CN109668620B - Positioning method based on interference type distributed optical fiber vibration sensor - Google Patents
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Abstract
The invention discloses a positioning method based on an interference type distributed optical fiber vibration sensor, which can determine a disturbance signal of a disturbance point based on the interference type distributed optical fiber vibration sensor, analyze the disturbance signal to obtain a first phase signal and a second phase signal, perform Fourier transform based on the first phase signal and the second phase signal, calculate a first peak value and a second peak value of the first phase signal and the second phase signal on a frequency domain, calculate a peak value ratio of the first peak value and the second peak value, and finally calculate position information of the disturbance point according to the peak value ratio. When the number of the disturbance points is more than one, the disturbance points cannot be located from the time domain, the disturbance signals are converted into the frequency domain based on Fourier transform, and the position information of the disturbance points can be calculated based on the peak ratio value on the frequency domain.
Description
Technical Field
The invention relates to the technical field of electronics, in particular to a positioning method based on an interference type distributed optical fiber vibration sensor.
Background
At present, only one disturbance point of a sensing optical fiber on the interference type distributed interference sensor can be monitored through the interference type distributed interference sensor to obtain a disturbance signal of the disturbance point, the position information of the disturbance point can be determined based on the phase ratio of the disturbance signal of the disturbance point on a time domain, but when the sensing optical fiber is provided with a plurality of disturbance points, the phase ratio of the disturbance point cannot be obtained through calculation, and further the position information of the disturbance point cannot be determined.
Disclosure of Invention
The embodiment of the invention provides a positioning method based on an interference type distributed optical fiber vibration sensor, which can solve the problem that the position information of a plurality of interference points cannot be determined through the interference type distributed optical fiber vibration sensor in the prior art.
The embodiment of the invention provides a positioning method based on an interference type distributed optical fiber vibration sensor, which comprises the following steps:
determining a disturbance signal of a disturbance point based on the interference type distributed optical fiber vibration sensor, and analyzing the disturbance signal to obtain a first phase signal and a second phase signal;
fourier transformation is carried out on the first phase signal and the second phase signal, a first peak value and a second peak value of the first phase signal and the second phase signal on a frequency domain are obtained based on the Fourier transformation result, and the peak value ratio of the first peak value and the second peak value is calculated;
based on the peak ratio, position information of the disturbance point is calculated.
Optionally, the first phase signal and the second phase signal are respectively expressed as:
wherein the content of the first and second substances,
respectively representing a first phase signal and a second phase signal;
phi (t) represents a disturbance signal of the ith disturbance point in the m disturbance points, wherein i is a positive integer;
n represents the effective refractive index of the fiber, c represents the speed of light;
Zxi、Zyirespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant.
Optionally, calculating a phase ratio of the first phase signal and the second phase signal includes:
wherein xi represents the phase ratio;
Zxi、Zyirespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant.
Optionally, performing fourier transform on the first phase signal and the second phase signal includes:
wherein the content of the first and second substances,
respectively representing a first phase signal and a second phase signal;
Φiomega represents the Fourier transform result of the disturbance signal phi i (t) of the ith disturbance point, wherein i is a positive integer;
n represents the effective refractive index of the fiber, c represents the speed of light;
Zxi、Zyirespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant.
Optionally, the first peak and the second peak are respectively expressed as:
wherein the content of the first and second substances,
respectively representing a first peak and a second peak of the first phase signal and the second phase signal on a frequency domain;
n represents the effective refractive index of the fiber, c represents the speed of light;
Zxi、Zyirespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant;
Ωi、Aithe center frequency and the amplitude of the disturbance signal at the ith disturbance point on the frequency domain are respectively shown.
Optionally, calculating a peak ratio of the first peak to the second peak includes:
wherein the content of the first and second substances,
respectively representing a first peak and a second peak of the first phase signal and the second phase signal on a frequency domain;
xi represents the phase ratio; n represents the effective refractive index of the fiber, c represents the speed of light;
Zxi、Zyirespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant;
Ωi、Aithe center frequency and the amplitude of the disturbance signal at the ith disturbance point on the frequency domain are respectively shown.
Optionally, calculating the position information of the disturbance point based on the phase ratio and the peak ratio includes:
make the peak ratio equal to the phase ratio:
and solving to obtain the position relation of the disturbance point:
wherein Z isxi、ZyiRespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant;
Ωi、Aithe center frequency and the amplitude of the disturbance signal at the ith disturbance point on the frequency domain are respectively shown.
Furthermore, the embodiment of the invention also provides a positioning device, which comprises a processor, a memory and a communication bus;
the communication bus is used for realizing connection communication between the processor and the memory;
the processor is configured to execute one or more programs stored in the memory to implement the steps of the interferometric-based distributed fiber optic vibration sensor positioning method described above.
Further, the embodiment of the present invention also provides a computer readable storage medium, which stores one or more programs, where the one or more programs are executable by one or more processors to implement the steps of the positioning method based on the interferometric distributed optical fiber vibration sensor.
Advantageous effects
The embodiment of the invention provides a positioning method based on an interference type distributed optical fiber vibration sensor, which can determine a disturbance signal of a disturbance point based on the interference type distributed optical fiber vibration sensor, analyze the disturbance signal to obtain a first phase signal and a second phase signal, calculate a phase ratio of the first phase signal and the second phase signal, perform Fourier transform based on the first phase signal and the second phase signal, further calculate a peak ratio of a first peak value and a second peak value of the first phase signal and the second phase signal in a frequency domain based on a Fourier transform result, and finally calculate position information of the disturbance point based on the phase ratio and the peak ratio.
When the number of the disturbance points is more than one, the phase ratio of disturbance signals of the disturbance points cannot be calculated from the time domain, but the positioning method provided by the invention can convert the disturbance signals into the frequency domain based on Fourier transform, calculate the first peak value and the second peak value of the first phase signal and the second phase signal on the frequency domain, and calculate the position information of the disturbance points based on the phase ratio and the peak ratio of the first peak value and the second peak value.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic structural diagram of an interferometric distributed fiber vibration sensor according to an embodiment of the present invention;
fig. 2 is a schematic flow chart of a method for positioning an interference point by using a signal processing apparatus of an interferometric distributed optical fiber vibration sensor according to an embodiment of the present invention;
FIG. 3 is a schematic structural diagram of another interferometric distributed fiber optic vibration sensor provided in accordance with an embodiment of the present invention;
fig. 4 is a schematic structural diagram of an interference point positioning device implemented by a signal processing device of an interference-type distributed optical fiber vibration sensor according to an embodiment of the present invention.
Detailed Description
In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Before the method is introduced, the interference type distributed optical fiber vibration sensor is simply introduced, and more detailed description contents can be seen later in the specification.
Referring to fig. 1, fig. 1 is a schematic structural diagram of an interferometric distributed optical fiber vibration sensor, which is a basis for implementing a positioning method provided in an embodiment of the present invention, and the interferometric distributed optical fiber vibration sensor includes a first segnar interferometer, a second segnar interferometer, a light source emitting device, and a signal processing device, where the first segnar interferometer and the second segnar interferometer are respectively connected to the signal processing device.
It should be understood that, the first and second segmenter interferometers include sensing optical fibers, and when a disturbance point acts on the sensing optical fibers, the optical waves transmitted in the sensing optical fibers are subjected to phase change due to the photoelastic effect, so as to obtain polarized light.
The light source emitting device can emit first polarized light and second polarized light which vibrate at a preset angle, the first polarized light and the second polarized light are respectively incident to the first Sagnac interferometer and the second Sagnac interferometer, and the first polarized light and the second polarized light which have phase changes are transmitted to the signal processing device because sensing optical fibers in the first Sagnac interferometer and the second Sagnac interferometer are influenced by disturbance points to have phase changes. In some examples, the predetermined angle is 90 degrees, i.e., the first polarized light is perpendicular to the second polarized light.
And the signal processing device is used for collecting the first polarized light and the second polarized light with the changed phases and realizing the positioning of the disturbance point based on the first polarized light and the second polarized light with the changed phases.
How the signal processing device locates the disturbance point acting on the sensing optical fiber based on the first polarized light and the second polarized light with the changed phases can be realized by a locating method (the following steps) provided by an embodiment of the present invention, referring to fig. 2, the locating method provided by the embodiment of the present invention includes:
s201, determining a disturbance signal of a disturbance point based on the interference type distributed optical fiber vibration sensor, and analyzing the disturbance signal to obtain a first phase signal and a second phase signal.
S202, Fourier transformation is carried out on the first phase signal and the second phase signal, a first peak value and a second peak value of the first phase signal and the second phase signal on a frequency domain are obtained based on Fourier transformation results, and a peak value ratio of the first peak value to the second peak value is calculated.
And S203, calculating the position information of the disturbance point based on the peak ratio.
For step S203, specifically, based on the relationship between the phase ratio and the peak ratio, the position relationship of the disturbance point is calculated: the peak ratio and the phase ratio are equal, and the position relation of the disturbance point can be solved.
The positioning method provided by the embodiment of the invention can solve the problem that the position information of the disturbance point cannot be determined based on the time domain when more than one disturbance point exists in the prior art, the positioning method provided by the embodiment of the invention converts the disturbance signal into the frequency domain based on Fourier transform, calculates the phase ratio of the disturbance signal of the disturbance point, calculates the first peak value and the second peak value of the first phase signal and the second phase signal in the frequency domain, and further calculates the peak ratio, thereby calculating the position information of the disturbance point based on the phase ratio and the peak ratio.
The following will continue to describe other examples of the positioning method provided by the present invention based on the positioning method provided by the above-described embodiment.
S201, determining a disturbance signal of a disturbance point based on the interference type distributed optical fiber vibration sensor, and analyzing the disturbance signal to obtain a first phase signal and a second phase signal.
Wherein, the first phase signal and the second phase signal can be respectively expressed as:
calculating the phase ratio of the first phase signal to the second phase signal:
xi represents the phase ratio;
phi (t) represents a disturbance signal of the ith disturbance point in the m disturbance points, wherein i is a positive integer;
n represents the effective refractive index of the fiber, c represents the speed of light;
Zxi、Zyirespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant.
S202, carrying out Fourier transform on the first phase signal and the second phase signal, obtaining a first peak value and a second peak value of the first phase signal and the second phase signal on a frequency domain based on a Fourier transform result, and calculating a peak value ratio of the first peak value to the second peak value;
the Fourier transform of the first phase signal and the second phase signal comprises the following steps:
it is to be understood that the following description,
respectively representing a first phase signal and a second phase signal;
Φiomega represents the Fourier transform result of the disturbance signal phi i (t) of the ith disturbance point, wherein i is a positive integer;
n represents the effective refractive index of the fiber, c represents the speed of light;
Zxi、Zyirespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant.
It should be understood that the first peak and the second peak are respectively expressed as:
wherein the content of the first and second substances,
respectively representing a first peak and a second peak of the first phase signal and the second phase signal on a frequency domain;
n represents the effective refractive index of the fiber, c represents the speed of light;
Zxi、Zyirespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant;
Ωi、Aithe center frequency and the amplitude of the disturbance signal at the ith disturbance point on the frequency domain are respectively shown.
And S203, calculating the position information of the disturbance point based on the phase ratio and the peak ratio.
Step S203 may be implemented by:
make the peak ratio equal to the phase ratio:
and solving to obtain the position relation of the disturbance point:
wherein Z isxi、ZyiRespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant;
Ωi、Aithe center frequency and the amplitude of the disturbance signal at the ith disturbance point on the frequency domain are respectively shown.
The theoretical implementation basis of the positioning method provided by the invention is described in detail as follows:
according to the demodulation principle of the 3 × 3 coupler, the first phase signal and the second phase signal can be respectively demodulated by utilizing three paths of output signals of the two 3 × 3 couplers through operation. When m disturbance signals fi (t) (i ═ 1, 2, …, m) act on the sensing optical fiber simultaneously, the relative positions of the loops where the first phase signal and the second phase signal are located are Zxi and Zyi (i ═ 1, 2, …, m). It should be appreciated that there is a constant d that allows Zxi and Zyi to satisfy the fixed relationship Zxi + Zyi ═ d.
In particular, when i is 1, the first phase signal
And a second phase signal
Can be expressed as
And
if the phase ratio is ordered
Then
Similarly, as can be seen from the independence of vibration, when a plurality of disturbance signals exist simultaneously, the phase ratio xi of each of the disturbance signals fi (t) at the corresponding positions Zxi and Zyi satisfies the relationship
The location of each disturbance can be determined using this relationship. But when there are more than two disturbances, the first phase signal
And a second phase signal
The phase ratio xi of each position cannot be obtained from the time domain, and the position of the disturbance signal (disturbance point) cannot be determined.
The first phase signal
And a second phase signal
The fourier transform is used to transform to the frequency domain. Fourier transform of the disturbance signal fi (t) if it is Fi(W), i.e. F [ fi (t)]＝Fi(W), the Fourier transform property can be obtained
Assume that the center frequency of each disturbance signal fi (t) is ΩiAnd amplitude of AiAnd the center frequency of each perturbation signal is different, it is easy to know that they are discrete and separated on the spectrogram of the frequency domain. At this time, the first phase signal
And a second phase signal
The spectrogram has a center frequency of ΩiWill all peak at that position
And the magnitude of the peak can be expressed as follows from the nature of the Fourier change
Therefore, the phase ratio corresponding to each perturbation position in the time domain
Convertible in the frequency domain to each omega in the frequency spectrumiRatio of peaks at frequency position, i.e.
Therefore, the position of each perturbation signal fi (t) can be calculatedIs composed of
Thereby realizing the simultaneous positioning of multi-point vibration.
Some other examples of interferometric distributed fiber optic vibration sensors are further described below with reference to the interferometric distributed fiber optic vibration sensor described in fig. 1, and with reference to fig. 3,
the first Sagnac interferometer comprises a first circulator (1), a first coupler (2), a first polarization beam splitter (3), a second polarization beam splitter (4), a third polarization beam splitter (5), a fourth polarization beam splitter (6), a first detector (7), a second detector (8), a third detector (9), optical fibers for connection and sensing optical fibers (20) for connecting a first end (31) of the first polarization beam splitter (3) and a first end (41) of the second polarization beam splitter (4).
It will be appreciated that some of the first and second segmentors are common, and these common instruments include: the polarization beam splitter comprises a first polarization beam splitter (3), a second polarization beam splitter (4), a third polarization beam splitter (5) and a fourth polarization beam splitter (6).
The second Sagnac interferometer comprises a second circulator (10), a second coupler (11), a fourth detector (12), a fifth detector (13), a sixth detector (14), a first polarization beam splitter (3), a second polarization beam splitter (4), a third polarization beam splitter (5) and a fourth polarization beam splitter (6);
the connection relationship of each device in the first Sagnac interferometer is as follows:
one end of the first coupler (2) is connected with a second end (32) of the first polarization beam splitter (3) and a first end (61) of the fourth polarization beam splitter (6) through optical fibers respectively, a second end (32) of the first polarization beam splitter (3) is connected with a first end (61) of the fourth polarization beam splitter (6) through optical fibers, and a first end (51) and a second end (52) of the third polarization beam splitter (5) are connected with a second end (62) of the fourth polarization beam splitter (6) and a second end (42) of the second polarization beam splitter (4) through optical fibers respectively;
the other end of the first coupler (2) is connected with a first detector (7) and a second detector (8) through optical fibers respectively, the other end of the first coupler (2) is further connected with a first end (1a) of the first circulator (1) through the optical fibers, a second end (1b) of the first circulator (1) is connected with a third detector (11) through the optical fibers, and the first detector (7), the second detector (8) and the third detector (9) are connected with a signal processing device (15) through the optical fibers respectively;
the connection relationship of each device in the second segmenter interferometer is as follows:
one end of the second coupler (11) is connected with the second end (42) of the second polarization beam splitter (4) and the second end (52) of the fourth polarization beam splitter (5) through optical fibers respectively.
The other end of the second coupler (11) is connected with the fourth detector (12) and the fifth detector (13) through optical fibers respectively, the other end of the second coupler (11) is further connected with the first end (10a) of the second circulator (10) through the optical fibers, the second end (10b) of the second circulator (10) is connected with the sixth detector (14) through the optical fibers, and the fourth detector (12), the fifth detector (13) and the sixth detector (14) are connected with the signal processing device (15) through the optical fibers respectively.
The first polarized light emitted by the light source emitting device is incident to the first Seger interferometer through the third end (1c) of the first circulator (1), and the second polarized light emitted by the light source emitting device is incident to the first Seger interferometer through the third end (10c) of the second circulator (10). It should be noted that the first polarized light and the second polarized light vibrate at a predetermined angle, which is 90 degrees in this embodiment, that is, the first polarized light and the second polarized light are perpendicular to each other.
It is to be understood that the first detector (9), the second detector (10), the third detector (11), the fourth detector (12), the fifth detector (13) and the sixth detector (14) are indium gallium arsenide (InGaAs) detectors.
The light source emitting device in fig. 3 includes a light source (16), a polarizer (17), and a third coupler (18);
one end of the third coupler (18) is respectively connected with the third end (1c) of the first circulator (1) and the third end (10c) of the second circulator (10) through optical fibers;
light emitted by the light source (16) is incident to the third coupler (18) through the polarizer (17), and is split into first polarized light and second polarized light through the third coupler (18).
In some examples, the light source (16) is an amplified spontaneous emission light source operating in the C-band, with a wavelength range of 1530nm to 1605 nm.
The signal processing device comprises a photoelectric converter (151), a signal collector (152) and a signal demodulation arithmetic unit (153), wherein the photoelectric converter (151) is connected with the signal demodulation arithmetic unit (153) through the signal collector (152).
The functions of the various devices in the interferometric distributed fiber optic vibration sensor provided in embodiments of the present invention are described herein:
a light source (16) in the light source emitting device uses an ASE broadband light source, and works in a C wave band with a wavelength range of 1530-1605 nm.
Polarizer (17) in the light source emitting device: a device for obtaining polarized light.
Coupler comprising a first coupler (2), a second coupler (11): the beam splitting and beam combining of the light are realized.
Circulator, comprising a first circulator (1), a second circulator (10): the incident wave entering any port of the multi-port device is transmitted into the multi-port device of the next port according to the direction sequence determined by the static bias magnetic field, and can only be output in a fixed direction during working.
Polarizing beam splitter comprising a first polarizing beam splitter (3), a second polarizing beam splitter (4), a third polarizing beam splitter (5), a fourth polarizing beam splitter (6): the two orthogonal polarized light beams are respectively and singly output to two optical fibers (positive working), or the two orthogonal polarized light beams are coupled into one optical fiber (negative working).
Sensing fiber (20): unlike conventional optical fibers, the optical fiber used for positioning is called a sensing fiber only during operation.
The detector comprises a first detector (7), a second detector (8), a third detector (9), a fourth detector (12), a fifth detector (13) and a sixth detector (14): for devices for converting light intensity signals into electrical signals, a C-band detector usually uses indium gallium arsenide (InGaAs) material.
And the signal processing device (15) is mainly used for carrying out next-step processing on the electric signals converted by the detector, including the steps of sequentially collecting the electric signals by a collecting card, then demodulating the signals by a computer to obtain disturbance signals of disturbance points on the sensing optical fiber, and then carrying out positioning calculation based on the disturbance signals.
The invention provides a positioning method based on an interference type distributed optical fiber vibration sensor, wherein the optical fiber vibration sensor comprises a first Sagnac interferometer, a second Sagnac interferometer, a light source emitting device and a signal processing device, and the first Sagnac interferometer and the second Sagnac interferometer are respectively connected with the signal processing device; the first Sagnac interferometer and the second Sagnac interferometer comprise sensing optical fibers, the light source emitting device emits first polarized light and second polarized light which vibrate at preset angles, the first polarized light and the second polarized light are respectively incident into the first Sagnac interferometer and the second Sagnac interferometer, the sensing optical fibers in the first Sagnac interferometer and the second Sagnac interferometer are affected by a disturbance point to generate phase change, the first polarized light and the second polarized light which generate the phase change are transmitted to the signal processing device, and the signal processing device is used for positioning the disturbance point based on the first polarized light and the second polarized light which generate the phase change.
Specifically, when a disturbance point acts on the sensing fiber, the phase change of the light wave transmitted in the sensing fiber is caused due to the photoelastic effect, and the phase change of the first polarized light and the second polarized light is different due to the fact that the time of the first polarized light and the time of the second polarized light passing through the disturbance point are different, so that the disturbance point can be positioned based on the first polarized light and the second polarized light of which the phases are changed.
The present embodiment further provides a positioning apparatus, as shown in fig. 4, which includes a processor 401, a memory 402, and a communication bus 403, wherein:
the communication bus 403 is used for realizing connection communication between the processor 401 and the memory 402;
the processor 401 is configured to execute the positioning program based on the interferometric distributed optical fiber vibration sensor stored in the memory 402 to implement the steps of the positioning method based on the interferometric distributed optical fiber vibration sensor in the embodiments described above.
The present embodiment also provides a computer readable storage medium, which stores one or more programs that can be executed by one or more processors to implement the steps of the positioning method based on the interferometric distributed fiber vibration sensor in the above embodiments.
It should be noted that, for the sake of simplicity, the above-mentioned method embodiments are described as a series of acts or combinations, but those skilled in the art should understand that the present invention is not limited by the described order of acts, as some steps may be performed in other orders or simultaneously according to the present invention. Further, those skilled in the art will appreciate that the embodiments described in the specification are presently preferred and that no acts or modules are necessarily required of the invention.
In the above embodiments, the description of each embodiment has its own emphasis, and parts of a certain embodiment that are not described in detail can be referred to related descriptions of other embodiments, and the above serial numbers of the embodiments of the present invention are merely for description and do not represent advantages and disadvantages of the embodiments, and those skilled in the art can make many forms without departing from the spirit and scope of the present invention and as claimed in the claims, and these forms are within the protection of the present invention.
Claims (9)
1. A positioning method based on an interference type distributed optical fiber vibration sensor is characterized by comprising the following steps:
determining a disturbance signal of a disturbance point based on the interference type distributed optical fiber vibration sensor, and analyzing the disturbance signal to obtain a first phase signal and a second phase signal;
performing Fourier transformation on the first phase signal and the second phase signal, obtaining a first peak value and a second peak value of the first phase signal and the second phase signal on a frequency domain based on a Fourier transformation result, and calculating a peak value ratio of the first peak value to the second peak value;
calculating position information of the disturbance point based on the peak ratio;
the interference type distributed optical fiber vibration sensor comprises a first Sagnac interferometer, a second Sagnac interferometer, a light source emission device and a signal processing device, wherein the first Sagnac interferometer and the second Sagnac interferometer are respectively connected with the signal processing device, the first Sagnac interferometer and the second Sagnac interferometer comprise sensing optical fibers, the light source emission device emits first polarized light and second polarized light which mutually vibrate at a preset angle, the first polarized light and the second polarized light are respectively incident into the first Sagnac interferometer and the second Sagnac interferometer and generate phase change due to the influence of disturbance points on the sensing optical fibers in the first Sagnac interferometer and the second Sagnac interferometer, and the first polarized light and the second polarized light which generate the phase change are transmitted to the signal processing device, the signal processing device is used for positioning the disturbance point based on the first polarized light and the second polarized light with the changed phases;
the first Sagnac interferometer comprises a first circulator, a first coupler, a first polarization beam splitter, a second polarization beam splitter, a third polarization beam splitter, a fourth polarization beam splitter, a first detector, a second detector, a third detector, an optical fiber for connection and a sensing optical fiber for connecting the first end of the first polarization beam splitter and the first end of the second polarization beam splitter, wherein one end of the first coupler is respectively connected with the second end of the first polarization beam splitter and the first end of the fourth polarization beam splitter through the optical fiber, the second end of the first polarization beam splitter is connected with the first end of the fourth polarization beam splitter through the optical fiber, and the first end and the second end of the third polarization beam splitter are respectively connected with the second end of the fourth polarization beam splitter and the second end of the second polarization beam splitter through the optical fiber;
the other end of the first coupler is connected with the first detector and the second detector through optical fibers respectively, the other end of the first coupler is also connected with the first end of the first circulator through optical fibers, the second end of the first circulator is connected with the third detector through optical fibers, and the first detector, the second detector and the third detector are connected with the signal processing device through optical fibers respectively;
the first polarized light will be incident on the first Seger interferometer through the third end of the first circulator.
2. The positioning method of claim 1, wherein the first phase signal and the second phase signal are respectively expressed as:
wherein the content of the first and second substances,
respectively representing the first phase signal and the second phase signal;
phi (t) represents a disturbance signal of the ith disturbance point in the m disturbance points, wherein i is a positive integer;
n represents the effective refractive index of the fiber, c represents the speed of light;
Zxi、Zyirespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant.
3. The positioning method of claim 1, wherein said calculating a phase ratio of said first phase signal to said second phase signal comprises:
wherein xi represents the phase ratio;
Zxi、Zyirespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant.
4. The positioning method of claim 1, wherein said fourier transforming the first phase signal and the second phase signal comprises:
wherein the content of the first and second substances,
respectively representing the first phase signal and the second phase signal;
Φiomega represents the Fourier transform result of the disturbance signal phi i (t) of the ith disturbance point, wherein i is a positive integer;
n represents the effective refractive index of the fiber, c represents the speed of light;
Zxi、Zyirespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant.
5. The positioning method according to claim 1, wherein the first peak value and the second peak value are respectively expressed as:
wherein the content of the first and second substances,
respectively representing a first peak and a second peak of the first phase signal and the second phase signal on a frequency domain;
n represents the effective refractive index of the fiber, c represents the speed of light;
Zxi、Zyirespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant;
Ωi、Aithe center frequency and the amplitude of the disturbance signal at the ith disturbance point on the frequency domain are respectively shown.
6. The positioning method of claim 1, wherein said calculating a peak ratio of said first peak to said second peak comprises:
wherein the content of the first and second substances,
respectively representing a first peak and a second peak of the first phase signal and the second phase signal on a frequency domain;
xi represents the phase ratio; n represents the effective refractive index of the fiber, c represents the speed of light;
Zxi、Zyirespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant;
Ωi、Aithe center frequency and the amplitude of the disturbance signal at the ith disturbance point on the frequency domain are respectively shown.
7. The method of claim 1, wherein the calculating the position information of the disturbance point based on the peak ratio value comprises:
equating the peak ratio to the phase ratio:
and solving to obtain the position relation of the disturbance point:
wherein Z isxi、ZyiRespectively represents the distance between the ith disturbance point and the midpoint of an optical fiber loop in the interference type distributed optical fiber vibration sensor, and Zxi+ZyiD is a constant;
Ωi、Aithe center frequency and the amplitude of the disturbance signal at the ith disturbance point on the frequency domain are respectively shown.
8. A positioning device, comprising a processor, a memory, and a communication bus;
the communication bus is used for realizing connection communication between the processor and the memory;
the processor is configured to execute one or more programs stored in the memory to implement the steps of the interferometric-based distributed fiber optic vibration sensor positioning method of any one of claims 1-7.
9. A computer readable storage medium, storing one or more programs which are executable by one or more processors to perform the steps of the method according to any one of claims 1 to 7.
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