CN103884358B - A kind of digital closed-loop optic fiber gyroscope full loop detection and emulation test system - Google Patents

Abstract

The invention discloses a digital closed-loop optical fiber gyroscope full-loop detection and simulation test system, which includes an optical system module, a preamplifier module, a digital processing module, a feedback module, a communication module, and a ground inspection and simulation test system. The present invention can realize the full-loop detection of the fiber optic gyroscope without the use of a turntable; it can complete the stand-alone bandwidth test of the fiber optic gyroscope without the use of an angular vibration table and a sudden stop table, and avoids traditional mechanical testing during the test process. Due to the limitation of the equipment itself, the dynamic simulation function of the sub-system can be realized without adding any auxiliary circuit for ground detection, avoiding the parameter limitation of the auxiliary circuit, and completing complex dynamic simulation. The invention reduces the power consumption and weight of the product, lowers the cost, and realizes the miniaturization and low-cost design of the product.

Description

A digital closed-loop fiber optic gyroscope full-loop detection and simulation test system

technical field

The invention belongs to the technical field of inertial attitude sensor systems, and relates to a digital closed-loop fiber optic gyroscope full-loop detection and simulation test system.

Background technique

In recent years, due to the prosperity of the micro-satellite market, the research on low-cost and miniaturized inertial attitude sensors has developed rapidly. In order to perform ground physical simulation for satellite products, all stand-alone machines must have a ground detection function, so it is necessary to increase the auxiliary circuit to realize the ground detection function, which increases the power consumption, size and weight of the product.

As an important frequency characteristic, bandwidth test is an important content of gyroscope performance test. The traditional method is to use mechanical equipment such as sudden stop table and angular vibration table to obtain the frequency response curve, and then calculate the bandwidth of the fiber optic gyroscope according to the model of the closed-loop fiber optic gyroscope. Limited by the conditions of the mechanical equipment such as the sudden stop table and the angular vibration table, it is impossible to do a limit test on the bandwidth of the fiber optic gyroscope.

The ground inspection function of the gyro (fiber optic gyro dynamics simulation) is an indispensable function during the ground test process of the whole satellite. The traditional method is to apply electrical signal excitation to the closed-loop system of the gyroscope through the auxiliary hardware circuit, so that the gyroscope outputs a certain regular angular velocity signal, which is used to simulate the movement of the satellite, thereby completing the dynamics of the ground whole-satellite orbit control algorithm. Simulation. Since the added auxiliary hardware circuits are no longer used after the satellite goes into the sky, it can be said that this part of the hardware circuit is only used during ground testing, which cannot but be said to be a resource for satellites with extremely demanding weight requirements. waste.

To sum up, if the above-mentioned frequency characteristics measurement and ground detection functions can be realized by software, then the limit test of the bandwidth of the fiber optic gyroscope can be done, which can reduce the cost of the product, reduce the weight of the product, and reduce the test cost of the product.

Contents of the invention

The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, to provide a digital closed-loop fiber optic gyroscope full-circuit detection and simulation test system, to use software technology to reduce the cost of research and development, production, and test of the fiber optic gyroscope, and to save ground inspection auxiliary circuits , while avoiding the use of traditional mechanical equipment such as sudden stop tables and angular vibration tables, not only can reduce product costs, reduce product dimensions, but also simplify test programs and accelerate product development and production progress.

The technical solution of the present invention is: a digital closed-loop fiber optic gyroscope full-loop detection and simulation test system, including an optical system module, a preamplifier module, a digital processing module, a feedback module, a communication module, and a ground inspection and simulation test system;

The ground inspection and simulation test system sends test instructions to the digital processing module through the communication module;

The digital processing module includes a data demodulation unit, a digital filter unit, a modulated signal generation unit, a signal superposition unit and an instruction analysis unit; the instruction analysis unit receives the test instructions sent by the ground inspection and simulation test system through the communication module, and executes the instruction Analyze to obtain the fiber optic gyroscope angular rate signal in the instruction; then the instruction analysis unit sends the fiber optic gyroscope angular rate signal to the signal superposition unit, and the signal superposition unit combines the received fiber optic gyroscope angular rate signal with the optical fiber output from the data demodulation unit The gyroscope angular rate signal and the digital square wave generated by the modulation signal generation unit are superimposed to form a modulation signal containing the fiber optic gyroscope angular rate signal, and the modulation signal is output to the feedback module, wherein the digital square wave generated by the modulation signal generation unit is modulated by the phase The electrical parameters of the device are determined;

The feedback module includes a driving circuit and a D/A converter. The D/A converter receives the modulation signal output by the digital processing module through the signal superposition unit, converts it into an analog signal, and outputs it to the optical system module through the driving circuit;

The optical system module includes a light source, a coupler, a phase modulator, an optical fiber ring, and a photoelectric converter. The optical signal sent by the light source is transmitted to the phase modulator through the coupler. The phase modulator divides the received optical signal into two beams of light, and the phase The modulator modulates the two beams of light according to the modulation signal sent by the feedback module. After modulation, the two beams of light enter the fiber ring and transmit clockwise and counterclockwise around the fiber ring respectively. When the two beams of light pass through the fiber ring After being transmitted to the phase modulator, it is modulated by the phase modulator again. After the above two modulations, the two beams of light interfere at the splitting/combining place of the phase modulator, and the interfering optical signal is output to the optoelectronics through the coupler. Converter, the photoelectric converter converts the interfering optical signal into an electrical signal and outputs it to the preamplifier module. The electrical signal contains the optical fiber gyroscope angular rate signal and modulation signal. The optical fiber gyroscope angular rate signal includes the input of the optical fiber gyroscope body The angular rate signal and the optical fiber gyroscope angular rate signal in the test command issued by the ground inspection and simulation test system;

The preamp module includes a preamplifier and an A/D converter. The preamplifier amplifies the electrical signal output by the optical system module and outputs it to the A/D converter. The A/D converter converts the amplified electrical signal into a digital After the signal is output to the data demodulation unit of the digital processing module, the data demodulation unit of the digital processing module demodulates the received digital signal to obtain the optical fiber gyroscope angular rate signal, and the optical fiber gyroscope angular rate signal is output to the digital processing unit on the one hand. The signal superposition unit of the module performs the next round of closed-loop control, and on the other hand outputs to the digital filter unit for filtering. The optical fiber gyroscope angular rate signal obtained after filtering is sent to the ground inspection and simulation test system through the communication module, and the ground inspection and simulation test system According to the received angular rate signal of the fiber optic gyroscope, the fiber optic gyroscope closed loop detection, bandwidth test and fiber optic gyroscope dynamics simulation test are completed.

The test command sent by the ground inspection and simulation test system to the digital processing module through the communication module consists of two bytes, the first byte is the command information, and the second byte is the angular rate information of the fiber optic gyroscope.

The specific methods for the ground inspection and simulation test system to complete the fiber optic gyroscope closed-loop detection, bandwidth test and fiber optic gyroscope dynamics simulation test according to the received optical fiber gyroscope angular rate signal are as follows:

When performing closed-loop detection on the fiber optic gyroscope, the test command sent by the ground inspection and simulation test system to the digital processing module through the communication module is the fiber optic gyroscope closed-loop loop detection command, and the ground inspection and simulation test system calculates the received angular rate signal of the fiber optic gyroscope and the difference between the input angular rate signal of the fiber optic gyroscope body, and complete the closed-loop online detection of the fiber optic gyroscope by judging the consistency between the difference between the above two angular rate signals and the fiber optic gyroscope angular rate signal in the fiber optic gyroscope closed-loop loop detection command;

When testing the bandwidth of the fiber optic gyroscope, the test command sent by the ground inspection and simulation test system to the digital processing module through the communication module is the bandwidth test command of the fiber optic gyroscope. The amplitude of the angular rate signal; the ground inspection and simulation test system collects each angular rate signal output by the fiber optic gyroscope, and records the moment when each angular rate signal is received, and calculates the bandwidth of the fiber optic gyroscope through the formula;

When performing dynamic simulation on the fiber optic gyroscope, the test command sent by the ground inspection and simulation test system to the digital processing module through the communication module is the fiber optic gyroscope dynamic simulation command; the ground inspection and simulation test system outputs the fiber optic gyroscope according to the entire satellite control period The angular rate signal is collected, and the angular rate signal is introduced into the input end of the dynamics simulation system, and a cycle of dynamics simulation is completed through the calculation of the on-board computer.

When testing the bandwidth of the fiber optic gyroscope, the formula for calculating the bandwidth of the fiber optic gyroscope is as follows:

$\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 0.75</span>}}{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}$

Among them, l is the bandwidth of the fiber optic gyroscope, _t2 is the moment when the ground inspection and simulation test system receives the angular rate signal output by the fiber optic gyroscope, and the angular rate signal of the fiber optic gyroscope received by the ground inspection and simulation test system at this moment is the same as that of the fiber optic gyroscope body The amplitude of the difference between the input angular rate signals is 95% of the amplitude of the fiber optic gyroscope angular rate signal amplitude in the fiber optic gyroscope bandwidth test command issued by the ground inspection and simulation test system, and _t1 is the bandwidth test of the fiber optic gyroscope sent by the ground inspection and simulation test system. moment of instruction.

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

(1) The present invention makes full use of the "digital" advantage of the digital closed-loop fiber optic gyroscope, and uses an additional "digital quantity" to simulate the angular velocity signal of the fiber optic gyroscope, which can complete the full-loop functional self-test of the optical fiber gyroscope's optical path and circuit.

(2) The present invention realizes full-circuit detection and dynamic simulation through a digital communication interface, and the method is simple and easy to implement.

(3) The present invention can avoid the limitation of the ability of the ground detection auxiliary circuit itself, and complete more complicated physical simulation tests.

(4) The present invention applies "digital excitation" to the product through communication, and realizes "on-line" measurement and simulation of angular velocity.

(5) The "digital excitation" method used in the present invention avoids the limitations of traditional mechanical equipment such as sudden stop table and angular vibration table, and can complete the limit test of the frequency characteristics of the fiber optic gyroscope.

Description of drawings

Fig. 1 The principle block diagram of the digital closed-loop fiber optic gyroscope full-loop detection and simulation test system;

Figure 2 is a block diagram of the transfer function of the full loop detection and simulation test system;

Fig. 3 is a schematic diagram of digital closed-loop fiber optic gyroscope staircase wave;

Fig. 4 is a schematic diagram of a phase difference waveform of a digital closed-loop fiber optic gyroscope.

detailed description

In the digital closed-loop fiber optic gyroscope, the external angular velocity is used as the input signal to cause the phase difference between the forward and reverse beams. As a feedback signal, the step wave is added to the phase modulator, which also causes a phase difference between the two beams of light. The phase difference is proportional to the step height of the step wave and is given by the digital signal processing circuit. Using a specific step wave (sine, or step) to simulate the required external angular velocity input signal can easily realize the optical path of the fiber optic gyroscope, the function detection of the circuit, the test of the dynamic characteristics and the realization of the dynamic simulation function.

In the digital closed-loop fiber optic gyroscope, both the feedback signal and the output signal are the step height of the digital staircase wave calculated by the digital controller. The schematic block diagram of the digital closed-loop fiber optic gyroscope full-loop detection and simulation test system is shown in Figure 1, including an optical system module 100, a preamplifier module 200, a digital processing module 300, a feedback module 400, a communication module 500, and a ground inspection and simulation test system 600 ;

The ground inspection and simulation test system 600 sends test instructions to the digital processing module 300 through the communication module 500 .

The digital processing module 300 is composed of an FPGA chip and its internal hardware algorithm, including a data demodulation unit, a digital filter unit, a modulation signal generation unit, a signal superposition unit and an instruction analysis unit; wherein the instruction analysis unit receives ground inspection and the simulation test system 600 passes The test instruction sent by the communication module 500 is analyzed to obtain the optical fiber gyroscope angular rate signal in the instruction; then the instruction analysis unit sends the optical fiber gyroscope angular rate signal to the signal superposition unit, and the signal superposition unit will receive the The optical fiber gyroscope angular rate signal is superimposed with the optical fiber gyroscope angular rate signal output by the data demodulation unit and the digital square wave generated by the modulation signal generating unit to form a modulation signal containing the optical fiber gyroscope angular rate signal, and the modulation signal is output to the feedback module 400 , where the digital square wave generated by the modulation signal generation unit is determined by the electrical parameters of the phase modulator.

The feedback module 400 includes a driving circuit and a D/A converter. The D/A converter receives the modulated signal output by the digital processing module 300 through the signal superposition unit, converts it into an analog signal, and outputs it to the optical system module 100 through the driving circuit.

The optical system module 100 includes a light source, a coupler, a phase modulator, an optical fiber ring, and a photoelectric converter. The optical signal sent by the light source is transmitted to the phase modulator through the coupler, and the phase modulator divides the received optical signal into two beams of light, The phase modulator modulates the two beams of light according to the modulation signal sent by the feedback module 400. The modulated two beams of light enter the fiber optic ring and transmit clockwise and counterclockwise around the fiber ring respectively. The input angular rate of the main body rotates, so that the input angular rate of the fiber optic gyroscope body is superimposed on the two beams of light. When the two beams of light are transmitted from the fiber optic ring to the phase modulator, they are again transmitted by the phase modulator according to the next step. The modulation signal sent by the periodic feedback module 400 is modulated. After the above two modulations, the two beams of light interfere at the light splitting/combining place of the phase modulator, and the interfering light signal is output to the photoelectric converter through the coupler. The photoelectric converter converts the optical signal into an electrical signal and outputs it to the preamplifier module 200. The electrical signal includes the optical fiber gyro angular rate signal and the modulation signal. The optical fiber gyroscope angular rate signal includes the input angular rate signal of the optical fiber gyroscope body and the ground detector. And the angular rate signal of the fiber optic gyroscope in the test command issued by the simulation test system 600 .

The preamplifier module 200 includes a preamplifier and an A/D converter. The preamplifier amplifies the electrical signal output by the optical system module 100 and outputs it to the A/D converter. The A/D converter converts the amplified electrical signal After the digital signal is output to the data demodulation unit of the digital processing module 300, the data demodulation unit of the digital processing module 300 demodulates the received digital signal to obtain an optical fiber gyroscope angular rate signal. On the one hand, the optical fiber gyroscope angular rate signal Output to the signal superposition unit of the digital processing module 300 for the next round of closed-loop control, and on the other hand output to the digital filter unit for filtering, and the optical fiber gyroscope angular rate signal obtained after filtering is sent to the ground inspection and simulation test system 600 through the communication module 500 , the ground inspection and simulation test system 600 completes the fiber optic gyroscope closed-loop loop detection, bandwidth test and fiber optic gyroscope dynamics simulation test according to the sent test command and the received fiber optic gyroscope angular rate signal.

The ground inspection and simulation test system 600 is composed of a ground inspection control box, a computer, and a simulation algorithm. The specific way to realize the closed-loop detection of the fiber optic gyroscope, the bandwidth test, and the dynamic simulation test of the fiber optic gyroscope is as follows: when performing the closed-loop loop detection of the fiber optic gyroscope, The test instruction sent by the ground inspection and simulation test system 600 to the digital processing module 300 through the communication module 500 is an optical fiber gyroscope closed loop detection instruction, which contains a simulated optical fiber gyroscope angular rate signal, and the ground inspection and simulation test system 600 calculates and receives The difference between the angular rate signal of the fiber optic gyroscope and the input angular rate signal of the fiber optic gyroscope body, and by judging the difference between the above two angular rate signals and the consistency of the fiber optic gyroscope angular rate signal in the fiber optic gyroscope closed-loop loop detection command to complete the fiber optic gyroscope Closed-loop online detection.

When testing the bandwidth of the fiber optic gyroscope, the test command sent by the ground detection and simulation test system 600 to the digital processing module 300 through the communication module 500 is the fiber optic gyroscope bandwidth test command, which contains the simulated fiber optic gyroscope angular rate signal. The inspection and simulation test system 600 records the time when the command is issued (accurate to the second level, millisecond level, or even microsecond level as required) and the amplitude of the optical fiber gyroscope angular rate signal in the command; the ground inspection and simulation test system 600 collects the output of the fiber optic gyroscope Each angular rate signal, and record the moment when the ground inspection and simulation test system 600 receives each angular rate signal, and calculate the bandwidth of the fiber optic gyroscope through the formula.

The formula for calculating the fiber optic gyroscope bandwidth is as follows:

$\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 0.75</span>}}{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}$

Among them, l is the bandwidth of the fiber optic gyroscope, _t2 is the moment when the ground inspection and simulation test system 600 receives the angular rate signal output by the fiber optic gyroscope, and the angular rate signal of the fiber optic gyroscope received by the ground inspection and simulation test system 600 at this moment is in line with the optical fiber The amplitude of the difference between the input angular rate signals of the gyroscope body is 95% of the amplitude of the optical fiber gyroscope angular rate signal amplitude in the fiber optic gyroscope bandwidth test command issued by the ground inspection and simulation test system 600, and _t1 is sent by the ground inspection and simulation test system 600. The timing of the fiber optic gyro bandwidth test command.

When performing dynamic simulation on the fiber optic gyroscope, the test command sent by the ground inspection and simulation test system 600 to the digital processing module 300 through the communication module 500 is a fiber optic gyroscope dynamics simulation command, which contains a simulated fiber optic gyroscope angular rate signal, It must be consistent with the angular rate generated by the actuator of the satellite system; the ground inspection and simulation test system 600 collects the angular rate signal output by the fiber optic gyroscope according to the entire satellite control period, and introduces the angular rate signal into the input of the dynamics simulation system At the end, a cycle of dynamic simulation is completed through the calculation of the on-board computer.

The test instruction sent by the ground inspection and simulation test system 600 to the digital processing module 300 through the communication module 500 consists of two bytes, the first byte is instruction information, and the second byte is the angular rate information of the fiber optic gyroscope.

The realization principle of the digital closed-loop fiber optic gyroscope full-loop detection and simulation test system is as follows:

The output of the data demodulation unit of the digital processing module 300 is the step amount of the angular rate of the fiber optic gyroscope. Before the step height is accumulated to obtain the digital step wave, an additional signal P is added (that is, the ground inspection and simulation test system 600 passes the communication module 500 to the digital processing module 300 sent to the digital processing module 300 to test the optical fiber gyro angular rate signal), change the step height of the staircase wave, and at the same time superimpose with the digital square wave generated by the modulation signal generating unit to obtain a new staircase wave. The phase difference between the two beams of light caused by the step wave is proportional to the step height, the phase difference caused by the step wave ΔΦ _JT = ΔΦ _R + ΔΦ _P , where ΔΦ _R is the phase difference caused by the feedback amount, and ΔΦ _P is caused by the external signal Phase difference. Assume that the input angular velocity is zero, that is, ΔΦ _S =0. When the external signal P is initially added, the error signal after demodulation is not zero, the digital controller changes the size of the feedback amount according to the control algorithm, and dynamically tracks the external signal until the error is zero, that is, ΔΦ _R =-ΔΦ _P , the feedback amount can Reflects the magnitude of the external signal. The output angular velocity of the fiber optic gyroscope can be obtained through the output module, and the dynamic corresponding characteristics of the fiber optic gyroscope can be obtained by analyzing the output data. The output of the fiber optic gyroscope can be used as an input signal for dynamic simulation.

The transfer function block diagram of the gyroscope system after adding the external signal to the feedback is shown in Figure 2, and the external signal is represented by P(Z). Let the input angular velocity Ω(Z)=0, it can be obtained that the transfer function of the output signal D _OUT (Z) relative to the external signal P(Z) is:

$\begin{array}{c}{\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; P</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; out</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; C</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}{\mathrm{<span\; class="notranslate">\; Z</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 3</span>}}\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; C</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}{\mathrm{<span\; class="notranslate">\; Z</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 3</span>}}\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; )</span>}\\ <span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; C</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; Z</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; C</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; )</span>}\end{array}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Let the external signal P(Z)=0, it can be obtained that the transfer function of the output signal D _OUT (Z) relative to the input angular velocity Ω(Z) is:

$\begin{array}{c}\mathrm{<span\; class="notranslate">\; G</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; out</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; \&Omega;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; Z</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\frac{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; Z</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; C</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}{\mathrm{<span\; class="notranslate">\; Z</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 3</span>}}\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; )</span>}\\ <span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}\mathrm{<span\; class="notranslate">\; ZD</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; Z</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; C</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; )</span>}\end{array}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

Comparing formula (1) and formula (2), it can be seen that the denominators of the two formulas are exactly the same, and the numerators are only different It shows that the output caused by the external signal and the output caused by the input angular velocity have exactly the same shape, but the amplitude differs by a proportional coefficient (that is, the scaling factor of the gyroscope), there is a period of lag in time, which can be compensated in subsequent data processing. It can be seen that by superimposing the simulated angular velocity signal on the feedback signal of the phase modulator, the input of the angular velocity can be completely equivalent, and the full loop detection of the fiber optic gyroscope, the test of the dynamic characteristics and the realization of the dynamic simulation function can be realized.

Take the step response as an example to illustrate the principle of simulating the input angular velocity of the fiber optic gyroscope. When testing the bandwidth of the closed-loop fiber optic gyroscope, in order to obtain the step response curve, the external signal should be a fixed-size digital quantity, which corresponds to the feedback quantity formed by the forward channel. Superposition, after integration, the finally formed analog staircase wave V _JT (t) waveform is shown in Figure 3, where the solid line is V _JT (t), and the dotted line is V _JT (t-τ). Figure 4 shows the phase difference ΔΦ _JT between the positive and negative beams caused by the staircase wave, ΔΦ _R is the phase difference caused by the feedback amount, and ΔΦ _P is the phase difference caused by the external signal.

If it is desired that the output caused by the external signal and the output value caused by the input angular velocity are the same, then there is a proportional coefficient between the two which is For the step response test in this project, it is not necessary to know the specific value of this proportional coefficient, because according to the automatic control theory and the closed-loop principle of the fiber optic gyroscope, as long as the amplitude of the external signal does not exceed the maximum angular acceleration of the fiber optic gyroscope, any external signal The resulting response times should be consistent.

The digital closed-loop fiber optic gyroscope full-loop detection and simulation test system can realize the full-loop detection function of the fiber optic gyroscope, and can perform functional testing of the working status of the fiber optic gyroscope without the use of a turntable; it can avoid the conditions of traditional mechanical equipment itself Limit, complete the limit test of fiber optic gyroscope bandwidth, simplify the single-machine bandwidth test process; the ground detection function can be realized, and the dynamic simulation function of the subsystem can be realized without adding any ground detection auxiliary circuit, avoiding the parameter limitation of the auxiliary circuit , to complete the complex dynamic simulation; thereby reducing the power consumption, weight and cost of the product, and realizing the miniaturization and low-cost design of the product.

The above is only the best specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can simply deduce or replace within the technical scope disclosed in the present invention, All should be covered within the protection scope of the present invention.

The content that is not described in detail in the description of the present invention belongs to the well-known technology of those skilled in the art.

Claims (4)

1. a digital closed-loop optic fiber gyroscope full loop detection and emulation test system, it is characterized in that: comprise Optical system module (100), front amplification module (200), digital signal processing module (300), feedback module (400), communication module (500) and ground inspection and emulation test system (600);

Ground inspection and emulation test system (600) send test instruction by communication module (500) to digital signal processing module (300);

Digital signal processing module (300) comprises data demodulation unit, digital filtering unit, modulation signal generation unit, Signal averaging unit and instructions parse unit; Wherein instructions parse unit receives the test instruction that ground is examined and emulation test system (600) is sent by communication module (500), and this instruction is resolved, and obtains the fiber optic gyro angle rate signal in this instruction; Then this fiber optic gyro angle rate signal is sent to Signal averaging unit by instructions parse unit, the fiber optic gyro angle rate signal that the fiber optic gyro angle rate signal received and data demodulation unit are exported by Signal averaging unit and the digital square wave that modulation signal generation unit produces carry out superposing the modulation signal being formed and comprising fiber optic gyro angle rate signal, and this modulation signal is exported to feedback module (400), the digital square wave that wherein modulation signal generation unit produces is determined by the electric parameter of phase modulator;

Feedback module (400) comprises driving circuit and D/A transmodulator, the modulation signal that D/A converter accepts digital signal processing module (300) is exported by Signal averaging unit, and export to Optical system module (100) by driving circuit after being converted into simulating signal;

Optical system module (100) comprises light source, coupling mechanism, phase modulator, fiber optic loop and photoelectric commutator, the optical signal that light source sends through coupler transfer to phase modulator, the optical signal received is divided into two-beam by phase modulator, this two-beam is modulated by the simulating signal that phase modulator sends over according to feedback module (400), this two-beam after modulation enters fiber optic loop and clockwise around fiber optic loop respectively, counterclockwise transmission, after this two-beam is transferred to phase modulator again from fiber optic loop, again by phase modulator modulation, after above-mentioned twice modulating action, two-beam produces at phase modulator separation/combination place to interfere, optical signal after this interference exports to photoelectric commutator by coupling mechanism, by photoelectric commutator the optical signal after this interference is converted to electrical signal and exports to front amplification module (200), this electrical signal comprises fiber optic gyro angle rate signal and modulation signal, this fiber optic gyro angle rate signal comprises the input angle rate signal of fiber optic gyro body and the fiber optic gyro angle rate signal in the test instruction that ground is examined and emulation test system (600) sends,

Front amplification module (200) comprises prime amplifier and A/D converter, prime amplifier exports to A/D converter after being amplified by the electrical signal that Optical system module (100) exports, A/D converter exports to the data demodulation unit of digital signal processing module (300) after the electrical signal after amplification is converted to numerary signal, the numerary signal received is carried out demodulation by the data demodulation unit of digital signal processing module (300), obtain fiber optic gyro angle rate signal, the Signal averaging unit that this fiber optic gyro angle rate signal one side exports to digital signal processing module (300) carries out next and takes turns closed-loop control, exporting to digital filtering unit carries out filtering on the other hand, the fiber optic gyro angle rate signal obtained after filtering is examined by communication module (500) and emulation test system (600) with being sent to, ground inspection and emulation test system (600) complete the detection of fiber optic gyro closed loop according to the fiber optic gyro angle rate signal received, bandwidth test and the emulation test of fiber optic gyro kinetics.

2. a kind of digital closed-loop optic fiber gyroscope full loop detection according to claim 1 and emulation test system, it is characterized in that: the test instruction that ground inspection and emulation test system (600) are sent to digital signal processing module (300) by communication module (500) is made up of two bytes, first character joint is instruction information, and the 2nd byte is fiber optic gyro angular rate information.

3. a kind of digital closed-loop optic fiber gyroscope full loop detection according to claim 1 and emulation test system, it is characterised in that: examine and concrete mode that emulation test system (600) completes the detection of fiber optic gyro closed loop, bandwidth test and the emulation test of fiber optic gyro kinetics according to the fiber optic gyro angle rate signal received is describedly:

When fiber optic gyro being carried out closed loop and detects, ground inspection and emulation test system (600) by communication module (500) to the test instruction that digital signal processing module (300) sends be fiber optic gyro closed loop detection instruction, ground inspection and emulation test system (600) calculate the difference of the input angle rate signal of fiber optic gyro angle rate signal and the fiber optic gyro body received, and the closed loop on-line checkingi of fiber optic gyro is completed by the consistence of the fiber optic gyro angle rate signal judged in the difference of above-mentioned two angle rate signals and the detection instruction of fiber optic gyro closed loop,

When fiber optic gyro being carried out bandwidth and tests, ground inspection and emulation test system (600) are fiber optic gyro bandwidth test instruction by communication module (500) to the test instruction that digital signal processing module (300) sends, and examine and emulation test system (600) records the amplitude of fiber optic gyro angle rate signal in the moment and instruction sending instruction simultaneously; Ground inspection and emulation test system (600) gather each angle rate signal that fiber optic gyro exports, and record the moment receiving each angle rate signal, by the bandwidth of formulae discovery fiber optic gyro;

When fiber optic gyro is carried out kinetics emulate time, ground inspection and emulation test system (600) by communication module (500) to the test instruction that digital signal processing module (300) sends be fiber optic gyro kinetics emulation instruction; The angle rate signal that fiber optic gyro exports is gathered by ground inspection and emulation test system (600) according to whole star control cycle, and this angle rate signal is introduced the input terminus of dynamic simulation system, the calculating through On board computer completes the kinetics emulation of one-period.

4. a kind of digital closed-loop optic fiber gyroscope full loop detection according to claim 3 and emulation test system, it is characterised in that: when fiber optic gyro carrying out bandwidth and tests, the formula calculating fiber optic gyro bandwidth is as follows:

$l=\frac{0.75}{t_2-t_1}$

Wherein, l is fiber optic gyro bandwidth, t₂For ground inspection and emulation test system (600) receive the moment of the angle rate signal that fiber optic gyro exports, and the amplitude of the difference of the input angle rate signal of fiber optic gyro angle rate signal of receiving of this ground inspection and emulation test system (600) and fiber optic gyro body in moment be examine and in fiber optic gyro bandwidth test instruction that emulation test system (600) sends fiber optic gyro angle rate signal amplitude 95%, t₁For ground inspection and emulation test system (600) send the moment of fiber optic gyro bandwidth test instruction.