An all-optoelectronic integrated fiber-optic gyroscope

Abstract

The application provides a full optoelectronic integrated fiber-optic gyroscope, which is internally provided with an integrated optical path module, three integrated optical modulators, three fiber rings, a light source circuit board and a detection circuit board; the integrated optical path module is integrated with a light source, a first coupler, three second couplers and three photodiodes; a SIP integrated circuit chip on the detection circuit board is integrated with an analog-digital conversion module, a processing module and a digital-analog conversion module; the second coupler, the integrated optical modulator, the fiber ring and the photodiode with a corresponding relationship 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 dividing the main light signal into three detection light signals and introducing the three detection light signals into the three detection branches respectively; the SIP integrated circuit chip is used for processing voltage analog signals output by the photodiodes to obtain angular rate data and optoelectronic control signals corresponding to the integrated optical modulators. The full optoelectronic integrated fiber-optic gyroscope has a smaller volume relative to the existing closed-loop fiber-optic gyroscope due to the integrated design of internal devices.

Description

Technical Field

[0001] This invention belongs to the field of fiber optic gyroscope technology, and more specifically, relates to a fully optoelectronic integrated fiber optic gyroscope. Background Technology

[0002] A fiber optic gyroscope is an angular rate sensor that senses relative inertial angular motion. It is currently the primary sensor used to determine the spatial attitude of moving objects and can be applied in various fields, including land, sea, air, and space. In recent years, various application fields have not only continuously increased the requirements for the sensing accuracy of fiber optic gyroscopes but also have a growing demand for miniaturization. Summary of the Invention

[0003] In view of this, the present invention provides a fully optoelectronic integrated fiber optic gyroscope, which can be made smaller in size compared to existing closed-loop fiber optic gyroscopes.

[0004] The fully optoelectronic integrated fiber optic gyroscope of the present invention includes a package 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 package housing;

[0005] The integrated optical path module integrates a light source, a first coupler, three second couplers, and three photodiodes;

[0006] 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.

[0007] 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.

[0008] The light source is configured to output a main light signal under the drive of the light source circuit board;

[0009] 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;

[0010] 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.

[0011] Alternatively, for any detection branch:

[0012] 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.

[0013] Optionally, a TIA chip is provided on the light source circuit board, which is used to amplify the voltage analog signal output by the photodiode.

[0014] Optionally, a pre-stage operational amplifier module and a post-stage operational amplifier module are also provided on the detection circuit board.

[0015] The preamplifier module is used to amplify the output signal of the TIA chip;

[0016] The analog-to-digital conversion module is used to perform analog-to-digital conversion on the output signal of the pre-amplifier module.

[0017] 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;

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

[0019] 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.

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

[0021] Alternatively, the integrated optical modulator can be implemented using a Y-waveguide.

[0022] The beneficial effects of this invention are as follows:

[0023] Firstly, the fully optoelectronic integrated fiber optic gyroscope of the present invention integrates the light source, first coupler, three second couplers, and three photodiodes into an integrated optical path module. Compared with the existing closed-loop fiber optic gyroscopes where the light source, coupler, and photodiodes are all implemented using discrete devices, the present invention uses a silicon photonics integration scheme to achieve chip-level packaging of the light source, coupler, and photodiodes, thereby reducing the size of the fully optoelectronic integrated fiber optic gyroscope to a corresponding extent. Secondly, the analog-to-digital conversion module, processing module, and digital-to-analog conversion module in the present invention are implemented using SIP integrated circuit chips, while the corresponding analog-to-digital conversion module, processing module, and digital-to-analog conversion module in the existing closed-loop fiber optic gyroscopes exist discretely. The size of the detection circuit board in the present invention can be made relatively smaller, thereby further reducing the size of the fully optoelectronic integrated fiber optic gyroscope.

[0024] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0025] The present invention can be better understood by referring to the following description taken in conjunction with the accompanying drawings, in which the same or similar reference numerals are used throughout the drawings to denote the same or similar parts.

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

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

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

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

[0030] Figure 5 A top view of an all-optical-integrated fiber optic gyroscope according to an embodiment of the present invention is shown. Detailed Implementation

[0031] To enable those skilled in the art to more fully understand the technical solutions of the present invention, exemplary embodiments of the present invention will be described more comprehensively and in detail below with reference to the accompanying drawings. Obviously, the one or more embodiments of the present invention described below are merely one or more specific ways to implement the technical solutions of the present invention, and are not exhaustive. It should be understood that other ways belonging to a general inventive concept can be used to implement the technical solutions of the present invention, and should not be limited to the embodiments described exemplary. Based on one or more embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0032] Example: Figure 1 A structural block diagram of the fully optoelectronic integrated fiber optic gyroscope according to an embodiment of the present invention is shown. Figure 2 The diagram shows the device distribution of the integrated optical path module according to an embodiment of the present invention.

[0033] Reference Figure 1 and Figure 2 The fully optoelectronic integrated fiber optic gyroscope of this invention includes a package housing 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 disposed within the package housing.

[0034] The integrated optical path module 100 integrates 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 equipped with a SIP integrated circuit chip 510, which integrates 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 the 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 the 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 the third detection branch;

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

[0040] The first coupler Y1 is used to divide the main optical signal output by the light source SLD into three detection optical signals, and to input the three detection optical 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 to process 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, as well as three photoelectric control signals for photoelectric control of the first integrated optical modulator 210, the second integrated optical modulator 220, and the third integrated optical modulator 230.

[0042] Specifically, the all-optical-integrated fiber optic gyroscope of this invention is based on the Sagnac effect, where the relationship between the intensity of the interference light 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 -π / 2 light intensity. When the gyroscope rotates, the light intensity at the π / 2 phase is no longer equal to the -π / 2 light intensity. At this point, a feedback phase difference is introduced until the light intensity at the π / 2 phase is equal to the -π / 2 light intensity. This yields the Sagnac phase difference, which is proportional to the angular rate, allowing the calculation of the angular rate, which is then output via a serial port.

[0043] Further, in this embodiment of the invention, for any detection branch: the coupler therein is used to transmit the detection optical signal entering it to the corresponding fiber optic ring through the corresponding integrated optical modulator, and the fiber optic ring is used to transmit the feedback signal corresponding to the detection optical signal to the corresponding photoelectric sensor in sequence through the corresponding integrated optical modulator and the corresponding coupler. Taking the first detection branch as an example, the second coupler Y2 is used to transmit the detection optical signal sent by the first coupler Y1 to the first fiber optic ring 310 through the first integrated optical modulator 210, and the first fiber optic ring 310 is used to transmit the feedback signal corresponding to the detection optical signal to the first photodiode PD1 in sequence through the first integrated optical modulator 210 and the second coupler Y2.

[0044] Furthermore, in this embodiment of the invention, a TIA chip is provided on the light source circuit board 400. The TIA chip is used to amplify the voltage analog signals output by the first photodiode PD1, the second photodiode PD2, and the third photodiode PD3.

[0045] Furthermore, in this embodiment of the invention, a pre-amplifier module 520 and a post-amplifier module 530 are also provided on the detection circuit board 500;

[0046] The preamplifier module 520 is used to amplify the output signal of the TIA chip;

[0047] The analog-to-digital converter module 511 is used to perform analog-to-digital conversion on the output signal of the preamplifier module 520;

[0048] Processing module 512 is used to process the output signal of analog-to-digital conversion module 511 to obtain angular rate data and photoelectric control signal;

[0049] The digital-to-analog converter module 513 is used to perform digital-to-analog conversion on the photoelectric control signal output by the processing module 512;

[0050] The post-amplifier module 530 is used to amplify the output signal of the digital-to-analog converter module 513 and transmit it to the corresponding integrated optical modulator.

[0051] Furthermore, in this embodiment of the invention, the processing module 512 sends the angular rate data to the external data receiving end through the internal serial port submodule.

[0052] Furthermore, in this embodiment of the invention, the first integrated optical modulator 210, the second integrated optical modulator 220 and the third integrated optical modulator 230 are implemented using Y-waveguides, i.e., lithium niobate waveguide optical integrated devices.

[0053] The fully optoelectronic integrated fiber optic gyroscope of the present invention will be described in more detail below:

[0054] 1) Structural design scheme:

[0055] The external dimensions are 89mm × 77mm × 48mm. The main objectives of the structural design are: first, to ensure a reasonable layout of internal components, secure component fixing, simplified assembly process, and good consistency of meter performance while strictly meeting overall structural requirements; second, to consider heat conduction issues and reduce the impact of heat generated by active components on sensitive elements; and third, to implement vibration-resistant design, which requires certain simulation processes to ensure basic redundancy in vibration characteristics. The structural shape is as follows. Figure 4 and Figure 5 As shown.

[0056] 2) Optical path design:

[0057] The integrated optical path module utilizes a silicon photonics integration solution to achieve chip-level replacement of traditional discrete fiber optic devices. It simultaneously integrates an SLD light source, coupler, and photodiode into a single package, providing functions such as light emission, beam splitting, and detection. The integrated layout of the optical path module is as follows: Figure 2 As shown.

[0058] 3) Circuit design:

[0059] Traditional detection circuit boards, to fulfill their functions, need to include a detector, a pre-amplifier (ADC), a signal processing FPGA, a post-amplifier (DAC), a signal amplifier circuit, and a power management circuit (LDO). Traditional circuit boards with these functions are at least 85mm × 85mm in size, which does not meet the requirements for integration and miniaturization. Therefore, this invention adopts a SiP (System-in-Package) circuit integration solution.

[0060] In this embodiment of the invention, the integrated optical path module directly outputs electrical signals, saving the need for a detector with photoelectric conversion function. The three-channel front-end analog-to-digital converter (ADC), signal processing FPGA, and three-channel rear-end digital-to-analog converter (DAC) are integrated into a SIP integrated circuit chip, significantly reducing the size of the signal processing unit. In addition to the signal processing unit, the chip also integrates a configuration memory unit (FLASH), multiple power management units (LDO), a communication unit (RS-422), etc., greatly reducing the size of the circuit board and the cost of the product while ensuring product accuracy, keeping the size of the detection circuit board within 45mm × 45mm. The circuit integration layout of the SIP integrated circuit chip is as follows: Figure 3 As shown.

[0061] The light source circuit board needs to provide power supply and drive, as well as temperature control, for the integrated optical path module. In this embodiment of the invention, the constant current function and the drive function are integrated on a single chip, further reducing the size of the light source circuit board. Furthermore, the circuit has a feedback function, using closed-loop feedback control of the light source power in the integrated optical path module by detecting changes in the current of the photodiode in the circuit.

[0062] This invention relates to an all-optical-integrated fiber optic gyroscope. The optical path consists of an integrated optical path module, a Y-waveguide, and a fiber optic ring. Compared to the five major optical components of traditional optics, this optical path only has three components; it integrates the light source, coupler, and detector into a single device. The circuitry consists of a light source circuit board and a detector circuit board. The light source circuit board primarily powers the integrated optical path module and implements constant current control and temperature control. The detector circuit board performs digital-to-analog conversion, signal processing, and serial port output, employing a SiP integrated chip. Compared to traditional solutions, this reduces the number of modules by two-thirds and the volume by half.

[0063] The fully optoelectronic integrated fiber optic gyroscope of this invention has the following beneficial effects:

[0064] 1. Compared with traditional closed-loop fiber optic gyroscopes, this solution reduces the volume by 1 / 3 under the same accuracy conditions, realizing product miniaturization and adapting to more demanding usage environments.

[0065] 2. This solution features full optoelectronic integration, reducing the number of major components by 2 / 3 and achieving lower product costs.

[0066] 3. This solution optimizes the assembly process by integrating optoelectronic devices, reducing assembly difficulty and decreasing assembly time by 1 / 3.

[0067] 4. Low cost, integrated, miniaturized, and easy to install; it can replace traditional medium and low fiber optic gyroscopes and is a standard component with high versatility and replaceability.

[0068] While one or more embodiments of the present invention have been described above, those skilled in the art will recognize that the present invention can be implemented in any other form without departing from its spirit and scope. Therefore, the embodiments described above are illustrative and not restrictive, and many modifications and substitutions will be apparent to those skilled in the art without departing from the spirit and scope of the invention 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, and the fiber optic ring is used to transmit the feedback signal corresponding to the detection optical signal to the photodiode 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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