratio of the polarization maintaining fiber stress sensing system, and improves the identification capacity of weak coupling points and the sensitivity of a coupling test. Under the environment of relatively low signal-to-noise ratio, microstress can be detected well.
Description
technical field [0001] The invention relates to a method for measuring stress parameters of a polarization device, belonging to the technical field of optical measurement, in particular to a data demodulation method for stress sensing of an optical polarization-maintaining device based on an interferometry method. Background technique [0002] When the polarization-maintaining fiber is disturbed by external force, magnetic field, bending, torsion and other factors, polarization coupling will occur. The measurement of polarization-maintaining fiber polarization coupling can realize the sensing of disturbance physical quantity. White-light interferometric polarization-coupled distributed polarization-maintaining fiber optic sensors have been widely used in stress, strain, temperature, gas, and position sensing due to their high spatial resolution and wide dynamic range. Its biggest feature is that it can realize distributed sensing on a single optical fiber, and any part of th...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): G01L1/24
Inventor 张红霞叶雯婷陈信伟贾大功温国强刘铁根
Owner TIANJIN UNIV