Hybrid parametric synchronous measurement method based on fiber fabry-perot interference microcavity

Abstract

The application discloses a kind of mixed parameter synchronous measurement methods based on optical fiber Fabry-Perot interference microcavity, and measurement steps include: the wavelength sensitivity and reflectivity sensitivity of optical fiber sensor under temperature, medium concentration, transverse strain and torsion angle are calibrated, then the relationship between wavelength correlation coefficient, reflectivity correlation coefficient and three sensitivities is combined to construct matrix, so as to obtain the synchronous measurement and decoupling relationship of mixed parameter.The application utilizes wavelength and reflectivity double correlation detection method, can realize the synchronous measurement and decoupling of two different types of parameters, eliminates the influence of cross-sensitivity between parameters, improves the sensitivity of optical fiber sensor, and has the advantages of feasible and reliable, simple calibration process, and lower implementation cost.

Description

Technical Field

[0001] This invention relates to the synchronous measurement and decoupling of mixed parameters, specifically an optical measurement method that distinguishes between constant cavity length parameters such as temperature and medium concentration and variable cavity length parameters such as strain and torsion angle. Background Technology

[0002] Fiber Bragg grating (FBG) sensing technology boasts significant advantages in numerous aspects, such as high sensitivity, compact size, immunity to electromagnetic interference, ease of sensor network construction, and powerful multiplexing capabilities. It has attracted widespread attention, particularly in the measurement of parameters like temperature, refractive index, strain, and pressure, making FBGs a highly promising sensing element for fields such as biochemical sensing, structural health monitoring, and gas / oil exploration. While the simple structure of FBG sensors offers good linearity and stability, their relatively low sensitivity makes them unsuitable for high-precision sensing applications. To improve measurement sensitivity, microfabrication methods such as chemical etching, arc discharge, mechanical polishing, and femtosecond laser finishing have been employed. However, these methods, while increasing measurement sensitivity, may reduce mechanical strength and lifespan. Therefore, FBG applications require a balance between sensitivity and reliability, striving to further improve the sensitivity of FBGs while maintaining their mechanical strength and lifespan to meet a wider range of high-precision sensing needs.

[0003] Typically, fiber Bragg grating sensors only use wavelength as the detection method for the measured parameter, which limits their ability to directly distinguish different parameters and easily leads to cross-sensitivity. Cross-sensitivity, as the name suggests, occurs when a sensor parameter is simultaneously sensitive to multiple external physical quantities. To determine changes in a single external physical quantity, this cross-sensitivity is undesirable, so the influence of other physical quantities on this parameter must be eliminated. To overcome this problem, researchers are constantly exploring new methods and structures, such as multi-grating structures, special fiber structures, polymer coatings, and multi-sensor networks. These innovative measures aim to improve the multi-parameter measurement capabilities and anti-cross-interference capabilities of fiber Bragg grating sensors.

[0004] For example, in simultaneous temperature and strain measurements, 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 an FBG sensor to compensate for the temperature of the FBG sensor. Strain measurement temperature compensation methods, which embed a strain-free FBG sensor in a capillary tube and measure its temperature, are also widely used. Furthermore, many hybrid structures have been proposed, such as cascading an FBG with a Fabry-Perot cavity, cascading an FBG with an upper conical Mach-Zehnder interferometer, and cascading an FBG with multimode fiber. All of these methods utilize two or more sensors, with one acting as a compensation sensor to eliminate cross-sensitivity, to achieve simultaneous measurement of multiple parameters. This significantly increases the complexity of the sensing system. In addition, the academic community generally employs post-processing of data or device compensation to minimize the impact of cross-sensitivity on the accuracy of the measurement results, which to some extent increases the cost of fiber optic sensors. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by proposing a hybrid parameter synchronous measurement method based on a fiber optic Fabry-Perot interferometer microcavity. This method aims to identify the commonalities and differences among various parameters, eliminate the influence of cross-sensitivity between parameters, and improve sensor sensitivity. It enables synchronous hybrid parameter measurement using a single fiber optic grating sensor without any coating, demonstrating significant application potential and value in engineering health monitoring, biosensing, chemical process monitoring, and other related measurement fields.

[0006] The present invention adopts the following technical solution to solve the technical problem:

[0007] The present invention provides a method for synchronous measurement of hybrid parameters based on a fiber optic Fabry-Perot interferometer microcavity, characterized by the following steps:

[0008] Step 1: Construct the wavelength change Δλ of the m-th interference peak of the fiber optic sensor using equation (1) for the fiber optic Fabry-Perot interferometer microcavity. m The relationship between the axial strain Δε of the fiber optic sensor and the following formula:

[0009] Δλ m =(1-P e )·λ m ·Δε=K ε ·Δε (1)

[0010] In equation (1): P e λ is the effective photoelastic coefficient of the optical fiber; m It is the wavelength of the m-th interference peak; K ε It is the wavelength sensitivity to strain;

[0011] The reflectivity change ΔR of the m-th interference peak of the fiber optic sensor is constructed using equation (2). m The relationship between the axial strain Δε of the fiber optic sensor and the following formula:

[0012]

[0013] In equation (2): α is the normalization coefficient under a certain range calibration; L M S represents the length of the fiber Fabry-Perot interferometer microcavity; ε It is the reflectivity sensitivity to strain;

[0014] Step 2: Use equation (3) to construct the wavelength change Δλ of the m-th interference peak of the fiber optic sensor. m The relationship between the torsion angle Δθ of the fiber optic sensor and the following formula:

[0015]

[0016] In equation (3): r is the core radius of the optical fiber; d is the length of the torsion beam; K θ It is the wavelength sensitivity of the torsional angle;

[0017] The reflectivity change ΔR of the m-th interference peak of the fiber optic sensor is constructed using equation (4). m The relationship with the torsion angle Δθ is as follows:

[0018]

[0019] In equation (4): S θ It is the reflectivity sensitivity at the torsion angle Δθ;

[0020] Step 3: Use equation (5) to construct the wavelength change ΔR of the m-th interference peak of the fiber optic sensor. m The relationship between the ambient temperature ΔT and the ambient temperature is as follows:

[0021]

[0022] In equation (5): ζ is the thermo-optic coefficient of the optical fiber; α is the thermal expansion coefficient of the optical fiber; K T It is the wavelength sensitivity to temperature;

[0023] Step 4: Use equation (6) to construct the wavelength change Δλ of the m-th interference peak of the fiber optic sensor. m The relationship between the medium concentration ΔW and the following formula:

[0024]

[0025] In equation (6): δ w It is the coefficient of refractive index variation of a certain medium; n eff n is the effective refractive index of the optical fiber;core It is the refractive index of the fiber core; K w It represents the wavelength sensitivity of the medium concentration; L represents the total length of the fiber grating.

[0026] Step 5: Construct the wavelength correlation coefficient Δv using equation (7). λ The relationship between wavelength sensitivity coefficient and:

[0027] Δv λ =K C ·ΔC+K V ·ΔV (7)

[0028] In equation (7): ΔC represents constant cavity length parameters such as temperature and medium concentration; ΔV represents variable cavity length parameters such as transverse strain and torsional angle; K C It is the sensitivity coefficient for the wavelength shift of the interference peak when the constant cavity length parameter changes independently; K V It is the sensitivity coefficient for the wavelength shift of the interference peak when the variable cavity length parameter changes independently;

[0029] Step 6: Construct the dual reflectance correlation coefficient Δv using equation (8). R The relationship between the variable cavity length parameter ΔV and the following formula:

[0030] Δv R =(S C1 -S C2 )·ΔC+(S V1 -S V2 )·ΔV=δS V ·ΔV (8)

[0031] In equation (8): S C1 S C2 It is the sensitivity coefficient of the reflectance response of the dual correlation peaks λ1 and λ2 in the reflectance correlation spectrum when the parameters of the constant cavity length change independently, and S C1 -S C2 =0; S V1 S V2 It is the sensitivity coefficient of the reflectance response of the dual correlation peaks λ1 and λ2 in the reflectance correlation spectrum when the variable cavity length parameter changes independently; δS V It is the dual reflectivity coefficient, and δS V =S V1 -S V2 ;

[0032] Step 7: Construct matrix expressions for the wavelength correlation coefficient, dual reflectivity correlation coefficient, and three sensitivity coefficients using equation (9):

[0033]

[0034] Step 8: Solve the matrix of equation (9) to obtain the constant cavity length parameter ΔC (temperature and medium concentration type) and the variable cavity length parameter ΔV (strain and torsion angle type) using equation (10):

[0035]

[0036] The present invention provides an electronic device, including a memory and a processor, wherein the memory is used to store a program that supports the processor in executing the hybrid parameter synchronous measurement method, and the processor is configured to execute the program stored in the memory.

[0037] The present invention discloses a computer-readable storage medium on which a computer program is stored, wherein the computer program is executed by a processor to perform the steps of the hybrid parameter synchronization measurement method.

[0038] Compared with existing technologies, the beneficial effects of this invention are reflected in:

[0039] 1. In this invention, different measured parameters are categorized into two main types based on their mechanisms of action: one type is constant cavity length parameters, which only cause changes in the fiber grating's own parameters (grating period, effective refractive index), such as temperature and medium concentration; the other type is variable cavity length parameters, which, while causing changes in the fiber grating's own parameters, also alter the length of the interference cavity, such as strain and torsion angle. By utilizing the different mechanisms of action of these two types of parameters, correlations and differences are established between different measured parameters, thereby enabling synchronous sensing of mixed parameters.

[0040] 2. This invention employs a fiber optic Fabry-Perot interferometer microcavity, which consists of two apodized fiber gratings (FBGs) and a central microcavity, integrally formed within the apodized FBG using resistance heating. Due to its unique microcavity structure, compared to the single-peak characteristics of a uniform fiber grating, its reflection spectrum contains multiple interference peaks. These peaks can form dual correlation peaks to eliminate the influence of the constant cavity length parameter on reflectivity, thereby improving measurement sensitivity.

[0041] 3. This invention introduces a dual-correlation detection method using wavelength and reflectivity. Compared to methods using only wavelength detection, traditional wavelength detection methods can only calibrate the wavelength drift sensitivity coefficient by changing the wavelength when each parameter acts independently. When multiple parameters (e.g., strain and temperature) change simultaneously and are applied to the same FBG sensor, using only individual wavelength drift results in unknown cross-coupling of FBG wavelength drift caused by mixed parameters, and the contribution of each parameter cannot be distinguished. Therefore, by combining wavelength detection and reflectivity detection, true synchronous detection of the two parameters is achieved based on their changes, enabling the distinction of each parameter's contribution and eliminating the influence of cross-sensitivity between parameters.

[0042] 4. This invention establishes cross-decoupling relationships between constant cavity length parameters and variable cavity length parameters, and between the wavelengths of multiple interference peaks and the normalized reflectivity of dual peaks. By tracking the changes in wavelength and normalized reflectivity in the reflection spectrum, synchronous measurement and decoupling of the mixed parameters can be achieved. This method is feasible and reliable, has a simple calibration process, low implementation cost, and certain general applicability. Attached Figure Description

[0043] Figure 1 This is a simulation diagram of the reflection spectrum of an optical fiber sensor with a cavity length of 0.4 mm;

[0044] Figure 2 This is a simulation diagram of the reflection spectrum of an optical fiber sensor with a cavity length of 0.8 mm;

[0045] Figure 3 This is a schematic diagram of the structure of a fiber optic Fabry-Perot interferometer microcavity;

[0046] Figure 4 This is a graph showing the wavelength calibration measurement results of multiple interference peaks within a temperature range of 26-40℃;

[0047] Figure 5 It is a graph of normalized reflectance calibration measurement data of multiple interference peaks in the temperature range of 26-40℃;

[0048] Figure 6 This is a graph showing the wavelength calibration measurement results of multiple interference peaks within the strain range of 0-800με;

[0049] Figure 7 This is a graph showing the normalized reflectance calibration measurement results of multiple interference peaks within the strain range of 0-800με;

[0050] Figure 8 This is a graph showing the wavelength calibration measurement results of multiple interference peaks within the 0-360° torsion angle range;

[0051] Figure 9 This is a graph showing the normalized reflectance calibration measurement results of multiple interference peaks within the 0-360° torsion angle range;

[0052] Figure 10 This is a graph showing the average wavelength measurements of the first and second dual interference peaks during simultaneous temperature and strain measurements.

[0053] Figure 11 This is a normalized mean reflectance measurement plot of the first and second dual interference peaks during simultaneous temperature and strain measurements. Detailed Implementation

[0054] In this embodiment, a hybrid parameter synchronous measurement method based on a fiber optic Fabry-Perot interferometer microcavity is presented. This method explores the physicochemical mechanisms by which factors such as ambient temperature, medium concentration, transverse strain, and torsion angle affect the parameters of the fiber grating and the interference structure. Various parameters are defined into two main categories: constant cavity length parameters and variable cavity length parameters. The microcavity length response characteristics based on reflectivity can differentiate between these two types of parameters, making this research universally applicable to physicochemical measurements using interference structures. Simultaneously, based on the multi-peak characteristics of the fiber optic Fabry-Perot interferometer microcavity reflection spectrum, a wavelength-reflectivity dual-correlation detection method using the microcavity length response characteristics can achieve synchronous measurement and decoupling of the two different types of parameters, eliminating the influence of cross-sensitivity between parameters. Specifically, the method includes the following steps:

[0055] Step 1: Construct the wavelength change Δλ of the m-th interference peak of the fiber optic sensor using equation (1) for the fiber optic Fabry-Perot interferometer microcavity. m The relationship between the axial strain Δε of the fiber optic sensor and the following formula:

[0056] Δλ m =(1-P e )·λ m ·Δε=K ε ·Δε (1)

[0057] In equation (1): P e λ is the effective photoelastic coefficient of the optical fiber; m It is the wavelength of the m-th interference peak; K ε It is the wavelength sensitivity to strain;

[0058] The reflectivity change ΔR of the m-th interference peak of the fiber optic sensor is constructed using equation (2). m The relationship between the axial strain Δε of the fiber optic sensor and the following formula:

[0059]

[0060] In equation (2): α is the normalization coefficient under a certain range calibration; S ε It is the reflectivity sensitivity to strain; L M Indicates the length of the fiber Fabry-Perot interferometer microcavity;

[0061] Step 2: Use equation (3) to construct the wavelength change Δλ of the m-th interference peak of the fiber optic sensor. m The relationship between the torsion angle Δθ of the fiber optic sensor and the following formula:

[0062]

[0063] In equation (3): r is the core radius of the optical fiber; d is the length of the torsion beam; K θIt is the wavelength sensitivity of the torsional angle;

[0064] The reflectivity change ΔR of the m-th interference peak of the fiber optic sensor is constructed using equation (4). m The relationship with the torsion angle Δθ is as follows:

[0065]

[0066] In equation (4): S θ It is the reflectivity sensitivity at the torsion angle Δθ;

[0067] Step 3: Use equation (5) to construct the wavelength change ΔR of the m-th interference peak of the fiber optic sensor. m The relationship between the ambient temperature ΔT and the ambient temperature is as follows:

[0068] Δλ m =(α+ζ)·λ m ·ΔT=K T ·ΔT (5) In equation (5): ζ is the thermo-optic coefficient of the optical fiber; α is the thermal expansion coefficient of the optical fiber; K T It is the wavelength sensitivity to temperature;

[0069] Step 4: Use equation (6) to construct the wavelength change Δλ of the m-th interference peak of the fiber optic sensor. m The relationship between the medium concentration Δw and the following formula:

[0070]

[0071] In equation (6): δ w It is the coefficient of refractive index variation of a certain medium; n eff n is the effective refractive index of the optical fiber; core It is the refractive index of the fiber core; K w It represents the wavelength sensitivity of the medium concentration; L represents the total length of the fiber grating.

[0072] Step 5: Construct the wavelength correlation coefficient Δv using equation (7). λ The relationship between wavelength sensitivity coefficient and:

[0073] Δv λ =K C ·ΔC+K V ·ΔV (7)

[0074] In equation (7): ΔC represents constant cavity length parameters such as temperature and medium concentration; ΔV represents variable cavity length parameters such as transverse strain and torsional angle; K C It is the sensitivity coefficient for the wavelength shift of the interference peak when the constant cavity length parameter changes independently; K V It is the sensitivity coefficient for the wavelength shift of the interference peak when the variable cavity length parameter changes independently;

[0075] Step 6: Construct the dual reflectance correlation coefficient Δv using equation (8). R The relationship between the variable cavity length parameter ΔV and the following formula:

[0076] Δv R =(S C1 -S C2 )·ΔC+(S V1 -S V2 )·ΔV=δS V ·ΔV (8)

[0077] In equation (8): S C1 S C2 It is the sensitivity coefficient of the reflectance response of the dual correlation peaks λ1 and λ2 in the reflectance correlation spectrum when the parameters of the constant cavity length change independently, and S C1 -S C2 =0; S V1 S V2 It is the sensitivity coefficient of the reflectance response of the dual correlation peaks λ1 and λ2 in the reflectance correlation spectrum when the variable cavity length parameter changes independently; δS V It is the dual reflectivity coefficient, and δS V =S V1 -S V2 ;

[0078] Step 7: Construct matrix expressions for the wavelength correlation coefficient, dual reflectivity correlation coefficient, and three sensitivity coefficients using equation (9):

[0079]

[0080] Step 8: Solve the matrix of equation (9) to obtain the synchronous measurement relationship between constant cavity length parameter ΔC (temperature and medium concentration type) and variable cavity length parameter ΔV (strain and torsion angle type) using equation (10):

[0081]

[0082] Therefore, equation (10) gives the functional relationship between constant cavity length parameters, variable cavity length parameters and wavelength and reflectivity. By tracking the changes in wavelength and dual reflectivity of multiple interference peaks, the simultaneous measurement and decoupling of hybrid parameters can be achieved.

[0083] In this embodiment, a fiber optic Fabry-Perot interferometer microcavity sensor was fabricated using resistance heating technology. The microcavity was integrally formed with an apodized FBG, and its diameter and length were 110 μm and 1.1 mm, respectively. The transfer function of the fiber optic Fabry-Perot interferometer microcavity can be expressed as:

[0084]

[0085] In equation (11): a[Z0] and b[Z0] represent the forward and backward light at one end of the fiber Fabry-Perot interferometer microcavity, and a[Z1] and b[Z1] are the forward and backward light at the other end; β and β0 represent the propagation constants of ordinary optical fiber and micro-optical fiber, respectively; L and L M represents 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 It is the transmission matrix of the left and right apodized fiber grating reflectors.

[0086] Therefore, Equation (11) gives the transfer function of the fiber Fabry-Perot interferometer microcavity, which can simulate the changes in reflection and transmission spectra under the influence of constant cavity length and variable cavity length parameters, and also gives the spectral shapes under different microcavity lengths, which can be used for the fabrication of comb filters. It also reveals that changes in grating period and effective refractive index cause changes in wavelength, while changes in microcavity length cause changes in reflectivity, providing feasibility for simultaneous measurement of mixed parameters.

[0087] Figure 1 This is the reflection spectrum when the microcavity length is 0.4 mm. At this time, the four interference peaks in the spectrum are axially symmetrical. Figure 2 This is the reflection spectrum when the microcavity length is 0.8 mm. At this time, the five interference peaks in the spectrum are axially symmetrical. Figure 3 This is a schematic diagram of the shape of a fiber optic Fabry-Perot interferometer microcavity, which consists of two apodized FBG parts and an interferometer microcavity.

[0088] In this example, the wavelength drift sensitivity coefficient and normalized reflectivity drift sensitivity coefficient need to be calibrated first under the individual effects of temperature, strain and torsion angle.

[0089] To verify the effect of different temperatures on the reflection spectrum of a fiber Fabry-Perot interferometer microcavity, a temperature range of 26-40℃ was set. Figure 4 As shown, the wavelengths of the multiple interference peaks exhibit a consistent linear change under the influence of temperature, from which the wavelength sensitivity coefficient K can be obtained. T ≈12pm / ℃; Figure 5 This indicates that the normalized reflectance of the multi-interference peaks also exhibits a consistent linear change under the influence of temperature.

[0090] In this embodiment, to provide axial micro-strain of the optical fiber, the X-axis of the three-dimensional displacement platform is connected to the stepper motor shaft via a coupling, and the motor rotation is controlled by an FPGA program to achieve a precise strain resolution of 1 με. In this embodiment, to verify the influence of different strains on the reflection spectrum of the fiber Fabry-Perot interferometer structure, a strain range of 0-800 με is set. Figure 6This indicates that the wavelengths of the multiple interference peaks exhibit a linear relationship with increasing strain, from which the wavelength drift sensitivity K of the strain can be obtained. ε ≈0.8pm / με; Figure 7 This indicates that the normalized reflectance of different interference peaks exhibits inconsistent linear changes with strain. Considering the normalized reflectance variation trend observed in temperature measurements, the influence of temperature can be eliminated by utilizing the difference between the two interference peaks in simultaneous temperature and strain measurements. The strain sensitivity of the normalized reflectance of interference peaks λ1 and λ2 is 0.00249 / με, which is the dual reflectance coefficient δS of the strain. V Provide specific numerical values.

[0091] In this embodiment, the fiber optic clamp is fixed to a special coupling and connected to a stepper motor shaft, ensuring that the fiber optic cable and the center of the shaft are on the same horizontal line. The motor rotation is controlled by an FPGA program to change the torsion angle, with a resolution of 0.72°. To verify the influence of different torsion angles on the reflection spectrum of the fiber optic Fabry-Perot interferometer microcavity, a torsion angle range from 0 to 360° was set in this embodiment. Figure 8 This indicates that the wavelengths of the multiple interference peaks exhibit a consistent cosine variation with the torsion angle, and the wavelength sensitivity coefficient K of the torsion angle... θ ≈310.6pm; Figure 9 This indicates that the normalized reflectance of different interference peaks exhibits a cosine variation with strain, which is inconsistent with the trend of the variation. Similarly, in the simultaneous measurement of temperature and torsion angle, the influence of temperature can be eliminated by using the difference method, and the dual reflectance coefficient δS of the torsion angle can be obtained. V It is 0.935.

[0092] In this example, simultaneous measurements of temperature (constant cavity length parameter) and strain (variable cavity length parameter) were performed. To accurately control the strain and temperature parameters, the experiment consisted of three steps: First, prestress was applied to keep the optical fiber taut and straight, and the temperature of the constant temperature chamber was kept constant. This state was recorded as the initial state (I), and the wavelength and optical power measurements were recorded. The displacement platform in the X direction was moved by 50 μm, corresponding to an axial stress of 500 με in the optical fiber. This state was recorded as the transition state (II), and the wavelength and optical power measurements were recorded at this time. Maintaining this stress, the temperature was increased by about 3°C. This state was recorded as the final state after the temperature and strain changed simultaneously (III), and the final wavelength and optical power measurements were recorded. Figure 10 It is the average wavelength measurement of the first and second dual interference peaks under three states, and the wavelength correlation coefficient. Figure 11 It represents the average reflectance measurements of the first and second dual interference peaks under three states, and the correlation coefficient of the dual reflectance. By substituting the correlation coefficient between the wavelength and the dual reflectivity into the cross-decoupling formula, and combining it with the calibrated sensitivity coefficient, simultaneous measurement of temperature and strain can be achieved. Furthermore, after error correction, using a strain change of 500 με and a temperature change of 3.0 °C as standard quantities, the relative error between the actual measurement and the decoupling calculation of strain is 0.8%, and the relative error of temperature is 4.0%, demonstrating the feasibility of simultaneous measurement of mixed parameters.

[0093] In summary, through modeling and spectral simulation of fiber Fabry-Perot interferometer microcavities, the relationship between the wavelength response characteristics of constant-cavity-length and variable-cavity-length parameters and the reflectivity microcavity length response characteristics was established. The mechanism of synchronous measurement and decoupling of hybrid parameters based on microcavity length correlation was analyzed. This paper categorizes various parameters into two main types based on their influencing mechanisms: constant-cavity-length and variable-cavity-length parameters. The correlation response characteristics of different types of parameters are used to distinguish and decouple various parameters using the microcavity length. This method provides a universally applicable theoretical approach for the synchronous measurement of multiple parameters. It also realizes the mechanism and method for simultaneous measurement of multiple parameters using a single fiber Bragg grating sensor without any coating, and offers advantages such as low cost, simple manufacturing, and controllable parameters.

[0094] In this embodiment, an electronic device includes a memory and a processor. The memory stores a program that supports the processor in executing the above-described method, and the processor is configured to execute the program stored in the memory.

[0095] In this embodiment, a computer-readable storage medium stores a computer program, which is executed by a processor to perform the steps of the above method.

Claims

1. A hybrid parametric synchronous measurement method based on a fiber optic Fabry-Perot interferometer microcavity, characterized in that, Includes the following steps: Step 1: Construct the wavelength change Δλ of the m-th interference peak of the fiber optic sensor using equation (1) for the fiber optic Fabry-Perot interferometer microcavity. m The relationship between the axial strain Δε of the fiber optic sensor and the following formula: Dl m =(1-P e )·l m ·No=K ε ·No (1) In equation (1): P e λ is the effective photoelastic coefficient of the optical fiber; m It is the wavelength of the m-th interference peak; K ε It is the wavelength sensitivity to strain; The reflectivity change ΔR of the m-th interference peak of the fiber optic sensor is constructed using equation (2). m The relationship between the axial strain Δε of the fiber optic sensor and the following formula: In equation (2): α is the normalization coefficient under a certain range calibration; L M S represents the length of the fiber Fabry-Perot interferometer microcavity; ε It is the reflectivity sensitivity to strain; Step 2: Use equation (3) to construct the wavelength change Δλ of the m-th interference peak of the fiber optic sensor. m The relationship between the torsion angle Δθ of the fiber optic sensor and the following formula: In equation (3): r is the core radius of the optical fiber; d is the length of the torsion beam; K θ It is the wavelength sensitivity of the torsional angle; The reflectivity change ΔR of the m-th interference peak of the fiber optic sensor is constructed using equation (4). m The relationship with the torsion angle Δθ is as follows: In equation (4): S θ It is the reflectivity sensitivity at the torsion angle Δθ; Step 3: Use equation (5) to construct the wavelength change ΔR of the m-th interference peak of the fiber optic sensor. m The relationship between the ambient temperature ΔT and the ambient temperature is as follows: Dl m =(a+z)·l m ·ΔT=K T ·ΔT (5) In equation (5): ζ is the thermo-optic coefficient of the optical fiber; α is the thermal expansion coefficient of the optical fiber; K T It is the wavelength sensitivity to temperature; Step 4: Use equation (6) to construct the wavelength change Δλ of the m-th interference peak of the fiber optic sensor. m The relationship between the medium concentration Δw and the following formula: In equation (6): δ w It is the coefficient of refractive index variation of a certain medium; n eff n is the effective refractive index of the optical fiber; core It is the refractive index of the fiber core; K w It represents the wavelength sensitivity of the medium concentration; L represents the total length of the fiber grating. Step 5: Construct the wavelength correlation coefficient Δν using equation (7). λ The relationship between wavelength sensitivity coefficient and: Dn λ =K C ·ΔC+K V ·ΔV (7) In equation (7): ΔC represents constant cavity length parameters such as temperature and medium concentration; ΔV represents variable cavity length parameters such as transverse strain and torsional angle; K C It is the sensitivity coefficient for the wavelength shift of the interference peak when the constant cavity length parameter changes independently; K V It is the sensitivity coefficient for the wavelength shift of the interference peak when the variable cavity length parameter changes independently; Step 6: Construct the dual reflectivity correlation coefficient Δv using equation (8). R The relationship between the variable cavity length parameter ΔV and the following formula: Dn R =(S C1 -S C2 )·ΔC+(S V1 -S V2 )·ΔV=δS V ·ΔV (8) In equation (8): S C1 S C2 It is the sensitivity coefficient of the reflectance response of the dual correlation peaks λ1 and λ2 in the reflectance correlation spectrum when the parameters of the constant cavity length change independently, and S C1 -S C2 =0; S V1 S V2 It is the sensitivity coefficient of the reflectance response of the dual correlation peaks λ1 and λ2 in the reflectance correlation spectrum when the variable cavity length parameter changes independently; δS V It is the dual reflectivity coefficient, and δS V =S V1 -S V2 ; Step 7: Construct matrix expressions for the wavelength correlation coefficient, dual reflectivity correlation coefficient, and three sensitivity coefficients using equation (9): Step 8: Solve the matrix of equation (9) to obtain the constant cavity length parameter ΔC (temperature and medium concentration type) and the variable cavity length parameter ΔV (strain and torsion angle type) using equation (10):

2. An electronic device, comprising a memory and a processor, characterized in that, The memory is used to store a program that supports the processor in executing the hybrid parameter synchronous measurement method of claim 1, wherein the processor is configured to execute the program stored in the memory.

3. A computer-readable storage medium storing a computer program, characterized in that, The computer program is executed by the processor to perform the steps of the hybrid parameter synchronous measurement method of claim 1.

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