阅读说明：本技术 一种光纤陀螺闭环控制方法、系统、电子设备及存储介质 (Fiber-optic gyroscope closed-loop control method and system, electronic equipment and storage medium ) 是由 杜石鹏 张琛 凌卫伟 段威 刘金辉 于 2021-11-03 设计创作，主要内容包括：本发明涉及一种光纤陀螺闭环控制方法及系统,在光纤陀螺的光路中施加频率为本征频率奇数倍的正负交替的方波调制信号；分别确定方波调制信号在正半周期和负半周期调制时,相位调制器中的两路光形成的干涉信号的光强和,计算解调信号为光强和差值；根据修正闭环反馈相移；以闭环反馈相移为阶梯波高度,以一个渡越时间为周期,进行阶梯波累加得到反馈阶梯波,基于反馈阶梯波控制相位调制器；采用本征频率奇数倍的方波作为调制信号,通过提高调制解调与闭环反馈的频率提高载体对于外界角速率输入的响应速度,有效提升了光纤陀螺的响应带宽并提升光纤陀螺的动态性能。(The invention relates to a closed-loop control method and a system of a fiber-optic gyroscope, wherein a square wave modulation signal with the frequency of odd times of the eigenfrequency alternating between positive and negative is applied to the light path of the fiber-optic gyroscope; when the square wave modulation signal is modulated in the positive half period and the negative half period, the light intensity of an interference signal formed by two paths of light in the phase modulator is respectively determined And calculating the demodulated signal as light intensity And difference value (ii) a According to Correcting closed loop feedback phase shift (ii) a Phase shift with closed loop feedback Taking one transit time as a period as the step wave height, performing step wave accumulation to obtain a feedback step wave, and controlling the phase modulator based on the feedback step wave; the square wave with odd times of the intrinsic frequency is used as a modulation signal, the response speed of the carrier to the external angular rate input is improved by improving the frequency of modulation and demodulation and closed loop feedback, the response bandwidth of the fiber-optic gyroscope is effectively improved, and the dynamic performance of the fiber-optic gyroscope is improved.)

1. A fiber optic gyroscope closed loop control method, the fiber optic gyroscope comprising: digital signal processing module and phase modulator, characterized in that, the control method comprises:

step 1, applying a positive and negative alternate square wave modulation signal with the frequency k times of the eigenfrequency in a light path of the fiber-optic gyroscope, wherein k is an odd number more than 1;

step 2, respectively determining the light intensity of interference signals formed by two paths of light in the phase modulator when the square wave modulation signals are modulated in the positive half period and the negative half periodAndcalculating a demodulated signal as said light intensityAnddifference value；

Step 3, according to the demodulation signalCorrecting closed loop feedback phase shift(ii) a Phase shifting with said closed loop feedbackAnd taking one transit time as a period for the height of the step wave, accumulating the step wave to obtain a feedback step wave, and controlling the phase modulator based on the feedback step wave.

2. The control method according to claim 1, wherein the light intensity is determined in step 2Andthe process comprises the following steps: setting an enabling signal to sample and store the interference signal, wherein the sampling value corresponding to the square wave modulation signal in the positive half period isThe sampling value corresponding to the square wave modulation signal during the negative half-cycle modulation is；

Updating the sampling value when the square wave modulation signal finishes sampling in the positive half periodSaid square wave modulating signalUpdating the sample value when the signal completes the negative half-cycle sample。

3. The control method according to claim 1, wherein the step 3 is performed based on the demodulated signalCorrecting closed loop feedback phase shiftThe formula of (1) is:

；

wherein the content of the first and second substances,is a closed loop feedback coefficient.

4. The control method according to claim 1, wherein the formula for obtaining the feedback step wave by performing step wave accumulation in step 3 is as follows:

；

wherein the content of the first and second substances,andthe feedback step wave value is the current time and the feedback step wave value one degree before the current time.

5. The control method according to claim 1, characterized in that the step 3 includes:

k registers are generated in the digital signal processing module to store feedback step wave values in a transition time before the current time, and the value stored in the ith register is the feedback step wave；

After finishing the feedback phase shift updating operation of the square wave modulation signal in the positive half period sampling or the negative half period, the current feedback step wave value is usedSave to the first register=And sequentially sending the feedback step wave stored in the ith registerTo the (i + 1) th register=；

The formula for obtaining the feedback step wave by performing step wave accumulation in the step 3 is as follows:

；

wherein the content of the first and second substances,is the current feedback step wave.

6. The control method according to claim 1, wherein the step 3 of controlling the phase modulator based on the feedback step wave comprises:

and after the feedback step wave and the square wave modulation signal are added, the feedback step wave and the square wave modulation signal are converted into control voltage applied to the phase modulator through a driving circuit.

7. A fiber optic gyroscope closed loop control system, the fiber optic gyroscope comprising: a digital signal processing module, a photoelectric conversion component and a phase modulator,

the digital signal processing module applies positive and negative alternate square wave modulation signals with the frequency k times of the eigenfrequency in the optical path of the fiber-optic gyroscope, wherein k is an odd number larger than 1;

the digital signal processing module samples the signal converted by the photoelectric conversion component and respectively determines the light intensity of an interference signal formed by two paths of light in the phase modulator when the square wave modulation signal is modulated in a positive half period and a negative half periodAndcalculating a demodulated signal as said light intensityAnddifference value；

The digital signal processing module demodulates the signal according to the signalNumber (C)Correcting closed loop feedback phase shift(ii) a Phase shifting with said closed loop feedbackAnd taking one transit time as a period for the height of the step wave, accumulating the step wave to obtain a feedback step wave, and controlling the phase modulator based on the feedback step wave.

8. An electronic device, comprising a memory, a processor for implementing the steps of the fiber-optic gyroscope closed-loop control method according to any one of claims 1-6 when executing a computer management class program stored in the memory.

9. A computer-readable storage medium, having stored thereon a computer management-like program which, when executed by a processor, implements the steps of the fiber-optic gyroscope closed-loop control method of any of claims 1-6.

Technical Field

The invention relates to the technical field of fiber optic gyroscopes, in particular to a fiber optic gyroscope closed-loop control method, a fiber optic gyroscope closed-loop control system, electronic equipment and a storage medium.

Background

The fiber optic gyroscope is an all-solid-state angular velocity sensor based on the Sagnac effect as a theory, has the advantages of high reliability, flexible design, high precision, large dynamic range, no central working point and the like, and becomes an indispensable part in the core inertial device at present.

As shown in fig. 1, a schematic structural diagram of an interferometric digital closed-loop fiber optic gyroscope is shown in fig. 1, and the digital closed-loop fiber optic gyroscope includes a light source 1, a coupler 2, a phase modulator 3, a fiber optic ring 4, a photoelectric conversion module 5, an amplification and filtering module 6, an a/D conversion module 7, a digital signal processing module 8, a D/a conversion module 9, and a driving circuit 10.

The measurement of the rotation speed by the fiber optic gyroscope is realized by measuring the nonreciprocal phase difference (namely, Sagnac phase shift) generated by the rotation speed of two beams of light which are transmitted in opposite directions in the fiber optic ring 4. The digital closed-loop fiber optic gyroscope applies a feedback phase which is equal to the Sagnac phase shift in magnitude and opposite in direction to the Sagnac phase shift in a light path in a closed-loop feedback mode to control the phase difference of the two beams to be close to zero. The feedback phase is obtained by signal modulation and digital demodulation of the interference signal, the modulated and demodulated signal being generated by the digital signal processing block 8. The feedback phase is realized by applying a control voltage to the phase modulator 3, and the phase modulation generated by the phase modulator 3 on the optical signal is proportional to the control voltage.

Generally, the fiber optic gyroscope adopts a modulation and demodulation scheme of an eigenfrequency square wave or a 'four-state' square wave, namely square wave/the 'four-state' square wave with the same frequency as the eigenfrequency is applied in an optical path to generate bias, a difference is made between sampling values of positive and negative bias signals to obtain a demodulation signal, the demodulation signal generates a feedback signal which is in direct proportion to the rotating speed after being accumulated, the feedback signal acts on the phase modulator 3 in a step wave accumulation mode, and the feedback frequency is the same as the demodulation frequency. Fig. 2 is a schematic diagram of an eigenfrequency square wave modulation process. In the drawingsIndicating the modulation signal to which the interference optical signal generated in the phase modulator 3 is subjected,represents a modulation signal to which one path of light propagating counterclockwise interfered in the phase modulator 3 is subjected,the modulation and demodulation scheme can meet the requirement under the condition that the requirement on the environmental dynamic characteristic is not high, but under the high-dynamic environment, the requirement that the fiber-optic gyroscope can quickly respond to the external change can be difficult to meet the requirement, and even under the transient impact environment, the cross-fringe phenomenon can be caused.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides a fiber-optic gyroscope closed-loop control method, a system, electronic equipment and a storage medium, wherein square waves with odd times of intrinsic frequency are used as modulation signals, the response speed of a carrier to external angular rate input is improved by improving the frequency of modulation, demodulation and closed-loop feedback, the response bandwidth of the fiber-optic gyroscope is effectively improved, and the dynamic performance of the fiber-optic gyroscope is effectively improved by optimizing a software algorithm under the condition of ensuring that the precision is not changed.

According to a first aspect of the present invention, there is provided a fiber optic gyroscope closed-loop control method, the fiber optic gyroscope including: digital signal processing module and phase modulator, the control method includes:

step 1, applying a positive and negative alternate square wave modulation signal with the frequency k times of the eigenfrequency in a light path of the fiber-optic gyroscope, wherein k is an odd number more than 1;

step 2, respectively determining the light intensity of interference signals formed by two paths of light in the phase modulator when the square wave modulation signals are modulated in the positive half period and the negative half periodAndcalculating a demodulated signal as said light intensityAnddifference value；

Step 3, according to the demodulation signalCorrecting closed loop feedback phase shift(ii) a Phase shifting with said closed loop feedbackAnd taking one transit time as a period for the height of the step wave, accumulating the step wave to obtain a feedback step wave, and controlling the phase modulator based on the feedback step wave.

On the basis of the technical scheme, the invention can be improved as follows.

Optionally, the light intensity is determined in step 2Andthe process comprises the following steps: setting an enabling signal to sample and store the interference signal, wherein the sampling value corresponding to the square wave modulation signal in the positive half period isThe sampling value corresponding to the square wave modulation signal during the negative half-cycle modulation is；

Updating the sampling value when the square wave modulation signal finishes sampling in the positive half periodUpdating the sampling value when the square wave modulation signal completes the sampling of the negative half period。

Optionally, the step 3 is performed according to the demodulated signalCorrecting closed loop feedback phase shiftThe formula of (1) is:

；

wherein the content of the first and second substances,is a closed loop feedback coefficient.

Optionally, the formula for obtaining the feedback step wave by performing step wave accumulation in step 3 is as follows:

；

wherein the content of the first and second substances,andthe feedback step wave value is the current time and the feedback step wave value one degree before the current time.

Optionally, step 3 includes:

k registers are generated in the digital signal processing module to store feedback step wave values in a transition time before the current time, and the value stored in the ith register is the feedback step wave；

After finishing the feedback phase shift updating operation of the square wave modulation signal in the positive half period sampling or the negative half period, the current feedback step wave value is usedSave to the first register=And sequentially sending the feedback step wave stored in the ith registerTo the (i + 1) th register=；

The formula for obtaining the feedback step wave by performing step wave accumulation in the step 3 is as follows:

；

wherein the content of the first and second substances,is the current feedback step wave.

Optionally, the step 3 of controlling the phase modulator based on the feedback step wave includes:

and after the feedback step wave and the square wave modulation signal are added, the feedback step wave and the square wave modulation signal are converted into control voltage applied to the phase modulator through a driving circuit.

According to a second aspect of the present invention, there is provided a fiber optic gyroscope closed loop control system, the fiber optic gyroscope comprising: the device comprises a digital signal processing module, a photoelectric conversion component and a phase modulator;

the digital signal processing module applies positive and negative alternate square wave modulation signals with the frequency k times of the eigenfrequency in the optical path of the fiber-optic gyroscope, wherein k is an odd number larger than 1;

the digital signal processing module samples the signal converted by the photoelectric conversion component and respectively determines the light intensity of an interference signal formed by two paths of light in the phase modulator when the square wave modulation signal is modulated in a positive half period and a negative half periodAndcalculating a demodulated signal as said light intensityAnddifference value；

The digital signal processing module demodulates the signal according to the demodulation signalCorrecting closed loop feedback phase shift(ii) a Phase shifting with said closed loop feedbackAnd taking one transit time as a period for the height of the step wave, accumulating the step wave to obtain a feedback step wave, and controlling the phase modulator based on the feedback step wave to complete closed-loop control.

According to a third aspect of the present invention, there is provided an electronic device comprising a memory, a processor for implementing the steps of the fiber-optic gyroscope closed-loop control method when executing a computer management class program stored in the memory.

According to a fourth aspect of the present invention, there is provided a computer readable storage medium, on which a computer management-like program is stored, which, when executed by a processor, implements the steps of the fiber-optic gyroscope closed-loop control method.

According to the closed-loop control method, the closed-loop control system, the electronic equipment and the storage medium of the fiber-optic gyroscope, the dynamic performance of the fiber-optic gyroscope is effectively improved through the optimization of a software algorithm on the basis of not changing hardware; the problem of bandwidth reduction of the high-precision fiber-optic gyroscope caused by the increase of the length of the fiber-optic ring is effectively solved; through the design of the modulation frequency, the phenomenon of cross-stripe of the fiber-optic gyroscope under the large-scale transient impact can be effectively inhibited.

Drawings

FIG. 1 is a schematic structural diagram of an interferometric digital closed-loop fiber optic gyroscope;

FIG. 2 is a schematic diagram of an eigenfrequency square wave modulation process;

FIG. 3 is a schematic diagram of a 3-fold square wave modulation signal according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a 3-fold square wave modulation process according to an embodiment of the present invention;

fig. 5 is a schematic diagram of a step wave curve modulated by square waves with 3 times of eigenfrequency according to an embodiment of the present invention;

FIG. 6 is a timing diagram illustrating odd-multiplied square wave modulation and demodulation according to an embodiment of the present invention;

FIG. 7 is a schematic diagram illustrating an update process of a feedback step value within a transit time prior to a current time according to the present invention;

FIG. 8 is a schematic diagram of a four-state wave modulation process according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of a hardware structure of a possible electronic device according to the present invention;

fig. 10 is a schematic diagram of a hardware structure of a possible computer-readable storage medium according to the present invention.

In the drawings, the components represented by the respective reference numerals are listed below:

1. the device comprises a light source, 2, a coupler, 3, a phase modulator, 4, an optical fiber ring, 5, a photoelectric conversion component, 6, an amplification and filtering module, 7, an A/D conversion module, 8, a digital signal processing module, 9, a D/A conversion module, 10 and a driving circuit.

Detailed Description

The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention.

On one hand, the requirement for the fiber optic gyroscope to rapidly respond to the high dynamic angular rate change is higher and higher, and the bandwidth of the fiber optic gyroscope needs to be improved; on the other hand, in order to improve the precision, a scheme of increasing the length of the optical fiber ring is generally adopted, so that the eigenfrequency of the optical fiber gyro is reduced, and the bandwidth of the optical fiber gyro is reduced. Aiming at the problems of application requirements of the optical fiber gyroscope in a high dynamic environment and bandwidth reduction of the high-precision optical fiber gyroscope, the dynamic performance of the optical fiber gyroscope is effectively improved through optimization of a software algorithm under the condition of ensuring that the precision is not changed.

Referring to fig. 1, light output from the fiber optic gyroscope light source 1 enters the phase modulator 3, is divided into 2 beams, and then propagates in the fiber optic ring 4 clockwise and counterclockwise respectively, and a control voltage applied by the driving circuit 10 is applied to one branch of the phase modulator 3. Thus, the clockwise and counterclockwise light beams are converged at the phase modulator 3 after one rotation in the optical fiber ring 4, and the modulated phases of the two beams are temporally different by one transit time(the time it takes for the light to travel one week in the fiber optic ring 4).

Digital signal processing module 8 of optical fiber gyroscope outputs digital quantity，N is the number of bits of the D/a converter in the D/a conversion module 9), an and is generated on one branch of the phase modulator 3 through the D/a conversion module 9 and the driving circuit 10Proportional voltage signalThe voltage signal modulates one branch of the phase modulator 3 to generate an amplitude value in the optical pathThe modulation phase of (2). Modulating phaseAnd the modulation signal digital quantity output by the signal processing module 8In proportion, the design of the amplitude and frequency of the modulated signal can be achieved by software programming within the digital signal processing module 8.

Specifically, the closed-loop control method for the fiber-optic gyroscope provided by the invention comprises the following steps:

step 1, applying a positive and negative alternate square wave modulation signal with the frequency k times of the eigenfrequency in an optical path of the fiber-optic gyroscope, wherein k is an odd number larger than 1.

In specific implementation, a square wave modulation signal of the fiber-optic gyroscope is generated according to requirements, the frequency of the square wave modulation signal is multiple of the eigenfrequency k (k =3,5, …) of a fiber-optic ring, and the amplitude of the square wave modulation signal is multiple of the eigenfrequency k (k =3,5, …)And the duty cycle is 50/50. Under the modulation of the square wave modulation signal with odd times of eigenfrequency, the modulation signal received by the optical path is a series of square wave signals with frequency of k times of the eigenfrequency and alternating positive and negative, and the signal in one modulation period can be modulated and demodulated once and fed back in a closed loop.

The method for generating the square wave modulation signal can be as follows: the digital signal processing module 8 generates a time sequence control signal by counting the clock according to the required frequency, and the digital signal processing module 8 controls the D/A conversion module 9 to output the modulation signal when the time sequence control signal is at high levelWhen the control signal is at low level, the digital signal processing module 8 controls the D/a conversion module 9 to output the modulation signal 0.

Step 2, respectively determining the light intensity of interference signals formed by two paths of light in the phase modulator when the square wave modulation signals are modulated in the positive half period and the negative half periodAndcalculating the demodulated signal as light intensityAnddifference value。

It can be understood that the interference signal is sampled by the digital signal processing module 8 controlling the a/D conversion module 7 to sample the signal converted by the photoelectric conversion component 5.

The square wave modulation signal modulates the positive half cycle (+)) The light intensity of the interference signal formed by the two lights interfering in the phase modulator 3 can be expressed as:

（1）

the light intensity of the interference signal formed by the two paths of light interfering in the phase modulator 3 during the modulation of the negative half cycle by the square wave modulation signal can be expressed as:

（2）

wherein the content of the first and second substances,the light intensity of the clockwise or anticlockwise single-path optical signal;in the light pathsagnac phase shift;the phase shift is closed loop feedback phase shift and is obtained by operation;is the modulation phase.

Then demodulate the signal （3）

Wherein the content of the first and second substances,。

it can be understood that the fiber-optic gyroscope is in a closed loop steady stateDemodulating the signalAt this time, the process of the present invention,the effective part of the signal converted by the photoelectric conversion component 5 is a straight line; when the gyroscope rotates, the bias point shifts,the optical signal received by the detector is a square wave signal with the same frequency as the modulation signal.

In a possible embodiment, the light intensity is determined in step 2Andthe process comprises the following steps: setting an enabling signal to sample and store the interference signal, wherein the square wave modulation signal is in a positive half periodThe time corresponding to a sampling value ofThe sampling value corresponding to the square wave modulation signal during the negative half-cycle modulation is。

Updating sampling value when square wave modulation signal finishes positive half period samplingUpdating sampling value when the square wave modulation signal finishes sampling in negative half period。

Step 3, according to the demodulation signalCorrecting closed loop feedback phase shift(ii) a Phase shift with closed loop feedbackAnd (3) taking the transition time as a period as the height of the step wave, accumulating the step wave to obtain a feedback step wave, and controlling the phase modulator based on the feedback step wave to complete closed-loop control.

In a possible embodiment, step 3 is based on the demodulated signalCorrecting closed loop feedback phase shiftThe formula of (1) is:

（4）

wherein the content of the first and second substances,is a closed loop feedback coefficient.

Calculating the demodulation signal according to the formula (4) to generate the feedback phase shift of the current timeFeedback phase shiftAnd demodulating the signalIs proportional.

In a possible embodiment, the formula for obtaining the feedback step wave by performing step wave accumulation in step 3 is as follows:

（5）

wherein the content of the first and second substances,andthe feedback step wave value is the current time and the feedback step wave value one degree before the current time.

In a possible embodiment, k registers are generated in the digital signal processing module 8 to store the feedback step wave value in a transit time before the current time, and the value stored in the ith register is the feedback step wave，i=1,2,…,k。

After finishing sampling the square wave modulation signal in the positive half period or the feedback phase of the negative half periodAfter the updating operation, the current feedback step wave value is usedSave to the first register=And sequentially sending the feedback step wave stored in the ith registerTo the (i + 1) th register=。

In specific implementation, after sampling of the positive half period of the square wave modulation is completed, the current feedback step wave value is obtainedIs stored toOf the precedingIs transmitted to… are sequentially transmitted and lost earlier in time(ii) a Updating sample values. Or square wave modulated negative half cycle feedback phase shift update operationAfter the calculation is finished, the current feedback step wave value is storedOf the precedingIs transmitted to… are sequentially transmitted and lost earlier in time(ii) a Updating sample values。

The formula for obtaining the feedback step wave by performing step wave accumulation in the step 3 is as follows:

（6）

wherein the content of the first and second substances,the current feedback step wave;and the feedback step wave stored by the kth register is shown, namely the feedback step wave before the current time by one transit time.

In a possible embodiment, the step 3 of controlling the phase modulator based on the feedback step wave includes:

the feedback stepped wave and the square wave modulation signal are added and converted into a control voltage to be applied to the phase modulator 3 by the drive circuit 10.

According to the closed-loop control method of the fiber-optic gyroscope, square waves with odd times of intrinsic frequency are used as modulation signals, the response speed of a carrier to external angular rate input is improved by improving the frequency of modulation and demodulation and closed-loop feedback, the response bandwidth of the fiber-optic gyroscope is effectively improved, and the dynamic performance of the fiber-optic gyroscope is effectively improved by optimizing a software algorithm under the condition that the accuracy is not changed.

Example 1

Embodiment 1 provided in the present invention is an embodiment of a fiber-optic gyroscope closed-loop control method provided in the present invention, and this embodiment takes a square wave modulation signal with an eigenfrequency of a fiber-optic ring 3 times (k = 3) as an example to explain a signal demodulation principle of the present invention, as shown in fig. 3 and fig. 4, which are a schematic diagram of a square wave modulation signal with an eigenfrequency of 3 times and a schematic diagram of a square wave modulation process with an eigenfrequency of 3 times provided in the embodiment of the present invention, respectively, fig. 5 is a schematic diagram of a stepped wave curve for modulating a square wave with an eigenfrequency of 3 times provided in the embodiment of the present invention, and fig. 6 is a timing diagram for modulating and demodulating a square wave with an eigenfrequency of odd number times provided in the embodiment of the present invention.

The embodiment comprises the following steps:

step 1, applying a positive and negative alternate square wave modulation signal with the frequency k times of the eigenfrequency in an optical path of the fiber-optic gyroscope, wherein k is an odd number larger than 1.

The amplitude value generated in the digital signal processing module 8 isWith a period ofA square wave signal with a duty ratio of 50/50, which is applied to the phase modulator 3 via the D/a conversion module 9 and the driving circuit 10, so that a branch optical path generates a square wave signal with a phase amplitude of 50/50With a period ofA square wave signal with a duty cycle of 50/50. As the clockwise and anticlockwise light are converged at the phase modulator 3 after propagating for one circle in the optical fiber ring 4, the modulation phases of the clockwise and anticlockwise light are different by one transit time in timeWorkshopThe modulation phase received by the interference signal sensitive to the fiber-optic gyroscope is actually equal to the difference between the modulation phase at the current moment and the modulation phase at the last transit time, and the modulation signal actually received by the optical path has a phase amplitude of +/-With a period ofA square wave signal with a duty cycle of 50/50.

The method for generating the square wave modulation signal can be as follows: the digital signal processing module 8 generates a time sequence control signal by counting the clock according to the required frequency, and the digital signal processing module 8 controls the D/A conversion module 9 to output the modulation signal when the time sequence control signal is at high levelWhen the control signal is at low level, the digital signal processing module 8 controls the D/a conversion module 9 to output the modulation signal 0. Fig. 6 a is a waveform diagram of the timing control signal in the case of 3-fold eigenfrequency modulation.

Step 2, respectively determining the light intensity of interference signals formed by two paths of light in the phase modulator when the square wave modulation signals are modulated in the positive half period and the negative half periodAndcalculating the demodulated signal as light intensityAnddifference value。

In fig. 6, b is a waveform diagram of an enable signal (high effective) during 3-times eigenfrequency modulation, when the enable signal is effective, the a/D conversion module 7 is controlled to sample and store the interference signal under the driving of the sampling clock, and c in fig. 6 is a control timing (high effective) of the demodulation signal during 3-times eigenfrequency modulation. In FIG. 6, the sampling value corresponding to the timing control signal a at a high level is recorded as(described by equation (1)), the sampling value corresponding to the timing control signal a at a low level is recorded as(described in equation (2)), the other odd multiples of the eigenfrequency modulation (k is an odd number greater than 1, and k ≠ 3) is the same as the 3-fold eigenfrequency modulation, i.e. the demodulation process is performed once per square wave period.

Step 3, according to the demodulation signalCorrecting closed loop feedback phase shift(ii) a Phase shift with closed loop feedbackAnd (3) taking the transition time as a period as the height of the step wave, accumulating the step wave to obtain a feedback step wave, and controlling the phase modulator based on the feedback step wave to complete closed-loop control.

In one possible embodiment, step 3 uses equation (4) to demodulate the signalCorrecting closed loop feedback phase shift。

In fig. 6, d is the control timing (high efficiency) of the feedback phase shift update operation during 3 times of eigenfrequency modulation, and other odd-number times eigenfrequency modulation (k is an odd number greater than 1, and k ≠ 3) is the same as the 3 times eigenfrequency modulation, i.e. the feedback phase shift is updated with the demodulation signal after each signal demodulation is completed.

In one possible embodiment, step 3 comprises:

k registers are generated in the digital signal processing module 8 to store the feedback step wave value in a transition time before the current time, and the value stored in the ith register is the feedback step wave，i=1,2,…,k。

After finishing the feedback phase shift updating operation of the square wave modulation signal in the positive half period sampling or the negative half period, the current feedback step wave value is usedSave to the first register=And sequentially sending the feedback step wave stored in the ith registerTo the (i + 1) th register=。

In specific implementation, after sampling of the positive half period of the square wave modulation is completed, the current feedback step wave value is obtainedIs stored toOf the precedingIs transmitted to… are sequentially transmitted and lost earlier in time(ii) a Updating sample values. Or after the feedback phase shift updating operation of the square wave modulation negative half period is finished, saving the current feedback step wave valueOf the precedingIs transmitted to… are sequentially transmitted and lost earlier in time(ii) a Updating sample values。

In fig. 6, e is a step waveform dynamic storage control timing (high activity) at the time of 3-fold eigenfrequency modulation, dynamic storage of a step waveform signal is performed at the time of high level of the signal, and other odd-fold eigenfrequency modulation (k is an odd number larger than 1, and k ≠ 3) is basically the same as the 3-fold eigenfrequency modulation, and only the number of registers to be generated is different. FIG. 7 is a diagram of a time prior to a current time provided by the present inventionFeedback step wave value in one transit timeSchematic diagram of the updating process.

The update value of the feedback step wave is calculated by equation (6).

In a possible embodiment, the step 3 of controlling the phase modulator based on the feedback step wave includes:

the feedback stepped wave and the square wave modulation signal are added and converted into a control voltage to be applied to the phase modulator 3 by the drive circuit 10.

The modulation and demodulation principle of other odd times of eigenfrequency square wave modulation is basically the same as that described above, and the modulation and demodulation frequencies and the number of the stored step wave signals in the previous degree crossing time are different.

The present invention is also applicable to a scheme of four-state square wave modulation, and as shown in fig. 8, is a schematic diagram of a four-state wave modulation process provided by the embodiment of the present invention, the modulation frequency can also be raised to be an odd multiple of the eigenfrequency, the demodulation formula is the same as the scheme of the eigenfrequency four-state square wave, and the implementation manner is the same as the scheme of the odd multiple of the eigenfrequency square wave modulation.

Example 2

Embodiment 2 provided in the present invention is an embodiment of a fiber optic gyroscope closed-loop control system provided in the present invention, where the fiber optic gyroscope includes: digital signal processing module, photoelectric conversion subassembly and phase modulator.

And the digital signal processing module applies positive and negative alternate square wave modulation signals with the frequency k times of the eigenfrequency in the optical path of the fiber-optic gyroscope, wherein k is an odd number larger than 1.

The digital signal processing module samples the signal converted by the photoelectric conversion component and respectively determines the light intensity of an interference signal formed by two paths of light in the phase modulator when the square wave modulation signal is modulated in a positive half period and a negative half periodAndcalculating a demodulated signal as said light intensityAnddifference value。

The digital signal processing module demodulates the signal according to the demodulation signalCorrecting closed loop feedback phase shift(ii) a Phase shifting with said closed loop feedbackAnd taking one transit time as a period for the height of the step wave, accumulating the step wave to obtain a feedback step wave, and controlling the phase modulator based on the feedback step wave to complete closed-loop control.

It can be understood that the fiber-optic gyroscope closed-loop control system provided by the present invention corresponds to the fiber-optic gyroscope closed-loop control methods provided in the foregoing embodiments, and the related technical features of the fiber-optic gyroscope closed-loop control system may refer to the related technical features of the fiber-optic gyroscope closed-loop control method, and are not described herein again.

Referring to fig. 9, fig. 9 is a schematic view of an embodiment of an electronic device according to an embodiment of the invention. As shown in fig. 9, an embodiment of the present invention provides an electronic device, which includes a memory 1310, a processor 1320, and a computer program 1311 stored in the memory 1320 and executable on the processor 1320, where the processor 1320 executes the computer program 1311 to implement the following steps: applying positive and negative alternate square wave modulation with the frequency k times of the eigenfrequency in the optical path of the fiber-optic gyroscopeSignal, k is an odd number greater than 1; when the square wave modulation signal is modulated in the positive half period and the negative half period, the light intensity of an interference signal formed by two paths of light in the phase modulator is respectively determinedAndcalculating a demodulated signal as said light intensityAnddifference value(ii) a According to the demodulation signalCorrecting closed loop feedback phase shift(ii) a Phase shifting with said closed loop feedbackAnd taking one transit time as a period for the height of the step wave, accumulating the step wave to obtain a feedback step wave, and controlling the phase modulator based on the feedback step wave to complete closed-loop control.

Referring to fig. 10, fig. 10 is a schematic diagram of an embodiment of a computer-readable storage medium according to the present invention. As shown in fig. 10, the present embodiment provides a computer-readable storage medium 1400, on which a computer program 1411 is stored, which computer program 1411, when executed by a processor, implements the steps of: applying a positive and negative alternative square wave modulation signal with the frequency k times of the eigenfrequency in the optical path of the fiber-optic gyroscope, wherein k is an odd number larger than 1; respectively determining the positive half cycle and the negative half cycle of the square wave modulation signalThe light intensity of interference signal formed by two paths of light in the phase modulator during phase modulationAndcalculating a demodulated signal as said light intensityAnddifference value(ii) a According to the demodulation signalCorrecting closed loop feedback phase shift(ii) a Phase shifting with said closed loop feedbackAnd taking one transit time as a period for the height of the step wave, accumulating the step wave to obtain a feedback step wave, and controlling the phase modulator based on the feedback step wave to complete closed-loop control.

According to the fiber optic gyroscope closed-loop control method, the system and the storage medium provided by the embodiment of the invention, on the basis of not changing hardware, the dynamic performance of the fiber optic gyroscope is effectively improved through the optimization of a software algorithm; the problem of bandwidth reduction of the high-precision fiber-optic gyroscope caused by the increase of the length of the fiber-optic ring is effectively solved; through the design of the modulation frequency, the phenomenon of cross-stripe of the fiber-optic gyroscope under the large-scale transient impact can be effectively inhibited.

It should be noted that, in the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to relevant descriptions of other embodiments for parts that are not described in detail in a certain embodiment.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded computer, 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, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.