Method and device for reducing detection noise of fiber-optic gyroscope

Abstract

The application discloses a method and device for reducing detection noise of an optical fiber gyroscope. The method comprises: constructing a finite element simulation model of an optical modulator; the simulation model comprises equivalent transverse resistance and capacitance and equivalent longitudinal resistance and capacitance; based on the simulation model, equivalent resistance and capacitance parameters of the optical modulator under different electrode parameters are calculated respectively, and multiple sets of equivalent resistance and capacitance parameters are obtained; the electrode parameters comprise electrode width and electrode spacing; based on each set of equivalent resistance and capacitance parameters, a quantitative relationship between effective modulation signal drift time and drift amount on the optical modulator and the electrode parameters is determined; based on the quantitative relationship, final electrode parameters of the optical modulator under a set requirement are determined; the set requirement comprises a set drift amount and a set drift time. According to the application, the output drift of the optical modulator can be reduced, the reset error of the optical fiber gyroscope can be reduced, and the detection noise of the optical fiber gyroscope can be reduced.

Description

Technical Field

[0001] This invention relates to the field of fiber optic gyroscope technology, and in particular to a method and apparatus for reducing detection noise in fiber optic gyroscopes. Background Technology

[0002] Fiber optic gyroscopes, due to their long lifespan, good anti-interference performance, short startup time, large dynamic range, and high reliability, have been widely used in satellite, submarine, and vehicle applications, becoming one of the mainstream angular velocity sensors in the inertial field. With the continuous expansion of high-precision fiber optic inertial navigation systems, the demand for high-level detection noise control of the core component, the fiber optic gyroscope, is increasing. Currently, noise suppression through circuit optimization methods such as adding filtering circuits has reached its limit; it is necessary to suppress noise at its source. In fiber optic gyroscopes, the drift characteristics of the integrated optical modulator leading to gyroscope reset error and light source intensity noise are significant factors affecting the detection noise level of fiber optic gyroscopes.

[0003] Integrated optical modulators utilize the electro-optic effect to convert voltage signals applied to the device into phase changes in the transmitted light, thereby achieving phase modulation of the sensitive beam in a fiber optic gyroscope. Typically, integrated optical modulators are fabricated using LiNbO3 material. Electrodes located on both sides of the optical transmission channel and on the upper surface of the substrate generate a modulation electric field, which in turn alters the phase of the transmitted beam. However, due to the presence of impurity ions in the modulator substrate and the vertical component of the modulation electric field, a modulation phase drift occurs when the modulator is subjected to DC bias modulation. This phase drift, or phase response instability, causes reset errors in the gyroscope and increases the detection noise of the fiber optic gyroscope.

[0004] Therefore, there is an urgent need for a method and device to reduce the detection noise of fiber optic gyroscopes in order to meet the high-precision application requirements of fiber optic gyroscopes. Summary of the Invention

[0005] This invention provides a method for reducing the detection noise of a fiber optic gyroscope. By reducing the electrical signal drift of the optical modulator, the reset error of the gyroscope is suppressed, thereby reducing the detection noise of the fiber optic gyroscope. The technical solution is as follows:

[0006] On the one hand, a method for reducing detection noise of a fiber optic gyroscope is provided, the method comprising:

[0007] A finite element simulation model of an optical modulator is constructed; the simulation model includes equivalent transverse resistance and capacitance and equivalent longitudinal resistance and capacitance.

[0008] Based on the simulation model, the equivalent resistance and capacitance parameters of the optical modulator under different electrode parameters are calculated to obtain multiple sets of equivalent resistance and capacitance parameters; the electrode parameters include electrode width and electrode spacing.

[0009] Based on each set of equivalent resistance and capacitance parameters, a quantitative relationship is determined between the drift time and drift amount of the effective modulated electrical signal on the optical modulator and the electrode parameters.

[0010] Based on the quantitative relationship, the final electrode parameters of the optical modulator under the set requirements are determined; the set requirements include the set drift amount and the set drift time.

[0011] On the other hand, an apparatus for reducing detection noise of a fiber optic gyroscope is provided, the apparatus comprising:

[0012] A building unit is used to construct a finite element simulation model of an optical modulator; the simulation model includes equivalent transverse resistance and capacitance and equivalent longitudinal resistance and capacitance.

[0013] The calculation unit is used to calculate the equivalent resistance and capacitance parameters of the optical modulator under different electrode parameters based on the simulation model, and obtain multiple sets of equivalent resistance and capacitance parameters; the electrode parameters include electrode width and electrode spacing;

[0014] The first determining unit is used to determine the quantitative relationship between the drift time and drift amount of the effective modulated electrical signal on the optical modulator and the electrode parameters based on each set of equivalent resistance and capacitance parameters;

[0015] The second determining unit is used to determine the final electrode parameters of the optical modulator under the set requirements based on the quantitative relationship; the set requirements include the set drift amount and the set drift time.

[0016] On the other hand, a computer device is provided, the computer device including a memory and a processor, the memory for storing a computer program, and the processor for executing the computer program stored in the memory to implement the steps of the method for reducing the detection noise of a fiber optic gyroscope as described above.

[0017] On the other hand, a computer-readable storage medium is provided, wherein a computer program is stored therein, and when executed by a processor, the computer program implements the steps of the method for reducing the detection noise of a fiber optic gyroscope as described above.

[0018] On the other hand, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the method for reducing detection noise of a fiber optic gyroscope as described above.

[0019] This invention provides a method for reducing detection noise in fiber optic gyroscopes. By constructing a finite element simulation model of the optical modulator, the transient phase response of the modulator under a step signal can be obtained, and the relationship between the effective modulation signal drift time and drift amount and the electrode parameters can be quantitatively determined. Thus, once the required drift amount and drift time are determined, the electrode parameters can be determined based on this quantitative relationship. By adjusting the electrode parameters, the RC network model parameters and modulation electric field distribution characteristics can be changed, altering the transient phase response characteristics of the modulator, suppressing the phase drift degree of the modulator, thereby reducing the gyroscope's reset error and ultimately reducing detection noise. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a method for reducing detection noise of a fiber optic gyroscope according to an embodiment of the present invention;

[0022] Figure 2 This is a structural diagram of a device for reducing detection noise of a fiber optic gyroscope according to an embodiment of the present invention;

[0023] Figure 3 This is a hardware architecture diagram of a computer device provided in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of a finite element simulation model of an optical modulator provided in an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram showing the variation of the longitudinal RC parameters of the modulator with the electrode width.

[0026] Figure 6 Curves showing the variation of the modulator's transverse RC parameters with electrode width for different electrode spacings;

[0027] Figure 7 A schematic diagram of the drift process of the effectively modulated electrical signal under different electrode parameters;

[0028] Figure 8 A schematic diagram showing the change in drift amount as a function of electrode width for effectively modulating electrical signals;

[0029] Figure 9 This is a schematic diagram of the structure of a fiber optic gyroscope provided in an embodiment of the present invention;

[0030] Figure 10 This is a schematic diagram of a traditional fiber optic ring.

[0031] Figure 11 This is a schematic diagram of the integrated fiber optic ring of the present invention;

[0032] Figure 12 This is a schematic diagram of the correlation curves between the sensitive signal and the reference signal before compensation of the reference optical path;

[0033] Figure 13 This is a schematic diagram of the correlation curves between the sensitive signal and the reference signal after the reference optical path has been compensated using the method of this application;

[0034] Figure 14 This is a schematic diagram comparing the noise reduction effect before and after noise removal using the method of this application. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0036] The specific implementation of the method in this application is described in detail below.

[0037] Please refer to Figure 1 The present invention provides a method for reducing detection noise of a fiber optic gyroscope, the method comprising:

[0038] Step 100: Construct a finite element simulation model of the optical modulator; the simulation model includes equivalent transverse resistance and capacitance and equivalent longitudinal resistance and capacitance.

[0039] Step 102: Based on the simulation model, calculate the equivalent resistance and capacitance parameters of the optical modulator under different electrode parameters to obtain multiple sets of equivalent resistance and capacitance parameters; the electrode parameters include electrode width and electrode spacing.

[0040] Step 104: Based on each set of equivalent resistance and capacitance parameters, determine the quantitative relationship between the drift time and drift amount of the effective modulated electrical signal on the optical modulator and the electrode parameters;

[0041] Step 106: Based on the quantitative relationship, determine the final electrode parameters of the optical modulator under the set requirements; the set requirements include the set drift amount and the set drift time.

[0042] In this embodiment, by constructing a finite element simulation model of the optical modulator, the transient phase response of the modulator under a step signal can be obtained, and the relationship between the effective modulation signal drift time and drift amount and the electrode parameters can be quantitatively determined. Thus, once the required drift amount and drift time are determined, the electrode parameters can be determined based on this quantitative relationship. By adjusting the electrode parameters, the RC network model parameters and modulation electric field distribution characteristics can be changed, altering the transient phase response characteristics of the modulator, suppressing the phase drift degree of the modulator, thereby reducing the gyroscope's reset error and consequently reducing detection noise.

[0043] The following description Figure 1 The execution method for each step is shown.

[0044] First, regarding step 100:

[0045] like Figure 4 The figure shows a finite element simulation model of an optical modulator. As can be seen from the figure, the model includes an equivalent lateral resistor-capacitor (RC) and equivalent longitudinal resistors-capacitors (RCs) positioned on either side of the equivalent lateral RC. The equivalent lateral RC includes a lateral resistance R1 and a lateral capacitance C1, and each equivalent longitudinal RC includes a longitudinal resistance R2 and a longitudinal capacitance C2. The parallel RC groups represent the ability of different regions in the modulator to store, conduct, and inject charge. The stepped wave signal applied to the modulator can be considered as a step signal within the time period of each step. Figure 4 As shown, when the optical modulator is subjected to a unit step signal V m (t) During modulation, the effective modulation electrical signal applied to the transverse resistor-capacitor junctions on both sides of the optical transmission channel is V. mt (t).

[0046] For step 102, the following are included:

[0047] Determine the lithium niobate crystal parameters of the optical modulator;

[0048] Set multiple different sets of electrode parameters;

[0049] The electrode parameters are iterated over. For each set of electrode parameters encountered, the following steps are performed: the set of electrode parameters and the lithium niobate crystal parameters are used as input to perform electric field distribution simulation calculation on the simulation model to obtain the equivalent resistance and capacitance parameters under the set of electrode parameters; this process is repeated until all electrode parameters are traversed to obtain multiple sets of equivalent resistance and capacitance parameters.

[0050] In this step, the electrode parameters for each group can be determined according to the simulation requirements. For example... Figure 5The figure shows the variation curves of longitudinal resistance R2 and longitudinal capacitance C2 for different electrode widths. It can be seen from the figure that the modulator can be equivalent to a combination of a large resistor and a small capacitor, with its longitudinal equivalent resistance R2 on the order of tens of TΩ and its longitudinal equivalent capacitance C2 on the order of tens of pF. Furthermore, as the electrode width increases, the longitudinal resistance gradually decreases, while the longitudinal capacitance increases approximately linearly.

[0051] like Figure 6 As shown, the transverse resistance and capacitance parameters vary with the electrode width W. e The graph shows the variation curves. As can be seen from the graph, the lateral resistance R1 is almost linearly proportional to the electrode width, with a value in the hundreds of TΩ range, nearly an order of magnitude larger than the longitudinal resistance R2. This ensures that most of the voltage division of the modulated signal applied to the modulator is applied to both sides of the optical transmission channel, guaranteeing high modulation efficiency. The lateral capacitance C1 gradually decreases with increasing electrode width, and its value is an order of magnitude smaller than the longitudinal capacitance C2. Compared to the electrode width, the electrode spacing has a smaller impact on the lateral resistance and capacitance parameters.

[0052] For step 104, the following are included:

[0053] Based on the simulation model, the calculation formula for the effective modulation electrical signal loaded on both sides of the optical transmission channel when the optical modulator is modulated by a unit step signal is determined; the calculation formula consists of the steady-state part and the voltage drift part of the effective modulation electrical signal.

[0054] Substitute each set of equivalent resistance and capacitance parameters into the calculation formula to obtain the corresponding drift time and DC drift amount;

[0055] The variation curves of drift time, DC drift amount and electrode parameters are calculated to obtain the quantitative relationship between the drift time and drift amount of the effective modulated electrical signal and the electrode parameters.

[0056] In this step, the formula for calculating the effective modulated electrical signal is:

[0057] V mt (t)=V1+V2(t)

[0058]

[0059] In the formula, V mt V(t) represents the effective modulated electrical signal loaded on both sides of the optical transmission channel; V1 and V2(t) represent the steady-state part and voltage drift part of the effective modulated electrical signal, respectively; R1 and C1 are the transverse resistance and transverse capacitance of the optical modulator, respectively; R2 and C2 are the longitudinal resistance and longitudinal capacitance of the optical modulator, respectively; τ is a time constant, which characterizes the drift time required for the signal to reach a steady state.

[0060] In the above formula, the effective modulated electrical signal Vmt The equation (t) consists of two parts. The first part is the steady-state value V1, which determines the modulation efficiency of the modulator. The second part is the voltage drift caused by capacitors C1 and C2, where τ is a time constant, representing the time required for the signal to reach a steady state, and is an important cause of DC drift in the modulator. By changing the equivalent capacitances C1 and C2 of the modulator, the voltage drift amplitude in the above equation can be changed, thus suppressing the DC drift phenomenon of the modulator.

[0061] By substituting each set of equivalent resistance and capacitance parameters into the voltage drift section using the above calculation formula, the DC drift amount and drift time of the signal can be obtained.

[0062] Based on the calculated data, the drift process curves of the effectively modulated electrical signal with different electrode widths can be plotted, such as... Figure 7 As shown in the figure, the electrode width has a more significant impact on the drift of the electrical signal. As the electrode width increases, the amplitude of the electrical signal drift gradually decreases, while the difference in the settling time is not significant.

[0063] In addition, the effective modulation of the electrical signal drift change ΔV over 1 second is used. drift The ratio of the voltage to the steady-state voltage Vs characterizes the amount of drift in the electrical signal, and this drift varies with the electrode width as follows: Figure 8 As shown in the figure. It can be seen from the figure that a larger electrode spacing G... e The electrical signal drift corresponding to the electrode width is smaller, and the effect of electrode width is greater. For example, increasing the electrode width from the conventional 20μm to 25μm can reduce the change in electrical signal drift by about 35% per second.

[0064] Finally, regarding step 106:

[0065] Once the quantitative relationship between drift amount, drift time, and electrode parameters is established, it is only necessary to determine the set drift amount and set drift time according to actual needs. Then, the electrode spacing and width can be determined based on this quantitative relationship, yielding the optimal electrode parameters. By using these optimal electrode parameters, the distribution characteristics of the modulation electric field can be improved, and the gyroscope's reset error can be suppressed.

[0066] Furthermore, the inventors discovered that in fiber optic gyroscopes, as bandwidth increases, noise cannot be reduced through filtering; measures must be taken to suppress the noise at its source. Through theoretical analysis, the inventors found that ASE light source intensity noise accounts for over 50% of the noise sources in fiber optic gyroscopes, which is the main reason for the low measurement accuracy of existing fiber optic gyroscopes. Based on this, to reduce the detection noise of fiber optic gyroscopes, the inventors proposed adding a reference optical path to the fiber optic gyroscope to cancel out noise from the light source.

[0067] Based on the above concept, the method of this application also includes: improving the fiber optic gyroscope, such as... Figure 9 As shown, the improved fiber optic gyroscope includes:

[0068] The system includes a light source, a coupler with at least four ends, a sensitive optical path, a reference optical path, a subtractor, an A / D module, an FPGA, a D / A module, and a waveguide driver connected in sequence. The light emitted from the light source is split into two paths by the coupler and then enters the sensitive optical path and the reference optical path respectively.

[0069] The sensitive optical path includes an optical modulator, a sensitive fiber optic ring, a coupler, a first photodetector, and a first preamplifier connected in sequence; the output terminal of the waveguide driver is connected to the modulation electrode of the optical modulator.

[0070] The reference optical path includes a reference fiber ring, a second photodetector, and a second preamplifier connected in sequence, and a compensation fiber of a preset length is connected in the reference optical path to make the optical path of the sensitive optical path and the reference optical path equal.

[0071] The outputs of the first and second preamplifiers are respectively connected to the input of the subtractor; the subtractor is used to subtract the signal output by the first preamplifier from the signal output by the second preamplifier to obtain a noise-removed photoelectric signal.

[0072] In this system, both the sensitive and reference optical paths originate from the same light source. The sensitive signal includes both rotational speed and noise information, while the reference signal only contains noise information. Therefore, by splicing a compensation fiber of a predetermined length into the reference optical path, the optical path lengths of the sensitive and reference optical paths are made equal, resulting in identical signal delays. This ensures that the noise contained in the two light waves arriving at the subtractor is the same. Finally, by subtracting the signals output from the two preamplifiers using the subtractor, the noise in the sensitive signal is canceled out, improving the speed demodulation accuracy.

[0073] In addition, such as Figure 9 As shown, in the fiber optic gyroscope, the light source is an ASE light source, and the coupler is preferably a 2×2 coupler. The light emitted by the ASE light source is split into two paths after passing through the coupler. One path enters the optical modulator and the sensitive fiber loop, where the angular velocity information is detected. Then, it passes back through the optical modulator and coupler and is output to the first photodetector. The other path enters the reference fiber loop and is output from the reference fiber loop to the second photodetector. The two signals are respectively preamplified and then enter a subtractor. After processing by the subtractor, the noise in the sensitive signal is canceled, and only the angular velocity information is retained. Then, the angular velocity information is output after being processed by the detection circuit consisting of an A / D module, an FPGA, a D / A module, and a waveguide driver.

[0074] It should be noted that before the compensation fiber is connected, the difference in length between the two loops and the optical path introduced by other components in the optical path will cause a delay between the sensitive signal and the reference signal. At this time, the noise in the two signals is inconsistent and cannot be canceled. Therefore, a compensation fiber is required.

[0075] In some implementations, the length of the compensation fiber is determined as follows:

[0076] Construct an initial gyroscope without compensation fiber;

[0077] Based on the two channels of the multi-channel acquisition system, the output signals of the first and second photodetectors in the initial gyroscope are acquired according to the set sampling rate, respectively, to obtain two time sequence signals;

[0078] The correlation between two time-series signals is calculated to obtain a cross-correlation sequence.

[0079] The delay between the sensitive signal and the reference signal is determined based on the cross-correlation sequence;

[0080] The optical path difference between the sensitive signal and the reference signal is determined based on the time delay.

[0081] The length of the compensation fiber is determined based on the optical path difference.

[0082] In this step, the length of the compensation fiber, which is the delay difference between the two signals, can be calculated using the correlation between the two signals. If the delays of the two signals are the same, the sampling point with the highest correlation should appear at the midpoint of the cross-correlation curve after cross-correlation calculation; if the delays are different, the delay difference can be calculated based on the distance between the maximum value point and the midpoint of the cross-correlation curve, and thus the length of the compensation fiber can be determined.

[0083] In some implementations, determining the delay between the sensitive signal and the reference signal based on the cross-correlation sequence includes:

[0084] Determine the sampling location of the sampling point with the highest correlation in the cross-correlation sequence;

[0085] Calculate the distance difference between the sampling location and the location of the central sampling point;

[0086] The delay between the sensitive signal and the reference signal is determined based on this distance difference and the sampling rate.

[0087] In some implementations, the delay between the sensitive signal and the reference signal is calculated using the following formula:

[0088]

[0089] In the formula, T is the delay between the sensitive signal and the reference signal; N is the distance difference between the sampling position of the sampling point with the highest correlation and the position of the center sampling point; and f is the sampling rate.

[0090] In some implementations, the optical path difference between the sensitive signal and the reference signal is calculated using the following formula:

[0091] S = cT

[0092] In the formula, S is the optical path difference between the sensitive signal and the reference signal; c is the speed of light in vacuum.

[0093] In some implementations, the length of the compensation fiber is calculated using the following formula:

[0094]

[0095] In the formula, L is the length of the compensation fiber; r is the refractive index of the compensation fiber.

[0096] In some implementations, the sensitive fiber ring and the reference fiber ring are of equal length and are wrapped around the same fiber ring.

[0097] The reference fiber ring combines the functions of the sensitive fiber ring (fiber padding) and the reference optical transmission function, and both the sensitive fiber ring and the reference fiber ring have two pigtails.

[0098] In some implementations, a compensation fiber of a predetermined length is fused to the fiber between the reference fiber loop and the second photodetector.

[0099] like Figure 10 The diagram shows a schematic of a traditional fiber optic ring. In addition to the sensitive fiber ring, it also includes a thin layer of fiber padding for stress buffering and thermal stress release, ensuring structural stability. Figure 11 The diagram shows the integrated optical fiber of this application. In the diagram, the reference fiber ring replaces the original pad fiber ring, which not only provides protection but also serves as the optical path for the reference signal. Thus, by adopting an integrated design, the delay difference caused by temperature inconsistencies and the intensity difference caused by inconsistent radiation loss between the sensitive fiber ring and the reference fiber ring can be further reduced, improving the intensity noise cancellation effect during long-term use in space environments.

[0100] To demonstrate the noise reduction effect of this application, the inventors used the following parameters for verification:

[0101] The sampling frequency of the acquisition system was set to 2.5 G / s, and the number of sampling points for each detector was 100,000. Under the initial fiber reference fiber length (i.e., without the compensation fiber connected), the correlation curves of the sensitive signal and the reference signal output by the two detectors are shown in the diagram below. Figure 12 As shown:

[0102] As shown in the graph, the point with the highest correlation is point 96432, which is N = 3568 points away from the center point 100000. Based on a sampling rate of 2.5 G / s, the time delay between the two signals is:

[0103]

[0104] Considering the speed of light c is 3 × 10 8 From m / s, the optical path difference S between the two signals can be calculated to be 428.16m.

[0105] Given that the refractive index r of the delay-compensating fiber is 1.45, the length of the compensation fiber is 295.28m.

[0106] The calculated compensation fiber was fused into the fiber optic gyroscope path of this application, and the correlation curves of the sensitive signal and reference signal output by the two detectors were recalculated. The results are as follows: Figure 13 As shown in the figure, after adjustment, the maximum correlation point is located at the midpoint of the sequence, and the maximum correlation value is 0.93265, indicating that the delay between the two signals is basically zero. Figure 14 The diagram shows a comparison of system noise before and after noise cancellation. As can be seen from the diagram, the method of this application can significantly remove light source noise.

[0107] In addition, the optical path difference error L between the two signals determined using the method of this application error The maximum value can be calculated using the following formula:

[0108]

[0109] Optical path difference error is the distance light travels within half the system sampling period. Based on the actual sampling rate of 2.5 Gbps, the maximum optical path difference between the sensitive signal and the reference signal after delay fiber compensation in this application will not exceed 5 cm. Therefore, the method in this application can precisely adjust the time delay between the sensitive signal and the reference signal, ensuring good intensity noise cancellation.

[0110] like Figure 2 , Figure 3 As shown, this embodiment of the invention provides a device for reducing detection noise of a fiber optic gyroscope. The device embodiment can be implemented through software, hardware, or a combination of both. From a hardware perspective, such as... Figure 2 The diagram shown is a hardware architecture diagram of a computing device containing a device for reducing detection noise of a fiber optic gyroscope, as provided in an embodiment of the present invention. Except for... Figure 2In addition to the processor, memory, network interface, and non-volatile memory shown, the computing device in the embodiment may also include other hardware, such as a forwarding chip responsible for processing packets. Taking software implementation as an example, such as... Figure 3 As shown, a device in a logical sense is formed by the CPU of the computing device in which it is located reading the corresponding computer program from the non-volatile memory into the memory for execution.

[0111] Please refer to Figure 3 This invention provides a device for reducing detection noise of a fiber optic gyroscope, the device comprising:

[0112] Building unit 300 is used to build a finite element simulation model of the optical modulator; the simulation model includes equivalent transverse resistance and capacitance and equivalent longitudinal resistance and capacitance.

[0113] The calculation unit 302 is used to calculate the equivalent resistance and capacitance parameters of the optical modulator under different electrode parameters based on the simulation model, and obtain multiple sets of equivalent resistance and capacitance parameters; the electrode parameters include electrode width and electrode spacing.

[0114] The first determining unit 304 is used to determine the quantitative relationship between the drift time and drift amount of the effective modulated electrical signal on the optical modulator and the electrode parameters based on each set of equivalent resistance and capacitance parameters.

[0115] The second determining unit 306 is used to determine the final electrode parameters of the optical modulator under the set requirements based on the quantitative relationship; the set requirements include the set drift amount and the set drift time.

[0116] In some implementations, the computing unit 302 is used to perform the following operations:

[0117] Determine the lithium niobate crystal parameters of the optical modulator;

[0118] Set multiple different sets of electrode parameters;

[0119] The electrode parameters are iterated over. For each set of electrode parameters encountered, the following steps are performed: the set of electrode parameters and the lithium niobate crystal parameters are used as input to perform electric field distribution simulation calculation on the simulation model to obtain the equivalent resistance and capacitance parameters under the set of electrode parameters; this process is repeated until all electrode parameters are traversed to obtain multiple sets of equivalent resistance and capacitance parameters.

[0120] In some implementations, the first determining unit 304 is used to perform the following operations:

[0121] Based on the simulation model, the calculation formula for the effective modulation electrical signal loaded on both sides of the optical transmission channel when the optical modulator is modulated by a unit step signal is determined; the calculation formula consists of the steady-state part and the voltage drift part of the effective modulation electrical signal.

[0122] Substitute each set of equivalent resistance and capacitance parameters into the calculation formula to obtain the corresponding drift time and DC drift amount;

[0123] The variation curves of drift time, DC drift amount and electrode parameters are calculated to obtain the quantitative relationship between the drift time and drift amount of the effective modulated electrical signal and the electrode parameters.

[0124] In some implementations, the formula for calculating the effective modulated electrical signal is:

[0125] V mt (t)=V1+V2(t)

[0126]

[0127] In the formula, V mt V(t) represents the effective modulated electrical signal loaded on both sides of the optical transmission channel; V1 and V2(t) represent the steady-state part and voltage drift part of the effective modulated electrical signal, respectively; R1 and C1 are the transverse resistance and transverse capacitance of the optical modulator, respectively; R2 and C2 are the longitudinal resistance and longitudinal capacitance of the optical modulator, respectively; τ is a time constant, which characterizes the drift time required for the signal to reach a steady state.

[0128] It should be noted that the device for reducing fiber optic gyroscope detection noise provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the device for reducing fiber optic gyroscope detection noise provided in the above embodiments and the method embodiments for reducing fiber optic gyroscope detection noise belong to the same concept, and the specific implementation process is detailed in the method embodiments, which will not be repeated here.

[0129] Embodiments of this application also provide a computer device, please refer to... Figure 3 The computer device includes a processor and a memory, the memory storing at least one instruction, at least one program, code set or instruction set, the at least one instruction, at least one program, code set or instruction set being loaded and executed by the processor to implement the method for reducing fiber optic gyroscope detection noise provided in the above-described method embodiments.

[0130] Embodiments of this application also provide a computer-readable storage medium storing at least one instruction, at least one program, code set, or instruction set, wherein the at least one instruction, at least one program, code set, or instruction set is loaded and executed by a processor to implement the method for reducing the detection noise of a fiber optic gyroscope provided in the above-described method embodiments.

[0131] Embodiments of this application also provide a computer program product, which includes a computer program. A processor of a computer device reads the computer program from a computer-readable storage medium and executes the computer program, causing the computer device to perform any of the methods for reducing fiber optic gyroscope detection noise described in the above embodiments.

[0132] For ease of description, the above systems or devices are described separately as various modules or units based on their functions. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware components.

[0133] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of this application.

[0134] Finally, it should be noted that in this document, relational terms such as first, second, third, and fourth are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0135] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for reducing detection noise of a fiber optic gyroscope, characterized in that, The method includes: A finite element simulation model of an optical modulator is constructed; the simulation model includes equivalent transverse resistance and capacitance and equivalent longitudinal resistance and capacitance. Based on the simulation model, the equivalent resistance and capacitance parameters of the optical modulator under different electrode parameters are calculated to obtain multiple sets of equivalent resistance and capacitance parameters; the electrode parameters include electrode width and electrode spacing. Based on each set of equivalent resistance and capacitance parameters, a quantitative relationship is determined between the drift time and drift amount of the effective modulated electrical signal on the optical modulator and the electrode parameters. Based on the quantitative relationship, the final electrode parameters of the optical modulator under the set requirements are determined; the set requirements include the set drift amount and the set drift time.

2. The method according to claim 1, characterized in that, Based on the simulation model, the equivalent resistance and capacitance parameters of the optical modulator under different electrode parameters are calculated respectively, resulting in multiple sets of equivalent resistance and capacitance parameters, including: Determine the lithium niobate crystal parameters of the optical modulator; Set multiple different sets of electrode parameters; The electrode parameters are iterated over. For each set of electrode parameters encountered, the following steps are performed: the set of electrode parameters and the lithium niobate crystal parameters are used as input to perform electric field distribution simulation calculation on the simulation model to obtain the equivalent resistance and capacitance parameters under the set of electrode parameters; this process is repeated until all electrode parameters are traversed to obtain multiple sets of equivalent resistance and capacitance parameters.

3. The method according to claim 2, characterized in that, The determination of the quantitative relationship between the drift time and drift amount of the effective modulated electrical signal on the optical modulator and the electrode parameters based on each set of equivalent resistance and capacitance parameters includes: Based on the simulation model, the calculation formula for the effective modulation electrical signal loaded on both sides of the optical transmission channel when the optical modulator is modulated by a unit step signal is determined; the calculation formula consists of the steady-state part and the voltage drift part of the effective modulation electrical signal. Substitute each set of equivalent resistance and capacitance parameters into the calculation formula to obtain the corresponding drift time and DC drift amount; The variation curves of the drift time, the DC drift amount, and the electrode parameters are calculated to obtain the quantitative relationship between the effective modulation signal drift time, the drift amount, and the electrode parameters.

4. The method according to claim 3, characterized in that, The formula for calculating an effective modulated electrical signal is: In the formula, V mt V(t) represents the effective modulated electrical signal loaded on both sides of the optical transmission channel; V1 and V2(t) represent the steady-state part and voltage drift part of the effective modulated electrical signal, respectively; R1 and C1 are the transverse resistance and transverse capacitance of the optical modulator, respectively; R2 and C2 are the longitudinal resistance and longitudinal capacitance of the optical modulator, respectively; τ is a time constant, which characterizes the drift time required for the signal to reach a steady state.

5. A device for reducing detection noise of a fiber optic gyroscope, characterized in that, The device includes: A building unit is used to construct a finite element simulation model of an optical modulator; the simulation model includes equivalent transverse resistance and capacitance and equivalent longitudinal resistance and capacitance. The calculation unit is used to calculate the equivalent resistance and capacitance parameters of the optical modulator under different electrode parameters based on the simulation model, and obtain multiple sets of equivalent resistance and capacitance parameters; the electrode parameters include electrode width and electrode spacing; The first determining unit is used to determine the quantitative relationship between the drift time and drift amount of the effective modulated electrical signal on the optical modulator and the electrode parameters based on each set of equivalent resistance and capacitance parameters; The second determining unit is used to determine the final electrode parameters of the optical modulator under the set requirements based on the quantitative relationship; the set requirements include the set drift amount and the set drift time.

6. The apparatus according to claim 5, characterized in that, The computing unit is used to perform the following operations: Determine the lithium niobate crystal parameters of the optical modulator; Set multiple different sets of electrode parameters; The electrode parameters are iterated over. For each set of electrode parameters encountered, the following steps are performed: the set of electrode parameters and the lithium niobate crystal parameters are used as input to perform electric field distribution simulation calculation on the simulation model to obtain the equivalent resistance and capacitance parameters under the set of electrode parameters; this process is repeated until all electrode parameters are traversed to obtain multiple sets of equivalent resistance and capacitance parameters.

7. The apparatus according to claim 6, characterized in that, The first determining unit is used to perform the following operations: Based on the simulation model, the calculation formula for the effective modulation electrical signal loaded on both sides of the optical transmission channel when the optical modulator is modulated by a unit step signal is determined; the calculation formula consists of the steady-state part and the voltage drift part of the effective modulation electrical signal. Substitute each set of equivalent resistance and capacitance parameters into the calculation formula to obtain the corresponding drift time and DC drift amount; The variation curves of the drift time, the DC drift amount, and the electrode parameters are calculated to obtain the quantitative relationship between the effective modulation signal drift time, the drift amount, and the electrode parameters.

8. The apparatus according to claim 7, characterized in that, The formula for calculating an effective modulated electrical signal is: In the formula, V mt V(t) represents the effective modulated electrical signal loaded on both sides of the optical transmission channel; V1 and V2(t) represent the steady-state part and voltage drift part of the effective modulated electrical signal, respectively; R1 and C1 are the transverse resistance and transverse capacitance of the optical modulator, respectively; R2 and C2 are the longitudinal resistance and longitudinal capacitance of the optical modulator, respectively; τ is a time constant, which characterizes the drift time required for the signal to reach a steady state.

9. A computer device, characterized in that, The computer device includes a memory and a processor. The memory is used to store computer programs, and the processor is used to execute the computer programs stored in the memory to implement the steps of the method according to any one of claims 1-4.

10. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements the steps of the method described in any one of claims 1-4.

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