CN113252021A - High-coverage-rate pre-flight self-inspection method and system for fiber-optic gyroscope - Google Patents
High-coverage-rate pre-flight self-inspection method and system for fiber-optic gyroscope Download PDFInfo
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- CN113252021A CN113252021A CN202110755295.3A CN202110755295A CN113252021A CN 113252021 A CN113252021 A CN 113252021A CN 202110755295 A CN202110755295 A CN 202110755295A CN 113252021 A CN113252021 A CN 113252021A
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- G01C19/00—Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects
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Abstract
The invention belongs to a self-checking method and a self-checking system of a fiber-optic gyroscope, and aims to solve the technical problems that the coverage rate of the existing self-checking method of the closed-loop fiber-optic gyroscope is low and only partial self-checking can be carried out on functional faults of the existing self-checking method of the closed-loop fiber-optic gyroscope; the light intensity values of the non-modulation state and the modulation state are detected in the closed loop state, and difference value operation is performed after the noise is removed, so that the light path self-detection is realized. Through the self-checking of the fiber-optic gyroscope, the fault state of the sensor can be accurately judged before flying, the probability of the fault of the air system is reduced to the greatest extent, and the flying safety is ensured.
Description
Technical Field
The invention belongs to a self-checking method and a self-checking system of a fiber-optic gyroscope, and particularly relates to a high-coverage-rate pre-flight self-checking method and a high-coverage-rate pre-flight self-checking system of a fiber-optic gyroscope.
Background
The fiber optic gyroscope is used as a core angular rate sensor in a flight control system, and very high requirements are provided for the self-checking capability before flight. The closed-loop optical fiber gyroscope is used as a new-generation optical inertial instrument and widely applied to flight control systems of moving bodies such as airplanes, ships, rockets, satellites and missiles. However, the existing closed-loop fiber-optic gyroscope self-detection method has low coverage rate, and can only carry out partial self-detection on the functional fault.
Disclosure of Invention
The invention mainly aims to solve the technical problems that the coverage rate of the existing closed-loop fiber-optic gyroscope self-detection method is low and only partial self-detection can be carried out on functional faults of the closed-loop fiber-optic gyroscope self-detection method, and provides a high-coverage-rate pre-flight self-detection method and a self-detection system for a fiber-optic gyroscope.
In order to achieve the purpose, the invention provides the following technical scheme:
a self-checking method before flight of a high-coverage rate fiber-optic gyroscope is characterized by comprising the following steps:
s1, closed loop light path self-checking
Acquiring a detector output light intensity value at a non-modulation moment in a closed loop state, comparing the difference value of the filtered detector output light intensity value with the detector output light intensity value at a modulation moment, and outputting a closed loop light path working normal signal to a flight control computer if the difference value is smaller than a preset light intensity threshold value; otherwise, outputting a closed-loop light path fault signal to the flight control computer;
s2, self-checking of angular rate tracking precision
S2.1, calibrating the closed-loop fiber optic gyroscope by using a turntable, and locking feedback digital quantities corresponding to different angular rates in an internal register of a gyroscope FPGA to serve as angular rate tracking precision self-detection excitation signals in the calibration process;
s2.2, performing analog-to-digital conversion on the angular rate tracking precision self-detection excitation signal, and superposing a controllable digital step wave on a phase modulator to perform electro-optic modulation to obtain phase difference interference light intensity of two light waves of the closed-loop fiber optic gyroscope corresponding to an excitation value after the analog-to-digital conversion;
s2.3, resolving according to the phase difference interference light intensity obtained in the step S2.2 to obtain an equivalent angular rate, and combining the angular rate tracking precision self-detection excitation signal in the step S2.1 to realize angular rate tracking precision self-detection;
s3, self-checking of analog output precision
Performing analog-to-digital conversion on the closed-loop optical fiber gyroscope angular rate analog output, performing digital low-pass filtering, comparing the difference with a standard analog output sampling digital quantity, and outputting a signal meeting the output precision self-checking requirement to a flight control computer if the difference is smaller than a preset output precision threshold; otherwise, outputting a precision fault signal to the flight control computer.
Further, step S1 is preceded by:
step S0, sending a ground self-detection instruction to the closed-loop fiber-optic gyroscope through the flight control computer; converting the ground self-detection instruction into two self-detection signals for the FPGA to identify, and executing the step S1 when the two self-detection signals are effective simultaneously; and if not, continuing to wait for receiving the ground self-detection instruction.
Further, in step S0, when the two self-test signals are simultaneously valid, specifically, when the two self-test signals are simultaneously valid and the duration is greater than 10 ms.
Further, the step S2.3 specifically includes:
s2.3.1, resolving according to the phase difference interference light intensity obtained in the step S2.2 to obtain an equivalent angular rate;
s2.3.2, acquiring the equivalent angular rate obtained in the step S2.3.1, performing smooth filtering processing, comparing the difference with the angular rate tracking precision self-detection excitation signal recorded in the step S2.1, and if the difference is smaller than a preset angular rate threshold, outputting a signal meeting the angular rate self-detection requirement to a flight control computer; otherwise, outputting an angular rate fault signal to the flight control computer.
Further, step S4 is included, where the power supply self-test:
after the closed-loop fiber optic gyroscope is powered on, acquiring a voltage value of a power supply to be monitored through an A/D (analog-to-digital) converter, converting the voltage value into a corresponding voltage digital quantity and supplying the voltage digital quantity to the FPGA, comparing the difference value of the converted voltage digital quantity with a corresponding voltage theoretical value through the FPGA, and outputting a power supply normal signal to a flight control computer if all the converted voltage digital quantity meets a preset voltage value; otherwise, outputting a power failure signal to the flight control computer.
Further, in step S2.1, the feedback digital quantity corresponding to the rotation speed is locked in the gyro FPGA internal register, specifically, the feedback digital quantity corresponding to the rotation speed is subjected to smoothing filtering processing and then locked in the gyro FPGA internal register.
Further, in step S2.1, the calibrating of the closed-loop fiber optic gyroscope by using the turntable specifically includes:
s2.1.1, mounting the closed loop fiber-optic gyroscope on a turntable, and enabling an input shaft corresponding to an excitation value to be calibrated of the closed loop fiber-optic gyroscope to be parallel to a rotary shaft of the turntable;
s2.1.2, rotating the turntable at least at the forward rotation maximum angular rate, the forward rotation 50% maximum angular rate, the reverse rotation 50% maximum angular rate, the zero angular rate point start, and the zero angular rate point end respectively.
Further, in step S1, the acquiring the output light intensity value of the detector at the non-modulation time in the closed loop state specifically includes:
and acquiring a detector signal at a non-modulation moment in a closed-loop state, amplifying and then carrying out digital quantitative coding, and carrying out smooth filtering after a difference is made between a light intensity value at the non-modulation state and a light intensity value at the modulation moment in an eigenperiod of the closed-loop fiber optic gyroscope to obtain an output light intensity value of the detector.
In addition, the invention also provides a high-coverage-rate fiber-optic gyroscope pre-flight self-inspection system which is characterized by comprising an angular rate tracking precision self-inspection module, a closed-loop light path self-inspection module and an analog output precision self-inspection module;
the closed loop light path self-checking module is used for acquiring the detector output light intensity value at the non-modulation moment in the closed loop state, comparing the difference value of the filtered detector output light intensity value with the detector output light intensity value at the modulation moment, and outputting a closed loop light path working normal signal to the flight control computer if the difference value is smaller than a preset light intensity threshold value; otherwise, outputting a closed-loop light path fault signal to the flight control computer;
the angular rate tracking precision self-checking module is used for locking feedback digital quantities corresponding to different angular rates in a gyro FPGA (field programmable gate array) internal register when the rotary table is used for calibrating the closed-loop fiber optic gyro, performing analog-to-digital conversion, then superimposing controllable digital step waves on the phase modulator to perform electro-optic modulation to obtain phase difference interference light intensity of two light waves of the closed-loop fiber optic gyro corresponding to an excitation value after the analog-to-digital conversion, resolving to obtain an equivalent angular rate, and then performing self-checking on the angular rate tracking precision by combining the feedback digital quantities corresponding to the different angular rates;
the analog output precision self-checking module is used for performing analog-to-digital conversion on the closed-loop optical fiber gyroscope angular rate analog output, then performing digital low-pass filtering, then performing difference comparison on the digital value and a standard analog output sampling digital value, and if the digital value is smaller than a preset output precision threshold value, outputting a signal which meets the output precision self-checking requirement to the flight control computer; otherwise, outputting an output precision fault signal to the flight control computer.
Further, the device also comprises a power supply self-checking module;
the power supply self-checking module is used for acquiring the voltage value of a power supply to be monitored through the A/D (analog-to-digital) converter after the closed-loop fiber-optic gyroscope is powered on, converting the voltage value into corresponding voltage digital quantity and supplying the voltage digital quantity to the FPGA (field programmable gate array), comparing the difference value of the converted voltage digital quantity with the corresponding voltage theoretical value through the FPGA, and outputting a power supply normal signal to the flight control computer if all the voltage values meet a preset voltage value; otherwise, outputting a power failure signal to the flight control computer.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention provides a high-coverage-rate pre-flight self-detection method for a closed-loop fiber-optic gyroscope, which can accurately judge the functional and performance fault state of the fiber-optic gyroscope before flight by a high-coverage-rate self-detection means, reduce the probability of carrier air system faults to the maximum extent, avoid attitude out of control and ensure that a carrier executes safe and reliable flight tasks.
2. The invention also carries out the validity detection of the self-checking instruction before the self-checking of the angular rate tracking precision, thereby further enhancing the validity and the controllability of the self-checking.
3. The self-detection method also comprises power supply self-detection, and can detect the working state of the power supply in real time after the closed-loop fiber-optic gyroscope is powered on, so that the voltage stability of the closed-loop fiber-optic gyroscope in the working process is ensured.
4. In the invention, smooth filtering processing is firstly carried out on feedback digital quantity in the gyro FPGA internal register, so that the data accuracy is higher.
5. According to the method, the angular rate tracking precision self-check is started when the two self-check signals are simultaneously carried out and the duration time is longer than 10ms, so that the error starting of a self-check program is avoided.
6. The self-checking system comprises an angular rate tracking precision self-checking module, a closed-loop light path self-checking module and an analog output precision self-checking module, wherein the fiber optic gyroscope is accurately calibrated in a closed-loop feedback digital quantity, and a calibrated self-checking excitation signal digital quantity is locked in a register of an FPGA self-checking module in the fiber optic gyroscope and is used for simulating the angular rate of a carrier during actual flight in the self-checking process so as to realize the full-range angular rate tracking precision self-checking; detecting the light intensity values of a non-modulation state and a modulation state in a closed loop state, performing noise removal on the light intensity values, performing difference value operation, and judging whether the light intensity values are in a required range to realize light path self-detection; designing an analog output precision self-detection module to complete analog output precision self-detection; whether the full-range internal angular rate tracking precision, the optical path performance and the angular rate output analog quantity precision of the fiber-optic gyroscope meet the use requirements or not is determined, the self-detection coverage rate of the closed-loop fiber-optic gyroscope is greatly improved, the fault state of the sensor can be accurately judged before flying through the self-detection of the fiber-optic gyroscope, the probability of faults of an air system is reduced to the maximum extent, and the flying safety is ensured.
7. The power supply self-checking module can complete the detection of the power supply state of the sensor, and further ensures the safety detection of the flight.
Drawings
FIG. 1 is a diagram of a standard mathematical model of a fiber optic gyroscope according to an embodiment of the present invention;
fig. 2 is a mathematical model diagram of the fiber-optic gyroscope with external excitation added in the embodiment of the invention.
Detailed Description
The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention and the accompanying drawings, and it is obvious that the described embodiments do not limit the present invention.
The invention provides a high-coverage self-checking method of a fiber-optic gyroscope before flight, which can accurately judge the fault state of the function and the performance of the fiber-optic gyroscope before flight by a high-coverage self-checking means, reduce the probability of the fault of a carrier aerial system to the maximum extent, avoid the out-of-control attitude and ensure that the carrier executes a safe and reliable flight task. The self-detection of all functions and performances of the optical path and the circuit of the optical fiber gyroscope is realized, a quantitative test result is given, and the self-detection capability of the closed-loop optical fiber gyroscope is greatly improved.
The self-checking method of the invention is summarized as follows: when a self-checking instruction is received, the self-checking work can be completed within T time, the T time can be set, and the self-checking method covers the functions, performance detection and working state detection of the fiber-optic gyroscope. After the self-checking before flying begins, firstly, the optical path function and the performance self-checking are carried out, comb waves in T time are sampled through a 12-bit AD digital-to-analog converter, the sampled values are filtered smoothly in the T time, the calculation result is compared with a preset value, the optical path state is good within a preset threshold value, and the performance meets the requirement. After the optical path self-checking is finished, if the optical path is normal, a dynamic performance self-checking mark of the optical fiber gyroscope is generated inside the optical path to perform dynamic performance self-checking, a fixed step quantity (a preset angular rate test set value) is generated by the FPGA self-checking module and is superposed on a modulation wave, a fixed phase shift is added, and at the moment, the optical fiber gyroscope outputs a corresponding angular rate. After the self-checking work of the optical fiber gyroscope is finished, the optical fiber gyroscope enters a working state, the working state is detected in a whole-course state, and a main monitoring object comprises: and power supply +/-15V, +/-5V and 1.5V power supply detection (PS _ TEST) and analog output precision detection (DA _ WA) are carried out, fault logic judgment is realized by the FPGA, and corresponding working states are output.
The self-checking method of the invention is specifically implemented as follows:
and (3) detecting the validity of the self-checking instruction, converting the ground self-checking instruction into two self-checking signals (DS _ P, DS _ N) which can be identified by the FPGA through a self-checking signal conversion circuit when the optical fiber gyro group receives the ground self-checking instruction sent by the flight control computer, judging through the logic of judging the mutual difference, when the self-checking signal DS _ P and the self-checking signal DS _ N are simultaneously effective and the duration is more than 10ms, the self-checking signal is effective, starting the self-checking by the optical fiber gyro to perform the step S2, and otherwise, cutting off the self-checking.
When the optical fiber gyroscope is started to perform self-checking through screwing, the self-checking includes angular rate tracking precision self-checking, closed loop light path self-checking, analog output precision self-checking and power supply working state monitoring.
When the optical fiber gyroscope receives a starting self-checking instruction, the closed loop light path self-checking module works to acquire the output light intensity value of the detector at the non-modulation moment in the closed loop state, the output light intensity value is subjected to filtering removal processing and then is compared with the output light intensity value of the detector at the modulation moment, the difference value is judged, if the difference value is smaller than a preset light intensity threshold value, a light path normal state word is output to the flight control computer, and otherwise, a light path fault state word is output. In order to ensure the detection accuracy of the closed loop light path, the fiber-optic gyroscope is in a closed loop state at the moment, a detector signal is amplified and then enters an ADC (analog-to-digital converter) for digital quantity quantization coding, a binary difference value calculation method is adopted for the calculation of the detected light intensity, and one eigenperiod of the fiber-optic gyroscope is
Using intensity values in the non-modulated state
（
Time period) and the light intensity value at the moment of modulation
（
Time period) is subtracted and then smoothed, and the average value of the detected light intensity is expressed as
。
Wherein, the setting basis of the preset light intensity threshold is as follows: the function and the performance of a light path are detected by monitoring comb waves output by a detector, an acquisition circuit is built by using an ADC (analog to digital converter), comb wave signals output by the detector are acquired, and an eigenperiod is acquired according to the closed-loop demodulation principle of the fiber-optic gyroscope and the characteristics of signals output by the detector
And carrying out difference operation after smoothing filtering on the internal modulation state output voltage and the non-modulation state output voltage. When the modulation signal is +/-
When the voltage is/2, the theoretical difference between the modulation state and the non-modulation state is half of the total light-passing bias voltage of the gyroscope group, and is recorded as
. In engineering application, by combining sampling error, noise interference and photoelectric signal conversion error, 50% of sampling error, noise interference and photoelectric signal conversion error are selected
The judgment value of the comb-shaped wave spines is output as a detector. When more than 50 percent
In time, the function and performance of the optical path of the gyroscope group are normal; when the content is less than 50 percent
But more than 10%
When the performance of the optical path of the gyroscope group is reduced, the performance is reduced to less than 10 percent
Time, gyroscope group light pathAnd (4) failure.
The self-checking method of the closed loop light path is based on the following principle: when the optical fiber gyroscope works, the output signal of the detector is in a comb wave state, when a fault exists in a light path or a circuit, the modulation square wave is distorted or does not exist, the light wave cannot be modulated, and the peak amplitude of the comb wave output by the detector is reduced or disappears; when the light source of the light path is in failure or the light path loss is increased to cause the light power to be reduced or disappear, the peak amplitude of the comb wave output by the detector is reduced or disappears; when the prior amplifier circuit or the A/D conversion fails, the comb wave amplitude value received by the FPGA is reduced or cannot be received. And judging whether the amplitude of the spike pulse signal is in a specified range in the FPGA, and qualitatively judging the state of the fiber-optic gyroscope.
Self-checking of angular rate tracking precision: before the carrier flies, the optical fiber gyro is powered on and started, when the optical fiber gyro is effectively connected with a self-detection signal, self-detection is started, the FPGA self-detection module generates a fixed step quantity (a preset angular rate excitation signal) to be superposed on a modulation wave, a fixed phase shift ϕ z is added, the optical fiber gyro outputs a corresponding angular rate, an error value is calculated, and whether the output error meets the performance requirement or not is detected.
Firstly, a preset standard excitation value used for angular rate tracking precision self-checking is required to be obtained, the fiber-optic gyroscope is precisely calibrated by using a rotary table, the fiber-optic gyroscope is installed on the rotary table, an input shaft corresponding to the excitation value to be calibrated is parallel to a rotary shaft of the rotary table, the error does not exceed a specified value, the fiber-optic gyroscope is connected with output measuring equipment, under the condition that the rotary table rotates according to a preset rotating speed point, corresponding fiber-optic gyroscope closed-loop feedback digital quantity within T time (T is not less than 10 s) of each rotating speed point is recorded and is subjected to smooth filtering to obtain Dn which is a standard preset excitation value, the corresponding angular rate during equivalent actual work is input, after an accurate preset angular rate test set value Dn is determined, the input angular rate is injected into a register of a fiber-optic gyroscope self-checking module and is used for a dynamic excitation signal before flight, and in the calibration process of the preset standard excitation value, the input angular rate point of the rotary table is selected from forward rotation, Within the range of the input angular rate of the reverse direction, respectively, not less than 6 points, including a maximum input angular rate ±)
50% rate point
Zero angular rate point
. Recording the average value of gyroscope output in unit time under input of different angular rates in a full range, performing smooth filtering processing on the feedback digital quantity of the closed-loop fiber-optic gyroscope in corresponding rotating speed, latching the average value in a register in an FPGA of the gyroscope, taking the average value as an angular rate tracking precision self-detection excitation signal, performing analog-to-digital conversion on the feedback digital quantity, superposing a controllable digital step wave on a phase modulator for electro-optical modulation, quantitatively outputting the phase difference interference light intensity of two light waves of the fiber-optic gyroscope corresponding to the excitation value to be equivalent to the external input angular rate, acquiring the smooth filtering of the angular rate output value of the fiber-optic gyroscope in unit time, calculating the angular rate tracking ratio difference precision of the output value of the fiber-optic gyroscope with a standard output value in calibration, outputting a tracking normal state word to a flight control computer if the output value is less than a preset angular rate threshold value and meets the precision, otherwise outputting a tracking fault state word, therefore, the gyroscope angular rate tracking function and performance detection in the full range can be accurately simulated when the optical fiber gyroscope is in a working state. For example, 6 points in the output dynamic range of the fiber-optic gyroscope are respectively set on the turntable and respectively correspond to W1, W2, W3, … and W6, internal closed-loop digital quantities of the fiber-optic gyroscope are stored, a discrete quantity digital model is established through an FPGA inside the fiber-optic gyroscope, a calibrated closed-loop digital quantity is pre-stored, the fiber-optic gyroscope is respectively corresponding to the output of the 6 points actually output by the sensor through the FPGA, the error meets the precision requirement, at the moment, a standard digital excitation model is determined, the corresponding angular rate input during actual work is simulated, and the accurate preset angular rate test set value is determined.
The preset angular rate threshold value is obtained by comparing the obtained equivalent angular rate digital quantity with an angular rate tracking precision self-detection excitation signal, taking the relative error between the two as a preset value, and generally setting the preset error value to 10% according to engineering experience and the service condition of the fiber optic gyroscope.
The principle of the angular rate tracking accuracy self-check is as follows:
the standard mathematical model of the fiber-optic gyroscope is shown in fig. 1 according to the closed-loop fiber-optic gyroscope principle, where K is shown in fig. 1sProportional coefficient, K, for the Sagnac effectpdIs the proportionality coefficient of the photodetector, K1Is the amplification factor of the front-end amplifier, KADIs the analog-to-digital conversion coefficient of the A/D converter, K2Being the cumulative multiple of digital cumulative filtering, KrThe demodulation coefficient for the rotation speed can be approximated to 1, and the angular rate integrator and the step integrator as the accumulator of the discrete signal can be equivalent to 1/(1-z)-1)，KG1Digital gain 1, K due to variation of the number of bitsMSince the feedback phase is the step height of the step wave, the Y waveguide phase modulator can be expressed as (1-z) as a modulation factor of the Y waveguide phase modulator-1). In FIG. 1, the conversion factor of the first D/A converter is set via a second closed loop, where KDA1For the conversion coefficient of the first path D/A converter, the phase modulation error integrator is an accumulator, which can be equivalent to 1/(1-z)-1)。
As can be seen from fig. 1:
thus, the transfer function of the fiber optic gyroscope system shown in fig. 1 is:
wherein the content of the first and second substances,K A=K pd K 1 K AD K 2，K B=K M K DA1 K G1。
according to the working principle of the fiber-optic gyroscope, the external rotating speed can cause the phase difference of two beams of polarized light, and the Y waveguide phase modulator can also generate the phase difference of the two beams of polarized light through an electric field, so that the Y waveguide phase modulator can be used for generating phase modulation excitation and simulating the phase difference generated by the external rotating speed, thereby realizing the closed-loop self-detection of the fiber-optic gyroscope, and a mathematical model added with the external excitation is shown in figure 2. In fig. 2, p (z) is a software generated phase modulated excitation.
As can be seen by comparison, the phase modulation excitation generated by the Y waveguide has opposite sign with the phase difference generated by the rotating speed, and only exists in the proportional relation-K S/K BTherefore, the closed-loop self-detection of the fiber-optic gyroscope can be realized by adding phase modulation excitation to the Y waveguide.
And when the optical fiber gyroscope receives a starting self-checking instruction, starting analog output precision self-checking, performing analog-to-digital conversion on the angular rate analog output of the optical fiber gyroscope, performing digital low-pass filtering, comparing and judging with a standard analog output sampling digital quantity, if the angular rate analog output is smaller than a preset output precision threshold value, and meeting the requirement, outputting an analog output wrap-around normal state word to a flight control computer, otherwise, outputting an analog output wrap-around fault state word. The output precision threshold value is obtained by comparing actual angular rate output data with standard analog sampling digital quantity (calculating relative error), combining actual use conditions of the fiber-optic gyroscope and sampling errors brought by analog acquisition, generally setting the relative error between the actual angular rate output data and the standard analog sampling digital quantity to be 5% -20%, setting the specific setting value to be dependent on the accuracy requirement of the gyroscope and the error size of digital-analog acquisition, setting the error to be 5% for the high-accuracy fiber-optic gyroscope, selecting high-accuracy analog acquisition, and setting the error to be 20% for the low-accuracy fiber-optic gyroscope.
And when the optical fiber gyroscope receives a starting self-checking instruction, power supply self-checking can be carried out at the same time, and corresponding power supply state discrete quantities are output to the flight control computer through the power supply monitoring circuit. Comparing the acquired and converted voltage digital quantity with a corresponding voltage theoretical value, and outputting a power supply normal signal to a flight control computer if all the acquired and converted voltage digital quantity meets a preset voltage value; otherwise, outputting a power failure signal to the flight control computer. The preset voltage value can be compared according to the relative error of the preset voltage value and is set to be 20%, the error value is consistent with the requirement of the fiber-optic gyroscope on the power supply voltage, and the fiber-optic gyroscope can normally work within the error range.
In the self-checking method, in order to improve the coverage rate of monitoring the working state, the DA of an output channel is subjected to wrap-around test, a working power supply is monitored, and fault logic comprehensively outputs monitoring information in an FPGA.
Based on the self-detection method, the invention also provides a self-detection system for executing the self-detection method, which comprises an angular rate tracking precision self-detection module, a closed loop light path self-detection module, an analog output precision self-detection module and a power supply self-detection module. The closed loop light path self-checking module is used for acquiring the output light intensity value of the detector at the non-modulation moment in the closed loop state, comparing the filtered output light intensity value with the output light intensity value of the detector at the modulation moment, and outputting a working normal signal of the closed loop light path to the flight control computer if the filtered output light intensity value is smaller than a preset light intensity threshold; otherwise, outputting a closed loop light path fault signal to the flight control computer. The angular rate tracking precision self-checking module is used for locking feedback digital quantities corresponding to different angular rates in a gyro FPGA (field programmable gate array) internal register when the rotary table is used for calibrating the closed-loop fiber optic gyro, performing analog-to-digital conversion, then superimposing controllable digital step waves on the phase modulator to perform electro-optical modulation to obtain phase difference interference light intensity of two light waves of the closed-loop fiber optic gyro corresponding to an excitation value after the analog-to-digital conversion, resolving to obtain an equivalent angular rate, and then performing self-checking on the angular rate tracking precision by combining the feedback digital quantities corresponding to the different angular rates. The analog output precision self-checking module is used for performing analog-to-digital conversion on the angular rate analog output of the closed-loop optical fiber gyroscope, then performing digital low-pass filtering, comparing the digital value with a standard analog output sampling digital value, and outputting a signal meeting the output precision self-checking requirement to the flight control computer if the digital value is smaller than a preset output precision threshold value; otherwise, outputting an output precision fault signal to the flight control computer. The power supply self-checking module is used for acquiring the voltage value of a power supply to be monitored through the A/D (analog-to-digital) converter after the closed-loop fiber-optic gyroscope is powered on, converting the voltage value into corresponding voltage digital quantity and supplying the voltage digital quantity to the FPGA (field programmable gate array), comparing the difference value of the converted voltage digital quantity with the corresponding voltage theoretical value through the FPGA, and outputting a power supply normal signal to the flight control computer if all the voltage values meet the preset voltage value; otherwise, outputting a power failure signal to the flight control computer.
The above description is only an embodiment of the present invention, and is not intended to limit the scope of the present invention, and all equivalent structural changes made by using the contents of the present specification and the drawings, or applied directly or indirectly to other related technical fields, are included in the scope of the present invention.
Claims (10)
1. A self-checking method before flight of a high-coverage rate fiber-optic gyroscope is characterized by comprising the following steps:
s1, closed loop light path self-checking
Acquiring a detector output light intensity value at a non-modulation moment in a closed loop state, comparing the difference value of the filtered detector output light intensity value with the detector output light intensity value at a modulation moment, and outputting a closed loop light path working normal signal to a flight control computer if the difference value is smaller than a preset light intensity threshold value; otherwise, outputting a closed-loop light path fault signal to the flight control computer;
s2, self-checking of angular rate tracking precision
S2.1, calibrating the closed-loop fiber optic gyroscope by using a turntable, and locking feedback digital quantities corresponding to different angular rates in an internal register of a gyroscope FPGA to serve as angular rate tracking precision self-detection excitation signals in the calibration process;
s2.2, performing analog-to-digital conversion on the angular rate tracking precision self-detection excitation signal, and superposing a controllable digital step wave on a phase modulator to perform electro-optic modulation to obtain phase difference interference light intensity of two light waves of the closed-loop fiber optic gyroscope corresponding to an excitation value after the analog-to-digital conversion;
s2.3, resolving according to the phase difference interference light intensity obtained in the step S2.2 to obtain an equivalent angular rate, and combining the angular rate tracking precision self-detection excitation signal in the step S2.1 to realize angular rate tracking precision self-detection;
s3, self-checking of analog output precision
Performing analog-to-digital conversion on the closed-loop optical fiber gyroscope angular rate analog output, performing digital low-pass filtering, comparing the difference with a standard analog output sampling digital quantity, and outputting a signal meeting the output precision self-checking requirement to a flight control computer if the difference is smaller than a preset output precision threshold; otherwise, outputting a precision fault signal to the flight control computer.
2. The method for self-checking the high-coverage fiber-optic gyroscope before flight according to claim 1, wherein the step S1 is preceded by the steps of:
step S0, sending a ground self-detection instruction to the closed-loop fiber-optic gyroscope through the flight control computer; converting the ground self-detection instruction into two self-detection signals for the FPGA to identify, and executing the step S1 when the two self-detection signals are effective simultaneously; and if not, continuing to wait for receiving the ground self-detection instruction.
3. The method according to claim 2, wherein in step S0, when the two-way self-test signals are simultaneously valid, specifically, when the two-way self-test signals are simultaneously valid and the duration is longer than 10 ms.
4. The method for self-checking the high-coverage rate fiber-optic gyroscope before flight according to claim 1, wherein the step S2.3 is specifically as follows:
s2.3.1, resolving according to the phase difference interference light intensity obtained in the step S2.2 to obtain an equivalent angular rate;
s2.3.2, acquiring the equivalent angular rate obtained in the step S2.3.1, performing smooth filtering processing, comparing the difference with the angular rate tracking precision self-detection excitation signal recorded in the step S2.1, and if the difference is smaller than a preset angular rate threshold, outputting a signal meeting the angular rate self-detection requirement to a flight control computer; otherwise, outputting an angular rate fault signal to the flight control computer.
5. The method for self-checking the high-coverage fiber-optic gyroscope before flight according to any one of claims 1 to 4, further comprising the step S4 of self-checking the power supply:
after the closed-loop fiber optic gyroscope is powered on, acquiring a voltage value of a power supply to be monitored through an A/D (analog-to-digital) converter, converting the voltage value into a corresponding voltage digital quantity and supplying the voltage digital quantity to the FPGA, comparing the difference value of the converted voltage digital quantity with a corresponding voltage theoretical value through the FPGA, and outputting a power supply normal signal to a flight control computer if all the converted voltage digital quantity meets a preset voltage value; otherwise, outputting a power failure signal to the flight control computer.
6. The method according to claim 5, wherein in step S2.1, the feedback digital values corresponding to different angular rates are latched in a gyro FPGA internal register, and specifically, the feedback digital values corresponding to the rotation speed are latched in the gyro FPGA internal register after being subjected to smoothing filtering.
7. The method for self-checking the high-coverage-rate fiber-optic gyroscope before flying as claimed in claim 6, wherein in step S2.1, the calibrating the closed-loop fiber-optic gyroscope by using the turntable specifically comprises:
s2.1.1, mounting the closed loop fiber-optic gyroscope on a turntable, and enabling an input shaft corresponding to an excitation value to be calibrated of the closed loop fiber-optic gyroscope to be parallel to a rotary shaft of the turntable;
s2.1.2, rotating the turntable at least at the forward rotation maximum angular rate, the forward rotation 50% maximum angular rate, the reverse rotation 50% maximum angular rate, the zero angular rate point start, and the zero angular rate point end respectively.
8. The method according to claim 7, wherein in step S1, the step of collecting the output intensity value of the detector at the non-modulation time in the closed loop state is specifically:
and acquiring a detector signal at a non-modulation moment in a closed-loop state, amplifying and then carrying out digital quantitative coding, and carrying out smooth filtering after a difference is made between a light intensity value at the non-modulation state and a light intensity value at the modulation moment in an eigenperiod of the closed-loop fiber optic gyroscope to obtain an output light intensity value of the detector.
9. The utility model provides a self-checking system before high coverage rate fiber optic gyroscope flight which characterized in that: the system comprises an angular rate tracking precision self-checking module, a closed loop light path self-checking module and an analog output precision self-checking module;
the closed loop light path self-checking module is used for acquiring the detector output light intensity value at the non-modulation moment in the closed loop state, comparing the difference value of the filtered detector output light intensity value with the detector output light intensity value at the modulation moment, and outputting a closed loop light path working normal signal to the flight control computer if the difference value is smaller than a preset light intensity threshold value; otherwise, outputting a closed-loop light path fault signal to the flight control computer;
the angular rate tracking precision self-checking module is used for locking feedback digital quantities corresponding to different angular rates in a gyro FPGA (field programmable gate array) internal register when the rotary table is used for calibrating the closed-loop fiber optic gyro, performing analog-to-digital conversion, then superimposing controllable digital step waves on the phase modulator to perform electro-optic modulation to obtain phase difference interference light intensity of two light waves of the closed-loop fiber optic gyro corresponding to an excitation value after the analog-to-digital conversion, resolving to obtain an equivalent angular rate, and then performing self-checking on the angular rate tracking precision by combining the feedback digital quantities corresponding to the different angular rates;
the analog output precision self-checking module is used for performing analog-to-digital conversion on the closed-loop optical fiber gyroscope angular rate analog output, then performing digital low-pass filtering, then performing difference comparison on the digital value and a standard analog output sampling digital value, and if the digital value is smaller than a preset output precision threshold value, outputting a signal which meets the output precision self-checking requirement to the flight control computer; otherwise, outputting an output precision fault signal to the flight control computer.
10. The utility model provides a self-checking system before high coverage rate fiber optic gyroscope flight which characterized in that: the power supply self-checking module is also included;
the power supply self-checking module is used for acquiring the voltage value of a power supply to be monitored through the A/D (analog-to-digital) converter after the closed-loop fiber-optic gyroscope is powered on, converting the voltage value into corresponding voltage digital quantity and supplying the voltage digital quantity to the FPGA (field programmable gate array), comparing the difference value of the converted voltage digital quantity with the corresponding voltage theoretical value through the FPGA, and outputting a power supply normal signal to the flight control computer if all the voltage values meet a preset voltage value; otherwise, outputting a power failure signal to the flight control computer.
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Denomination of invention: A high coverage pre flight self-test method and self-test system for fog Effective date of registration: 20221205 Granted publication date: 20211102 Pledgee: Bank of China Limited Xi'an Second Ring Century Star Sub branch Pledgor: XI'AN SINO HUAXIN MEASUREMENT & CONTROL CO.,LTD. Registration number: Y2022980025102 |