Interference type optical fiber gyroscope impact resistance method based on integrator prejudgment

Abstract

The invention belongs to the technical field of fiber-optic gyroscopes, and provides an interference type fiber-optic gyroscope impact resistance method based on integrator prejudgment. On the basis of a traditional closed-loop feedback system of the optical fiber gyroscope, an integrator in the closed-loop feedback system is pre-judged, so that phase compensation adjustment is performed, the difference between the closed-loop tracking rate and the actual carrier rotating speed is always smaller than the pi phase shift, and it is ensured that the actual carrier rotating speed can be effectively tracked through a closed-loop feedback value; and performing real-time processing and output on the accumulatively changed phase compensation amount and the current integrator output to obtain the actual angular velocity change sensed by the optical fiber gyroscope. According to the invention, the optical fiber gyroscope can still be ensured to be lossless in precision and work normally when being subjected to large impact, and measurement errors caused by working point offset are avoided. Meanwhile, the original optical path and circuit structure of the optical fiber gyroscope are not changed, the striped phenomenon is corrected only through an optimization algorithm, the requirements of low cost and miniaturization of the optical fiber gyroscope are met, and the optical fiber gyroscope is suitable for being applied to various occasions.

Description

Technical Field

[0001] The 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 have the advantages of wide precision coverage, large dynamic range, high reliability, long life, long-term parameter stability, and fast startup speed. They are widely used in military fields such as inertial navigation equipment, guidance and control, as well as civilian fields such as oil exploration, geological mapping, and drone cruise. In the actual application of fiber optic gyroscopes, the dynamic measurement range is an important performance evaluation indicator. Once the dynamic measurement range is exceeded, the output of the fiber optic gyroscope will produce significant errors, thus affecting its normal operation. This situation is particularly common when the fiber optic gyroscope is impacted. The fiber optic gyroscope is usually fixedly connected to the carrier, and the impact on the carrier is directly transmitted to the fiber optic gyroscope, that is, there is a radial impact component on the fiber ring, which will produce a large instantaneous angular velocity, exceeding the dynamic measurement range of the fiber optic gyroscope, causing 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, after 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 square wave phase difference applied to the phase modulator, Represents the phase difference of the closed-loop feedback. According to the relevant theory of the Sagnac effect, it can be known that Among them, Ω represents the angular velocity that the fiber ring of the fiber optic gyroscope is sensitive to, L represents the fiber length of the fiber ring, D represents the diameter of the fiber ring, λ is the average wavelength of the light source, and c is the light beam in vacuum. When the length and diameter of the fiber ring are determined, the Sagnac phase shift of the two beams of light transmitted in opposite directions is proportional to the angular velocity. Represents a square wave signal with alternating positive and negative Its changes over time are 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 demodulated closed-loop error until the closed-loop error demodulated by the closed-loop system is 0, and the fiber optic gyroscope works normally. The closed loop process of traditional fiber optic gyroscope is as follows Figure 4 shown. The introduction of limits the gyroscope operating point to the original operating 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 in 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 the fiber optic gyroscope, the output angular velocity comes from the closed-loop feedback In this case the output angular velocity is no longer The corresponding angular velocity, the fiber optic gyroscope output has an error. At this time, the closed loop of the fiber optic gyroscope system is out of adjustment, the closed loop working point is offset, and the closed loop is at 2πn (n=±1,±2···), which is no longer the original working point. The working state of the gyroscope corresponds to the nth level of fringes. This phenomenon is the cross-fringe phenomenon. The angular velocity output by the fiber optic gyroscope has an error and the working state cannot be restored to normal. For the fiber optic gyroscope closed-loop system, the cross-fringe phenomenon means that the closed-loop tracking characteristics cannot effectively track the input signal, that is, when the closed-loop tracking rate (gyro integrator tracking value) differs from the actual carrier speed by π phase shift, the fiber optic gyroscope has a cross-fringe problem.

[0006] At present, with the improvement of the accuracy of fiber optic gyroscopes, its application fields are also constantly expanding. The cross-stripe phenomenon introduced by vibration and impact has gradually become one of the problems that fiber optic gyroscopes need to solve. At present, the main solutions include increasing the angular velocity measurement reference and limiting the dynamic range of the gyroscope. Increasing the angular velocity measurement reference usually uses a micro-electromechanical system (MEMS) gyroscope or introduces a large and small ring scheme as a reference. Both schemes use two gyroscopes with different precision to calibrate each other to avoid the occurrence of cross-stripe. However, the measurement bandwidth of the MEMS gyroscope is much smaller than that of the fiber optic gyroscope. When correcting the cross-stripe phenomenon, it is inevitable that the fiber optic gyroscope output will produce errors, resulting in system accuracy loss. At the same time, the MEMS gyroscope itself is sensitive to impact vibration signals. When measuring such signals, its data reliability is difficult to guarantee. In addition, the failure mode of the MEMS gyroscope is different from that of the fiber optic gyroscope, and the overall reliability of the system is reduced. The large and small ring scheme also has the disadvantages of complex structure and difficulty in meeting the current low-cost and miniaturization requirements. Limiting the dynamic range of the fiber optic gyroscope is mainly achieved by limiting the closed-loop integrator phase to within ±π (or ±2π), but this also limits the measurement range of the fiber optic gyroscope, affecting its wide application in various fields. In addition, in a specific application range, for high-frequency impact signals, the AD demodulation value of the forward channel is usually limited so that the fiber optic gyroscope integrator cannot effectively track the input signal, thereby avoiding the cross-fringe problem. However, this solution essentially reduces the gyro closed-loop bandwidth, making the integral value of the integrator unable to track the high-frequency impact signal, and the cross-fringe phenomenon is more likely to occur under high angular acceleration signals. For the high angular acceleration tracking problem caused by the introduction of line angle coupling by a large number of magnitude impacts, a high-order closed-loop method is generally used to increase the bandwidth, but the bandwidth improvement effect is limited and it is difficult to meet application requirements; or by judging the AD demodulation value, if high angular acceleration occurs, the fiber optic gyroscope closed-loop integrator range is limited to the ±π range, and the cross-fringe phenomenon is solved by suppressing the dynamic range, which essentially sacrifices the impact measurement accuracy. In summary, the above measures can alleviate the cross-fringe problem to a certain extent, but they all involve a compromise in efficiency, a reduction in gyro bandwidth, and a loss of accuracy under certain application conditions. Therefore, the study of the cross-fringe problem caused by impact is particularly important. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention proposes an anti-shock method for an interferometric fiber optic gyroscope based on pre-judgment of 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 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 solution of the present invention is as follows:

[0009] An anti-shock method for an interferometric fiber optic gyroscope based on pre-judgment by an integrator, wherein an integrator is arranged in a logic processing unit of the interferometric fiber optic gyroscope, and the anti-shock 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 and negative 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 located 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 as the actual interferometric fiber optic gyroscope sensitive angular velocity output;

[0015] Step S6: Return to step S2 to 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 according to the change of 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 of the working point of the interferometric fiber optic gyroscope after being impacted according to 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 gyroscope changes positively, 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 gyroscope changes positively, 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 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 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 gyro integrator changes in the positive direction, the adjusted phase compensation amount is a positive value; when the interferometric fiber optic gyro integrator changes in the negative direction, the adjusted phase compensation amount is a negative value;

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

[0026] Preferably, the interferometric fiber optic gyroscope includes a light source, a plurality of optical passive devices, 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 anti-shock method of the interferometric fiber optic gyroscope based on pre-judgment of the integrator of the present invention aims at the problem that the closed-loop tracking rate of the interferometric fiber optic gyroscope differs from the actual carrier angular velocity by a phase shift of π under impact conditions, that is, the cross-fringe phenomenon of the fiber optic gyroscope occurs. By pre-judging the integrator in the closed-loop feedback system and making corresponding adjustments at appropriate thresholds, the difference between the closed-loop tracking rate and the actual carrier rotation speed is always less than the phase shift of π, which ensures that the output angular velocity of the fiber optic gyroscope is consistent with the actual rotation speed and avoids the measurement error caused by the working point offset.

[0030] 2. The anti-shock method of the interferometric fiber optic gyroscope based on pre-judgment of the 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 when the interferometric fiber optic gyroscope is in an open-loop state, the input of the preamplifier directly corresponds to the demodulation value, which avoids the bandwidth limitation problem caused by the closed loop.

[0031] 3. The anti-shock method of the interferometric fiber optic gyroscope based on pre-judgment of the integrator of the present invention does not change the original optical path and circuit structure of the interferometric fiber optic gyroscope, but corrects the cross-fringe phenomenon through an optimization algorithm, meets the requirements of low cost and miniaturization of the interferometric fiber optic gyroscope, and is suitable for application in various occasions. The method also does not need to rely on additional sensors for correction, avoiding the loss of system accuracy caused by sensor bandwidth mismatch and data reliability issues.

[0032] 4. The anti-shock method of the interferometric fiber optic gyroscope based on pre-judgment of the integrator of the present invention will not limit the integrator phase range of the fiber optic gyroscope closed-loop feedback system, that is, it will not limit the measurement range of the fiber optic gyroscope. At the same time, the high closed-loop bandwidth characteristic of the gyroscope is maintained, and high-frequency impact signals and high angular acceleration signals can be effectively tracked. 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 drawings required for use in the embodiments will be briefly introduced below. The features and advantages of the present invention can be more clearly understood by referring to the drawings. 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 creative work.

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

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

[0036] Figure 3 It is a schematic diagram of 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 It is a 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 purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments 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 protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0041] Figure 1 This is a flow chart of the anti-shock method for an interferometric fiber optic gyroscope based on integrator prejudgment proposed by the present invention, which aims to improve the anti-shock performance of the interferometric fiber optic gyroscope. The method optimizes the closed-loop tracking process so that the difference between the closed-loop tracking rate and the actual carrier 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, avoiding the offset of the closed-loop working point of the fiber optic gyroscope, that is, avoiding the occurrence of the cross-fringe phenomenon.

[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 a pre-circuit such as a high-pass filter and an operational amplifier, 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 velocity signal and the half-wave voltage error, as well as the functions of angular velocity signal output and modulation signal generation. In the present invention, square wave modulation is used as the modulation signal for description, and the modulation process and results are shown in the figure. Figure 3 The digital quantity of the feedback signal and modulation signal output by the logic processing unit is converted into an analog voltage signal by a digital-to-analog converter, and then the closed-loop feedback gain is adjusted by filtering and amplification of the post-drive circuit, and then applied to both ends of the electrode 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 above 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 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, which are: and The quantitative relationship between these four integral value thresholds is: The size relationship is These four integral value thresholds correspond to the zero-order fringes of the interferometric fiber optic gyroscope. If the angular velocity exceeds the zero-order fringes, that is, when the fringes cross, the integral value threshold can be used for pre-judgment and the current integral value of the integrator can be dynamically adjusted. The judgment order of these four integral value thresholds is related to the change of the working point of the fiber optic gyroscope.

[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 and negative of the working point.

[0047] The angular velocity direction to which the interferometric fiber optic gyroscope is sensitive can be determined based on the integral value. The integral value is the accumulation of the angular velocity demodulation error of the fiber optic gyroscope, and the angular velocity demodulation error is related to the sensitive direction of the gyroscope. The change in the working point of the interferometric fiber optic gyroscope after being impacted can be obtained based on the demodulation error, which can be further compared with the integral 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 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 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, that is, the integral value corresponding to the phase is the threshold When the angular velocity continues to increase, the integral value is Towards 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 increases from the threshold Towards 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 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 increases from the threshold Towards 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 corresponding threshold judgment order 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 corresponding threshold judgment order 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 changes suddenly, 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 all 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: outputting 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, so 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 interferometric fiber optic gyroscope sensitive angular velocity output.

[0056] In step S5, the working point of the interferometric fiber optic gyroscope is positive or negative, and the current integral value needs to be added or subtracted from the phase adjustment amount of the integrator, and the number of additions or subtractions depends on the number of phase adjustments m (m = 0, 1, 2, ...) during the positive or negative threshold judgment. If the angular velocity direction of the fiber optic gyroscope changes suddenly during the measurement process, that is, the integrator judges that there is both a positive judgment or a negative judgment, then it is necessary to add the current integral value to the phase adjustment amount of the positive judgment, and at the same time subtract the phase adjustment amount during the negative judgment, and finally output it as the angular velocity actually sensed by the interferometric fiber optic gyroscope.

[0057] For a traditional interferometric fiber optic gyroscope, the current integral value phase will be output as the actual angular velocity and closed-loop feedback value. When the cross-fringe phenomenon occurs, the angular velocity output will produce an error. Step S5 separates the actual angular velocity and the current integral value, and the phase difference between the adjusted current integral value phase and the actual integral value phase is nπ phase shift. Therefore, it is necessary to superimpose the current integral value with the adjusted cumulative phase shift nπ, and then filter and output it, which ensures that the angular velocity corresponding to the current integral value after the cumulative phase adjustment can be consistent with the angular velocity corresponding to the actual integral value.

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

[0059] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

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

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

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An anti-shock 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 and negative 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 located 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 as the actual interferometric fiber optic gyroscope sensitive angular velocity output; Step S6: Return to step S2 to 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, characterized in that: The step S2 specifically includes: judging the angular velocity direction to which the interferometric fiber gyroscope is sensitive according to the change of the current integral value, wherein the current integral value is the accumulation of the angular velocity demodulation error of the interferometric fiber gyroscope, and obtaining the change of the working point of the interferometric fiber gyroscope after being impacted according to the angular velocity demodulation error of the interferometric fiber gyroscope.

4. The anti-shock method for an interferometric fiber optic gyroscope according to claim 2, characterized in that: The rules for real-time adjustment in step S3 are as follows: (1) If the working point of the interferometric fiber gyroscope changes positively, 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 gyroscope changes positively, 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 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 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, characterized in that: The step S5 specifically includes: (1) When the interferometric fiber optic gyro integrator changes in the positive direction, the adjusted phase compensation amount is a positive value; when the interferometric fiber optic gyro integrator changes in the negative direction, the adjusted phase compensation amount is a negative value; (2) Accumulate the phase compensation amount, and add the accumulated phase compensation amount to the adjusted current integral value as the angular velocity output sensitive to the actual interferometric fiber optic gyroscope.

6. The anti-shock method for an interferometric fiber optic gyroscope according to claim 1, characterized in that: The interferometric fiber optic gyroscope comprises a light source, a plurality of optical passive components, a photoelectric detector, 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, characterized in that: 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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