Miniaturized three-axis resonant fiber optic gyroscope detection system with broadband light source multiplexing

Abstract

The present invention discloses a miniaturized three-axis resonant fiber optic gyroscope detection system with broadband light source multiplexing. The entire system consists of two parts: an optical system and a signal detection system. The optical system includes a broadband light source, three push-pull Y branches, three circulators, three transmission-type fiber optic ring resonators, and three photodetectors; the signal detection system includes a digital / analog conversion module, an analog / digital conversion module, a modulation and demodulation module, a servo control module, a frequency shift drive module, and a low-pass filter module. In the present invention, the first resonant cavity is connected to the broadband light source using a symmetrical connection method, and the optical signals output from the two reflection ports of the first resonant cavity respectively drive the other two resonant fiber gyroscopes using the same connection method, thereby cleverly forming a three-axis integrated structure. In this way, light source multiplexing can be achieved without adding additional devices, which not only simplifies the system structure but also effectively improves the utilization rate of the broadband light source.

Description

Technical Field

[0001] The present invention relates to a miniaturized three-axis resonant fiber optic gyroscope detection system with broadband light source multiplexing, including the design of optical path systems under gyroscope open-loop and closed-loop systems and a signal detection solution. Background Art

[0002] A fiber-optic gyroscope (FOG) is a high-precision angular velocity sensor based on the optical Sagnac effect and is widely used in the field of inertial navigation. It primarily includes two types: the interferometric fiber-optic gyroscope (IFOG) and the resonator fiber-optic gyroscope (RFOG). The IFOG uses a multi-turn fiber ring as its sensing element, detecting angular velocity by measuring the intensity of the interfering light of clockwise and counterclockwise light beams. For a given fiber ring diameter, its theoretical sensitivity is positively correlated with the ring length. The RFOG, on the other hand, uses a high-definition fiber ring resonator as its sensing element, leveraging the multi-turn transmission of a light beam within the resonator to enhance the optical Sagnac effect. Its theoretical sensitivity is half the product of the cavity length and cavity resolution. Therefore, for the same diameter and fiber length, the RFOG has higher detection sensitivity. However, while the resonant cavity increases the theoretical sensitivity, it also amplifies various optical parasitic effects, including backscattering, polarization effect, and Kerr effect. The existence of these optical parasitic effects deteriorates the long-term stability of RFOG.

[0003] A recently proposed broadband light-driven RFOG scheme reduces the effects of various optical noises by reducing the coherence of the light source, thereby effectively improving the long-term stability of the gyroscope. However, due to the resonant cavity, only light with frequencies that are integer multiples of the resonant frequency can be effectively utilized. This significantly reduces the light source's power utilization, making it particularly important to improve light source utilization.

[0004] Gyroscopes used in practical applications can generally be divided into two types: single-axis gyroscopes and three-axis gyroscopes. A single-axis gyroscope can only measure the quantity of one axis. Therefore, a practical inertial navigation system usually requires three single-axis gyroscopes to meet the needs. A three-axis gyroscope can achieve simultaneous measurement of three-axis rotation. Therefore, the three-axis gyroscope has outstanding advantages such as small size, light weight, and simple structure. It is also the development trend of future optical gyroscopes. Summary of the Invention

[0005] The purpose of the present invention is to address the deficiencies of the prior art and provide a miniaturized three-axis resonant fiber optic gyroscope detection system with wide-spectrum light source multiplexing.

[0006] The object of the present invention is achieved through the following technical solutions:

[0007] The present invention first provides an open-loop detection system for a miniaturized three-axis resonant fiber optic gyroscope with broadband light source multiplexing, comprising an optical system and a signal detection system. The optical system is composed of a broadband light source, three push-pull Y-branches, three circulators, three transmissive fiber optic ring resonators, and three photodetectors. The signal detection system is composed of a digital-to-analog conversion module, an analog-to-digital conversion module, a modulation and demodulation module, and a low-pass filtering module.

[0008] Port 1 of the first circulator is connected to a broadband light source, port 2 of the first circulator is connected to an input end of a first push-pull Y-branch, port 3 of the first circulator is connected to a first photodetector, and two output ports of the first push-pull Y-branch are respectively connected to the same-side input ends of two couplers of the first fiber ring resonator; two vacant ports of the two couplers of the first fiber ring resonator are respectively connected to port 1 of the second circulator and port 1 of the third circulator; port 2 of the second circulator is connected to an input port of a second push-pull Y-branch, port 3 of the second circulator is connected to a second photodetector, and two output ports of the second push-pull Y-branch are respectively connected to the same-side input ends of the two couplers of the second fiber ring resonator; port 2 of the third circulator is connected to an input port of a third push-pull Y-branch, port 3 of the third circulator is connected to a third photodetector, and two output ports of the third push-pull Y-branch are respectively connected to the same-side input ends of the two couplers of the third fiber ring resonator;

[0009] The three sinusoidal wave modulation signals generated by the modulation and demodulation module are respectively applied to the first push-pull Y branch, the second push-pull Y branch, and the third push-pull Y branch after passing through the digital-to-analog conversion module; the three electrical signals output by the first photodetector, the second photodetector, and the third photodetector are synchronously demodulated in the modulation and demodulation module after passing through the analog-to-digital conversion module, and the frequencies of the demodulated signals are respectively the same as the frequencies of the modulation signals applied to the first push-pull Y branch, the second push-pull Y branch, and the third push-pull Y branch; the three demodulated output signals of the modulation and demodulation module are collected by the data recorder after passing through the low-pass filter module and are respectively used as the gyro outputs of the three axes of the three-axis gyroscope system.

[0010] In the present invention, the first circulator, the first push-pull Y-branch, the first fiber ring resonator, and the first photodetector constitute a gyroscope for a first axis; the second circulator, the second push-pull Y-branch, the first fiber ring resonator, and the first photodetector constitute a gyroscope for a second axis; the third circulator, the third push-pull Y-branch, the third fiber ring resonator, and the third photodetector constitute a gyroscope for a third axis; and the three gyroscopes are driven by only one broadband light source without adding any additional optical elements.

[0011] As a preferred solution of the present invention, the frequency of the modulation signal applied to the first push-pull Y branch is different from the frequencies of the modulation signals applied to the second push-pull Y branch and the third push-pull Y branch.

[0012] As a preferred solution of the present invention, the three ring resonators are all transmissive fiber ring resonators, and adopt a transmissive symmetrical connection method in which clockwise and counterclockwise optical signals share input and output ports.

[0013] On the other hand, the present invention also provides a closed-loop detection system for a miniaturized three-axis resonant fiber optic gyroscope with broadband light source multiplexing, which includes an optical system and a signal detection system; the optical system is composed of a broadband light source, three push-pull Y branches, three circulators, three transmissive fiber optic ring resonators, and three photodetectors; the signal detection system is composed of a digital / analog conversion module, an analog / digital conversion module, a modulation and demodulation module, a servo control module, a frequency shift drive module, and a low-pass filter module;

[0014] Port 1 of the first circulator is connected to a broadband light source, port 2 of the first circulator is connected to an input end of a first push-pull Y-branch, port 3 of the first circulator is connected to a first photodetector, and two output ports of the first push-pull Y-branch are respectively connected to the same-side input ends of two couplers of the first fiber ring resonator; two vacant ports of the two couplers of the first fiber ring resonator are respectively connected to port 1 of the second circulator and port 1 of the third circulator; port 2 of the second circulator is connected to an input port of a second push-pull Y-branch, port 3 of the second circulator is connected to a second photodetector, and two output ports of the second push-pull Y-branch are respectively connected to the same-side input ends of the two couplers of the second fiber ring resonator; port 2 of the third circulator is connected to an input port of a third push-pull Y-branch, port 3 of the third circulator is connected to a third photodetector, and two output ports of the third push-pull Y-branch are respectively connected to the same-side input ends of the two couplers of the third fiber ring resonator;

[0015] The three sinusoidal wave modulation signals generated by the modulation and demodulation module are respectively applied to the first push-pull Y branch, the second push-pull Y branch and the third push-pull Y branch after passing through the digital-to-analog conversion module; the three electrical signals output by the first photodetector, the second photodetector and the third photodetector are synchronously demodulated in the modulation and demodulation module after passing through the analog-to-digital conversion module, and the frequencies of the demodulated signals are respectively the same as the frequencies of the modulation signals applied to the first push-pull Y branch, the second push-pull Y branch and the third push-pull Y branch; the three demodulated output signals of the modulation and demodulation module are sent to the servo control module, and the output signals of the servo control module are output to the frequency shift drive module and the low-pass filter module. The three output signals of the frequency shift drive module are respectively applied to the three push-pull Y branches after passing through the digital-to-analog conversion module, and the three output signals of the low-pass filter module are collected by the data recorder and used as the gyro outputs of the three axes of the three-axis gyroscope system.

[0016] Preferably, the demodulated output signal of the modulation and demodulation module generates a frequency control word (FCW) after passing through the servo control module and sends it to the frequency shift driving module. The frequency shift driving module generates a sawtooth wave signal with a frequency equal to half of the resonant frequency difference between the clockwise and counterclockwise light beams and an amplitude equal to the full-wave voltage of the push-pull Y branch based on the value of FCW. After passing through the digital / analog conversion module, it acts on the push-pull Y branch, so that the resonant frequency difference between the clockwise and counterclockwise light beams is 0.

[0017] The present invention has the beneficial effects:

[0018] The miniaturized three-axis resonant fiber optic gyroscope detection system with broadband light source multiplexing provided by the present invention can drive three gyroscope systems using only one broadband light source without requiring additional optical elements, which is extremely beneficial to miniaturization.

[0019] The miniaturized three-axis resonant fiber optic gyroscope detection system with wide-spectrum light source multiplexing provided by the present invention utilizes the signal from the reflection end of the first fiber optic ring resonator to drive the other two single-axis gyroscope systems, thereby greatly improving the utilization rate of the light source.

[0020] The miniaturized three-axis resonant fiber optic gyroscope detection system with broadband light source multiplexing provided by the present invention effectively reduces optical parasitic effects in the system by utilizing the broadband light source, thereby greatly improving the stability of the system.

[0021] The miniaturized three-axis resonant fiber optic gyroscope detection system with wide-spectrum light source multiplexing provided by the present invention utilizes a servo control module and a frequency shift drive module to apply a sawtooth frequency shift signal equivalent to rotation to a push-pull Y branch, thereby significantly improving the dynamic range and linearity of the gyroscope output.

[0022] The miniaturized three-axis resonant fiber optic gyroscope detection system with broadband light source multiplexing provided by the present invention ensures the independence of the operation of the three single-axis gyroscopes by controlling the frequency difference between the modulation signal applied to the first push-pull Y branch and the modulation signal applied to the other two push-pull Y branches. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the structural diagram of the first miniaturized three-axis resonant fiber optic gyroscope open-loop detection system with broadband light source multiplexing;

[0024] Figure 2 This is a schematic diagram of the structure of a miniaturized three-axis resonant fiber optic gyroscope closed-loop detection system with a second wide-spectrum light source multiplexing;

[0025] Figure 3 It is a schematic diagram of the demodulation curve of the single-axis output after signal demodulation;

[0026] Figure 4 This is a schematic diagram of a specific implementation case of a miniaturized three-axis resonant fiber optic gyroscope open-loop detection system with wide-spectrum light source multiplexing;

[0027] Figure 5 The diagram is a specific implementation case diagram of a closed-loop detection solution for a miniaturized three-axis resonant fiber optic gyroscope with wide-spectrum light source multiplexing.

[0028] In the figure: 1. Broad-spectrum light source; 2. First circulator; 3. First push-pull Y-branch; 4. First fiber ring resonator; 5. First photodetector; 6. Second circulator; 7. Second push-pull Y-branch; 8. Second fiber ring resonator; 9. Second photodetector; 10. Third circulator; 11. Third push-pull Y-branch; 12. Third fiber ring resonator; 13. Third photodetector; 14. Analog / digital conversion module; 15. Modem module; 16. Servo control module; 17. Low-pass filter module; 18. Frequency shift drive module; 19. Digital / analog conversion module; 20. Data recorder. DETAILED DESCRIPTION

[0029] The present invention will be described in detail below with reference to examples and drawings, but the present invention is not limited thereto.

[0030] Example 1, as Figure 1 and 4 As shown, the present invention provides a miniaturized three-axis resonant fiber optic gyroscope open-loop detection system with broadband light source multiplexing. The system includes an optical system consisting of a broadband light source, three push-pull Y branches, three circulators, three transmissive fiber optic ring resonators, and three photodetectors, as well as a signal detection system consisting of a digital-to-analog and analog-to-digital conversion module, a modulation and demodulation module, and a low-pass filtering module.

[0031] The broadband light source 1 in the present invention simultaneously drives three gyroscopes without the need for additional optical components. The three gyroscopes can measure rotational components along three axes. The gyroscope for the first axis consists of a first circulator 2, a first push-pull Y-branch 3, a first fiber ring resonator 4, and a first photodetector 5. The gyroscope for the second axis consists of a second circulator 6, a second push-pull Y-branch 7, a second fiber ring resonator 8, and a second photodetector 9. The gyroscope for the third axis consists of a third circulator 10, a third push-pull Y-branch 11, a third fiber ring resonator 12, and a third photodetector 13. The modulation signals and signal processing for the three gyroscopes are all implemented using an FPGA development board.

[0032] Furthermore, the specific connections between the three gyroscopes are as follows: port 1 of the first circulator 2 is connected to the broadband light source 1, port 2 of the first circulator 2 is connected to the input end of the first push-pull Y branch 3, port 3 of the first circulator 2 is connected to the first photodetector 5, and the two output ports of the first push-pull Y branch 3 are respectively connected to the same-side input ends of the two couplers of the first fiber ring resonator 4; the two vacant ports of the two couplers of the first fiber ring resonator 4 are respectively connected to port 1 of the second circulator 6 and the third circulator 10; port 2 of the second circulator 6 is connected to the input port of the second push-pull Y branch 7, port 3 of the second circulator 6 is connected to the second photodetector 9, and the two output ports of the second push-pull Y branch 7 are respectively connected to the same-side input ends of the two couplers of the second fiber ring resonator 8; port 2 of the third circulator 10 is connected to the input port of the third push-pull Y branch 11, port 3 of the third circulator 10 is connected to the third photodetector 13, and the two output ports of the third push-pull Y branch 11 are respectively connected to the same-side input ends of the two couplers of the third fiber ring resonator 12;

[0033] The three sinusoidal modulation signals generated by the modulation and demodulation module 15 are passed through the digital-to-analog conversion module 19 and applied to the first push-pull Y branch 3, the second push-pull Y branch 7, and the third push-pull Y branch 11, respectively. The three electrical signals output by the first photodetector 5, the second photodetector 9, and the third photodetector 13 are synchronously demodulated in the modulation and demodulation module after passing through the analog-to-digital conversion module 14. The frequencies of the demodulated signals are the same as the frequencies of the modulation signals applied to the first push-pull Y branch 3, the second push-pull Y branch 7, and the third push-pull Y branch 11, respectively. The three demodulated output signals of the modulation and demodulation module 15 are passed through the low-pass filter module 17 and collected by the data recorder 20 as the three axial gyroscope outputs of the three-axis gyroscope system.

[0034] The specific working process of the above optical gyroscope open-loop detection system is as follows:

[0035] After passing through the first circulator 2, the broadband light output by the broadband light source 1 is modulated at the first push-pull Y-branch 3 and split into two optical signals of equal optical power. The two modulated optical signals enter the resonant cavity from the same-side ports of the two couplers of the first fiber ring resonator 4 in a clockwise and counterclockwise direction, respectively, and transmit multiple turns within the cavity. After exiting the cavity, the two optical signals interfere at the input port of the first push-pull Y-branch 3 and are then input into the first photodetector 5 through port 3 of the first circulator 2 for photoelectric conversion. The output light from the two vacant ports of the two couplers of the first fiber ring resonator 4 is used to drive two other gyroscopes. The paths of the light beams in the other two gyroscopes are exactly the same as those described above, so they will not be described in detail. The phase modulation and demodulation module 15 generates three high-frequency sinusoidal modulation signals of different frequencies, which, after passing through the digital-to-analog conversion module 19, act on the three push-pull Y-branch signals respectively. The output signals of the three photodetectors pass through the analog / digital conversion module 14 and enter the modulation and demodulation module 15 for synchronous demodulation. The three demodulated outputs pass through the low-pass filter module 17 and are output to the data recorder 20. After the turntable is calibrated, the rotation information of the three axes can be represented.

[0036] The design of this series-connected three-axis gyroscope does not require additional optical components such as couplers to achieve light source reuse, as in previous three-axis gyroscopes. This makes the system structure simpler. At the same time, using the output light of the vacant port of the first fiber ring resonator 4 to drive the gyroscopes of the two outer axes also greatly improves the utilization rate of the light source power. All of these will greatly accelerate the process of practical application of resonant fiber optic gyroscopes.

[0037] From the above solutions, it can be seen that the present invention can drive three gyroscope systems using only one broadband light source without adding additional optical elements, which greatly simplifies the structure of the system and effectively improves the utilization rate of the light source.

[0038] The frequency of the modulation signal applied to the first push-pull Y branch is different from the frequency of the modulation signal applied to the second and third push-pull Y branches, thereby ensuring the independent operation of the three single-axis gyroscopes.

[0039] The three ring resonators in this scheme are all transmissive fiber ring resonators, and adopt a transmissive symmetrical connection method in which the clockwise and counterclockwise optical signals share the same input and output ports, which is extremely beneficial to improving the signal-to-noise ratio of the gyroscope output.

[0040] like Figure 3Figure 1 shows the single-axis output demodulation curve of a closed-loop detection system for a miniaturized three-axis resonant fiber gyroscope with broadband light source multiplexing. The demodulation curve shows that when the system is stationary, the demodulation output is 0. However, when the system rotates—that is, when there is a resonant frequency difference between the clockwise and counterclockwise beams—the demodulation output begins to change. By calibrating the relationship between the demodulation output and the actual angular velocity of the system's rotation, the angular velocity of the system's rotation can be obtained from the demodulation output.

[0041] Example 2, as Figure 2 and 5 As shown, this embodiment provides a closed-loop detection system for a miniaturized three-axis resonant fiber optic gyroscope with broadband light source multiplexing, which includes an optical system consisting of a broadband light source, three push-pull Y branches, three circulators, three transmission fiber optic ring resonators, and three photodetectors, as well as a signal detection system consisting of a digital / analog and analog / digital conversion module, a modulation and demodulation module, a servo control module, a frequency shift drive module, and a low-pass filter module. Compared with Example 1, the composition and structure of the optical part are corresponding, but Example 2 differs from Example 1 in the signal detection system. This embodiment also uses a broadband light source 1 to drive three gyroscopes simultaneously, and there is no need to add additional optical elements. The three gyroscopes can test the rotation components of the three axes respectively. The connection relationship of the components of the optical system is exactly the same as that of Example 1.

[0042] In Example 2, the three sinusoidal wave modulation signals generated by the modulation and demodulation module 15 are respectively applied to the first push-pull Y branch 3, the second push-pull Y branch 7 and the third push-pull Y branch 11 after passing through the digital-to-analog conversion module 19; the three electrical signals output by the first photodetector 5, the second photodetector 9 and the third photodetector 13 are synchronously demodulated in the modulation and demodulation module 15 after passing through the analog-to-digital conversion module 14, and the frequencies of the demodulated signals are respectively the same as the frequencies of the modulation signals applied to the first push-pull Y branch 3, the second push-pull Y branch 7 and the third push-pull Y branch 11. The three demodulated output signals of the modulation and demodulation module 15 are sent to the servo control module 16. The output signals of the servo control module 16 are output to the frequency shift drive module 18 and the low-pass filter module 17. The three output signals of the frequency shift drive module 18 are respectively applied to the three push-pull Y branches after passing through the digital-to-analog conversion module 19. The three output signals of the low-pass filter module 17 are collected by the data recorder 20 and used as the gyro outputs of the three axes of the three-axis gyroscope system.

[0043] The demodulated output signal of the modulation and demodulation module passes through the servo control module to generate a frequency control word (FCW) and send it to the frequency-shifting drive module. Based on the value of the FCW, the frequency-shifting drive module generates a sawtooth wave signal with a frequency equal to half the resonant frequency difference between the clockwise and counterclockwise beams and an amplitude equal to the full-wave voltage of the push-pull Y branch. After passing through the digital-to-analog conversion module, it acts on the push-pull Y branch, making the resonant frequency difference between the clockwise and counterclockwise beams zero.

[0044] The specific working process of the above optical gyro closed-loop system is as follows:

[0045] After passing through the first circulator 2, the broadband light output by the broadband light source 1 is modulated at the first push-pull Y-branch 3 and split into two optical signals of equal optical power. The two modulated optical signals enter the first fiber ring resonator 4 from the same-side ports of the two couplers in the clockwise and counterclockwise directions, respectively, and undergo multiple loops of transmission within the cavity. After exiting the cavity, the two optical signals interfere at the input port of the first push-pull Y-branch 3 and are then input into the first photodetector 5 through port 3 of the first circulator 2 for photoelectric conversion. The output light from the two unused ports of the two couplers of the first fiber ring resonator 4 is used to drive two additional gyroscopes. The paths of the light beams in the other two gyroscopes are identical to those described above and are therefore not further described. The modulation and demodulation module 15 generates three high-frequency sinusoidal modulation signals of different frequencies. After passing through the digital-to-analog conversion module 19, they act on the three push-pull Y-branch signals to modulate the optical signal. The servo control module 16 generates three different frequency control words based on the three demodulated output signals from the modulation and demodulation module 15 and transmits them to the frequency-shifting drive module 18, which generates the sawtooth wave signals used to implement a closed-loop system. The three sawtooth wave signals output by the frequency-shifting drive module 18 pass through the digital-to-analog conversion module 19 and are then applied to the three push-pull Y branches, thus achieving a closed-loop system. The sawtooth wave frequency should be exactly half the frequency difference between the clockwise and counterclockwise light beams caused by the rotation. The output signal of the servo control module 16 passes through the low-pass filtering module 17 and is then transmitted to the data recorder 20. After turntable calibration, it can represent the rotation information along the three axes.

[0046] The implementation of closed-loop detection will effectively improve the dynamic range of the gyroscope output and the linearity of the scale factor, thereby improving the overall performance of the gyroscope.

[0047] The above-described embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. Persons skilled in the art will readily appreciate that variations and modifications may be made without departing from the scope of the present invention, all of which fall within the scope of protection of the present invention.

Claims

1. An open-loop detection system for a miniaturized three-axis resonant fiber optic gyroscope with broadband light source multiplexing, characterized in that: It includes an optical system and a signal detection system. The optical system is composed of a broadband light source, three push-pull Y branches, three circulators, three transmission fiber ring resonators, and three photodetectors. The signal detection system is composed of a digital / analog conversion module, an analog / digital conversion module, a modulation and demodulation module, and a low-pass filter module. Port 1 of the first circulator is connected to a broadband light source, port 2 of the first circulator is connected to an input end of a first push-pull Y-branch, port 3 of the first circulator is connected to a first photodetector, and two output ports of the first push-pull Y-branch are respectively connected to the same-side input ends of two couplers of the first fiber ring resonator; two vacant ports of the two couplers of the first fiber ring resonator are respectively connected to port 1 of the second circulator and port 1 of the third circulator; port 2 of the second circulator is connected to an input port of a second push-pull Y-branch, port 3 of the second circulator is connected to a second photodetector, and two output ports of the second push-pull Y-branch are respectively connected to the same-side input ends of the two couplers of the second fiber ring resonator; port 2 of the third circulator is connected to an input port of a third push-pull Y-branch, port 3 of the third circulator is connected to a third photodetector, and two output ports of the third push-pull Y-branch are respectively connected to the same-side input ends of the two couplers of the third fiber ring resonator; The three sinusoidal wave modulation signals generated by the modulation and demodulation module are respectively applied to the first push-pull Y branch, the second push-pull Y branch, and the third push-pull Y branch after passing through the digital-to-analog conversion module; the three electrical signals output by the first photodetector, the second photodetector, and the third photodetector are synchronously demodulated in the modulation and demodulation module after passing through the analog-to-digital conversion module, and the frequencies of the demodulated signals are respectively the same as the frequencies of the modulation signals applied to the first push-pull Y branch, the second push-pull Y branch, and the third push-pull Y branch; the three demodulated output signals of the modulation and demodulation module are collected by the data recorder after passing through the low-pass filter module and are respectively used as the gyro outputs of the three axes of the three-axis gyroscope system.

2. The open-loop detection system of a miniaturized three-axis resonant fiber optic gyroscope with broadband light source multiplexing according to claim 1, characterized in that: The first circulator, the first push-pull Y-branch, the first fiber ring resonator and the first photodetector constitute a gyroscope of the first axis; The second circulator, the second push-pull Y-branch, the second fiber ring resonator and the second photodetector constitute a gyroscope of the second axis; The third circulator, the third push-pull Y-branch, the third fiber ring resonator and the third photodetector constitute a gyroscope of the third axis; The three gyroscopes are driven by only one broadband light source without adding any additional optical elements.

3. The open-loop detection system of a miniaturized three-axis resonant fiber optic gyroscope with broadband light source multiplexing according to claim 1, characterized in that: The frequency of the modulation signal applied to the first push-pull Y branch is different from the frequencies of the modulation signals applied to the second push-pull Y branch and the third push-pull Y branch.

4. The open-loop detection system of a miniaturized three-axis resonant fiber optic gyroscope with broadband light source multiplexing according to claim 1, characterized in that: The three ring resonators are all transmissive fiber ring resonators, and adopt a transmissive symmetrical connection method in which the optical signals in the clockwise and counterclockwise directions share the same input and output ports.

5. A closed-loop detection system for a miniaturized three-axis resonant fiber optic gyroscope with broadband light source multiplexing, characterized in that: It includes an optical system and a signal detection system; the optical system is composed of a broadband light source, three push-pull Y branches, three circulators, three transmission fiber ring resonators and three photodetectors; the signal detection system is composed of a digital / analog conversion module, an analog / digital conversion module, a modulation and demodulation module, a servo control module, a frequency shift drive module and a low-pass filter module; Port 1 of the first circulator is connected to a broadband light source, port 2 of the first circulator is connected to an input end of a first push-pull Y-branch, port 3 of the first circulator is connected to a first photodetector, and two output ports of the first push-pull Y-branch are respectively connected to the same-side input ends of two couplers of the first fiber ring resonator; two vacant ports of the two couplers of the first fiber ring resonator are respectively connected to port 1 of the second circulator and port 1 of the third circulator; port 2 of the second circulator is connected to an input port of a second push-pull Y-branch, port 3 of the second circulator is connected to a second photodetector, and two output ports of the second push-pull Y-branch are respectively connected to the same-side input ends of the two couplers of the second fiber ring resonator; port 2 of the third circulator is connected to an input port of a third push-pull Y-branch, port 3 of the third circulator is connected to a third photodetector, and two output ports of the third push-pull Y-branch are respectively connected to the same-side input ends of the two couplers of the third fiber ring resonator; The three sinusoidal wave modulation signals generated by the modulation and demodulation module are respectively applied to the first push-pull Y branch, the second push-pull Y branch and the third push-pull Y branch after passing through the digital-to-analog conversion module; the three electrical signals output by the first photodetector, the second photodetector and the third photodetector are synchronously demodulated in the modulation and demodulation module after passing through the analog-to-digital conversion module, and the frequencies of the demodulated signals are respectively the same as the frequencies of the modulation signals applied to the first push-pull Y branch, the second push-pull Y branch and the third push-pull Y branch; the three demodulated output signals of the modulation and demodulation module are sent to the servo control module, and the output signals of the servo control module are output to the frequency shift drive module and the low-pass filter module. The three output signals of the frequency shift drive module are respectively applied to the three push-pull Y branches after passing through the digital-to-analog conversion module, and the three output signals of the low-pass filter module are collected by the data recorder and used as the gyro outputs of the three axes of the three-axis gyroscope system.

6. The closed-loop detection system of a miniaturized three-axis resonant fiber optic gyroscope with broadband light source multiplexing according to claim 5, characterized in that: The demodulated output signal of the modulation and demodulation module passes through the servo control module to generate a frequency control word (FCW) and send it to the frequency-shifting drive module. Based on the value of the FCW, the frequency-shifting drive module generates a sawtooth wave signal with a frequency equal to half the resonant frequency difference between the clockwise and counterclockwise beams and an amplitude equal to the full-wave voltage of the push-pull Y branch. After passing through the digital-to-analog conversion module, it acts on the push-pull Y branch, making the resonant frequency difference between the clockwise and counterclockwise beams zero.

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