A shock-resistant method for interferometric fiber optic gyroscope based on integrator prejudgment

Abstract

The present invention belongs to the technical field of fiber optic gyroscopes and proposes an anti-shock method for an interferometric fiber optic gyroscope based on pre-judgment of an integrator. Based on the traditional closed-loop feedback system of the fiber optic gyroscope, the integrator in the closed-loop feedback system is pre-judged to perform phase compensation adjustment so that the difference between the closed-loop tracking rate and the actual carrier rotation speed is always less than the π phase shift, ensuring that the closed-loop feedback value can effectively track the actual carrier rotation speed. By real-time processing and outputting the accumulated phase compensation amount and the current integrator output, the actual angular velocity change that the fiber optic gyroscope is sensitive to is obtained. The present invention can ensure that the fiber optic gyroscope can still maintain accuracy and normal operation when subjected to a large impact, avoiding the measurement error caused by the working point offset. At the same time, the original optical path and circuit structure of the fiber optic gyroscope are not changed, and the cross-fringe phenomenon is corrected only through the optimization algorithm, meeting the low-cost and miniaturization requirements of the fiber optic gyroscope and being suitable for application in various occasions.

Description

Technical Field

[0001] The present invention relates to the technical field of fiber optic gyroscopes, and in particular to an anti-shock method for an interferometric fiber optic gyroscope based on pre-judgment by an integrator. Background Art

[0002] Interferometric fiber optic gyroscopes (FOGs) offer advantages such as wide accuracy coverage, large dynamic range, high reliability, long life, long-term parameter stability, and fast startup. They are widely used in military applications such as inertial navigation equipment, guidance and control, as well as civilian applications such as oil exploration, geological mapping, and drone patrol. In practical applications, the dynamic measurement range is a key performance metric for FOGs. Once the dynamic measurement range is exceeded, the FOG's output will produce significant errors, affecting its normal operation. This is particularly common when the FOG is subjected to shock. FOGs are typically rigidly coupled to a carrier, and shocks to the carrier are directly transmitted to the FOG. This creates a radial shock component on the fiber ring, which generates a large instantaneous angular velocity that exceeds the FOG's dynamic measurement range and causes measurement errors.

[0003] The traditional typical interferometric fiber optic gyroscope structure is as follows Figure 2 As shown in Figure 1, square wave modulation and step wave feedback technology are used. The square wave modulation of the fiber optic gyroscope and the corresponding detector output results are shown in Figure 1. Figure 3 After adding square wave modulation to the integrated phase modulator and undergoing closed-loop feedback, the output signal reaching the detector can be expressed as According to this formula, the interference signal is a cosine signal with a period of 2π. represents the intensity of the interference signal, I0 represents the intensity of the input light, represents the Sagnac phase shift of two light beams transmitted in opposite directions, represents the phase difference of the square wave applied to the phase modulator, Represents the phase difference of the closed-loop feedback. According to the relevant theory of Sagnac effect, it can be known that Where Ω represents the angular velocity sensed by the fiber loop of the fiber gyroscope, L represents the fiber length of the fiber loop, D represents the diameter of the fiber loop, λ represents the average wavelength of the light source, and c represents the light beam in vacuum. When the length and diameter of the fiber loop are fixed, the Sagnac phase shift between the two beams propagating in opposite directions is proportional to the angular velocity. Represents a square wave signal with alternating positive and negative values, that is, Its changes over time are as follows Figure 3 shown.

[0004] When the phase difference caused by the angular velocity after feedback within a closed-loop cycle satisfies When , for the high level of the square wave, the intensity of the interference signal is For the low level of the square wave, the strength of the interference signal is At this time, the demodulation value of the fiber optic gyroscope is expressed as Among them, closed-loop feedback The closed-loop controller adjusts the closed-loop error according to the demodulated closed-loop error until the closed-loop error demodulated by the closed-loop system is 0, and the fiber optic gyroscope works normally. In this case The closed loop process of traditional fiber optic gyroscope is as follows Figure 4 shown. The introduction of limits the gyroscope working point to the original working point, that is, the normal working state of the gyroscope corresponds to the zero-order fringe.

[0005] When the fiber optic gyroscope is subjected to a large radial impact, the phase difference caused by the angular velocity after feedback within a closed loop cycle satisfies or When there is always Make For a high level of the square wave, the strength of the interference signal is For the low level of the square wave, the strength of the interference signal is Then the demodulation value of the fiber optic gyroscope is expressed as The closed-loop detection circuit cannot distinguish the phase difference and When the closed-loop error demodulated by the closed-loop system is 0, For fiber optic gyroscopes, the output angular velocity comes from closed-loop feedback In this case the output angular velocity is no longer The corresponding angular velocity causes an error in the FOG output. At this point, the FOG system's closed loop is misaligned, and the closed-loop operating point shifts, closing to 2πn (n = ±1, ±2···), no longer at the original operating point. The gyroscope's operating state corresponds to the nth-order fringe. This phenomenon is known as straddling. The FOG's output angular velocity contains an error, and normal operation cannot be restored. For a FOG closed-loop system, straddling means that the closed-loop tracking characteristics cannot effectively track the input signal. Specifically, when the closed-loop tracking rate (the gyro integrator tracking value) differs from the actual carrier speed by a phase shift of π, the FOG experiences straddling.

[0006] As fiber optic gyroscopes (FOGs) achieve increasing precision and expand their application areas, the cross-fringe phenomenon introduced by vibration and shock has become a pressing issue for FOGs. Current solutions include increasing the angular velocity measurement reference and limiting the gyro's dynamic range. This approach typically employs a microelectromechanical system (MEMS) gyroscope or introduces a large-scale ring scheme as a reference. Both schemes employ two gyroscopes of varying precision for mutual correction to prevent cross-fringe. However, the measurement bandwidth of a MEMS gyroscope is much smaller than that of a FOG. Correcting for cross-fringe phenomenon inevitably introduces errors in the FOG output, resulting in a loss of system accuracy. Furthermore, MEMS gyroscopes are inherently sensitive to shock and vibration signals, making data reliability difficult to guarantee when measuring such signals. Furthermore, MEMS gyroscopes exhibit different failure modes than FOGs, reducing overall system reliability. The large-scale ring scheme also suffers from structural complexity, making it difficult to meet current demands for low cost and miniaturization. Limiting the dynamic range of a fiber optic gyroscope (FOG) is primarily achieved by restricting the closed-loop integrator phase to within ±π (or ±2π). However, this also limits the FOG's measurement range, hindering its widespread application in various fields. Furthermore, in specific applications, for high-frequency impact signals, the AD demodulation value of the forward channel is often limited, preventing the FOG integrator from effectively tracking the input signal, thereby avoiding the cross-fringe problem. However, this solution essentially reduces the gyro's closed-loop bandwidth, making the integrator's integral value unable to track high-frequency impact signals, and cross-fringe phenomena are more likely to occur under high angular acceleration signals. For tracking high angular accelerations caused by line-angle coupling introduced by large-scale impacts, a high-order closed-loop approach is currently generally used to increase the bandwidth, but the bandwidth increase is limited and difficult to meet application requirements. Alternatively, the AD demodulation value is determined. If high angular acceleration is present, the FOG closed-loop integrator range is limited to ±π, thereby suppressing the dynamic range to address the cross-fringe phenomenon, which essentially sacrifices impact measurement accuracy. In summary, the above measures can alleviate the cross-fringe problem to a certain extent, but they all involve a trade-off in efficiency, a reduction in gyro bandwidth, and a loss of accuracy under certain application conditions. Therefore, research on the cross-fringe problem caused by impact is particularly important. Summary of the Invention

[0007] In response to the deficiencies in the prior art, the present invention proposes an anti-shock method for an interferometric fiber optic gyroscope based on pre-judgment by an integrator. The anti-shock method optimizes the closed-loop tracking process to ensure that the difference between the closed-loop tracking rate and the actual carrier rotation speed is always less than the π phase shift, which is equivalent to speeding up the tracking rate of the closed-loop feedback angular acceleration, thereby avoiding the offset of the closed-loop operating point of the fiber optic gyroscope, that is, avoiding the occurrence of the cross-fringe phenomenon, thereby achieving the purpose of improving the anti-shock performance of the interferometric fiber optic gyroscope.

[0008] The technical solutions of the present invention are as follows:

[0009] A shock resistance method for an interferometric fiber optic gyroscope based on pre-judgment by an integrator is provided. An integrator is provided in a logic processing unit of the interferometric fiber optic gyroscope. The shock resistance method comprises the following steps:

[0010] Step S1: setting a plurality of integral value thresholds as adjustment thresholds for the closed-loop tracking rate of the interferometric fiber optic gyroscope after it is impacted;

[0011] Step S2: judging the rotation direction of the interferometric fiber optic gyroscope by the change of the current integral value of the integrator, and determining the direction that the fringes will cross after being impacted and the positive or negative sign of the working point;

[0012] Step S3: adjusting the current integral value in real time according to the current integral value, the integral threshold, and the positive or negative value of the working point so that the closed-loop working point is within the zero-order fringe;

[0013] Step S4: outputting the adjusted integral value as a feedback adjustment value of the digital step wave of the interferometric fiber optic gyroscope to adjust the feedback speed and stability of the closed-loop control system;

[0014] Step S5: When the interferometric fiber optic gyroscope integrator changes in a positive direction, the adjusted phase compensation amount is a positive value; when the interferometric fiber optic gyroscope integrator changes in a negative direction, the adjusted phase compensation amount is a negative value; the adjusted phase compensation amount is added to the adjusted current integral value to output the actual angular velocity to which the interferometric fiber optic gyroscope is sensitive;

[0015] Step S6: Return to step S2 and continuously adjust the impacted interferometric fiber optic gyroscope.

[0016] Preferably, the multiple integral value thresholds in step S1 are and in and

[0017] Preferably, the step S2 specifically includes: judging the angular velocity direction to which the interferometric fiber optic gyroscope is sensitive based on the change in the current integral value, the current integral value is the accumulation of the angular velocity demodulation error of the interferometric fiber optic gyroscope, and obtaining the change in the working point of the interferometric fiber optic gyroscope after being impacted based on the angular velocity demodulation error of the interferometric fiber optic gyroscope.

[0018] Preferably, the rules for real-time adjustment in step S3 are as follows:

[0019] (1) If the working point of the interferometric fiber optic gyroscope changes in the positive direction, the current integral value reaches the threshold When the current integral value is subtracted from the phase π, the current integral value is adjusted to

[0020] (2) If the working point of the interferometric fiber optic gyroscope changes in the positive direction, the current integral value reaches the threshold When the current integral value is subtracted from the phase π, the current integral value is adjusted to

[0021] (3) If the working point of the interferometric fiber optic gyroscope changes negatively, the current integral value reaches the threshold When the current integral value is added with the phase π, the current integral value is adjusted to

[0022] (4) If the working point of the interferometric fiber optic gyroscope changes negatively, the current integral value reaches the threshold When the current integral value is added with the phase π, the current integral value is adjusted to

[0023] Preferably, the step S5 specifically includes:

[0024] (1) When the interferometric fiber optic gyroscope integrator changes in the positive direction, the adjusted phase compensation amount is a positive value; when the interferometric fiber optic gyroscope integrator changes in the negative direction, the adjusted phase compensation amount is a negative value;

[0025] (2) Accumulating the phase compensation amount, and adding the accumulated phase compensation amount to the adjusted current integral value as the angular velocity output of the actual interferometric fiber optic gyroscope.

[0026] Preferably, the interferometric fiber optic gyroscope includes a light source, a plurality of optical passive components, a photodetector, an integrated phase modulator, a fiber optic ring and a signal processing circuit.

[0027] Preferably, the signal processing circuit includes: a preamplifier, an analog-to-digital converter, a logic processing unit, a digital-to-analog converter, and an amplifier.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention provides an anti-shock method for an interferometric fiber optic gyroscope based on pre-judgment of an integrator. This method addresses the problem of a phase shift of π between the closed-loop tracking rate of the interferometric fiber optic gyroscope and the actual carrier angular velocity under impact, i.e., the occurrence of a cross-fringe phenomenon in the fiber optic gyroscope. By pre-judging the integrator in the closed-loop feedback system and performing corresponding adjustments at appropriate thresholds, the method ensures that the difference between the closed-loop tracking rate and the actual carrier rotation speed is always less than the phase shift of π, thereby ensuring that the output angular velocity of the fiber optic gyroscope is consistent with the actual rotation speed and avoiding measurement errors caused by working point offsets.

[0030] 2. The anti-shock method for an interferometric fiber optic gyroscope based on pre-judgment of an integrator of the present invention directly judges the integrator in the closed-loop feedback system, and the input of the integrator is directly related to the demodulation value. That is, it can be understood that the input of the preamplifier of the interferometric fiber optic gyroscope in the open-loop state directly corresponds to the demodulation value, which avoids the bandwidth limitation problem caused by the closed loop.

[0031] 3. The present invention's impact resistance method for an interferometric fiber optic gyroscope (IFG) based on pre-judgment by an integrator does not modify the IFG's existing optical path and circuit structure. Instead, it uses an optimized algorithm to correct for cross-fringe phenomena, meeting the requirements for low cost and miniaturization of IFGs and making them suitable for a variety of applications. This method also eliminates the need for additional sensors for correction, avoiding system accuracy loss caused by sensor bandwidth mismatch and data reliability issues.

[0032] 4. The present invention's impact resistance method for an interferometric fiber-optic gyroscope (FOG) based on pre-determined integrator prediction does not limit the integrator phase range of the FOG's closed-loop feedback system, and therefore does not restrict the FOG's measurement range. It also maintains the gyroscope's high closed-loop bandwidth, effectively tracking high-frequency impact signals and high angular acceleration signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. By referring to the drawings, the features and advantages of the present invention can be more clearly understood. The drawings are schematic and should not be understood as limiting the present invention in any way. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0034] Figure 1 The present invention is a flow chart of the anti-shock method of the interferometric fiber optic gyroscope based on pre-judgment of the integrator.

[0035] Figure 2 This is a typical schematic diagram of the interferometric fiber optic gyroscope structure.

[0036] Figure 3 This is a schematic diagram of the square wave modulation of the fiber optic gyroscope in the present invention and a corresponding detector output result diagram.

[0037] Figure 4 Schematic diagram of the closed-loop feedback process of a traditional fiber optic gyroscope.

[0038] Figure 5 Schematic diagram of the closed-loop feedback process of the fiber optic gyroscope in the present invention. DETAILED DESCRIPTION

[0039] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features therein can be combined with each other without conflict.

[0040] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0041] Figure 1 This is a flowchart of the proposed method for impact resistance in an interferometric fiber optic gyroscope (FOG) based on integrator prejudgment. The method aims to improve the impact resistance of FOGs. By optimizing the closed-loop tracking process, this method ensures that the difference between the closed-loop tracking rate and the actual carrier rotational speed is always less than a π phase shift. This effectively speeds up the closed-loop feedback tracking rate of the angular acceleration, preventing the FOG's closed-loop operating point from shifting, thus avoiding the occurrence of cross-fringe phenomena.

[0042] Figure 2 This is a schematic diagram of the structure of a typical interferometric fiber optic gyroscope, which includes a light source, various optical passive devices, a photodetector, an integrated phase modulator, a fiber ring and a signal processing circuit. The signal processing circuit mainly includes a preamplifier, an analog-to-digital converter, a logic processing unit, a digital-to-analog converter and an amplifier. The analog voltage signal output by the photodetector is conditioned by the pre-circuit such as high-pass filtering and operational amplification, and then converted into a digital signal by the analog-to-digital converter. The logic processing unit then processes the digital signal to complete the demodulation, digital integration and gain adjustment of the angular rate signal and half-wave voltage error, as well as the angular rate signal output and modulation signal generation functions. In the present invention, square wave modulation is used as the modulation signal for description, and the modulation process and results are shown in FIG. Figure 3 The digital quantities of the feedback signal and modulation signal output by the logic processing unit are converted into analog voltage signals by the digital-to-analog converter, and then adjusted by filtering and amplification of the post-drive circuit to adjust the closed-loop feedback gain. The signals are then applied to both ends of the electrodes of the integrated optical phase modulator to form phase modulation, completing the closed-loop control of the entire system loop. The schematic diagram of the closed-loop feedback process is shown in Figure 4 shown.

[0043] The anti-shock method for an interferometric fiber optic gyroscope of the present invention implements algorithm optimization and adjustment in a logic processing circuit and pre-determines the integral value of an integrator. The specific implementation includes the following steps:

[0044] Step S1: setting a plurality of integral value thresholds as adjustment thresholds for the closed-loop tracking rate of the interferometric fiber optic gyroscope after it is impacted.

[0045] In some embodiments, a total of four integral value thresholds for pre-determination by the integrator need to be set, namely and The quantitative relationship between these four integral value thresholds is: The size relationship is These four integration thresholds correspond to the zero-order fringe of the interferometric fiber optic gyroscope. If the angular velocity exceeds the zero-order fringe, i.e., a fringe crossing occurs, the integration thresholds can be used to pre-determine and dynamically adjust the current integration value of the integrator. The order in which these four integration thresholds are determined is related to the changes in the fiber optic gyroscope's operating point.

[0046] Step S2: judging the rotation direction of the interferometric fiber optic gyroscope by the change of the current integral value of the integrator, and determining the direction that the fringes will cross after being impacted and the positive or negative sign of the working point.

[0047] The integrated value can be used to determine the angular velocity direction to which the interferometric fiber gyroscope is sensitive. The integrated value is the accumulation of the fiber gyroscope's angular velocity demodulation error, which is related to the gyroscope's sensitive direction. The demodulation error can be used to determine the change in the interferometric fiber gyroscope's operating point after an impact, which can then be compared with the integrated value threshold.

[0048] Step S3: adjusting the current integral value in real time according to the current integral value, the integral threshold and the positive or negative sign of the working point so that the closed-loop working point is located within the zero-order fringe.

[0049] (1) When the working point of the interferometric fiber optic gyroscope is positive, as the angular velocity increases in the positive direction, the integral value of the integrator also increases. When the integral value reaches the threshold When the integral value is subtracted from the phase π, the phase corresponding to the integral value is the threshold value. When the angular velocity continues to increase, the integral value is Towards the threshold Change, when reaching the threshold When , the integral value continues to subtract the phase π, that is, the phase corresponding to the integral value at this time is the threshold As the angular velocity continues to increase, the integral value is Towards the threshold Changes, when the integral value threshold reaches , repeat the above integrator phase adjustment.

[0050] When the working point of the interferometric fiber optic gyroscope is negative, as the angular velocity increases in the negative direction, the integral value of the integrator also decreases. When the integral value reaches the threshold When the integral value is added with the phase π, the integral value corresponding to the phase is the threshold value. When the angular velocity continues to increase in the negative direction, the integral value is Towards the threshold Change, when reaching the threshold When , the integral value continues to add phase π, that is, the phase corresponding to the integral value at this time is the threshold As the angular velocity continues to increase in the negative direction, the integral value is Towards the threshold Changes, when the integral value threshold reaches , repeat the above integrator phase adjustment.

[0051] (2) When the working point of the interferometric fiber optic gyroscope changes in the positive direction, regardless of whether the phase reaches the integral value threshold, if the angular velocity suddenly changes to a negative direction, the interferometric fiber optic gyroscope immediately operates in the state of measuring negative angular velocity, that is, the integrator is judged in the order of the threshold judgment corresponding to when the working point of the interferometric fiber optic gyroscope is negative, and the integral value operates according to the integral value adjustment rule when the working point is negative. When the working point of the fiber optic gyroscope changes in the negative direction, regardless of whether the phase reaches the integral value threshold, if the angular velocity suddenly changes to a positive direction, the fiber optic gyroscope immediately operates in the state of measuring positive angular velocity, that is, the integrator is judged in the order of the threshold judgment corresponding to when the working point of the fiber optic gyroscope is positive, and the integral value operates according to the integral value adjustment rule when the working point is positive.

[0052] Regardless of the phase value of the interferometric fiber optic gyroscope integrator, when the direction of the angular velocity suddenly changes, the adjustment rule of the integrator phase compensation is determined by the angular velocity direction and the integrator threshold. The determination of the integrator threshold must strictly comply with the conditions described in (1) and (2). Regardless of whether the angular velocity increases in the positive or negative direction, when the corresponding integral value threshold is reached, the phase π is added or subtracted from the integrator integral value, so that the closed-loop operating point of the fiber optic gyroscope is located within the zero-order interference fringe, and the corresponding accumulated or subtracted phase compensation amount is stored in the register. This ensures that when the interferometric fiber optic gyroscope is continuously impacted in various directions, the difference between the closed-loop tracking rate and the actual carrier speed is always less than the π phase shift, that is, the measurement error caused by the positive and negative axial impact components introduced by the fiber ring can be suppressed in real time.

[0053] Step S4: Output the adjusted integral value as the feedback adjustment value of the digital step wave of the interferometric fiber optic gyroscope to adjust the feedback speed and stability of the closed-loop control system.

[0054] The adjusted integral value output corresponds to the interference zero-order fringe. Therefore, the feedback adjustment value of the digital step wave of the interferometric fiber optic gyroscope remains similar to that of the traditional fiber optic gyroscope, which determines that the method provided by the present invention will not cause the accuracy loss of the fiber optic gyroscope.

[0055] Step S5: When the interferometric fiber optic gyroscope integrator changes in the positive direction, the adjusted phase compensation amount is a positive value; when the interferometric fiber optic gyroscope integrator changes in the negative direction, the adjusted phase compensation amount is a negative value; the adjusted phase compensation amount is added to the adjusted current integral value as the actual angular velocity output of the interferometric fiber optic gyroscope.

[0056] In step S5, if the interferometric fiber optic gyroscope's operating point is positive or negative, the current integral value is added to or subtracted from the integrator's phase adjustment. The number of additions or subtractions depends on the number of phase adjustments m (m = 0, 1, 2, ...) made during the positive or negative threshold determination. If the fiber optic gyroscope experiences a sudden change in angular velocity direction during measurement, meaning the integrator determines both a positive and negative direction, the current integral value is added to the phase adjustment for the positive determination, while the phase adjustment for the negative determination is subtracted. This is then output as the angular velocity actually sensed by the interferometric fiber optic gyroscope.

[0057] In a traditional interferometric fiber optic gyroscope, the current integral phase is output as the actual angular velocity and closed-loop feedback value. When cross-fringe phenomena occur, the angular velocity output will produce errors. Step S5 separates the actual angular velocity and the current integral value. The phase difference between the adjusted current integral phase and the actual integral phase is nπ phase shift. Therefore, it is necessary to superimpose the current integral value with the adjusted cumulative phase shift nπ before filtering and outputting it. This ensures that the angular velocity corresponding to the current integral value after the accumulated phase adjustment is consistent with the angular velocity corresponding to the actual integral value.

[0058] Step S6: Return to step S2 and continuously adjust the impacted interferometric fiber optic gyroscope.

[0059] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0060] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0061] In the present invention, the terms "first", "second", "third", and "fourth" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "plurality" refers to two or more, unless otherwise clearly defined.

[0062] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A shock resistance method for an interferometric fiber optic gyroscope based on pre-judgment by an integrator, characterized in that: An integrator is provided in a logic processing unit of the interferometric fiber optic gyroscope, and the anti-shock method comprises the following steps: Step S1: setting a plurality of integral value thresholds as adjustment thresholds for the closed-loop tracking rate of the interferometric fiber optic gyroscope after it is impacted; Step S2: judging the rotation direction of the interferometric fiber optic gyroscope by the change of the current integral value of the integrator, and determining the direction that the fringes will cross after being impacted and the positive or negative sign of the working point; Step S3: adjusting the current integral value in real time according to the current integral value, the integral threshold, and the positive or negative value of the working point so that the closed-loop working point is within the zero-order fringe; Step S4: outputting the adjusted integral value as a feedback adjustment value of the digital step wave of the interferometric fiber optic gyroscope to adjust the feedback speed and stability of the closed-loop control system; Step S5: When the interferometric fiber optic gyroscope integrator changes in a positive direction, the adjusted phase compensation amount is a positive value; when the interferometric fiber optic gyroscope integrator changes in a negative direction, the adjusted phase compensation amount is a negative value; the adjusted phase compensation amount is added to the adjusted current integral value to output the actual angular velocity to which the interferometric fiber optic gyroscope is sensitive; Step S6: Return to step S2 and continuously adjust the impacted interferometric fiber optic gyroscope.

2. The anti-shock method for an interferometric fiber optic gyroscope according to claim 1, characterized in that: The multiple integral value thresholds in step S1 are and in and 3. The anti-shock method for an interferometric fiber optic gyroscope according to claim 1, wherein: The step S2 specifically includes: determining the angular velocity direction to which the interferometric fiber optic gyroscope is sensitive based on a change in a current integral value, wherein the current integral value is the accumulation of an angular velocity demodulation error of the interferometric fiber optic gyroscope, and obtaining a change in the working point of the interferometric fiber optic gyroscope after being impacted based on the angular velocity demodulation error of the interferometric fiber optic gyroscope.

4. The anti-shock method for an interferometric fiber optic gyroscope according to claim 2, wherein: The rules for real-time adjustment in step S3 are as follows: (1) If the working point of the interferometric fiber optic gyroscope changes in the positive direction, the current integral value reaches the threshold When the current integral value is subtracted from the phase π, the current integral value is adjusted to (2) If the working point of the interferometric fiber optic gyroscope changes in the positive direction, the current integral value reaches the threshold When the current integral value is subtracted from the phase π, the current integral value is adjusted to (3) If the working point of the interferometric fiber optic gyroscope changes negatively, the current integral value reaches the threshold When the current integral value is added with the phase π, the current integral value is adjusted to (4) If the working point of the interferometric fiber optic gyroscope changes negatively, the current integral value reaches the threshold When the current integral value is added with the phase π, the current integral value is adjusted to 5. The anti-shock method for an interferometric fiber optic gyroscope according to claim 2, wherein: The step S5 specifically includes: (1) When the interferometric fiber optic gyroscope integrator changes in the positive direction, the adjusted phase compensation amount is a positive value; when the interferometric fiber optic gyroscope integrator changes in the negative direction, the adjusted phase compensation amount is a negative value; (2) Accumulating the phase compensation amount, and adding the accumulated phase compensation amount to the adjusted current integral value as the angular velocity output of the actual interferometric fiber optic gyroscope.

6. The anti-shock method for an interferometric fiber optic gyroscope according to claim 1, wherein: The interferometric fiber optic gyroscope includes a light source, a plurality of optical passive components, a photodetector, an integrated phase modulator, a fiber optic ring and a signal processing circuit.

7. The anti-shock method for an interferometric fiber optic gyroscope according to claim 6, wherein: The signal processing circuit includes: a preamplifier, an analog-to-digital converter, a logic processing unit, a digital-to-analog converter, and an amplifier.

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