Method for restraining long-term drift of equivalent sensitive area of fiber loop

Abstract

The application belongs to the technical field of long-term drift suppression of fiber-optic gyroscope zero bias and scale factor, and particularly relates to a long-term drift suppression method for equivalent sensitive area of a fiber coil. A homogenization, de-homogenization analysis idea and a finite element analysis approach are adopted to establish, verify and calibrate thermodynamic parameters of each non-metallic material of the fiber coil. A mathematical model of long-time drift of circumferential strain, radial strain and three-dimensional stress of a micro-element section of the fiber coil with time, temperature and other environmental conditions is calculated to obtain long-time drift of effective refractive index of each micro-element section. Finally, average long-time drift and dispersion characteristics of the effective refractive index of the fast axis of the fiber coil are obtained, so that long-time drift characteristics of the scale factor of the fiber-optic gyroscope are analyzed. In turn, according to the model, thermodynamic parameters and geometric proportions of each non-metallic material of the fiber coil are optimized to finally realize long-term drift suppression of the equivalent sensitive area of the fiber coil.

Description

Technical Field

[0001] This invention belongs to the field of long-term drift suppression technology for zero bias and scaling factor of fiber optic gyroscopes, and specifically relates to a method for suppressing long-term drift of the equivalent sensitive area of ​​an optical fiber ring. Background Technology

[0002] Fiber optic gyroscopes, as a new generation of all-solid-state inertial instruments, are based on the Sagnac principle and sense the rotational angular rate of a loaded object along its sensitive axis. The development of fiber optic gyroscopes relies not only on precise system architecture design and sophisticated signal processing technology, but also on the rapid advancements in fundamental technologies such as fiber optic communication and optical waveguides. Compared to mechanical gyroscopes, fiber optic gyroscopes possess inherent advantages such as long lifespan, light weight, low power consumption, low cost, and ease of manufacturing, making them promising for applications in defense fields such as aviation, aerospace, and marine engineering. In the aerospace industry, fiber optic gyroscopes have already replaced the previous generation of mechanical gyroscopes and are being mass-produced and installed in inertial navigation and attitude stabilization platforms for various aircraft.

[0003] During long-term operation, fiber optic gyroscopes experience slow drift in zero bias and scaling factor over their entire lifespan, which degrades product performance stability and reliability. Theoretical analysis and high-acceleration testing have verified that the slow drift in zero bias and scaling factor of fiber optic gyroscopes over long periods exhibits a functional relationship with the slow drift in fiber loop length, average diameter, and fast-axis effective refractive index. Due to the symmetrical winding process of the fiber loop, the long-term drift in zero bias of fiber optic gyroscopes is greatly mitigated. However, the long-term drift in scaling factor still exists and becomes a key factor limiting the overall stability of fiber optic gyroscopes throughout their lifespan.

[0004] The long-term drift of the scale factor in closed-loop fiber optic gyroscopes is mainly affected by two factors: the long-term drift of the average wavelength of the optical signal at the optical path terminal and the long-term drift of the equivalent sensitive area of ​​the fiber optic ring. For the long-term drift of the average wavelength of the optical signal at the optical path terminal, both domestic and international researchers have used real-time monitoring and tracking technologies to suppress the amount of average wavelength drift. However, a direct and effective technical solution has been lacking for the long-term drift of the equivalent sensitive area of ​​the fiber optic ring. In this regard, intrinsic frequency tracking technology is commonly used both domestically and internationally, which can solve the scaling factor temperature sensitivity problem. However, this technology changes the factors influencing the long-term drift of the equivalent sensitive area of ​​the fiber optic ring from the long-term drift of the fiber optic ring length and average diameter before the technology was adopted to the long-term drift of the average diameter and fast-axis effective refractive index of the fiber optic ring after the technology was adopted, thus increasing the difficulty of analysis. Summary of the Invention

[0005] The technical problem solved by this invention is to address the long-term drift of the equivalent sensitive area of ​​the fiber optic ring, which leads to the long-term drift of the scale factor of the fiber optic gyroscope. A mathematical model has been established and fully verified to show the long-term changes of the fiber optic ring length, average diameter, and fast-axis effective refractive index over time at any temperature. Based on the user's requirements for zero bias and long-term drift of the scale factor of the fiber optic gyroscope, the temperature and time characteristics and geometric proportions of the thermodynamic parameters of the non-metallic materials that make up the fiber optic ring are optimized in reverse based on the model, thereby achieving the goal of suppressing the peak-to-peak values ​​of the long-term drift of the fiber optic ring length, average diameter, and fast-axis effective refractive index.

[0006] The technical solution of the present invention:

[0007] A method for suppressing long-term drift of the equivalent sensitive area of ​​an optical fiber ring, the method comprising:

[0008] Step 1: Measure the time function of the thermodynamic parameters of each component material of the fiber optic ring under isothermal conditions;

[0009] Step 2: Treat the fiber optic ring as an orthogonal anisotropic composite material with the same transverse parameters but different circumferential parameters, and analyze the three-dimensional thermodynamic parameters of the fiber optic ring using the composite material two-dimensional mechanical parameter calculation method.

[0010] Step 3: Based on Step 1 and Step 2, obtain the time functions of the equivalent thermodynamic parameters of the fiber ring in the transverse and circumferential directions under isothermal conditions;

[0011] Step 4: Calculate the transverse and circumferential strains of the fiber ring based on the results of Step 3, obtain the time function of the circumferential strain of each layer of the fiber ring, and further obtain the time function of the circumferential stress of each layer of the fiber ring.

[0012] Step 5: Perform finite element decomposition of the fiber optic ring according to certain rules. Based on the fact that the vector sum of the forces inside the fiber optic ring is zero and the forces are orthogonally decomposed, calculate the time function of the three-dimensional stress of each micro-element segment based on the results of Step 4, and further obtain the time function of the three-dimensional strain of each micro-element segment; the three dimensions refer to: radial, axial, and circumferential.

[0013] Step 6: Calculate the change in effective refractive index along the fast axis based on the results of Step 5, obtain the time function of the change in effective refractive index along the fast axis for each micro-element segment, and further obtain the time function of the average effective refractive index along the fast axis for all micro-element segments;

[0014] Step 7: Calculate the change in fiber ring length based on the results of Step 5, and sum the circumferential strain of each micro-segment to obtain the time function of the change in fiber ring length.

[0015] Step 8: Calculate the change in average diameter of the fiber optic ring based on the results of Step 5. Accumulate the radial strain of the micro-segments with the same circumferential coordinates of the fiber optic ring to obtain the time function of the change in average diameter of the fiber optic ring.

[0016] Step 9: Based on the results of Steps 6, 7, and 8, calculate the fiber optic gyroscope scaling factor drift to obtain the time function of the fiber optic gyroscope scaling factor; based on the results of Steps 5 and 6, calculate the fiber optic gyroscope zero-bias drift to obtain the time function of the fiber optic gyroscope zero-bias.

[0017] Furthermore,

[0018] In step 1, the components of the fiber optic ring include: cladding, inner coating, outer coating, wrapping adhesive, and bonding adhesive; the thermodynamic parameters include: Young's modulus, Poisson's ratio, and linear thermal expansion coefficient.

[0019] Furthermore,

[0020] In step 2, the three-dimensional thermodynamic parameters of the fiber optic ring include: the equivalent thermodynamic parameters of the fiber optic ring in the transverse and circumferential directions.

[0021] Furthermore,

[0022] In step 9, the time function of zero bias of the fiber optic gyroscope is a functional relationship between the zero bias drift of the fiber optic gyroscope and the parameters of the fiber optic ring.

[0023] Furthermore,

[0024] The functional relationship between the zero-bias drift of the fiber optic gyroscope and the fiber loop parameters is as follows:

[0025]

[0026] Where ΔΩ represents the zero-bias drift of the fiber optic gyroscope, λ represents the average wavelength of the optical signal transmitted through the fiber optic ring, c represents the speed of light in vacuum, L represents the length of the fiber optic ring, and D represents the average diameter of the fiber optic ring.

[0027] These represent the phase change of the optical signal as it passes through a fiber segment with length coordinates z and Lz, and length δz, respectively, caused by temperature changes. Let α represent the rate of temperature change in a fiber segment with length coordinates z and Lz and length δz, where n represents the fast-axis effective refractive index of the fiber, and α represents the temperature change rate. T The subscript T represents temperature.

[0028] Furthermore,

[0029] The zero-bias drift of the fiber optic gyroscope is related to the effective refractive index n of the fast axis and its change dn of each micro-element segment inside the fiber optic loop, as well as the circumferential strain of each micro-element segment. Related; among them, the change in effective refractive index dn along the fast axis has a functional relationship with the three-dimensional stress on the infinitesimal segment:

[0030]

[0031] Among them, T nfast T represents the stress along the fast axis. nslow T represents the stress along the slow axis, which is perpendicular to the fast axis. nθ The stress represents the stress along the length direction perpendicular to both the fast and slow axes, and all stresses in the above formula are positive; E represents the Young's modulus of the material; the effective refractive index change dn along the fast axis has a functional relationship with the three-dimensional strain of the infinitesimal segment:

[0032]

[0033] Furthermore,

[0034] The zero-bias drift of a fiber optic gyroscope is also related to the length L and average diameter D of the fiber optic loop.

[0035] Furthermore,

[0036] In step 9, the time function of the fiber optic gyroscope scaling factor is a functional relationship between the fiber optic gyroscope scaling factor and the fiber optic ring parameters.

[0037] Furthermore,

[0038] The functional relationship between the fiber optic gyroscope scaling factor and the fiber optic loop parameters is as follows:

[0039]

[0040] When the intrinsic frequency of the fiber optic gyroscope is tracked in real time, the functional relationship between the fiber optic gyroscope scaling factor and the fiber optic loop changes as follows:

[0041]

[0042] The "→" symbol indicates the correlation between the scaling factor and the parameters mentioned above.

[0043] Furthermore,

[0044] The scaling factor drift of a fiber optic gyroscope is related to the length L of the fiber loop or the average effective refractive index n and average diameter D of the fast axis;

[0045] The change in fiber optic ring length is obtained by accumulating the circumferential strain of the micro-segments inside the fiber optic ring.

[0046] The average diameter change of the fiber optic ring is obtained by summing the radial strain of the micro-segments with the same circumferential coordinates to obtain the inner and outer contours of the fiber optic ring, and then calculating the average value of the inner and outer contours.

[0047] The average effective refractive index of the fast axis of the fiber ring is obtained by using the zero-bias calculation formula to obtain the effective refractive index of the fast axis of each micro-segment inside the fiber ring. After determining its maximum and minimum values, the average value is calculated.

[0048] The beneficial effects of this invention are:

[0049] By measuring the temperature and time functions of the thermodynamic parameters of each component material of the fiber optic ring, and drawing on the calculation ideas of homogenization and dehomogenization, key parameters such as the length, average diameter, fast-axis effective refractive index and its mean value of the fiber optic ring can be calculated relatively easily. This allows us to obtain the time functions of the zero bias and scaling factor of the fiber optic gyroscope under isothermal operating conditions. Through continuous verification and calibration of the model, we can directly provide a forward design method for the fiber optic ring material parameters for the long-term drift peak-to-peak values ​​of the zero bias and scaling factor of the fiber optic gyroscope. Attached Figure Description

[0050] Figure 1 Flowchart for modeling long-term drift of zero bias and scaling factor in fiber optic gyroscopes. Detailed Implementation

[0051] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0052] This invention employs a homogenization and dehomogenization analysis approach, along with finite element analysis, to establish, verify, and calibrate the thermodynamic parameters of each non-metallic material (inner coating, outer coating, wrapping adhesive, and bonding adhesive) in the fiber optic ring. It establishes, verifies, and calibrates mathematical models of the long-term drift of circumferential strain, radial strain, and three-dimensional stress of each micro-segment of the fiber optic ring under time, temperature, and other environmental conditions. In the fully calibrated mathematical model, the circumferential strain of each micro-segment is integrated according to a specific numbering rule to obtain the long-term drift of the fiber optic ring length; the radial strain of each micro-segment is integrated according to a specific numbering rule to obtain the long-term drift of the average diameter of the fiber optic ring; and the three-dimensional stress of each micro-segment is calculated. The long-term drift of the effective refractive index of the fast axis of each micro-segment is then calculated, ultimately yielding the average long-term drift and discrete characteristics of the effective refractive index of the fast axis of the fiber optic ring. This allows for the analysis of the long-term drift characteristics of the fiber optic gyroscope's scaling factor. Conversely, in response to the long-term drift peak requirement of the scaling factor, optimizing the thermodynamic parameters and geometric proportions of the non-metallic materials that make up the fiber optic ring based on the model, and ultimately achieving long-term drift suppression of the equivalent sensitive area of ​​the fiber optic ring, is a relatively reliable technical approach.

[0053] An optical fiber ring is a ring-shaped body, and its geometric parameters characterizing its shape are its inner diameter (inner radius), outer diameter (outer radius), and height. When calculating the time function of the length, average diameter, and fast-axis effective refractive index of an optical fiber gyroscope ring, the finite element method is used. This method decomposes the optical fiber ring into infinitesimal elements: radial length equal to the difference between the outer and inner radii of the optical fiber ring divided by the number of layers; axial length equal to the height of the optical fiber ring divided by the average number of turns per layer; and circumferential length divisible by the average circumference of the turns. For example, if the optical fiber ring has 64 layers and an average of 88 turns per layer, and the circumferential length of an infinitesimal element is equal to the length of the turns divided by 360, then the number of infinitesimal elements is 64 × 88 × 360 = 2027520. The more infinitesimal elements, the more accurate the time function of the length, average diameter, and fast-axis effective refractive index of the optical fiber ring, but the computational burden is extremely high.

[0054] The finite element method can accurately calculate the comprehensive thermodynamic parameters of the fiber optic ring. By substituting the temperature and time functions of the thermodynamic parameters (Young's modulus, Poisson's ratio, and linear thermal expansion coefficient) of each component material of the fiber optic ring (cladding, inner coating, outer coating, ring winding, and adhesive) into the finite element model, the comprehensive thermodynamic parameters of the fiber optic ring in the transverse (radial and axial) and circumferential directions are obtained. It is found that the comprehensive thermodynamic parameters of the fiber optic ring in the circumferential direction differ significantly from those in the transverse (radial and axial) direction, while the comprehensive thermodynamic parameters in the transverse (radial and circumferential) direction are basically equivalent. This indicates that the fiber optic ring belongs to an orthotropic composite material. By referring to the analytical formula of two-dimensional composite materials, basically the same calculation results are obtained. The calculation ideas of homogenization and dehomogenization are introduced into the fiber optic ring calculation program, which alleviates the huge computational burden of direct finite element decomposition of fiber optic rings.

[0055] The functional relationship between the zero-bias drift of the fiber optic gyroscope and the fiber loop parameters is as follows:

[0056]

[0057] Where: ΔΩ represents the zero-bias drift of the fiber optic gyroscope, λ represents the average wavelength of the optical signal transmitted through the fiber optic ring, c represents the speed of light in vacuum, L represents the length of the fiber optic ring, and D represents the average diameter of the fiber optic ring.

[0058] These represent the phase change of the optical signal as it passes through a fiber segment with length coordinates z and Lz, and length δz, respectively, caused by temperature changes. α represents the rate of temperature change in a fiber segment with length coordinates z and Lz and length δz. n represents the effective refractive index of the fiber along the fast axis. Since some fiber optic gyroscope schemes can also transmit optical signals along the slow axis, the subscript 'fast' is omitted. In the above formula, α T The subscript T represents temperature, but it can be replaced with other symbols, such as F to represent force. The phase change of the optical signal caused by the change in the representative force, and the corresponding It represents the rate of change of the force.

[0059] It can be seen that the zero-bias drift of the fiber optic gyroscope at this moment is related to the effective refractive index n of the fast axis and its change dn of each micro-segment inside the fiber optic loop, as well as the length strain of each micro-segment. (This is related to the same physical concept as the circumferential strain of an optical fiber). Specifically, the change in effective refractive index dn along the fast axis has a functional relationship with the three-dimensional stress experienced by the micro-element at this moment:

[0060]

[0061] Among them, T nfast T represents the stress along the fast axis. ns low represents the stress along the slow axis, which is perpendicular to the fast axis. T nθ The stress represents the stress along the length direction perpendicular to both the fast and slow axes, and all stresses in the above formula are positive. E represents the Young's modulus of the material. Since strain ε and stress T exist within the realm of elasticity... Therefore, the effective refractive index change dn along the fast axis has a functional relationship with the three-dimensional strain experienced by the infinitesimal segment at this moment:

[0062]

[0063] Since the fast axis changes randomly during the process of winding the optical fiber into a loop, the stress and strain mentioned above have random angles with the fast axis of the wound optical fiber. It is necessary to orthogonally decompose the stress and strain on the fast and slow axes to obtain the specific fast and slow axis stress and strain on each micro-segment, which will not be elaborated here.

[0064] It can be seen that the zero-bias drift of the fiber optic gyroscope at this moment is also related to the length L of the fiber optic loop at this moment and the average diameter D at this moment. The calculation method is analyzed in the calculation of the scaling factor drift of the fiber optic gyroscope.

[0065] The functional relationship between the fiber optic gyroscope scaling factor and the fiber optic loop parameters is as follows:

[0066]

[0067] When the intrinsic frequency of the fiber optic gyroscope is tracked in real time, the functional relationship between the fiber optic gyroscope scaling factor and the fiber optic loop changes as follows:

[0068]

[0069] The use of "→" indicates the correlation between the scaling factor and the above parameters. Since the scaling factor is also affected by the circuit parameters, it does not represent an equal relationship, so "=" is not used.

[0070] It can be seen that the scale factor drift of the fiber optic gyroscope at this moment is related to the length L of the fiber loop or the average value of the fast-axis effective refractive index n and the average diameter D. The change in the length of the fiber loop is obtained by directly accumulating the circumferential strain of the micro-segments inside the fiber loop. The change in the average diameter of the fiber loop is related to the radial strain of each micro-segment inside the fiber loop, but it is not directly accumulated. Instead, it is necessary to accumulate the radial strain of micro-segments with the same circumferential coordinates, depict the inner and outer contours of the fiber loop, and then calculate the average value of the inner and outer contours. The average value of the fast-axis effective refractive index of the fiber loop needs to be calculated by obtaining the fast-axis effective refractive index of each micro-segment inside the fiber loop at this moment according to the zero-bias calculation formula mentioned above, determining its maximum and minimum values, and then calculating the average value.

[0071] like Figure 1 As shown in the figure, the method for suppressing long-term drift of the equivalent sensitive area of ​​an optical fiber ring provided by an embodiment of the present invention includes the following steps:

[0072] Step 1: Measure the thermodynamic parameters (Young's modulus, Poisson's ratio, and linear thermal expansion coefficient) of each component material of the fiber optic ring (cladding, inner coating, outer coating, wrapping adhesive, and bonding adhesive) as a function of time under isothermal conditions.

[0073] Step 2: Drawing on the homogenization approach, the fiber optic ring is treated as an orthogonal anisotropic composite material with basically the same transverse (radial and axial) parameters but different circumferential parameters. Using the two-dimensional mechanical parameter calculation method for composite materials, the three-dimensional thermodynamic parameters of the fiber optic ring are obtained through analytical formulas, namely the equivalent thermodynamic parameters of the fiber optic ring in the transverse (radial and axial) and circumferential directions.

[0074] Step 3: Substitute the measured values ​​from Step 1 into Step 2 to obtain the time functions of the equivalent thermodynamic parameters of the fiber optic ring in the transverse and circumferential directions under isothermal conditions;

[0075] Step 4: Substitute the results of Step 3 into the fiber ring transverse and circumferential strain calculation program to obtain the time function of circumferential strain of each layer of the fiber ring, and further obtain the time function of circumferential stress of each layer of the fiber ring.

[0076] Step 5: Perform finite element decomposition of the fiber optic ring according to certain rules. Based on the fact that the vector sum of the forces inside the fiber optic ring is zero and the forces are orthogonally decomposed, and drawing on the idea of ​​dehomogenization, substitute the results of Step 4 into the calculation program to obtain the time function of the three-dimensional (radial, axial, and circumferential) stress of each micro-element segment, and then further obtain the time function of the three-dimensional (radial, axial, and circumferential) strain of each micro-element segment.

[0077] Step 6: Substitute the results of Step 5 into the fast axis effective refractive index change calculation program to obtain the time function of the effective refractive index change of each micro-element segment (the slow axis can also be calculated), and further obtain the time function of the average effective refractive index of the fast axis (or slow axis) of all micro-element segments.

[0078] Step 7: Substitute the results from Step 5 into the fiber optic ring length change calculation program, accumulate the circumferential strain of each micro-segment, and obtain the time function of the fiber optic ring length change.

[0079] Step 8: Substitute the results from Step 5 into the fiber optic ring average diameter change calculation program, accumulate the radial strain of the micro-segments with the same circumferential coordinates of the fiber optic ring, and obtain the time function of the average diameter change of the fiber optic ring.

[0080] Step 9: Substitute the results of Steps 6, 7, and 8 into the fiber optic gyroscope scaling factor drift calculation program to obtain the time function of the fiber optic gyroscope scaling factor; substitute the results of Steps 5 and 6 into the fiber optic gyroscope zero-bias drift calculation program to obtain the time function of the fiber optic gyroscope zero-bias.

[0081] This invention provides a relatively simple method for calculating key parameters such as fiber optic ring length, average diameter, fast-axis effective refractive index and its mean value by measuring the temperature and time functions of the thermodynamic parameters of each component material of the fiber optic ring and drawing on the calculation ideas of homogenization and dehomogenization. This allows for obtaining the time functions of zero bias and scaling factor of the fiber optic gyroscope under isothermal operating conditions. Through continuous verification and calibration of the model, this invention provides a forward design method for fiber optic ring material parameters to directly provide the long-term drift peak-to-peak values ​​of zero bias and scaling factor of the fiber optic gyroscope.

Claims

1. A method for suppressing long-term drift of the equivalent sensitive area of ​​an optical fiber ring, characterized in that, The method includes: Step 1: Measure the time function of the thermodynamic parameters of each component material of the fiber optic ring under isothermal conditions; Step 2: Treat the fiber optic ring as an orthogonal anisotropic composite material with the same transverse parameters but different circumferential parameters, and analyze the three-dimensional thermodynamic parameters of the fiber optic ring using the composite material two-dimensional mechanical parameter calculation method. Step 3: Based on Step 1 and Step 2, obtain the time functions of the equivalent thermodynamic parameters of the fiber ring in the transverse and circumferential directions under isothermal conditions; Step 4: Calculate the transverse and circumferential strains of the fiber ring based on the results of Step 3, obtain the time function of the circumferential strain of each layer of the fiber ring, and further obtain the time function of the circumferential stress of each layer of the fiber ring. Step 5: Perform finite element decomposition on the fiber optic ring. Based on the fact that the vector sum of the forces inside the fiber optic ring is zero and the forces are orthogonally decomposed, calculate the time function of the three-dimensional stress of each micro-element segment based on the results of Step 4, and further obtain the time function of the three-dimensional strain of each micro-element segment; the three dimensions refer to: radial, axial, and circumferential. Step 6: Calculate the change in effective refractive index along the fast axis based on the results of Step 5, obtain the time function of the change in effective refractive index along the fast axis for each micro-element segment, and further obtain the time function of the average effective refractive index along the fast axis for all micro-element segments; Step 7: Calculate the change in fiber ring length based on the results of Step 5, and sum the circumferential strain of each micro-segment to obtain the time function of the change in fiber ring length. Step 8: Calculate the change in average diameter of the fiber optic ring based on the results of Step 5. Accumulate the radial strain of the micro-segments with the same circumferential coordinates of the fiber optic ring to obtain the time function of the change in average diameter of the fiber optic ring. Step 9: Based on the results of Steps 6, 7, and 8, calculate the fiber optic gyroscope scaling factor drift to obtain the time function of the fiber optic gyroscope scaling factor; based on the results of Steps 5 and 6, calculate the fiber optic gyroscope zero-bias drift to obtain the time function of the fiber optic gyroscope zero-bias.

2. The method for suppressing long-term drift of the equivalent sensitive area of ​​an optical fiber ring according to claim 1, characterized in that, In step 1, the components of the fiber optic ring include: cladding, inner coating, outer coating, wrapping adhesive, and bonding adhesive; the thermodynamic parameters include: Young's modulus, Poisson's ratio, and linear thermal expansion coefficient.

3. The method for suppressing long-term drift of the equivalent sensitive area of ​​an optical fiber ring according to claim 2, characterized in that, In step 2, the three-dimensional thermodynamic parameters of the fiber ring include: the equivalent thermodynamic parameters of the fiber ring in the transverse and circumferential directions.

4. The method for suppressing long-term drift of the equivalent sensitive area of ​​an optical fiber ring according to claim 3, characterized in that, In step 9, the time function of zero bias of the fiber optic gyroscope is a functional relationship between the zero bias drift of the fiber optic gyroscope and the parameters of the fiber optic ring.

5. The method for suppressing long-term drift of the equivalent sensitive area of ​​an optical fiber ring according to claim 4, characterized in that, The functional relationship between the zero-bias drift of the fiber optic gyroscope and the fiber loop parameters is as follows: in, This represents the zero-bias drift of the fiber optic gyroscope. This represents the average wavelength of the optical signal transmitted through the fiber optic ring. Represents the speed of light in a vacuum. Represents the length of the fiber optic loop. This represents the average diameter of the fiber optic ring. , These represent the length coordinates respectively. , , length is In a fiber optic micro-segment, temperature changes cause phase changes in the optical signal as it passes through the micro-segment. , The length coordinate is , , length is The rate of temperature change in the fiber micro-segment The fast-axis effective refractive index represents the optical fiber. Subscript Represents temperature.

6. The method for suppressing long-term drift of the equivalent sensitive area of ​​an optical fiber ring according to claim 5, characterized in that, The zero-bias drift of the fiber optic gyroscope is related to the effective refractive index of the fast axis of each micro-element segment within the fiber optic loop. and its change and the circumferential strain of each micro-element segment. Related; among them, the change in effective refractive index of the fast axis There exists a functional relationship between the infinitesimal element and the three-dimensional stress it experiences: in, Represents the stress along the fast axis. This represents the stress along the slow axis, which is perpendicular to the fast axis. This represents the stress along the length direction that is perpendicular to both the fast and slow axes; all stresses in the above formula are positive. Young's modulus of representative materials; change in effective refractive index along the fast axis There is a functional relationship between the infinitesimal element and the three-dimensional strain: 。 7. The method for suppressing long-term drift of the equivalent sensitive area of ​​an optical fiber ring according to claim 6, characterized in that, The zero-bias drift of a fiber optic gyroscope is also related to the length of the fiber loop. Average diameter Related.

8. The method for suppressing long-term drift of the equivalent sensitive area of ​​an optical fiber ring according to claim 6, characterized in that, In step 9, the time function of the fiber optic gyroscope scaling factor is a functional relationship between the fiber optic gyroscope scaling factor and the fiber optic ring parameters.

9. The method for suppressing long-term drift of the equivalent sensitive area of ​​an optical fiber ring according to claim 8, characterized in that, The functional relationship between the fiber optic gyroscope scaling factor and the fiber optic loop parameters is as follows: When the intrinsic frequency of the fiber optic gyroscope is tracked in real time, the functional relationship between the fiber optic gyroscope scaling factor and the fiber optic loop changes as follows: The use of " "" indicates the correlation between the scaling factor and the above parameters.

10. The method for suppressing long-term drift of the equivalent sensitive area of ​​an optical fiber ring according to claim 9, characterized in that, The scaling factor drift of a fiber optic gyroscope is related to the length of the fiber loop. Or the average effective refractive index of the fast axis Average diameter Related; The change in fiber optic ring length is obtained by accumulating the circumferential strain of the micro-segments inside the fiber optic ring. The average diameter change of the fiber optic ring is obtained by summing the radial strain of the micro-segments with the same circumferential coordinates to obtain the inner and outer contours of the fiber optic ring, and then calculating the average value of the inner and outer contours. The average effective refractive index of the fast axis of the fiber ring is obtained by using the zero-bias calculation formula to obtain the effective refractive index of the fast axis of each micro-segment inside the fiber ring. After determining its maximum and minimum values, the average value is calculated.

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