All-photoelectric integrated fiber-optic gyroscope

Abstract

The invention provides an all-photoelectric integrated fiber-optic gyroscope. An integrated optical path module, three integrated optical modulators, three fiber-optic rings, a light source circuit board and a detection circuit board are arranged in the all-photoelectric integrated fiber-optic gyroscope; the integrated light path module is integrated with a light source, a first coupler, three second couplers and three photodiodes; an SIP integrated circuit chip on the detection circuit board is integrated with an analog-to-digital conversion module, a processing module and a digital-to-analog conversion module; the second coupler, the integrated optical modulator, the optical fiber ring and the photodiode which have a corresponding relation form a detection branch; the light source is configured to output a main light signal under the driving of the light source circuit board; the first coupler is used for equally dividing a main optical signal into three paths of detection optical signals and respectively guiding the three paths of detection optical signals into three detection branches; and the SIP integrated circuit chip is used for processing the voltage analog signal output by the photodiode to obtain angular rate data and a photoelectric control signal corresponding to the integrated optical modulator. Compared with the existing closed-loop fiber-optic gyroscope, the full-photoelectric integrated fiber-optic gyroscope disclosed by the invention has a smaller volume due to the integrated design of internal devices.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fiber-optic gyroscopes, and more particularly to a fully optoelectronic integrated fiber-optic gyroscope. BACKGROUND

[0002] A fiber-optic gyroscope is an angular rate sensor, a device for sensing angular motion in the inertial space, and a main sensor for determining the spatial motion posture of a moving body, which can be applied to various fields such as sea, land, air and space. In recent years, the application fields have not only continuously improved the sensing accuracy requirements of fiber-optic gyroscopes, but also increasingly demanded the miniaturization of fiber-optic gyroscopes. SUMMARY

[0003] Therefore, the present application provides a fully optoelectronic integrated fiber-optic gyroscope, which can be made smaller in size compared with existing closed-loop fiber-optic gyroscopes.

[0004] The fully optoelectronic integrated fiber-optic gyroscope of the present application comprises a packaging shell and an integrated optical path module, three integrated optical modulators, three fiber rings, a light source circuit board and a detection circuit board arranged in the packaging shell.

[0005] The integrated optical path module is integrated with a light source, a first coupler, three second couplers and three photodiodes.

[0006] The detection circuit board is provided with a SIP integrated circuit chip, which is integrated with an analog-to-digital conversion module, a processing module and a digital-to-analog conversion module.

[0007] The three second couplers, the three integrated optical modulators, the three fiber rings and the three photodiodes have a one-to-one correspondence relationship, and the second coupler, the integrated optical modulator, the fiber ring and the photodiode having the corresponding relationship constitute a detection branch.

[0008] The light source is configured to output a main optical signal under the driving of the light source circuit board.

[0009] The first coupler is used to divide the main optical signal into three detection optical signals and introduce the three detection optical signals into three detection branches, respectively.

[0010] The SIP integrated circuit chip is used to process the voltage analog signal output by the photodiode to obtain angular rate data and optoelectronic control signals for optoelectronic control of the integrated optical modulator.

[0011] As an option, for any detection branch:

[0012] The second coupler is used for transmitting the detection light signal into the integrated optical modulator to the optical fiber ring, and the optical fiber ring is used for transmitting the feedback signal corresponding to the detection light signal to the photoelectric sensor through the integrated optical modulator and the second coupler.

[0013] Optionally, a TIA chip is arranged on the light source circuit board, and the TIA chip is used for amplifying the voltage analog signal output by the photodiode.

[0014] Optionally, a front-stage operational amplifier module and a rear-stage operational amplifier module are further arranged on the detection circuit board.

[0015] The front-stage operational amplifier module is used for amplifying the output signal of the TIA chip.

[0016] The analog-to-digital conversion module is used for performing analog-to-digital conversion on the output signal of the front-stage operational amplifier module.

[0017] The processing module is used for processing the output signal of the analog-to-digital conversion module to obtain angular rate data and photoelectric control signals.

[0018] The digital-to-analog conversion module is used for performing digital-to-analog conversion on the photoelectric control signal output by the processing module.

[0019] The rear-stage operational amplifier module is used for amplifying the output signal of the digital-to-analog conversion module and transmitting the output signal to the integrated optical modulator.

[0020] Optionally, the processing module sends the angular rate data to an external data receiving end through an internal serial port submodule.

[0021] Optionally, the integrated optical modulator is implemented by using a Y waveguide.

[0022] The present application has the following beneficial effects:

[0023] In the first aspect, the all-optoelectronic integrated fiber-optic gyroscope of the present application integrates the light source, the first coupler, the three second couplers and the three photodiodes as an integrated optical path module. Compared with the prior art in which the light source, the coupler and the photodiode are realized by discrete devices, the present application adopts a silicon optical integration scheme to realize the chip-level packaging of the light source, the coupler and the photodiode, thereby reducing the volume of the all-optoelectronic integrated fiber-optic gyroscope to a certain extent. In the second aspect, the analog-digital conversion module, the processing module and the digital-analog conversion module in the present application are realized by an SIP integrated circuit chip, while the corresponding analog-digital conversion module, the processing module and the digital-analog conversion module in the prior art are discrete. The volume of the detection circuit board in the present application can be relatively smaller, thereby further reducing the volume of the all-optoelectronic integrated fiber-optic gyroscope.

[0024] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0025] The present application can be better understood by reference to the following description taken in connection with the accompanying drawings, in which like reference numerals refer to like elements or features, and in which:

[0026] Figure 1 A structural block diagram of an all-optoelectronic integrated fiber-optic gyroscope according to an embodiment of the present application is shown;

[0027] Figure 2 A device distribution diagram of an integrated optical path module according to an embodiment of the present application is shown;

[0028] Figure 3 A principle block diagram of an SIP integrated circuit chip according to an embodiment of the present application is shown;

[0029] Figure 4 A front view of an all-optoelectronic integrated fiber-optic gyroscope according to an embodiment of the present application is shown;

[0030] Figure 5 A top view of an all-optoelectronic integrated fiber-optic gyroscope according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0031] For those skilled in the art to have a more full understanding of the technical solutions of the present application, in the following, exemplary embodiments of the present application will be described more fully and in greater detail with reference to the accompanying drawings. Obviously, one or more embodiments of the present application described below are only one or more of the specific manners in which the technical solutions of the present application can be implemented, and are not exhaustive. It should be understood that the technical solutions of the present application can be implemented in other manners belonging to one general inventive concept without being limited by the exemplary described embodiments. Based on one or more embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts should belong to the scope of protection of the present application.

[0032] Embodiment: Figure 1 A structural block diagram of an all-optical integrated fiber-optic gyroscope according to an embodiment of the present application is shown, Figure 2 A device distribution diagram of an integrated optical path module according to an embodiment of the present application is shown.

[0033] With reference to Figure 1 and Figure 2 An all-optical integrated fiber-optic gyroscope according to an embodiment of the present application includes a packaging shell and an integrated optical path module 100, a first integrated optical modulator 210, a second integrated optical modulator 220, a third integrated optical modulator 230, a first fiber-optic ring 310, a second fiber-optic ring 320, a third fiber-optic ring 330, a light source circuit board 400 and a detection circuit board 500 arranged in the packaging shell;

[0034] The integrated optical path module 100 is integrated with a light source SLD, a first coupler Y1, a second coupler Y2, a third coupler Y3, a fourth coupler Y4, a first photodiode PD1, a second photodiode PD2 and a third photodiode PD3;

[0035] The detection circuit board 500 is provided with a SIP integrated circuit chip 510, and the SIP integrated circuit chip 510 is integrated with an analog-to-digital conversion module 511, a processing module 512 and a digital-to-analog conversion module 513;

[0036] The second coupler Y2, the first integrated optical modulator 210, the first fiber-optic ring 310 and the first photodiode PD1 constitute a first detection branch;

[0037] The third coupler Y3, the second integrated optical modulator 220, the second fiber-optic ring 320 and the second photodiode PD2 constitute a second detection branch;

[0038] The fourth coupler Y4, the third integrated optical modulator 230, the third fiber-optic ring 330 and the third photodiode PD3 constitute a third detection branch;

[0039] The light source SLD is configured to output a main light signal under the driving of the light source circuit board 400;

[0040] The first coupler Y1 is used for splitting the main light signal output by the light source SLD into three detection light signals and introducing the three detection light signals into the first detection branch, the second detection branch and the third detection branch respectively.

[0041] The SIP integrated circuit chip 510 is used for processing the voltage analog signals output by the first photodiode PD1, the second photodiode PD2 and the third photodiode PD3 to obtain X-axis angular rate data, Y-axis angular rate data and Z-axis angular rate data, and processing the three photoelectric control signals for photoelectrically controlling the first integrated optical modulator 210, the second integrated optical modulator 220 and the third integrated optical modulator 230.

[0042] Specifically, the all-optoelectronic integrated fiber-optic gyroscope of the embodiment of the present application is based on the Sagnac effect, and the relationship between the interference light intensity and the Sagnac phase shift is a cosine function. The method for detecting the Sagnac phase difference is to introduce a ±π / 2 modulation. When the gyroscope is stationary, the light intensity at the π / 2 phase is equal to the light intensity at the -π / 2 phase. When the gyroscope rotates, the light intensity at the π / 2 phase is not equal to the light intensity at the -π / 2 phase. At this time, a feedback phase difference is introduced until the light intensity at the π / 2 phase is equal to the light intensity at the -π / 2 phase. Thus, the Sagnac phase difference proportional to the angular rate is obtained, so that the angular rate is calculated and output through a serial port.

[0043] Further, in the embodiment of the present application, for any detection branch: the coupler therein is used for transmitting the detection light signal entering therein to the corresponding fiber ring through the corresponding integrated optical modulator; and the fiber ring therein is used for transmitting the feedback signal corresponding to the detection light signal to the corresponding photoelectric sensor in turn through the corresponding integrated optical modulator and the corresponding coupler. Taking the first detection branch as an example, the second coupler Y2 is used for transmitting the detection light signal sent by the first coupler Y1 to the first fiber ring 310 through the first integrated optical modulator 210, and the first fiber ring 310 is used for transmitting the feedback signal corresponding to the detection light signal to the first photodiode PD1 in turn through the first integrated optical modulator 210 and the second coupler Y2.

[0044] Still further, in the embodiment of the present application, a TIA chip is arranged on the light source circuit board 400, and the TIA chip is used for amplifying the voltage analog signals output by the first photodiode PD1, the second photodiode PD2 and the third photodiode PD3.

[0045] Still further, in the embodiment of the present application, a pre-stage operational amplifier module 520 and a post-stage operational amplifier module 530 are further arranged on the detection circuit board 500.

[0046] The pre-stage operational amplifier module 520 is used for amplifying the output signal of the TIA chip;

[0047] The analog-digital conversion module 511 is used for analog-digital converting the output signal of the pre-stage operational amplifier module 520;

[0048] The processing module 512 is used for processing the output signal of the analog-digital conversion module 511 to obtain the angular rate data and the optoelectronic control signal;

[0049] The digital-analog conversion module 513 is used for digital-analog converting the optoelectronic control signal output by the processing module 512;

[0050] The post-stage operational amplifier module 530 is used for amplifying the output signal of the digital-analog conversion module 513 and transmitting the output signal to the corresponding integrated optical modulator.

[0051] Further, in the embodiment of the present application, the processing module 512 sends the angular rate data to the external data receiving end through the internal serial port sub-module.

[0052] Further, in the embodiment of the present application, the first integrated optical modulator 210, the second integrated optical modulator 220 and the third integrated optical modulator 230 are implemented by Y waveguide, i.e. lithium niobate waveguide optical integrated device.

[0053] The all-optoelectronic integrated fiber optic gyroscope in the embodiment of the present application is described in more detail as follows:

[0054] 1) Structural scheme design:

[0055] The outer dimension is 89mmx77mmx48mm. The main purpose of the structural design is: firstly, to make the layout of internal components reasonable, the components fixed firmly, the assembly process simple and the performance of the table head consistent under the premise of strictly meeting the overall structural requirements; secondly, to consider the heat conduction problem and reduce the influence of the heat generated by the active device on the sensitive element; thirdly, to design the anti-vibration and need to go through a certain simulation link to ensure the basic redundancy of the vibration characteristics. The structural appearance is shown in Figure 4 and Figure 5 .

[0056] 2) Optical path scheme design:

[0057] The integrated optical path module uses the silicon optical integration scheme to realize the chip-level replacement of the traditional fiber discrete device, and realizes the three-in-one packaging of the SLD light source, the coupler and the photodiode, and has the functions of light emission, beam splitting and detection. The integrated layout of the integrated optical path module is shown in Figure 2 .

[0058] 3) Circuit scheme design:

[0059] The traditional detection circuit board needs to include a detector, a front-stage analog-to-digital converter (ADC), a signal processing FPGA, a rear-stage digital-to-analog converter (DAC), a signal amplification circuit, a power management circuit (LDO), etc. to complete its function. The volume of the traditional circuit board with the above functions is not less than 85mm*85mm, which does not meet the requirements of integration and miniaturization scheme, therefore, the SIP circuit integration scheme is adopted in the embodiment of the present application.

[0060] In the embodiment of the present application, the integrated optical path module directly outputs an electrical signal, and the detector for photoelectric conversion function is saved. The three-way front-stage analog-to-digital converter (ADC), the signal processing FPGA, and the three-way rear-stage digital-to-analog converter (DAC) are integrated into a SIP integrated circuit chip, which greatly saves the volume of the signal processing unit. In addition to the signal processing unit, the chip also integrates a configuration storage unit (FLASH), a plurality of power management units (LDO), a communication unit (RS-422), etc., which greatly saves the volume of the circuit board and the cost of the product while ensuring the accuracy of the product, so that the volume of the detection circuit board is ensured to be within 45mm*45mm. The circuit integration layout of the SIP integrated circuit chip is shown in Figure 3 .

[0061] The light source circuit board needs to realize power supply driving and temperature control for the integrated optical path module. In the embodiment of the present application, the constant current function and the driving function are monolithically integrated, which further reduces the volume of the light source circuit board. The circuit has a feedback function, which controls the power of the light source in the integrated optical path module through closed-loop feedback control of the current change of the photodiode in the detection circuit.

[0062] The all-optical-electric integrated fiber optic gyroscope in the embodiment of the present application has an optical path part composed of an integrated optical path module, a Y waveguide, and a fiber ring, and only three optical devices compared with the traditional five optical devices. The light source, the coupler, and the detector are integrated into one device. The circuit part is composed of a light source circuit board and a detection circuit board. The light source circuit board mainly supplies power for the integrated optical path module, and realizes constant current control and temperature control of the module. The detection circuit board realizes digital-to-analog conversion, signal processing, serial output, and adopts a SIP integrated chip. Compared with the traditional scheme, the module is reduced by 2 / 3, and the volume is reduced by 1 / 2.

[0063] The all-optical-electric integrated fiber optic gyroscope in the embodiment of the present application has the following beneficial effects:

[0064] 1. Compared with the traditional closed-loop fiber optic gyroscope, the volume is reduced by 1 / 3 under the same accuracy, which realizes the miniaturization of the product and can adapt to the use environment with more stringent volume requirements.

[0065] 2. The all-optical-electric integration of the present scheme reduces the main devices by 2 / 3, which realizes lower cost of the product.

[0066] 3. The scheme optimizes the assembly process through the integration of the photoelectric device, reduces the assembly difficulty, and reduces the assembly time by 1 / 3.

[0067] 4. The low-cost, integrated, miniaturized, and easy-to-install device can replace the traditional low-cost fiber-optic gyroscope and is a standard part with high universality and replaceability.

[0068] Although one or more embodiments of the present application have been described above with a certain degree of particularity, one skilled in the art could make numerous alterations to the details of the present application without departing from the spirit and the scope of the present application as defined in the appended claims.

Claims

1. A fully optoelectronic integrated fiber optic gyroscope, characterized in that, It includes a housing and an integrated optical path module, three integrated optical modulators, three fiber optic rings, a light source circuit board, and a detection circuit board disposed within the housing; The integrated optical path module integrates a light source, a first coupler, three second couplers, and three photodiodes; The detection circuit board is equipped with a SIP integrated circuit chip, which integrates an analog-to-digital conversion module, a processing module, and a digital-to-analog conversion module. There is a one-to-one correspondence between the three second couplers, the three integrated optical modulators, the three fiber optic rings, and the three photodiodes. The corresponding second couplers, integrated optical modulators, fiber optic rings, and photodiodes constitute a detection branch. The light source is configured to output a main light signal under the drive of the light source circuit board; The first coupler is used to split the main optical signal into three detection optical signals and to guide the three detection optical signals into three detection branches respectively; The SIP integrated circuit chip is used to process the voltage analog signal output by the photodiode to obtain angular rate data and photoelectric control signals for photoelectric control of the integrated optical modulator.

2. The fully optoelectronic integrated fiber optic gyroscope according to claim 1, characterized in that, For any detection branch: The second coupler is used to transmit the detection optical signal entering it to the fiber optic ring through the integrated optical modulator. The fiber optic ring is used to transmit the feedback signal corresponding to the detection optical signal to the photoelectric sensor in sequence through the integrated optical modulator and the second coupler.

3. The fully optoelectronic integrated fiber optic gyroscope according to claim 2, characterized in that, A TIA chip is provided on the light source circuit board, which is used to amplify the voltage analog signal output by the photodiode.

4. The fully optoelectronic integrated fiber optic gyroscope according to claim 3, characterized in that, The detection circuit board is also equipped with a pre-amplifier module and a post-amplifier module. The preamplifier module is used to amplify the output signal of the TIA chip; The analog-to-digital conversion module is used to perform analog-to-digital conversion on the output signal of the pre-amplifier module. The processing module is used to process the output signal of the analog-to-digital conversion module to obtain angular rate data and photoelectric control signals; The digital-to-analog conversion module is used to perform digital-to-analog conversion on the photoelectric control signal output by the processing module; The post-amplifier module is used to amplify the output signal of the digital-to-analog converter module and transmit it to the integrated optical modulator.

5. The fully optoelectronic integrated fiber optic gyroscope according to claim 4, characterized in that, The processing module sends the angular rate data to the external data receiving end through its internal serial port submodule.

6. The fully optoelectronic integrated fiber optic gyroscope according to claim 5, characterized in that, The integrated optical modulator is implemented using a Y-waveguide.

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