A fiber-optic gyroscope with high zero-bias stability in high-temperature variable-rate environment

Abstract

This invention provides a fiber optic gyroscope with high zero-bias stability in high-temperature, variable-rate environments. It includes a housing and a circuit module, an optical module, and a thermal insulation container structure housed within the housing. The optical module is disposed within the thermal insulation container structure and electrically connected to the circuit module via a first connector mounted on the thermal insulation container structure. The fiber optic gyroscope of this invention achieves thermal insulation for the optical module through the thermal insulation container structure. This design effectively reduces the impact of temperature gradients and temperature change rates on the optoelectronic components of the fiber optic gyroscope, thereby improving its zero-bias stability, especially in environments with high temperature change rates. Furthermore, the thermal insulation container structure isolates the optical module from the circuit module, eliminating interference between electrical and optical signals in the system.

Description

Technical Field

[0001] This invention belongs to the field of fiber optic gyroscope technology, and more specifically, relates to a fiber optic gyroscope with high zero-bias stability under high temperature and variable rate environments. Background Technology

[0002] The performance of each optoelectronic component in a fiber optic gyroscope changes under varying temperature conditions, thus affecting the overall performance of the gyroscope. For example:

[0003] For fiber optic loops, when the ambient temperature of a fiber optic gyroscope changes, a spatial temperature gradient is generated along the diameter or axis of the fiber coil. Heat will propagate from the high-temperature portion of the fiber coil to the low-temperature portion, and the rate of temperature change may differ at different points along the fiber's length. Since the fiber's refractive index changes with temperature, this difference in the rate of temperature change will generate a Shupe error, resulting in a zero-bias error. Simultaneously, thermal expansion and contraction of the fiber coil or the thermal expansion of the frame will cause scaling factor errors.

[0004] For the light source, the average wavelength varies with the cavity length due to the thermal expansion effect of the active region, and the shape of the spectrum (including the coherence function) varies with the scaling factor or zero-bias drift caused by temperature changes. The power of the light source varies with the gyro shot noise caused by temperature changes.

[0005] For photodetectors, the thermionic effect of the detector across resistance and the change in random walk performance caused by the change in dark current with temperature are considered.

[0006] For fiber optic couplers, thermal expansion and contraction cause changes in the splitting ratio and / or extinction ratio, increasing the noise of the fiber optic gyroscope.

[0007] For Y-waveguides, the coupling between the Y-waveguide and the optical fiber causes changes in the extinction ratio and splitting ratio due to thermal expansion, which affects zero-bias drift and noise. Changes in the Y-waveguide's photoelectric coefficient with temperature will cause changes in the half-wave voltage of the Y-waveguide, thus leading to changes in the scaling factor.

[0008] To address the impact of temperature changes on related optoelectronic components, the main techniques currently employed to suppress zero-bias shift in fiber optic gyroscopes under temperature variations include:

[0009] I. Rational layout and placement of heating elements;

[0010] II. Uniformity thermal design of distributed optical paths and thermal conductivity design of internal structures;

[0011] III. Uniformity design of the curing adhesive for fiber optic coils;

[0012] IV. The optical fiber ring is wound using a four-pole symmetric winding method to improve the thermal symmetry of the optical fiber ring;

[0013] Fifth, full-temperature compensation is performed on the fiber optic gyroscope through modeling to improve its zero-bias stability.

[0014] However, although the above technologies can suppress the zero bias of fiber optic gyroscopes to some extent, their suppression effect is not ideal when the fiber optic gyroscope is in a high-temperature, variable-rate application environment. Utility Model Content

[0015] The purpose of this invention is to solve the problem that the zero-bias suppression measures used in existing fiber optic gyroscopes are not effective in high-temperature variable-rate environments.

[0016] To achieve the above objectives, this utility model provides a fiber optic gyroscope with high zero-bias stability in a high-temperature variable-rate environment. The fiber optic gyroscope includes a package housing and a circuit module, an optical path module, and a thermal insulation container structure disposed within the package housing.

[0017] The optical path module is disposed within the thermal insulation container structure and is electrically connected to the circuit module through a first connector disposed on the thermal insulation container structure.

[0018] Optionally, the optical path module includes a light source, a coupler, a first detection branch, a second detection branch, and a third detection branch;

[0019] The first detection branch includes a first Y-waveguide, a first fiber optic loop, and a first photodetector;

[0020] The second detection branch includes a second Y-waveguide, a second fiber optic loop, and a second photodetector.

[0021] The third detection branch includes a third Y-waveguide, a third fiber optic loop, and a third photodetector;

[0022] The light source is used to output the main light signal;

[0023] The coupler is used to divide the main optical signal into three detection optical signals and to guide the three detection optical signals into three detection branches respectively.

[0024] Alternatively, the optical connections between the optical components in each detection branch are identical.

[0025] The first Y-waveguide is used to transmit the detection optical signal entering it to the first optical fiber ring, receive the feedback signal output by the first optical fiber ring corresponding to the detection optical signal, and transmit the feedback signal to the first photoelectric sensor.

[0026] Optionally, the circuit module includes:

[0027] A light source driver circuit board is used to drive the light source;

[0028] The detection circuit board is used to process the output signals of the first photodetector, the second photodetector, and the third photodetector 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 Y-waveguide, the second Y-waveguide, and the third Y-waveguide.

[0029] Optionally, the heat-insulating container structure is implemented using a threaded insulated can, which includes a can body and a cover, with the first connector disposed on the cover.

[0030] Optionally, the first Y-waveguide and the first fiber ring, the second Y-waveguide and the second fiber ring, and the third Y-waveguide and the third fiber ring are all implemented in the form of ring modules;

[0031] The ring module includes a corresponding Y-waveguide and a corresponding fiber optic ring, as well as a ring skeleton that matches the corresponding fiber optic ring and a magnetic shielding shell that encloses the corresponding Y-waveguide, fiber optic ring and ring skeleton.

[0032] Optionally, the optical path module may also include an adapter board;

[0033] The first photodetector, the second photodetector, and the third photodetector are all mounted on the adapter plate;

[0034] The adapter board is also provided with a light source connector, a Y-waveguide connector, and a second connector that matches the first connector.

[0035] Optionally, the light source driving circuit board is electrically connected to the detection circuit board;

[0036] A third connector that matches the first connector is provided on the detection circuit board.

[0037] The beneficial effects of this utility model are as follows:

[0038] This invention discloses a fiber optic gyroscope with high zero-bias stability under high-temperature and variable-rate environments. It includes a housing and a circuit module, an optical path module, and a thermal insulation container structure housed within the housing. The optical path module is disposed within the thermal insulation container structure and electrically connected to the circuit module via a first connector mounted on the thermal insulation container structure. The thermal insulation container structure provides thermal insulation for the optical path module, effectively reducing the impact of temperature gradients and rates of temperature change on the optoelectronic components of the fiber optic gyroscope, thereby improving its zero-bias stability, especially in environments with high temperature variations. Furthermore, the thermal insulation container structure isolates the optical path module from the circuit module, eliminating interference between electrical and optical signals within the system.

[0039] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0040] This 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.

[0041] Figure 1 A block diagram illustrating the principle of a fiber optic gyroscope with high zero-bias stability under high-temperature variable-rate conditions according to an embodiment of the present invention is shown.

[0042] Figure 2 A cross-sectional view of an assembly comprising an optical path module and a thermal insulation container structure according to an embodiment of the present invention is shown.

[0043] Figure 3 A schematic diagram of the electrical connection relationship according to an embodiment of the present invention is shown. Detailed Implementation

[0044] To enable those skilled in the art to more fully understand the technical solution of this utility model, exemplary embodiments of this utility model will be described more comprehensively and in detail below with reference to the accompanying drawings. Obviously, the one or more embodiments of this utility model described below are merely one or more specific ways to implement the technical solution of this utility model, and are not exhaustive. It should be understood that other ways belonging to a general inventive concept can be used to implement the technical solution of this utility model, and it should not be limited to the embodiments described exemplary. Based on one or more embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0045] Example: Figure 1 The diagram illustrates the principle block diagram of a fiber optic gyroscope with high zero-bias stability under high-temperature variable-rate conditions according to an embodiment of the present invention. Figure 2 This diagram shows a cross-sectional view of the assembly consisting of the optical path module and the heat-insulating container structure according to an embodiment of the present invention. Figure 3 A schematic diagram of the electrical connection relationship of an embodiment of the present invention is shown.

[0046] Reference Figures 1 to 3 The fiber optic gyroscope with high zero-bias stability in a high-temperature variable-rate environment according to this utility model embodiment includes a package housing 100 and a circuit module, an optical path module and a heat preservation container structure 200 disposed inside the package housing 100.

[0047] The optical path module is installed inside the heat-insulating container structure 200 and is electrically connected to the circuit module through the first connector 210 installed on the heat-insulating container structure 200.

[0048] Furthermore, in this embodiment of the present invention, the optical path module includes a light source 310, a coupler 320, a first detection branch, a second detection branch, and a third detection branch;

[0049] The first detection branch includes a first Y-waveguide, a first fiber optic loop, and a first photodetector 330;

[0050] The second detection branch includes a second Y-waveguide, a second fiber optic loop, and a second photodetector 340;

[0051] The third detection branch includes a third Y-waveguide, a third fiber optic loop, and a third photodetector 350;

[0052] Light source 310 is used to output the main light signal;

[0053] Coupler 320 is used to divide the main optical signal output by light source 310 into three detection optical signals and to guide the three detection optical signals into three detection branches respectively.

[0054] Furthermore, in this embodiment of the invention, the optical connection relationships between the optical devices in each detection branch are all the same;

[0055] The first Y-waveguide is used to transmit the detection optical signal entering it to the first optical fiber ring, receive the feedback signal output by the first optical fiber ring corresponding to the detection optical signal, and transmit the feedback signal to the first photoelectric sensor 330.

[0056] Furthermore, in this embodiment of the present invention, the coupler 320 is an integrated coupler;

[0057] Coupler 320 participates in the optical signal transmission of the first detection branch, the second detection branch, and the third detection branch simultaneously. Coupler 320 is used to divide the main optical signal output by the light source 310 into three detection optical signals. The first detection optical signal output by coupler 320 is transmitted to the first fiber ring through the first Y-waveguide. The first feedback signal output by the first fiber ring, corresponding to the first detection optical signal, is transmitted to the first photodetector 330 through the first Y-waveguide and coupler 320 in sequence. The second detection optical signal output by coupler 320 is transmitted to the second fiber ring through the second Y-waveguide. The second feedback signal output by the second fiber ring, corresponding to the second detection optical signal, is transmitted to the second photodetector 340 through the second Y-waveguide and coupler 320 in sequence. The third detection optical signal output by coupler 320 is transmitted to the third fiber ring through the third Y-waveguide. The third feedback signal output by the third fiber ring, corresponding to the third detection optical signal, is transmitted to the third photodetector 350 through the third Y-waveguide and coupler 320 in sequence.

[0058] Furthermore, in this embodiment of the invention, the circuit module includes:

[0059] The light source driver circuit board 410 is used to drive the light source 310;

[0060] The detection circuit board 420 is used to process the output signals of the first photodetector 330, the second photodetector 340, and the third photodetector 350 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 Y-waveguide, the second Y-waveguide, and the third Y-waveguide.

[0061] Furthermore, in this embodiment of the present invention, the heat-insulating container structure 200 is implemented using a threaded insulated can, which includes a can body 220 and a cover 230, with a first connector 210 disposed on the cover 230.

[0062] Furthermore, in this embodiment of the present invention, the first Y-waveguide and the first optical fiber ring are implemented in the form of a first ring module 360;

[0063] The second Y-waveguide and the second fiber optic ring are implemented in the form of a second ring module 370;

[0064] The third Y-waveguide and the third fiber optic ring are implemented in the form of a third ring module 380;

[0065] For any ring module, in addition to the corresponding Y-waveguide and the corresponding fiber ring, the ring module also includes a ring skeleton that matches the corresponding fiber ring and a magnetic shielding shell that encloses the corresponding Y-waveguide, fiber ring and ring skeleton.

[0066] Furthermore, in this embodiment of the present invention, the optical path module also includes an adapter board 390;

[0067] The first photodetector 330, the second photodetector 340, and the third photodetector 350 are all mounted on the adapter plate 390;

[0068] The adapter board 390 is also provided with a light source connector 391, a Y waveguide connector 392, and a second connector 393 that matches the first connector 210.

[0069] Furthermore, in this embodiment of the present invention, the light source driving circuit board 410 is electrically connected to the detection circuit board 420;

[0070] A third connector 421 that matches the first connector 210 is provided on the detection circuit board 420.

[0071] Specifically, in this embodiment of the present invention, the cover 230 is threadedly connected to the open end of the tank 220, and the first connector 210 is centrally and embeddedly disposed on the cover 230; the internal space of the heat-insulating container structure 200 is the accommodating space of the optical path module, and in the accommodating space from bottom to top are the light source 310, the internal support 240 for supporting each ring module, the assembly 3100 composed of the first ring module 360, the second ring module 370 and the third ring module 380, the adapter plate 390 and the fiber coil area 321 for placing the coupler 320.

[0072] Specifically, the fiber optic gyroscope with high zero-bias stability under high temperature and variable rate conditions in this embodiment of the present invention is a digital closed-loop fiber optic gyroscope. Digital closed-loop fiber optic gyroscopes operate based on the Sagnac effect. When the fiber optic gyroscope rotates, a phase difference (Φs) proportional to the rotational angular rate (Ω) is generated between two beams of light propagating clockwise and counterclockwise within the fiber loop. A photodetector converts this phase difference into a voltage signal, which is then converted into a digital signal by an analog-to-digital converter (A / D). The digital logic circuit demodulates this signal to obtain the phase error signal for the closed-loop control of the fiber optic gyroscope. This signal, after digital integration and filtering, becomes the output signal of the fiber optic gyroscope. Simultaneously, this phase error signal also serves as the phase feedback signal for the digital closed-loop fiber optic gyroscope. It is digitally integrated and superimposed with the fiber optic gyroscope bias modulation signal before entering the digital-to-analog converter (D / A). After signal amplification, it is applied to the Y-waveguide optical path device. The resulting phase difference between the two beams is equal in magnitude but opposite in sign to the Sagnac phase difference (Φs) caused by the rotation of the fiber optic gyroscope. Thus, the fiber optic gyroscope always operates near zero phase, forming a digital closed-loop feedback.

[0073] Specifically, in this embodiment of the invention, the insulated container structure 200 adopts thermos cup technology. Currently, thermos cup technology is very mature, achieving a 24-hour insulation level with an internal and external temperature difference of 70℃-80℃ or even higher. The insulated container structure 200 adopts a large-diameter flat insulated tank design, centrally arranging the light source 310, coupler 320, various ring modules, and various photodetectors—all of which are affected by temperature changes and thus impact the zero-bias stability of the fiber optic gyroscope—within the insulated container structure 200. This reduces the impact of external temperature changes on the optical devices of the fiber optic gyroscope, thereby improving the zero-bias stability of the fiber optic gyroscope.

[0074] The fiber optic gyroscope of this invention, exhibiting high zero-bias stability under high-temperature variable-rate conditions, has the following beneficial effects:

[0075] 1. Resistance to high temperature rate of change: When the temperature rate of change is very high, the optoelectronic device can still be guaranteed to be unaffected by the high temperature rate of change, thereby improving the stability of the product.

[0076] 2. Excellent sealing performance of optical devices: Reduces the impact of humidity on optical devices under temperature changes, and effectively protects the optical fibers in the optical devices during assembly and repair.

[0077] 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 present invention as defined in the appended claims.

Claims

1. A fiber optic gyroscope exhibiting high zero-bias stability under high-temperature variable-rate conditions, characterized in that, It includes a packaging housing and a circuit module, an optical module, and a thermal insulation container structure disposed within the packaging housing; The optical path module is disposed within the thermal insulation container structure and is electrically connected to the circuit module through a first connector disposed on the thermal insulation container structure.

2. The fiber optic gyroscope with high zero-bias stability under high-temperature variable-rate conditions according to claim 1, characterized in that, The optical path module includes a light source, a coupler, a first detection branch, a second detection branch, and a third detection branch; The first detection branch includes a first Y-waveguide, a first fiber optic loop, and a first photodetector; The second detection branch includes a second Y-waveguide, a second fiber optic loop, and a second photodetector. The third detection branch includes a third Y-waveguide, a third fiber optic loop, and a third photodetector; The light source is used to output the main light signal; The coupler is used to divide the main optical signal into three detection optical signals and to guide the three detection optical signals into three detection branches respectively.

3. The fiber optic gyroscope with high zero-bias stability under high-temperature variable-rate environment according to claim 2, characterized in that, The optical connections between the optical components in each detection branch are all the same; The first Y-waveguide is used to transmit the detection optical signal entering it to the first optical fiber ring, receive the feedback signal output by the first optical fiber ring corresponding to the detection optical signal, and transmit the feedback signal to the first photodetector.

4. The fiber optic gyroscope with high zero-bias stability under high-temperature variable-rate environment according to claim 3, characterized in that, The circuit module includes: A light source driver circuit board is used to drive the light source; The detection circuit board is used to process the output signals of the first photodetector, the second photodetector, and the third photodetector 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 Y-waveguide, the second Y-waveguide, and the third Y-waveguide.

5. The fiber optic gyroscope with high zero-bias stability under high-temperature variable-rate environment according to claim 4, characterized in that, The heat-insulating container structure is implemented using a threaded insulated can, which includes a can body and a cover, with the first connector disposed on the cover.

6. The fiber optic gyroscope with high zero-bias stability under high-temperature variable-rate environment according to claim 5, characterized in that, The first Y-waveguide and the first fiber ring, the second Y-waveguide and the second fiber ring, and the third Y-waveguide and the third fiber ring are all implemented in the form of ring modules; The ring module includes a corresponding Y-waveguide and a corresponding fiber optic ring, as well as a ring skeleton that matches the corresponding fiber optic ring and a magnetic shielding shell that encloses the corresponding Y-waveguide, fiber optic ring and ring skeleton.

7. The fiber optic gyroscope with high zero-bias stability under high-temperature variable-rate environment according to claim 6, characterized in that, The optical path module also includes an adapter board; The first photodetector, the second photodetector, and the third photodetector are all mounted on the adapter plate; The adapter board is also provided with a light source connector, a Y-waveguide connector, and a second connector that matches the first connector.

8. The fiber optic gyroscope with high zero-bias stability under high-temperature variable-rate conditions according to claim 7, characterized in that, The light source driving circuit board is electrically connected to the detection circuit board; A third connector that matches the first connector is provided on the detection circuit board.

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