A digital twin modeling method and system for fiber optic gyroscopes

Abstract

This invention provides a method and system for modeling a digital twin of a fiber optic gyroscope. The modeling method includes dividing the fiber optic gyroscope into an optical path and a circuit; further dividing the optical path into an integrated optical path and a fiber optic ring based on its basic structure, connecting them via connecting fibers, and constructing Jones matrices for the integrated optical path, fiber optic ring, and connecting fibers respectively; multiplying these Jones matrices sequentially to obtain the Jones matrix of the optical model, thus obtaining the optical model and calculating the output light intensity; and constructing a digital twin model of the fiber optic gyroscope based on the optical model. This invention simplifies the model construction method, improves modeling operability, facilitates online digital simulation, and enables the sensing, diagnosis, and prediction of the fiber optic gyroscope's state.

Description

Technical Field

[0001] This invention belongs to the field of fiber optic gyroscope modeling technology, specifically relating to a digital twin modeling method and system for fiber optic gyroscopes. Background Technology

[0002] Digital twins are high-fidelity simulation technologies for complex products, integrating multiple physics, scales, and domains. Since their initial conception in 2003, the application potential of digital twins in complex products and systems has garnered increasing attention over the past two decades. As an extension of modeling and simulation technologies, digital twins use mathematical models to construct virtual products and inject real-world product data collected through sensors into the mathematical model, achieving a mapping from the physical system to the mathematical system to assist in the full lifecycle management of the system. The widespread application of digital twins demonstrates their enormous potential in all stages of the complex product lifecycle, including design, manufacturing, and maintenance. Comprehensive analysis and virtual verification of various aspects of product performance through digital twin models will greatly improve product design quality and efficiency.

[0003] Fiber optic gyroscopes, as all-solid-state angular rate sensors, offer advantages such as low cost, long lifespan, and large dynamic range, and have been widely used in attitude positioning and navigation applications in fields such as space exploration, aerospace, and weaponry. As a multi-technology product integrating optics, mechanics, and electronics, fiber optic gyroscopes have a relatively complex composition, typically consisting of two parts: the optical path and the circuit. The optical path comprises a light source, coupler, Y-waveguide, fiber optic loop, and detector; the circuit amplifies, processes, and outputs the detector's output signal. Its basic principle is as follows: Figure 1 As shown, the optical factors affecting the performance of fiber optic gyroscopes are numerous and complex. To improve the design level of fiber optic gyroscopes and further optimize their performance, it is crucial to adopt an optical path digital twin model with interoperability, scalability, real-time performance, fidelity, and closed-loop capability, and implement online digital simulation to sense, diagnose, and predict the state of the fiber optic gyroscope. Summary of the Invention

[0004] The purpose of this invention is to provide a digital twin modeling method and system for fiber optic gyroscopes, which simplifies the model construction method, improves the operability of modeling, facilitates online digital simulation, and enables the sensing, diagnosis, and prediction of the state of fiber optic gyroscopes.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0006] A method for modeling a digital twin of a fiber optic gyroscope includes the following steps.

[0007] The fiber optic gyroscope is divided into two parts: the optical path and the circuit.

[0008] The optical path of the fiber optic gyroscope is divided into an integrated optical path and an optical fiber ring according to its basic structure. The two are connected by connecting optical fibers to construct the Jones matrix of the integrated optical path, the optical fiber ring, and the connecting optical fiber, respectively.

[0009] The Jones matrix of the integrated optical path, fiber ring, and connecting fiber is multiplied sequentially to obtain the Jones matrix of the optical model, and the output light intensity is calculated.

[0010] A digital twin model of a fiber optic gyroscope was constructed based on an optical model.

[0011] Furthermore, the digital twin modeling method for fiber optic gyroscopes also includes the following steps.

[0012] Construct a physical model of the fiber optic gyroscope and conduct data testing;

[0013] Test data from the fiber optic gyroscope digital twin model and test data from the physical model are collected and fused together. The state and parameters of the fiber optic gyroscope digital twin model are then adjusted based on the fused data.

[0014] A fiber optic gyroscope simulation model is constructed, and the simulation model is driven by fused data. The output data of the fiber optic gyroscope simulation model is fed back to the fiber optic gyroscope digital twin model.

[0015] The output data and fused data of the fiber optic gyroscope simulation model are analyzed to determine the design range of fiber optic gyroscope product parameters.

[0016] Furthermore, the Jones matrix of the integrated optical path is

[0017]

[0018] Where ε is the light attenuation coefficient in the optical fiber; l is the length of the polarization-maintaining fiber in the integrated optical path; k α The transmission matrix has α = 1 and 2, corresponding to the fast and slow axes in the integrated optical path, respectively. where n is the eigenfrequency, c is the speed of light in a vacuum, and n is the eigenfrequency. α is the refractive index.

[0019] Furthermore, the Jones matrix of the fiber optic ring is:

[0020]

[0021] Among them, t ij The transfer function coefficients are i and j = 1 and 2, respectively, representing the start and end points of the fiber optic loop; l0 is the fiber length of the fiber optic loop. n ij k is the relative refractive index. ij It is a relative transfer matrix.

[0022] Furthermore, the Jones matrix of the connecting optical fibers is...

[0023]

[0024] Where l1 is the length of the connecting optical fiber, and k α For the transmission matrix, α = 3, 4, corresponding to the fast axis and slow axis of the connecting optical fiber, respectively. where n is the eigenfrequency, c is the speed of light in a vacuum, and n is the eigenfrequency. α is the refractive index.

[0025] Furthermore, the fiber optic gyroscope transmits the Jones matrix clockwise as follows:

[0026] J = M·U·C·R(45°)·M

[0027]

[0028] This invention also provides a digital twin modeling system for fiber optic gyroscopes, including...

[0029] Optical model, used to generate optical models for fiber optic gyroscopes;

[0030] Digital twin model, used to generate a digital twin model based on an optical model;

[0031] The physical model is for fiber optic gyroscope hardware products;

[0032] The simulation model is used to simulate fiber optic gyroscopes and output data to correct the digital twin model.

[0033] The data testing module is used to collect test data from the digital twin model and the physical model of the fiber optic gyroscope.

[0034] The data fusion module is used to fuse the test data of the fiber optic gyroscope digital twin model with the test data of the physical model, and to adjust the state and parameters of the fiber optic gyroscope digital twin model.

[0035] The data analysis module is used to analyze simulation data and fused data to determine the design range of fiber optic gyroscope product parameters.

[0036] The beneficial effects of this invention compared to the prior art are as follows:

[0037] This invention simplifies the optical part of a fiber optic gyroscope into an integrated optical path and a fiber optic loop connected by a polarization-maintaining fiber. Corresponding Jones matrices are constructed for each, thereby obtaining a mathematical model of the optical part of the fiber optic gyroscope. Based on this, a digital twin model of the fiber optic gyroscope is constructed, simplifying the model construction method, improving the operability of modeling, facilitating online digital simulation, and enabling the sensing, diagnosis, and prediction of the state of the fiber optic gyroscope.

[0038] The fiber optic gyroscope digital twin model constructed in this invention combines physical model test data to obtain fused data, which is used to adjust the model's state and parameters. Simultaneously, it integrates with a simulation model, using virtual-real interactive feedback to drive the simulation model with dynamic data, thereby improving the accuracy of the digital twin model. Furthermore, through data fusion analysis, it analyzes the fused data and the data obtained from the simulation model, promoting the improvement of the simulation model. This allows the digital twin model to continuously approach the actual state of the fiber optic gyroscope, ultimately resulting in a digital twin integrated model that can accommodate models from all domains. This enables cross-departmental and cross-professional collaborative design and verification, providing support for optimized design.

[0039] The fiber optic gyroscope modeling method proposed in this invention for digital twin simulation is of great significance for online digital simulation analysis of fiber optic gyroscopes, optimizing fiber optic gyroscope design, and improving fiber optic gyroscope performance. Attached Figure Description

[0040] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0041] Figure 1 Schematic diagram of a fully digital closed-loop fiber optic gyroscope;

[0042] Figure 2 A schematic diagram of the basic optical model of a fiber optic gyroscope provided for a specific embodiment of the present invention;

[0043] Figure 3 A flowchart for establishing a digital twin model through dynamic data-driven simulation is provided for a specific embodiment of the present invention.

[0044] The above figures include the following reference numerals:

[0045] 1 is the optical model, 2 is the digital twin model, 3 is the physical model, 4 is the data test, 5 is the data fusion, 6 is the data analysis, and 7 is the simulation model. Detailed Implementation

[0046] Specific embodiments of the present invention will now be described in detail. In the following description, specific details are set forth for purposes of explanation and not limitation, in order to aid in a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced in other embodiments departing from these specific details.

[0047] It should be noted that, in order to avoid obscuring the invention with unnecessary details, only the device structure and / or processing steps closely related to the solution of the invention are shown in the accompanying drawings, while other details that are not closely related to the invention are omitted.

[0048] As one aspect of the present invention, a method for modeling a digital twin of a fiber optic gyroscope is provided, comprising the following steps:

[0049] The fiber optic gyroscope is divided into two parts: the optical path and the circuit.

[0050] The optical path of the fiber optic gyroscope is divided into an integrated optical path and an optical fiber ring according to its basic structure. The two are connected by connecting optical fibers to construct the Jones matrix of the integrated optical path, the optical fiber ring, and the connecting optical fiber, respectively.

[0051] The Jones matrix of the integrated optical path, fiber ring, and connecting fiber is multiplied sequentially to obtain the Jones matrix of the optical model, and the output light intensity is calculated.

[0052] A digital twin model of a fiber optic gyroscope was constructed based on an optical model.

[0053] This invention simplifies the optical component of a fiber optic gyroscope into an integrated optical path and an optical fiber loop connected by connecting optical fibers. Corresponding Jones matrices are constructed for each, thereby obtaining a mathematical model of the optical component of the fiber optic gyroscope. Based on this, a digital twin model of the fiber optic gyroscope is built, simplifying the model construction method, improving modeling operability, facilitating online digital simulation, and enabling the sensing, diagnosis, and prediction of the fiber optic gyroscope's state. It should be noted that the electrical component of the fiber optic gyroscope is fixed and can be described using conventional modeling methods.

[0054] Furthermore, in order to seamlessly link knowledge across disciplines and achieve collaborative design and verification across departments and professions, the aforementioned digital twin modeling method for fiber optic gyroscopes also includes the following steps:

[0055] Construct a physical model of the fiber optic gyroscope and conduct data testing;

[0056] Test data from the fiber optic gyroscope digital twin model and test data from the physical model are collected and fused. The state and parameters of the fiber optic gyroscope digital twin model are then adjusted based on the fused data.

[0057] A fiber optic gyroscope simulation model is constructed, and the simulation model is driven by fused data. The output data of the fiber optic gyroscope simulation model is fed back to the fiber optic gyroscope digital twin model.

[0058] The output data and fused data of the fiber optic gyroscope simulation model are analyzed to determine the reasonable range of fiber optic gyroscope product parameters and guide the subsequent design of fiber optic gyroscopes.

[0059] In this invention, the physical model of the fiber optic gyroscope mainly refers to the hardware product of the fiber optic gyroscope. The simulation model of the fiber optic gyroscope can be constructed using conventional simulation software. The data fusion method can employ conventional normalization methods, least squares methods, etc., to correct the digital twin model through data fusion.

[0060] This invention also provides a digital twin modeling system for fiber optic gyroscopes, including...

[0061] Optical model, used to generate optical models for fiber optic gyroscopes;

[0062] Digital twin model, used to generate a digital twin model based on an optical model;

[0063] The physical model is for fiber optic gyroscope hardware products;

[0064] The simulation model is used to simulate fiber optic gyroscopes and output data to correct the digital twin model.

[0065] The data testing module is used to collect test data from the digital twin model and the physical model of the fiber optic gyroscope.

[0066] The data fusion module is used to fuse the test data of the fiber optic gyroscope digital twin model with the test data of the physical model, and to adjust the state and parameters of the fiber optic gyroscope digital twin model.

[0067] The data analysis module is used to analyze simulation data and fused data to determine the design range of fiber optic gyroscope product parameters.

[0068] As another aspect of the present invention, in conjunction with the accompanying drawings and a specific embodiment, a method for constructing a digital twin model of a fiber optic gyroscope is proposed, which is a fiber optic gyroscope model oriented towards digital twin simulation, laying the foundation for online dynamic simulation analysis of fiber optic gyroscopes.

[0069] Digital twins are essentially comprehensive physical and functional descriptions of components, products, or systems, accurately reflecting the performance state of the physical system and simulating and predicting its behavior in a real environment. Therefore, the core of digital twins is establishing a model that accurately reflects the physical system. During the design phase, accurate analysis and simulation of a product's performance, state, and behavior through a digital model provides a basis and guidance for product design decisions and optimization, thereby achieving optimized product design. Through synchronous operation and interaction between the physical system and the virtual digital twin model, through interactive comparison between physical and simulated states, and through the fusion analysis of physical and simulated data, fault diagnosis and early warning for the product can be achieved.

[0070] Fiber optic gyroscope design involves knowledge from multiple disciplines such as optics, mechanics, and thermodynamics. Traditional design methods suffer from inconsistent models and rely heavily on documents to transmit engineering information, resulting in poor communication and fragmented design information across various documents, making management and maintenance difficult and hindering comprehensive optimization. A digital twin of a fiber optic gyroscope is a highly accurate mirror image of the physical gyroscope. By constructing a digital model, an integrated system encompassing models from all disciplines can be formed. Combined with dynamic data, this allows for seamless linking of knowledge across disciplines, enabling cross-departmental and cross-professional collaborative design and verification, and providing support for optimized design.

[0071] Depend on Figure 1 As can be seen, the optical path system of a fiber optic gyroscope relies on the coordinated operation of multiple optical components. In a digital twin model, processing each unit variable individually would be extremely labor-intensive and would hinder the separation of key factors affecting performance; therefore, the system configuration needs to be simplified. This embodiment provides a basic optical model of a fiber optic gyroscope, such as... Figure 2 As shown, it mainly consists of two parts: an integrated optical path (i.e., an assembly of optical devices) and an optical fiber ring connected at 45° via polarization-maintaining fibers.

[0072] The matrix optical model of a fiber optic gyroscope is as follows:

[0073] E out =JE in (1)

[0074] In the formula, E in E out J is the normalized Jones vector of the input and output light; J is the Jones matrix of the light path.

[0075] The Jones matrix of the integrated optical path is:

[0076]

[0077] In the formula, ε is the attenuation coefficient of light in the optical fiber; k α (α = 1, 2, 3, 4...) is the transfer matrix. in where n is the eigenfrequency, c is the speed of light in a vacuum, and n is the eigenfrequency. α (α = 1, 2, 3, 4...) is the refractive index; l is the length of the polarization-maintaining fiber in the integrated optical path.

[0078] Different α values ​​(1, 2, 3, 4...) correspond to the fast and slow axis portions of different optical paths, n α This represents the ability of different parts of the light to refract, and its value is provided by the actual physical model. k α This represents the ability of different parts to transmit light, and the values ​​are provided by the actual physical model.

[0079] In this embodiment, k1 and k2 are the transmission matrices of the fast axis and slow axis in the integrated optical path, respectively, and n1 and n2 are the refractive indices of the fast axis and slow axis in the integrated optical path, respectively.

[0080] The length of polarization-maintaining fiber in an integrated optical path mainly includes the length of the polarization-maintaining fiber connecting the light source, coupler, Y-waveguide, and detector in the integrated optical path.

[0081] The Jones matrix of the fiber optic ring, using a complex 2×2 matrix, is:

[0082]

[0083] In the formula, t ij (i, j = 1, 2) are the transfer function coefficients; n ij (i, j = 1, 2) are the relative refractive indices, and l0 is the fiber length of the fiber ring.

[0084] i and j represent the start and end points of the fiber optic loop, respectively, and t ij Let k represent the transfer function coefficients from i to j. ij Let n represent the transfer matrix from i to j. ij τ represents the relative refractive index from i to j. ij It is the transmitted light intensity from i to j.

[0085] The Jones matrix of the integrated optical path, which connects the fiber optic ring at a 45° angle through polarization-maintaining fiber, is as follows:

[0086]

[0087] In the formula, k3 and k4 are the transmission matrices of the fast axis and slow axis of the polarization-maintaining fiber, respectively; n3 and n4 are the refractive indices of the fast axis and slow axis of the polarization-maintaining fiber, respectively; and l1 is the length of the polarization-maintaining fiber.

[0088] The polarization-maintaining fiber is a Panda polarization-maintaining fiber with a fast axis and a slow axis. R(45°) refers to the polarization-maintaining fiber and the fiber ring fiber being fused together at a 45° angle when the fast axis is fused together to achieve a splitting ratio of 50:50, which introduces the splitting coefficient.

[0089] The Jones matrix of a fiber optic gyroscope transmitting clockwise can be obtained by multiplying the Jones matrices of each component of the optical path in sequence:

[0090] J = M·U·C·R(45°)·M

[0091]

[0092] In summary, the normalized output light intensity of a fiber optic gyroscope can be expressed as:

[0093]

[0094] In the formula, For E out The complex conjugate transpose of is denoted by , where represents the average light intensity over the detector response time.

[0095] The principle of a fiber optic gyroscope is as follows: input light propagates through the optical path of the fiber optic gyroscope, and after passing through various optical components, the output light changes. The rotational speed is sensed by detecting the change in the intensity of the interference between the two beams. The digital twin model of the fiber optic gyroscope transforms the optical components into corresponding Jones matrices to obtain mathematical models of the clockwise and counterclockwise optical paths.

[0096] It should be noted that the Jones matrix for clockwise transmission of a fiber optic gyroscope is the same as that for counterclockwise transmission; it is also the product of the Jones matrices of each component of the optical path in sequence.

[0097] In other embodiments, the construction of the Jones matrix for each part of the optical path will be transformed according to the characteristics of the fiber optic gyroscope optical model.

[0098] As another aspect of the present invention, in order to achieve a deep integration between real physical experiments and virtual simulation experiments and to improve the design level, a flowchart for using dynamic data-driven simulation to establish a digital twin model is provided as follows: Figure 3 As shown:

[0099] First, based on the optical model 1 of the fiber optic gyroscope matrix, a digital twin model 2 of the fiber optic gyroscope is established. Data testing is then conducted in conjunction with the physical model 3 of the fiber optic gyroscope. The test data is fused to obtain dynamic data of the fiber optic gyroscope. This dynamic data drives the simulation model 7 of the fiber optic gyroscope. On the one hand, the state and parameters of the digital twin model are adjusted in a targeted manner by fusing the data. On the other hand, through virtual-real interaction feedback (i.e., virtual-real interaction feedback between the physical model, simulation model and digital twin model), data fusion analysis and other means, the digital twin model is made to continuously approach the state of the real fiber optic gyroscope, and finally a digital twin integrated body that can take into account models in all fields is obtained.

[0100] As another aspect of the present invention, the fiber optic gyroscope modeling method for digital twin simulation is as follows:

[0101] First, a mathematical model of the fiber optic gyroscope's optical path is established. To reduce iterative workload and simplify the fiber optic gyroscope's optical path composition, the Jones matrix of the integrated optical path and fiber ring is obtained, leading to the matrix optical model of the fiber optic gyroscope:

[0102]

[0103] Therefore, the output light intensity is obtained as

[0104] Then, using the matrix optical model as the digital twin model of the fiber optic gyroscope, on the one hand, data testing is conducted and combined with physical model data testing. The two types of data are fused to obtain data that can adjust the model state and parameters. This data is then fed back to the digital twin model. Through virtual-real interactive feedback, the simulation model is driven by dynamic data to improve the accuracy of the digital twin model. On the other hand, through data fusion analysis, the data obtained from the fused data and the simulation model are analyzed to promote the improvement of the simulation model. This allows the digital twin model to continuously approach the actual state of the fiber optic gyroscope. Ultimately, a digital twin integrated body that can take into account models from all fields is obtained, enabling cross-departmental and cross-professional collaborative design and verification, and providing support for optimized design.

[0105] The features described and / or illustrated above for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or in combination with or in lieu of features in other embodiments.

[0106] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, whole, step, or component, but does not exclude the presence or addition of one or more other features, wholes, steps, components, or combinations thereof.

[0107] Many features and advantages of these embodiments are apparent from this detailed description, and therefore the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Furthermore, since many modifications and alterations will readily occur to those skilled in the art, the embodiments of the invention are not intended to be limited to the precise structures and operations illustrated and described, but rather to encompass all suitable modifications and equivalents falling within their scope.

[0108] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0109] The parts of this invention not described in detail are techniques known to those skilled in the art.

Claims

1. A method for modeling a digital twin of a fiber optic gyroscope, characterized in that, Includes the following steps The fiber optic gyroscope is divided into two parts: the optical path and the circuit. The optical path of the fiber optic gyroscope is divided into an integrated optical path and an optical fiber ring according to its basic structure. The two are connected by connecting optical fibers to construct the Jones matrix of the integrated optical path, the optical fiber ring, and the connecting optical fiber, respectively. The Jones matrix of the integrated optical path, fiber ring, and connecting fiber is multiplied sequentially to obtain the Jones matrix of the optical model, and the output light intensity is calculated. A digital twin model of a fiber optic gyroscope was constructed based on an optical model; The Jones matrix of the integrated optical path is ,in, is the attenuation coefficient of light in the optical fiber; The length of the integrated optical fiber; For the transmission matrix, These correspond to the fast axis and slow axis in the integrated optical path, respectively. , The intrinsic frequencies, The speed of light in a vacuum. The refractive index; The Jones matrix of the fiber optic ring is ,in, For the transfer function coefficients, , representing the start and end points of the fiber optic loop, respectively; The length of the fiber in the fiber optic loop; , The relative refractive index, It is a relative transfer matrix; The Jones matrix of the connecting optical fiber is ,in, The length of the connecting optical fiber, For the transmission matrix, These correspond to the fast and slow axes of the optical fiber connection, respectively. , The intrinsic frequencies, The speed of light in a vacuum. The refractive index; The fiber optic gyroscope transmits the Jones matrix clockwise. ， 。 2. The digital twin modeling method according to claim 1, characterized in that, It also includes the following steps Construct a physical model of the fiber optic gyroscope and conduct data testing; Test data from the fiber optic gyroscope digital twin model and test data from the physical model are collected and fused. The state and parameters of the fiber optic gyroscope digital twin model are then adjusted based on the fused data. A fiber optic gyroscope simulation model is constructed, and the simulation model is driven by fused data. The output data of the fiber optic gyroscope simulation model is fed back to the fiber optic gyroscope digital twin model. The output data and fused data of the fiber optic gyroscope simulation model are analyzed to determine the design range of fiber optic gyroscope product parameters.

3. A digital twin modeling system for a fiber optic gyroscope using the digital twin modeling method described in claim 1, characterized in that, include Optical model, used to generate optical models for fiber optic gyroscopes; Digital twin model, used to generate a digital twin model based on an optical model; The physical model is for fiber optic gyroscope hardware products; The simulation model is used to simulate fiber optic gyroscopes and output data to correct the digital twin model. The data testing module is used to collect test data from the digital twin model and the physical model of the fiber optic gyroscope. The data fusion module is used to fuse the test data of the fiber optic gyroscope digital twin model with the test data of the physical model, and to adjust the state and parameters of the fiber optic gyroscope digital twin model. The data analysis module is used to analyze simulation data and fused data to determine the design range of fiber optic gyroscope product parameters.

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