CN116698097A - Mixed parameter synchronous measurement method based on optical fiber Fabry-Perot interference microcavity - Google Patents

Abstract

The invention discloses a method for synchronously measuring mixed parameters based on optical fiber Fabry-Perot interference microcavity. The measuring steps include: measuring the wavelength sensitivity and reflectivity sensitivity of an optical fiber sensor under temperature, medium concentration, transverse strain and torsion angle Calibration, combined with the wavelength correlation coefficient, reflectivity correlation coefficient and the relationship between the three sensitivities to construct a matrix, so as to obtain the synchronous measurement and decoupling relationship of the mixed parameters. The present invention utilizes the dual correlation detection method of wavelength and reflectivity to realize synchronous measurement and decoupling of two different types of parameters, eliminates the influence of cross-sensitivity between parameters, and improves the sensitivity of the optical fiber sensor at the same time, which is feasible and reliable, and the calibration process is simple , and the advantages of lower implementation costs.

Description

Synchronous measurement method of mixed parameters based on optical fiber Fabry-Perot interference microcavity

technical field

The invention relates to synchronous measurement and decoupling of mixed parameters, specifically an optical measurement method for distinguishing constant cavity length parameters such as temperature and medium concentration from variable cavity length parameters such as strain and torsion angle.

Background technique

Fiber Bragg grating sensing technology has obvious advantages in many aspects, such as high sensitivity, compact size, anti-electromagnetic interference, easy construction of sensor networks, and powerful multiplexing capabilities. It has attracted widespread attention, especially in the measurement of parameters such as temperature, refractive index, strain, and pressure, making fiber Bragg gratings (FBG) a huge potential in the fields of biochemical sensing, structural health monitoring, and gas/oil exploration. potential sensitive components. Although the FBG sensor with simple structure has good linearity and stability, it is difficult to meet the requirements of high-precision sensing field due to its low sensitivity. In order to improve the measurement sensitivity, micromachining methods such as chemical etching, arc discharge, mechanical polishing, and femtosecond laser modification are used to process the grating. However, these methods may reduce mechanical strength and lifetime while improving measurement sensitivity. Therefore, FBG needs to balance the balance between sensitivity and reliability in the application, and is committed to further improving the sensitivity of fiber Bragg gratings while maintaining its mechanical strength and service life to meet a wider range of high-precision sensing needs.

Usually the fiber grating sensor only uses the wavelength as the detection method of the measured parameter, which limits its ability to directly distinguish different parameters and easily leads to cross-sensitivity. As the name implies, cross-sensitivity means that a parameter of the sensor is sensitive to multiple external physical quantities at the same time. To determine the change of a single external physical quantity, this cross-sensitivity is something we do not want to see, so the influence of other physical quantities on this parameter must be eliminated. In order to overcome this problem, researchers continue to explore new methods and structures, such as multi-grating structures, special fiber structures, adding polymer coatings, and multi-sensor networks. These innovative measures aim to improve the multi-parameter measurement of fiber grating sensors. ability and anti-interference ability.

For example, in the simultaneous measurement of temperature and strain, the temperature around the FBG sensor must be measured independently. The most common method is to embed a temperature sensor, such as a thermocouple and a FBG sensor, to compensate the temperature of the FBG sensor. By embedding in the capillary The strain measurement temperature compensation method of strain-free FBG sensor and measuring temperature has also been widely used. In addition, many hybrid structures have been proposed, such as cascading FBGs with Fabry-Perot cavities, cascading FBGs with upper tapered Mach-Zehnder interferometers, and cascading FBGs with multimode fibers; It is to use more than two sensors, one of which is used as a compensation sensor to eliminate cross-sensitivity, so as to realize simultaneous measurement of multiple parameters, which greatly increases the complexity of the sensing system. In addition, the academic community generally uses post-data processing or device compensation to minimize the impact of cross-sensitivity on the accuracy of measurement results, which increases the cost of fiber optic sensors to a certain extent.

Contents of the invention

The present invention is to solve the shortcomings of the above-mentioned prior art, and proposes a method for synchronous measurement of mixed parameters based on optical fiber Fabry-Perot interference microcavity, in order to find out the commonality and difference of various parameters, Eliminate the influence of cross-sensitivity between parameters, while improving the sensitivity of the sensor; thus realizing the simultaneous measurement of mixed parameters of a single fiber grating sensor without any coating layer, which has great potential in engineering health monitoring, biosensing, chemical process monitoring and other related measurement fields application potential and value.

The present invention adopts following technical scheme for solving technical problems:

A kind of mixed parameter synchronous measurement method based on optical fiber Fabry-Perot interference microcavity of the present invention is characterized in that, comprises the following steps:

Step 1, using formula (1) to construct the relationship between the wavelength variation Δλ _m of the mth interference peak of the optical fiber sensor of the optical fiber Fabry-Perot interference microcavity and the axial strain Δε of the optical fiber sensor:

Δλ _m = (1-P _e )·λ _m ·Δε=K _ε ·Δε (1)

In formula (1): P _e is the effective photoelastic coefficient of the fiber; λ _m is the wavelength of the mth interference peak; K _ε is the wavelength sensitivity of the strain;

Use formula (2) to construct the relationship between the reflectivity change ΔR _m of the m-th interference peak of the optical fiber sensor and the axial strain Δε of the optical fiber sensor:

In formula (2): α is the normalization coefficient under a certain range calibration; L _M represents the length of the optical fiber Fabry-Perot interference microcavity; S _ε is the reflectivity sensitivity of the strain;

Step 2, using formula (3) to construct the relationship between the wavelength variation Δλ _m of the m-th interference peak of the optical fiber sensor and the torsion angle Δθ of the optical fiber sensor:

In formula (3): r is the fiber core radius; d is the length of the torsion beam; K _θ is the wavelength sensitivity of the twist angle;

Use formula (4) to construct the relationship between the reflectivity change ΔR _m and the twist angle Δθ of the m-th interference peak of the optical fiber sensor:

In formula (4): S _θ is the reflectivity sensitivity of twist angle Δθ;

Step 3, using formula (5) to construct the relationship between the wavelength variation ΔR _m of the mth interference peak of the optical fiber sensor and the ambient temperature ΔT:

In formula (5): ζ is the thermo-optic coefficient of the optical fiber; α is the thermal expansion coefficient of the optical fiber; K _T is the wavelength sensitivity of temperature;

Step 4, using formula (6) to construct the relationship between the wavelength variation Δλ _m of the mth interference peak of the optical fiber sensor and the medium concentration ΔW:

In formula (6): δ _w is the coefficient of change of the refractive index of a certain medium; n _eff is the effective refractive index of the fiber; n _core is the refractive index of the fiber core; K _w is the wavelength sensitivity of the medium concentration; total length;

Step 5, using formula (7) to construct the relationship between the wavelength correlation coefficient Δv _λ and the wavelength sensitivity coefficient:

Δv _λ =K _C ·ΔC+K _V ·ΔV (7)

In formula (7): ΔC represents the constant cavity length parameters such as temperature and medium concentration; ΔV represents the variable cavity length parameters such as lateral strain and torsion angle; K _C is the interference peak wavelength shift when the constant cavity length parameters change independently The sensitivity coefficient of K _V is the sensitivity coefficient of the interference peak wavelength drift when the variable cavity length parameter changes independently;

Step 6. Use formula (8) to construct the relationship between the dual reflectance correlation coefficient Δv _R and the variable cavity length parameter ΔV:

Δv _R =(S _C1 -S _C2 )·ΔC+(S _V1 -S _V2 )·ΔV=δS _V ·ΔV (8)

In the formula (8): S _C1 and S _C2 are the sensitivity coefficients of the reflectance responses of the dual correlation peaks λ ₁ and λ ₂ in the reflectance correlation spectrum when the parameters of the constant cavity length change independently, and S _C1 -S _C2 =0; S _V1 and S _V2 are the sensitivity coefficients of the reflectance responses of the dual correlation peaks λ ₁ and λ ₂ in the reflectance correlation spectrum when the variable cavity length parameters change independently; δS _V is the dual reflectance coefficient, and δS _V =S _V1 - S _V2 ;

Step 7, using formula (9) to construct the matrix expressions of wavelength correlation coefficient, dual reflectance correlation coefficient and three sensitivity coefficients:

Step 8, solve the matrix of formula (9), so as to obtain the constant cavity length parameter ΔC of temperature and medium concentration and the variable cavity length parameter ΔV of strain and torsion angle by using formula (10):

An electronic device according to the present invention, comprising a memory and a processor, is characterized in that the memory is used to store a program that supports the processor to execute the method for synchronous measurement of mixed parameters, and the processor is configured to execute the method in the memory stored program.

The present invention is a computer-readable storage medium, wherein a computer program is stored on the computer-readable storage medium, and the computer program is executed by a processor to execute the steps of the mixed parameter synchronous measurement method.

Compared with the prior art, the beneficial effects of the present invention are reflected in:

1. In the present invention, different measured parameters are classified into two categories according to the mechanism of action: one is the constant cavity length type parameter, which only causes changes in the parameters of the fiber grating itself (period of the grating, effective refractive index), such as temperature, medium Concentration, etc.; the other type is variable cavity length parameters, which will change the length of the interference cavity, such as strain, torsion angle, etc., while causing changes in the parameters of the fiber grating itself. Through the different action mechanisms of the two types of parameters, the correlation and difference between different measured parameters are established, so that the synchronous sensing of mixed parameters can be realized.

2. In the present invention, an optical fiber Fabry-Perot interference microcavity is used, which is composed of two parts of apodized FBG and a microcavity in the middle, and is integrally formed in the middle of the apodized fiber grating by means of resistance heating. Due to its unique microcavity structure, compared with the single-peak characteristic of a uniform fiber grating, there are multiple interference peaks in its reflection spectrum, and dual correlation peaks can be formed between different peaks to eliminate the influence of constant cavity length parameters on reflectivity. At the same time, the sensitivity of the measurement is improved.

3. The present invention introduces a double-correlation detection method of wavelength and reflectivity. Compared with the method of only using wavelength detection, the calibration of wavelength drift sensitivity coefficient of traditional wavelength detection can only be obtained by changing the wavelength when each parameter acts independently. When multiple parameters (such as strain and temperature) are changed simultaneously and applied to the same FBG sensor, only the individual wavelength shifts are used, the cross-coupling of the FBG wavelength shift caused by the mixed parameters is unknown, and the contribution of each parameter cannot be distinguished. Therefore, through the combination of wavelength detection and reflectance detection, the real synchronous detection of the two parameters can be realized according to the changes of the two parameters, and the contribution of each parameter can be distinguished, thereby eliminating the influence of cross-sensitivity between parameters.

4. In the present invention, the cross-decoupling relationship between constant cavity length parameters and variable cavity length parameters and multi-interference peak wavelengths and even-peak normalized reflectivity is established. By tracking the wavelength change and normalization in the reflection spectrum The amount of change in reflectivity can realize the simultaneous measurement and decoupling of mixing parameters. The method is feasible and reliable, the calibration process is simple, the implementation cost is low, and it has certain universal applicability.

Description of drawings

Figure 1 is a simulation diagram of the reflection spectrum of an optical fiber sensor with a cavity length of 0.4 mm;

Figure 2 is a simulation diagram of the reflection spectrum of an optical fiber sensor with a cavity length of 0.8mm;

Fig. 3 is the structure diagram of optical fiber Fabry-Perot interference microcavity;

Figure 4 is a graph of wavelength calibration measurement results of multiple interference peaks in the temperature range of 26-40°C;

Figure 5 is a graph of normalized reflectance calibration measurement data of multiple interference peaks in the temperature range of 26-40°C;

Figure 6 is a graph of wavelength calibration measurement results of multiple interference peaks in the strain range of 0-800με;

Figure 7 is a graph of normalized reflectance calibration measurement results of multiple interference peaks within the strain range of 0-800με;

Fig. 8 is a graph of wavelength calibration measurement results of multiple interference peaks in the range of 0-360° torsion angle;

Fig. 9 is a graph of normalized reflectance calibration measurement results of multiple interference peaks in the range of 0-360° torsion angle;

Figure 10 is a graph of the wavelength measurement average of the first and second dual interference peaks in the simultaneous measurement of temperature and strain;

Fig. 11 is a graph of the normalized reflectance measurement average value of the first and second dual interference peaks in the simultaneous measurement of temperature and strain.

Detailed ways

In this embodiment, a method for synchronous measurement of mixed parameters based on fiber Fabry-Perot interference microcavity is to explore the influence factors such as ambient temperature, medium concentration, transverse strain and torsion angle on the parameters of the fiber grating itself and the interference structure. Influenced by the physical and chemical mechanism of the microcavity, various parameters are defined as constant cavity length parameters and variable cavity length parameters. At the same time, based on the multi-peak characteristics of the reflection spectrum of the optical fiber Fabry-Perot interference microcavity, using the double correlation detection method of wavelength and reflectance of the microcavity length response characteristics, two The simultaneous measurement and decoupling of two different types of parameters eliminates the influence of cross-sensitivity between parameters. Specifically, the method includes the following steps:

Step 1, using formula (1) to construct the relationship between the wavelength variation Δλ _m of the mth interference peak of the optical fiber sensor of the optical fiber Fabry-Perot interference microcavity and the axial strain Δε of the optical fiber sensor:

Δλ _m = (1-P _e )·λ _m ·Δε=K _ε ·Δε (1)

In formula (1): P _e is the effective photoelastic coefficient of the fiber; λ _m is the wavelength of the mth interference peak; K _ε is the wavelength sensitivity of the strain;

Use formula (2) to construct the relationship between the reflectivity change ΔR _m of the m-th interference peak of the optical fiber sensor and the axial strain Δε of the optical fiber sensor:

In formula (2): α is the normalization coefficient under a certain range calibration; S _ε is the reflectivity sensitivity of the strain; L _M represents the length of the optical fiber Fabry-Perot interference microcavity;

Step 2, using formula (3) to construct the relationship between the wavelength variation Δλ _m of the m-th interference peak of the optical fiber sensor and the torsion angle Δθ of the optical fiber sensor:

In formula (3): r is the fiber core radius; d is the length of the torsion beam; K _θ is the wavelength sensitivity of the twist angle;

Use formula (4) to construct the relationship between the reflectivity change ΔR _m and the twist angle Δθ of the m-th interference peak of the optical fiber sensor:

In formula (4): S _θ is the reflectivity sensitivity of twist angle Δθ;

Step 3, using formula (5) to construct the relationship between the wavelength variation ΔR _m of the mth interference peak of the optical fiber sensor and the ambient temperature ΔT:

Δλ _m = (α+ζ) λ _m ΔT=K _T ΔT (5) In formula (5): ζ is the thermo-optic coefficient of the optical fiber; α is the thermal expansion coefficient of the optical fiber; K _T is the wavelength sensitivity of temperature;

Step 4, using formula (6) to construct the relationship between the wavelength variation Δλ _m of the mth interference peak of the optical fiber sensor and the medium concentration Δw:

In formula (6): δ _w is the coefficient of change of the refractive index of a certain medium; n _eff is the effective refractive index of the fiber; n _core is the refractive index of the fiber core; K _w is the wavelength sensitivity of the medium concentration; total length;

Step 5, using formula (7) to construct the relationship between the wavelength correlation coefficient Δv _λ and the wavelength sensitivity coefficient:

Δv _λ =K _C ·ΔC+K _V ·ΔV (7)

In formula (7): ΔC represents the constant cavity length parameters such as temperature and medium concentration; ΔV represents the variable cavity length parameters such as lateral strain and torsion angle; K _C is the interference peak wavelength shift when the constant cavity length parameters change independently The sensitivity coefficient of K _V is the sensitivity coefficient of the interference peak wavelength drift when the variable cavity length parameter changes independently;

Step 6. Use formula (8) to construct the relationship between the dual reflectance correlation coefficient Δv _R and the variable cavity length parameter ΔV:

Δv _R =(S _C1 -S _C2 )·ΔC+(S _V1 -S _V2 )·ΔV=δS _V ·ΔV (8)

In the formula (8): S _C1 and S _C2 are the sensitivity coefficients of the reflectance responses of the dual correlation peaks λ ₁ and λ ₂ in the reflectance correlation spectrum when the parameters of the constant cavity length change independently, and S _C1 -S _C2 =0; S _V1 and S _V2 are the sensitivity coefficients of the reflectance responses of the dual correlation peaks λ ₁ and λ ₂ in the reflectance correlation spectrum when the variable cavity length parameters change independently; δS _V is the dual reflectance coefficient, and δS _V =S _V1 - S _V2 ;

Step 7, using formula (9) to construct the matrix expressions of wavelength correlation coefficient, dual reflectance correlation coefficient and three sensitivity coefficients:

Step 8, solve the matrix of formula (9), so as to use formula (10) to obtain the constant cavity length parameter ΔC of temperature and medium concentration, and the variable cavity length parameter ΔV of strain and torsion angle. Synchronous measurement relational formula:

Therefore, Equation (10) gives the functional relationship between constant cavity length parameters, variable cavity length parameters and wavelength and reflectivity. By tracking the wavelength and dual reflectivity changes of multiple interference peaks, the mixing parameters can be realized Simultaneous measurement and decoupling.

In this example, an optical fiber Fabry-Perot interference microcavity sensor was fabricated by resistive heating technology. The transfer function of the R-Perot interference microcavity can be expressed as:

In formula (11): a[Z ₀ ] and b[Z ₀ ] represent the forward and backward light at one end of the fiber Fabry-Perot interference microcavity, a[Z ₁ ] and b[Z ₁ ] are the other Forward and backward light at one end; β and _β0 denote the propagation constants of ordinary fiber and microfiber, respectively; L and L _M denote the total length of the fiber grating and the length of the interference microcavity, respectively; t is the transmittance of the fiber grating; F _A1 and F _A2 are the transmission matrices of the two left and right apodized FBG reflective surfaces.

Therefore, equation (11) gives the transfer function of the fiber Fabry-Perot interference microcavity, which can simulate the reflection and transmission spectrum changes under the influence of constant cavity length parameters and variable cavity length parameters, and gives The spectral shape under different microcavity lengths can be used in the preparation of comb filters. At the same time, it is revealed that the change of the grating period and the effective refractive index will cause the change of the wavelength, and the change of the length of the microcavity will cause the change of the reflectivity, which provides the feasibility for the simultaneous measurement of mixed parameters.

Figure 1 is the reflectance spectrum when the microcavity length is 0.4mm, and the four interference peaks in the spectrum are axisymmetric at this time; Figure 2 is the reflection spectrum when the microcavity length is 0.8mm, and the five interference peaks in the spectrum are Axisymmetric shape. Fig. 3 is a schematic diagram of the shape of an optical fiber Fabry-Perot interference microcavity, which consists of two parts of apodized FBG and an interference microcavity.

In this example, it is first necessary to calibrate the wavelength drift sensitivity coefficient and the normalized reflectance drift sensitivity coefficient under the independent effects of temperature, strain and torsion angle.

In order to verify the influence of different temperatures on the reflection spectrum of the optical fiber Fabry-Perot interference microcavity, a temperature range of 26-40 °C was set. As shown in Figure 4, under the influence of temperature, the wavelength of multiple interference peaks shows a consistent linear change, and the wavelength sensitivity coefficient K _T ≈ 12pm/℃ can be obtained; There is also a consistent linear change.

In this embodiment, in order to provide optical fiber axial micro-strain, the X-axis of the three-dimensional displacement platform is connected with the stepper motor shaft through a coupling, and the motor rotation is controlled by an FPGA program to achieve precise strain with a resolution of 1με. In this embodiment, in order to verify the influence of different strains on the reflection spectrum of the optical fiber Fabry-Perot interference structure, a strain range from 0-800 με is set. Figure 6 shows that the wavelength of multiple interference peaks and the strain increase linearly, and the wavelength drift sensitivity K _ε ≈ 0.8pm/με of the strain can be obtained; Figure 7 shows that the normalized reflectance of different interference peaks is inconsistent with the strain linear change. Combining with the change trend of normalized reflectance in temperature test, in the simultaneous measurement of temperature and strain, the influence of temperature can be eliminated by using the difference between two interference peaks, the normalized reflectance strain sensitivity of interference peaks λ ₁ and λ ₂ is 0.00249/με, providing a specific value for the dual reflectance coefficient δS _V of the strain.

In this embodiment, the optical fiber clamp is fixed with a special coupling, and at the same time it is connected to the rotating shaft of the stepping motor, so that the center of the optical fiber and the rotating shaft is at the same horizontal line, and the rotation of the motor is controlled by the FPGA program to change the torsion angle, with a resolution of 0.72° . In this embodiment, in order to verify the influence of different twist angles on the reflection spectrum of the optical fiber Fabry-Perot interference microcavity, a range of twist angles from 0° to 360° is set. Figure 8 shows that the wavelength of multiple interference peaks and the torsion angle show consistent cosine changes, and the wavelength sensitivity coefficient K _θ ≈ 310.6pm of torsion angles; Figure 9 shows that the normalized reflectivity and strain of different interference peaks show inconsistent cosine changes . Similarly, in the simultaneous measurement of temperature and torsion angle, the influence of temperature can be eliminated by using the differential method, and the dual reflectance coefficient δS _V of the torsion angle can be obtained as 0.935.

In this example, the simultaneous measurement of temperature (constant cavity length parameter) and strain (variable cavity length parameter) is carried out. In order to accurately control the strain and temperature parameters, the experiment is divided into three steps: firstly, prestress is applied to make the optical fiber in a state of tension and straightening, and the temperature of the thermostat is controlled to be constant. This state is recorded as the initial state (I) and the measured values of wavelength and optical power are recorded. ; The X-direction displacement platform moves 50um, corresponding to the fiber axial stress of 500με, this state is recorded as the transition state (II), and the measured value of wavelength and optical power at this time is recorded; keep this stress, increase the temperature by about 3°C, and The state is recorded as the final state (III) after simultaneous changes in temperature and strain. Record the final wavelength and optical power measurements. Figure 10 is the wavelength measurement average of the first and second dual interference peaks in the three states, and the wavelength correlation coefficient Figure 11 is the mean value of the reflectance measurement of the first and second dual interference peaks in the three states, and the correlation coefficient of the dual reflectance /> Substituting the correlation coefficient of wavelength and dual reflectivity into the cross decoupling formula, combined with the calibrated sensitivity coefficient, the simultaneous measurement of temperature and strain can be realized. At the same time, after error correction, the relative error of strain from actual measurement and decoupling calculation is 0.8%, and the relative error of temperature is 4.0%, taking the strain change of 500με and temperature change of 3.0°C as the standard quantity, which proves the feasibility of simultaneous measurement of mixed parameters sex.

To sum up, through the modeling and spectral simulation of the optical fiber Fabry-Perot interference microcavity, the relationship between the wavelength response characteristics of the constant cavity length type and variable cavity length type parameters and the reflectivity microcavity length response characteristics was established, and analyzed The mechanism of synchronous measurement and decoupling of mixing parameters based on microcavity length correlation is proposed. In this paper, various parameters are classified into two categories according to the difference in the influencing mechanism, namely, the two types of parameters of constant cavity length and variable cavity length, and use the length of the microcavity to distinguish the relevant response characteristics of different types of parameters. and decoupling. This method provides a theoretical method with universal applicability for simultaneous measurement of multiple parameters, and at the same time realizes the mechanism and method of simultaneous measurement of multiple parameters with a single fiber grating sensor without any coating layer, and has the advantages of low cost and simple manufacture , controllable parameters and other advantages.

In this embodiment, an electronic device includes a memory and a processor, the memory is used to store a program supporting the processor to execute the above method, and the processor is configured to execute the program stored in the memory.

In this embodiment, a computer-readable storage medium stores a computer program on the computer-readable storage medium, and the computer program executes the steps of the above method when the computer program is run by a processor.

Claims (3)

1. The mixed parameter synchronous measurement method based on the optical fiber Fabry-Perot interference microcavity is characterized by comprising the following steps of:

step 1, constructing wavelength variation delta lambda of mth interference peak of optical fiber sensor of optical fiber Fabry-Perot interference microcavity by utilizing step 1 _m Relation to axial strain Δε of the fiber sensor:

Δλ _m ＝(1-P _e )·λ _m ·Δε＝K _ε ·Δε (1)

in the formula (1): p (P) _e Is the effective photoelastic coefficient of the fiber; lambda (lambda) _m Is the wavelength of the mth interference peak; k (K) _ε Is the wavelength sensitivity of strain;

constructing the reflectance variation DeltaR of the mth interference peak of the optical fiber sensor by using the method (2) _m Relation to axial strain Δε of the fiber sensor:

in the formula (2): alpha is a normalization coefficient under a certain range calibration; l (L) _M Representing the length of the optical fiber Fabry-Perot interference microcavity; s is S _ε Is the reflectivity sensitivity of strain;

step 2, constructing the wavelength variation of the mth interference peak of the optical fiber sensor by using the step 3Δλ _m Relation to the torsion angle Δθ of the fiber sensor:

in the formula (3): r is the core radius of the fiber; d is the length of the torsion beam; k (K) _θ Wavelength sensitivity, which is the twist angle;

constructing the reflectance variation DeltaR of the mth interference peak of the optical fiber sensor by using the method (4) _m Relation to torsion angle Δθ:

in the formula (4): s is S _θ Is the reflectivity sensitivity of the torsion angle delta theta;

step 3, constructing the wavelength variation delta R of the mth interference peak of the optical fiber sensor by using the formula (5) _m Relationship with ambient temperature Δt:

Δλ _m ＝(α+ζ)·λ _m ·ΔT＝K _T ·ΔT (5)

in formula (5): ζ is the thermo-optic coefficient of the optical fiber; α is the coefficient of thermal expansion of the fiber; k (K) _T Is the wavelength sensitivity of temperature;

step 4, constructing the wavelength variation delta lambda of the mth interference peak of the optical fiber sensor by using the formula (6) _m Relationship with the medium concentration Δw:

in formula (6): delta _w Is the refractive index change coefficient of a certain medium; n is n _eff Is the effective refractive index of the fiber; n is n _core Is the refractive index of the core; k (K) _w Is the wavelength sensitivity of the medium concentration; l represents the total length of the fiber grating;

step 5, constructing a wavelength correlation coefficient Deltav by using the formula (7) _λ Relation with wavelength sensitivity coefficient:

Δν _λ ＝K _C ·ΔC+K _V ·ΔV (7)

in the formula (7): Δc represents constant-cavity length parameters such as temperature and medium concentration; deltaV represents a variable cavity length type parameter of transverse strain and torsion angle; k (K) _C The sensitivity coefficient of the interference peak wavelength drift when the constant-cavity length type parameters are independently changed; k (K) _V The sensitivity coefficient of the interference peak wavelength drift when the variable cavity length parameter is independently changed;

step 6, constructing a dual reflectivity correlation coefficient Deltav by utilizing the step (8) _R Relation with variable cavity length parameter DeltaV:

Δν _R ＝(S _C1 -S _C2 )·ΔC+(S _V1 -S _V2 )·ΔV＝6S _V ·ΔV (8)

in formula (8): s is S _C1 、S _C2 Is the dual correlation peak lambda in the reflectivity correlation spectrum when the constant cavity length parameter is changed independently ₁ And lambda (lambda) ₂ Sensitivity coefficient of reflectivity response of (c), and S _C1 -S _C2 ＝0；S _V1 、S _V2 Is the dual correlation peak lambda in the reflectivity correlation spectrum when the variable cavity length parameter is independently changed ₁ And lambda (lambda) ₂ Sensitivity coefficient of reflectivity response of (a); δS _V Is a dual reflectance coefficient, and δS _V ＝S _V1 -S _V2 ；

Step 7, constructing a matrix expression of the wavelength correlation coefficient, the dual reflectivity correlation coefficient and the three sensitivity coefficients by using the formula (9):

and 8, solving the matrix of the formula (9), thereby obtaining constant cavity length parameters delta C of temperature and medium concentration types and variable cavity length parameters delta V of strain and torsion angle types by using the formula (10):

2. an electronic device comprising a memory and a processor, wherein the memory is configured to store a program that supports the processor to perform the hybrid parameter synchronization measurement method of claim 1, the processor being configured to execute the program stored in the memory.

3. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, performs the steps of the hybrid parameter synchronization measurement method according to claim 1.