A laser gyroscope frequency stabilization method

Abstract

The application discloses a laser gyroscope frequency stabilization method and belongs to the technical field of precise laser gyroscopes. The application comprises the following steps: a mode (light intensity fluctuation change) is designed as a high-low period mode; high mode and low mode are denoised, analyzed, grouped and numbered in groups; the mode is selected and the mode corresponding position code is recorded so as to improve the stability of the frequency stabilization system; the frequency stabilization small dithering frequency adaptability is selected; and the frequency stabilization small dithering amplitude is adaptively adjusted. The application can effectively solve the mode selection problem of multiple types of laser gyroscopes, reduce the frequency stabilization fluctuation, improve the frequency stabilization mode selection accuracy and stability, and increase the small dithering adaptability and adaptability.

Description

Technical Field

[0001] This invention relates to a method for stabilizing the frequency of a laser gyroscope, belonging to the field of precision laser gyroscope technology. Background Technology

[0002] Unlike traditional mechanical gyroscopes, laser gyroscopes consist of closed quadrilateral or triangular resonant cavities. These gyroscope cavities are equipped with output mirrors, control mirrors, and bias mirrors. A helium-neon laser forms a closed loop through the mirrors, and a beam splitter divides the laser beam into two beams propagating in opposite directions. When an object moves and experiences angular displacement, the two laser beams meet and interfere, allowing the angular velocity of the object to be calculated with far greater accuracy than that of a mechanical gyroscope. Because laser gyroscopes have no moving parts, they are easy to maintain, highly reliable, and have a long service life, making them a core component of inertial reference systems.

[0003] The frequency stabilization control method is crucial to limiting the operating accuracy of laser gyroscopes. The essence of frequency stabilization control is that since the operation of a laser gyroscope relies on the planar film area, the slot film area, and the total internal and partial internal reflection film areas of the beam combining prism, and the internal optical path of the gyroscope is adjusted solely by the frequency stabilization system, a gripping system is needed to precisely adjust the slot film to achieve frequency stabilization and mode selection. The gripping system is a component system consisting of two piezoelectric ceramic pieces bonded together with an indium steel in the middle. Generally, the inner piece is applied with 0V, the outer piece with 300V, and the indium steel with a dynamic voltage of 0-300V. The voltage difference causes deformation of the ceramic pieces, thereby adjusting the slot film for frequency stabilization and mode selection. Generally, different mode positions result in different optical path losses and varying accuracy. The key to improving the frequency stabilization effect of a laser gyroscope lies in the stability and accuracy of mode selection, as well as the efficiency and flexibility of small jitter adjustments. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a laser gyroscope frequency stabilization method, which solves the problem of frequency stabilization of various types of laser gyroscopes, reduces the negative impact of small jitter on the grab adjustment, increases the accuracy of grab adjustment, and improves the accuracy and stability of the frequency stabilization system under different environments.

[0005] The technical solution of this invention is: a laser gyroscope frequency stabilization method, comprising:

[0006] The slot control mode of the laser gyroscope is designed to have an indefinite period and a number of high and low modes;

[0007] The acquisition window is designed based on the high and low modes and the number of periods in the laser gyroscope. A frequency stabilization circuit is designed to perform same-mode selection and tracking and to stabilize the frequency.

[0008] Denoising analysis is performed on the shape of the model;

[0009] Analyze the maxima of the high-mode and low-mode models and select the appropriate model;

[0010] Adjust the frequency of small jitters on the laser gyroscope to suit its operation.

[0011] The amplitude of small jitters on the laser gyroscope is adaptively adjusted to achieve frequency stabilization of the laser gyroscope.

[0012] Furthermore, the design of the slot control mode of the laser gyroscope as a high-mode and a low-mode with an indefinite period and number includes: setting the laser gyroscope to a high-mode and a low-mode with different periods and numbers, wherein the maximum difference between the high-mode and the low-mode exceeds 50%, and designing different high-modes to adapt to the gyroscope according to specific needs, and so on for the design of other multiple-cycle modes.

[0013] Furthermore, the design of the frequency stabilization circuit for same-mode selection and tracking and frequency stabilization includes: performing normal mode scanning on the laser gyroscope, and setting the analysis window length to at least N+1 based on the maximum number of consecutive high modes N.

[0014] Furthermore, the denoising analysis of the modulus includes: denoising the signal by discarding extreme values ​​and then using a moving average method; using the output array after window smoothing as the initial data after initial data processing; and further smoothing the processed initial data by finding the best matching function for the data by minimizing the sum of squared errors.

[0015] Furthermore, the analysis and selection of the modulus maxima includes: taking the second derivative of the data processed in step three to find the maxima points and storing them in the peak array; classifying the maxima, starting from the extreme point of the first modulus, defining a modulus whose difference from the next adjacent modulus is higher than a first preset value as a high modulus, a modulus whose difference from the next adjacent modulus is lower than the first preset value as a low modulus, and a modulus whose difference from the next adjacent modulus is less than a second preset value as the same type as the previous modulus; then, grouping according to the number of consecutive high modulus between two low modulus, thereby determining the group number; the number within each group is determined based on the position of the first low modulus, and the number of each modulus within each group is calculated from the position of the first high modulus, thereby enabling the software to select the modulus with the same group number and the number within the group during each power-on operation in different states.

[0016] Furthermore, the small jitter frequency adaptation adjustment includes: measuring the amplitude-frequency characteristics of the card-grabbing component on the gyroscope using an amplitude-frequency characteristic instrument, applying a fixed amplitude sinusoidal small jitter signal and an indium steel voltage to the card-grabbing system, and adjusting the frequency to observe the amplitude of the gyroscope light intensity fluctuation.

[0017] Furthermore, a standard for the amplitude of light intensity fluctuation of the laser gyroscope is set, and a suitable frequency within the standard range is selected as the reference based on the amplitude of light intensity fluctuation of the adjusted frequency, and recorded in the control center.

[0018] Furthermore, the adaptive adjustment of the small jitter amplitude includes: setting a proportional value; when the small jitter is working, if the difference between the maximum and minimum values ​​of the DC light intensity during the small jitter period exceeds or is less than a preset range, the small jitter amplitude is controlled to be amplified or reduced proportionally so that the DC light intensity fluctuation is within the standard tolerance.

[0019] A computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the laser gyroscope frequency stabilization method.

[0020] A laser gyroscope frequency stabilization device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the laser gyroscope frequency stabilization method.

[0021] The advantages of this invention compared to the prior art are:

[0022] (1) The effect achieved by the feature in step one of this invention is that the laser gyroscope frequency stabilization system can perform frequency stabilization mode selection based on the regularity of high and low modes. Mode grouping can be performed by the number of high modes between any two low modes. The group number can be located according to the order of the high modes between two low modes, thus providing data support for subsequent frequency stabilization mode selection based on the group number and the number within the group. At the same time, it provides users with multiple high modes to select the mode with higher accuracy, and always keeps working on the high-precision mode when the environmental conditions change.

[0023] (2) The effects achieved by the features in steps two, three, and four of this invention are to provide data support for frequency stabilization and mode selection, ensuring that the scan pattern contains at least two low-level modes, selecting an appropriate scan analysis window, and performing denoising fitting and maximum value analysis on the scan pattern. Based on the collected and analyzed maximum values, the modes are grouped and encoded within groups, and stored in the control circuit for mode selection. During the first frequency stabilization operation, based on the manually set mode range, scan results, and test accuracy, an optimal mode is determined through comprehensive analysis, and the corresponding group number and within-group number are stored. Denoising fitting of the scan pattern can more accurately stabilize it at the maximum light intensity, removing interference from jitter or other signals on the scan state. In addition, for incomplete mode parts, it can be extrapolated based on it under the condition of known modes, thereby ensuring that the frequency is stabilized on the accurate mode.

[0024] (3) The effect achieved by the present invention through steps five and six is ​​to reduce the negative impact of small jitter frequency during the frequency stabilization process, and at the same time reduce the negative impact of small jitter amplitude on the gyroscope during the frequency stabilization process. Excessive small jitter amplitude will excite the gyroscope, negatively affecting the internal light intensity. Insufficient small jitter will lead to a decrease in the adjustment effect of the laser gyroscope frequency stabilization system. Therefore, by adaptively selecting the small jitter frequency, the negative impact of the grabbing resonance can be reduced, while also reducing the negative impact of larger resonance amplitudes during the frequency stabilization process. Similarly, the small jitter amplitude is adaptively adjusted according to the magnitude of light intensity fluctuations, which can satisfy the closed-loop adjustment of the gyroscope's frequency stabilization and ensure consistent intensity applied to the gyroscope grabbing system, thereby achieving consistent adjustment amplitude and minimizing negative impacts. Furthermore, since small jitter with the same frequency amplitude will cause deviations in the effect on the grabbing system under different environmental conditions, appropriate compensation can be made through adaptive adjustment of the small jitter amplitude. Attached Figure Description

[0025] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0026] Figure 1 This is a schematic diagram of the method flow of the present invention;

[0027] Figure 2 This is a schematic diagram of the high and low cycle mode design of the present invention. Detailed Implementation

[0028] To better understand the above technical solutions, the technical solutions of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0029] The following description, in conjunction with the accompanying drawings, provides a more detailed explanation of a laser gyroscope frequency stabilization method provided in the embodiments of this application. Specific implementation methods may include (e.g.) Figures 1-2As shown: The laser gyroscope's mode is designed with high and low periods. The size of the mode sweep analysis window is set. Noise reduction and fitting analysis are performed on the laser gyroscope's mode sweep data. The maxima of the mode sweep graph are obtained based on the mode sweep data, and the maxima are grouped and numbered, with high-mode numbers assigned to each group. The small jitter frequency is adaptively adjusted. The small jitter amplitude is adaptively adjusted. The aforementioned control method is applied to the laser gyroscope card-grabbing system for frequency stabilization control.

[0030] The solution provided in this application includes the following steps:

[0031] Step 1: Design the slot control mode of the laser gyroscope as a mode with an indefinite period and number of modes. Specifically, set the laser gyroscope to have high-mode and low-mode modes with different periods and numbers. The maximum difference between the high-mode and low-mode modes generally needs to exceed 50%, for example, low-mode, high-mode, low-mode, high-mode, high-mode, low-mode, high-mode, high-mode, high-mode, etc. Different high-mode modes are designed to adapt to the gyroscope according to specific needs. The design of other multi-period modes can be deduced similarly.

[0032] The effect achieved by the feature in step one of this invention is that the laser gyroscope frequency stabilization system can perform frequency stabilization mode selection based on the regularity of high and low modes. Mode grouping can be performed by counting the number of high modes between any two low modes. The order of the high modes between two low modes can determine the group number, thus providing data support for subsequent frequency stabilization mode selection based on the group number and the number within the group. Simultaneously, it provides users with multiple high modes to select the most accurate mode and ensures stable operation on the high-precision mode even when environmental conditions change.

[0033] Step 2: Based on the high-mode and low-mode characteristics and the number of periods of the laser gyroscope, a frequency stabilization circuit can be designed to quickly perform same-mode selection and tracking, and then stabilize the frequency. Specifically, the laser gyroscope undergoes normal mode scanning, and the analysis window length is set to at least (N+1) based on the maximum number of consecutive high-modes N.

[0034] Step 3: Denoising analysis of the modulus. Specifically, a simple denoising process is performed on the signal using a moving average method after discarding extreme values. The output array after window smoothing is used as the initial data after initial data processing. Least squares fitting (or Gaussian fitting) is used to further smooth the initial data after preliminary processing, and the best matching function for the data is found by minimizing the sum of squared errors.

[0035] Step 4: Analyze and select the modulus maxima. Specifically, calculate the second derivative of the data processed in Step 3 to find the maxima and store them in the peak array. Classify the maxima: starting from the first modulus maxima, if the difference between the maxima and the next nearest maxima is higher than a first preset value, it is defined as a high modulus; if the difference is lower than the first preset value, it is defined as a low modulus; and if the difference between the maxima and the next nearest maxima is less than a second preset value, it is defined as the same type as the previous modulus. Then, group the modulus according to the number of consecutive high modulus, thus determining the group number. The position of each group can be determined based on the position of the first low modulus. The number of each modulus within each group can be calculated from the position of the first high modulus, thus enabling the software to select the modulus with the same group number and its sub-number during each power-on cycle under different conditions.

[0036] The effects achieved through steps two, three, and four of this invention provide data for frequency stabilization and mode selection, ensuring that the scan pattern contains at least two low-level modes. An appropriate scan analysis window is selected, and the scan pattern undergoes denoising, fitting, and maximum value analysis. Based on the acquired and analyzed maximum values, modes are grouped and encoded within groups, and stored in the control circuit for mode selection. During the initial frequency stabilization operation, an optimal mode is determined through comprehensive analysis based on the manually set mode range, scan results, and test accuracy, and the corresponding group number and within-group number are stored. Denoising and fitting the scan pattern can more accurately stabilize it at the maximum light intensity, reducing interference from jitter or other signals on the scan state. Furthermore, for incomplete mode portions, calculations can be performed based on known mode components, thereby ensuring frequency stabilization at the accurate mode.

[0037] Step 5: Small Jitter Frequency Adaptation Adjustment. Specifically, the amplitude-frequency characteristics of the card-grabbing component on the gyroscope are measured using a self-designed amplitude-frequency characteristic instrument. A fixed amplitude sinusoidal small jitter signal and an invar voltage are applied to the card-grabbing system. The frequency is adjusted, and the amplitude of the gyroscope light intensity fluctuation is observed. Generally, amplitude fluctuation detection requires software bandpass filtering of the DC light intensity first. A standard for the amplitude fluctuation of the laser gyroscope light intensity is set. Based on the amplitude fluctuation of the light intensity within the standard range, a suitable frequency is selected as the reference and recorded in the control center.

[0038] Step Six: Adaptive Adjustment of Small Jitter Amplitude. Specifically, the software sets a proportional value. When the small jitter is working, if the difference between the maximum and minimum values ​​of the DC light intensity during the small jitter cycle exceeds or falls below the tolerance range of the proportional value, the software controls the proportional amplification or reduction of the small jitter amplitude to keep the DC light intensity fluctuation within the standard tolerance.

[0039] The effect achieved by the features in steps five and six of this invention is to reduce the negative impact of small jitter frequency during the frequency stabilization process, and simultaneously reduce the negative impact of small jitter amplitude on the gyroscope during the frequency stabilization process. Excessive small jitter amplitude will excite the gyroscope, negatively affecting the internal light intensity. Insufficient small jitter will lead to a decrease in the adjustment effect of the laser gyroscope frequency stabilization system. Therefore, by adaptively selecting the small jitter frequency, the negative impact of the grabbing resonance can be reduced, while also reducing the negative impact of larger resonance amplitudes during the frequency stabilization process. Similarly, the small jitter amplitude is adaptively adjusted according to the magnitude of light intensity fluctuations, which can satisfy the closed-loop adjustment of the gyroscope's frequency stabilization and ensure consistent intensity applied to the gyroscope grabbing system, thereby achieving consistent adjustment amplitude and minimizing negative impacts. Furthermore, since small jitter with the same frequency amplitude will cause shifts in the effect on the grabbing system under different environmental conditions, appropriate compensation can be made through adaptive adjustment of the small jitter amplitude.

[0040] In this invention, high and low cycle modes can be achieved through coating and cavity adjustment. Frequency stabilization and mode selection can be controlled by a frequency stabilization closed-loop control circuit and software. Small jitter adaptation setting and amplitude self-adaptation are simple and convenient. For the frequency amplitude adaptation and adaptive control of small jitter signals, it can be implemented through analog circuits or through a more convenient direct digital frequency synthesis method.

[0041] This application provides a computer-readable storage medium storing computer instructions that, when executed on a computer, cause the computer to perform... Figure 1 The method described.

[0042] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0043] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1A device that provides the functions specified in one or more boxes.

[0044] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0045] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0046] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

[0047] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for stabilizing the frequency of a laser gyroscope, characterized in that, include: The slot control mode of the laser gyroscope is designed to have an indefinite period and a number of high and low modes; The acquisition window is designed based on the high and low modes and the number of periods in the laser gyroscope. A frequency stabilization circuit is designed to perform same-mode selection and tracking and to stabilize the frequency. Denoising analysis is performed on the shape of the model; Analyze the maxima of the high-mode and low-mode models and select the appropriate model; Adjust the frequency of small jitters on the laser gyroscope to suit its operation. The amplitude of small jitters on the laser gyroscope is adaptively adjusted to achieve frequency stabilization of the laser gyroscope; The small jitter frequency adaptation adjustment includes: measuring the amplitude and frequency characteristics of the card-grabbing component on the gyroscope using an amplitude-frequency characteristic instrument, applying a fixed amplitude sinusoidal small jitter signal and indium steel voltage to the card-grabbing system, and adjusting the frequency to observe the amplitude of the gyroscope light intensity fluctuation. Set a standard for the amplitude of light intensity fluctuation of the laser gyroscope, select a suitable frequency within the standard range as a reference based on the amplitude of light intensity fluctuation of the adjusted frequency, and record it in the control center; The adaptive adjustment of the small jitter amplitude includes: setting a proportional value; when the small jitter is working, if the difference between the maximum and minimum values ​​of the DC light intensity during the small jitter cycle exceeds or is less than a preset range, the small jitter amplitude is controlled to be amplified or reduced proportionally so that the DC light intensity fluctuation is within the standard tolerance.

2. The laser gyroscope frequency stabilization method according to claim 1, characterized in that, The design of the slot control mode of the laser gyroscope as a high-mode and a low-mode with an indefinite period and number includes: setting the laser gyroscope to a high-mode and a low-mode with different periods and numbers, wherein the maximum difference between the high-mode and the low-mode exceeds 50%, and designing different high-modes to adapt to the gyroscope according to specific needs, and so on for other multiple-cycle modes.

3. The laser gyroscope frequency stabilization method according to claim 1, characterized in that, The frequency stabilization circuit design includes the following steps for selecting and tracking the same mode and stabilizing the frequency: performing normal mode scanning on the laser gyroscope, and setting the analysis window length to at least N+1 based on the maximum number of consecutive high modes N.

4. The laser gyroscope frequency stabilization method according to claim 1, characterized in that, The denoising analysis of the modulus includes: denoising the signal by discarding extreme values ​​and then using a moving average method; using the output array after window smoothing as the initial data after initial data processing; smoothing the processed initial data again; and finding the best matching function for the data by minimizing the sum of squared errors.

5. The laser gyroscope frequency stabilization method according to claim 1, characterized in that, The process of analyzing and selecting the maximum value of the modulus includes: taking the second derivative of the data processed in step three to find the maximum value point and storing it in the peak value array; classifying the maximum values, starting from the extreme value point of the first modulus, if the difference between it and the next adjacent modulus is higher than a first preset value, it is defined as a high modulus; if the difference between it and the next adjacent modulus is lower than a first preset value, it is defined as a low modulus; if the difference between it and the next adjacent modulus is less than a second preset value, it is defined as a modulus of the same type as the previous modulus; then, grouping is performed according to the number of consecutive high modulus between two low modulus, thereby determining the group number; the number within each group is determined based on the position of the first low modulus, and the number of each modulus within each group is calculated from the position of the first high modulus, thereby enabling the selection of modulus with the same group number and the same number within the group by software during each power-on operation in different states.

6. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 5.

7. A laser gyroscope frequency stabilization device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 5.

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