Fiber Optic Gyroscope for Suppressing Startup Drift

Abstract

The present application relates to an optical fiber gyroscope for suppressing startup drift. On the basis of an existing optical fiber gyroscope including a light source, a coupler, a Y waveguide, an optical fiber ring, a detector and a signal processing circuit, a temperature sensor, a temperature control box and a hub are added. Among them, the coupler is respectively connected to the light source, the detector and the Y waveguide; the signal control circuit is respectively connected to the detector, the temperature sensor, the Y waveguide and the temperature control box. Since the optical fiber ring is wound with a first optical fiber and a second optical fiber, the Y waveguide and the optical fiber ring are connected through a first optical fiber pigtail and a second optical fiber pigtail, the hub is arranged in the temperature control box, and the first optical fiber pigtail or the second optical fiber pigtail is wound on the hub. During operation, the signal processing circuit performs temperature compensation on the first optical fiber pigtail or the second optical fiber pigtail wound on the hub in real time through the temperature control box according to the sensitive angular rate information and temperature information of the optical fiber gyroscope, so as to generate an error effect opposite to the temperature effect of the optical fiber ring and compensate for the zero drift of the optical fiber gyroscope caused by startup heat.

Description

Technical Field

[0001] This application relates to the technical field of angular rate sensors, and particularly to an optical fiber gyroscope for suppressing startup drift. Background Art

[0002] An optical fiber gyroscope is a temperature-sensitive angular rate sensor. In the application of an inertial navigation system of an optical fiber gyroscope, due to its own circuit heating and heat exchange between external devices and the environment, both will affect the zero position of the optical fiber gyroscope. Especially in the initial startup stage of the inertial navigation system, the heat of the heating components in the system will be conducted to the sensitive component of the optical fiber gyroscope - the optical fiber ring, resulting in startup zero position drift of the optical fiber gyroscope. Seriously, the gyroscope accuracy will be reduced by 1 - 2 orders of magnitude, which is not conducive to applications such as rapid alignment of the system. Summary of the Invention

[0003] To overcome the problems existing in the related art to at least a certain extent, this application provides an optical fiber gyroscope for suppressing startup drift.

[0004] The solution of this application is as follows:

[0005] An optical fiber gyroscope for suppressing startup drift, comprising:

[0006] A light source, a coupler, a Y waveguide, an optical fiber ring, a detector, a temperature sensor, a signal processing circuit, a temperature control box, and a hub;

[0007] The coupler is respectively connected to the light source, the detector, and the Y waveguide;

[0008] The signal control circuit is respectively connected to the detector, the temperature sensor, the Y waveguide, and the temperature control box;

[0009] The optical fiber ring is wound with a first optical fiber and a second optical fiber;

[0010] The Y waveguide and the optical fiber ring are connected through a first optical fiber pigtail and a second optical fiber pigtail;

[0011] The hub is arranged inside the temperature control box;

[0012] The first optical fiber pigtail or the second optical fiber pigtail is also wound around the hub;

[0013] The detector is used to detect the sensitive angular rate information of the optical fiber gyroscope and send it to the signal processing circuit;

[0014] The temperature sensor is used to detect the temperature information of the optical fiber gyroscope and send it to the signal processing circuit;

[0015] The signal processing circuit is used to perform temperature compensation on the first optical fiber pigtail or the second optical fiber pigtail wound on the wheel hub through the temperature control box according to the sensitive angular rate information and the temperature information.

[0016] Preferably, in an implementable manner of the present application,

[0017] The wheel hub is fixed in the temperature control box through a metal connecting piece.

[0018] Preferably, in an implementable manner of the present application,

[0019] The first optical fiber and the second optical fiber are wound on the optical fiber loop in opposite directions.

[0020] Preferably, in an implementable manner of the present application,

[0021] A semiconductor temperature control device is arranged in the temperature control box.

[0022] Preferably, in an implementable manner of the present application,

[0023] The wheel hub is a metal wheel hub.

[0024] Preferably, in an implementable manner of the present application,

[0025] The signal processing circuit includes: a signal control circuit and a temperature control circuit;

[0026] The signal control circuit is respectively connected to the detector, the temperature sensor, the Y waveguide and the temperature control circuit;

[0027] The temperature control circuit is connected to the temperature control box.

[0028] Preferably, in an implementable manner of the present application, the optical fiber pigtail wound on the wheel hub is the optical fiber pigtail with a lower equivalent temperature among the optical fiber temperature deviations of the first optical fiber and the second optical fiber obtained through simulation calculation.

[0029] Preferably, in an implementable manner of the present application, the winding length of the first optical fiber pigtail or the second optical fiber pigtail on the wheel hub is 50 cm - 100 cm.

[0030] Preferably, in an implementable manner of the present application, the winding length of the first optical fiber pigtail or the second optical fiber pigtail on the wheel hub is determined by the optical fiber temperature deviation between the first optical fiber and the second optical fiber.

[0031] Preferably, in an implementable manner of the present application,

[0032] The first optical fiber and the second optical fiber are wound around the optical fiber loop in a quadrupole symmetry manner.

[0033] The technical solution provided by this application may include the following beneficial effects:

[0034] In the fiber optic gyroscope for suppressing startup drift in this application, on the basis of the existing fiber optic gyroscope including a light source, a coupler, a Y waveguide, an optical fiber loop, a detector, and a signal processing circuit, a temperature sensor, a temperature control box, and a hub are added. Among them, the coupler is respectively connected to the light source, the detector, and the Y waveguide; the signal control circuit is respectively connected to the detector, the temperature sensor, the Y waveguide, and the temperature control box. Since the optical fiber loop is wound with the first optical fiber and the second optical fiber, the Y waveguide and the optical fiber loop are connected through the first optical fiber pigtail and the second optical fiber pigtail, and the hub is arranged in the temperature control box, and the first optical fiber pigtail or the second optical fiber pigtail is wound around the hub. During operation, the detector detects the sensitive angular rate information of the fiber optic gyroscope and sends it to the signal processing circuit, the temperature sensor detects the temperature information of the fiber optic gyroscope and sends it to the signal processing circuit, and the signal processing circuit compensates the temperature of the first optical fiber pigtail or the second optical fiber pigtail wound around the hub in real time through the temperature control box according to the sensitive angular rate information and temperature information of the fiber optic gyroscope, so as to generate an error effect opposite to the temperature effect of the optical fiber loop and compensate for the zero drift of the fiber optic gyroscope caused by startup heat.

[0035] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this application. Brief Description of the Drawings

[0036] The drawings here are incorporated into the specification and constitute a part of this specification, showing the embodiments in line with this application, and are used together with the specification to explain the principles of this application.

[0037] Figure 1 is a schematic structural diagram of a fiber optic gyroscope for suppressing startup drift provided by an embodiment of this application;

[0038] Figure 2 is a schematic structural diagram of a fiber optic gyroscope for suppressing startup drift provided by another embodiment of this application.

[0039] Reference Numerals: Light Source - 1; Coupler - 2; Y Waveguide - 3; Optical Fiber Loop - 4; Detector - 5; Signal Processing Circuit - 6; Signal Control Circuit - 61; Temperature Control Circuit - 62; Temperature Control Box - 7; Hub - 8; Temperature Sensor - 9. Detailed Description of the Embodiments

[0040] Exemplary embodiments will be described in detail herein, and examples thereof are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0041] Figure 1 It is a schematic structural diagram of an optical fiber gyroscope for suppressing startup drift provided by an embodiment of the present application. Referring to Figure 1 An optical fiber gyroscope for suppressing startup drift includes:

[0042] A light source 1, a coupler 2, a Y waveguide 3, an optical fiber loop 4, a detector 5, a temperature sensor 9, a signal processing circuit 6, a temperature control box 7, and a hub 8;

[0043] The coupler 2 is respectively connected to the light source 1, the detector 5, and the Y waveguide 3;

[0044] The signal control circuit 61 is respectively connected to the detector 5, the temperature sensor 9, the Y waveguide 3, and the temperature control box 7;

[0045] The optical fiber loop 4 is wound with a first optical fiber and a second optical fiber;

[0046] The Y waveguide 3 and the optical fiber loop 4 are connected through a first optical fiber pigtail and a second optical fiber pigtail;

[0047] The hub 8 is arranged inside the temperature control box 7;

[0048] The first optical fiber pigtail or the second optical fiber pigtail is wound around the hub 8;

[0049] The detector 5 is used to detect the sensitive angular rate information of the optical fiber gyroscope and send it to the signal processing circuit 6;

[0050] The temperature sensor 9 is used to detect the temperature information of the optical fiber gyroscope and send it to the signal processing circuit 6;

[0051] The signal processing circuit 6 is used to perform temperature compensation on the first optical fiber pigtail or the second optical fiber pigtail wound around the hub 8 through the temperature control box 7 according to the sensitive angular rate information and the temperature information.

[0052] In the manufacturing technology of the optical fiber loop 4, the optical fiber needs to be wound around the skeleton of the optical fiber loop 4 according to a certain winding method. According to the working principle of the optical fiber loop 4, the optical signal generated by the light source 1 is input from the two ends of the optical fiber respectively. In order to minimize the external disturbance received by the optical signal, after the optical signal is synchronously input into the optical fiber, the optical paths experienced are the same, and the external disturbances received at the same moment are the same. Only in this way can the error introduced by external factors be eliminated when the two beams of light return for interference, thereby ensuring the use accuracy of the optical fiber gyroscope.

[0053] The fiber optic pigtail refers to the remaining part after the first optical fiber and the second optical fiber are wound around the optical fiber loop 4.

[0054] Preferably, in this embodiment, the first optical fiber and the second optical fiber are wound around the optical fiber loop 4 in a quadrupole symmetric manner, largely eliminating the temperature-induced phase error.

[0055] Temperature is the most important environmental factor affecting the generation of phase error in the optical fiber loop 4. The Shupe effect of the fiber optic gyroscope caused by temperature can be expressed as:

[0056]

[0057] Among them, Ω is the zero drift of the gyroscope, n is the refractive index of the optical fiber, λ is the optical wavelength, c0 is the speed of light in vacuum, β0 is the optical propagation constant, ΔT(z) represents the temperature change at the z point of the optical fiber sensing loop, L is the length of the optical fiber, and D is the diameter of the loop. It can be seen from the formula that if there is a temperature difference between two points symmetric about the midpoint, it will cause a detection angular rate signal error in the final optical fiber loop 4.

[0058] During the startup phase of the fiber optic gyro inertial navigation system, each circuit component in the system starts to work and generates heat, which is conducted to the optical fiber loop 4 through heat conduction. The original thermal balance of the optical fiber loop 4 is broken. Since the materials used to make the optical fiber loop 4 are all poor conductors of heat, these heats will not quickly balance on the optical fiber loop 4, but will generate a temperature difference on the optical fiber loop 4, resulting in a zero drift of the optical fiber loop 4, that is, the so-called startup drift.

[0059] The fiber optic gyro generally consists of a light source 1, a coupler 2, a Y waveguide 3, an optical fiber loop 4, a detector 5, and a processing circuit. After the optical fiber loop 4 is wound, its drift with temperature is fixed, and startup drift will occur during the startup phase.

[0060] The first optical fiber and the second optical fiber are wound around the optical fiber loop in opposite directions. For example, the first optical fiber is wound clockwise around the optical fiber loop 4, and the second optical fiber is wound counterclockwise around the optical fiber loop 4.

[0061] In this embodiment, first, by means of simulation calculation, the influence of external heating devices on the optical fiber loop 4 in the initial startup stage is calculated to quantify the startup drift. At the same time, the startup process of the fiber optic gyro without the temperature control box 7 and the hub 8 is tested to verify the simulation calculation results and correct the parameters.

[0062] Since the first optical fiber and the second optical fiber may have different lengths, there will be a certain equivalent temperature deviation between the first optical fiber and the second optical fiber. Based on the simulation calculation results and verification tests, determine the temperature deviation of the optical fibers on both sides of the fiber optic loop 4 that is equivalent to the start-up drift. Wind the optical fiber pigtail with the lower equivalent temperature around the hub 8.

[0063] The winding length of the first optical fiber pigtail or the second optical fiber pigtail on the hub 8 is 50 cm - 100 cm, and the winding length is determined by the temperature deviation of the first optical fiber and the second optical fiber.

[0064] Using the start-up characteristic data obtained from the test, determine the magnitude of the temperature drift at different temperatures and the corresponding temperature deviation values. Control the temperature value in the temperature control box according to the gyro output value and the temperature deviation value. And as time goes by, the temperature control value also changes accordingly, matching the start-up drift curve.

[0065] Among them, the gyro output value is calculated by the signal processing circuit based on the sensitive angular rate information of the fiber optic gyro detected by the detector.

[0066] The temperature deviation value is obtained based on the temperature information detected by the temperature sensor.

[0067] When the fiber optic gyro starts up, the fiber optic loop 4 generates a zero-offset drift with temperature. The detector 5 detects the sensitive angular rate information of the fiber optic gyro and sends it to the signal processing circuit 6. The temperature sensor 9 detects the temperature information of the fiber optic gyro and sends it to the signal processing circuit 6. The signal processing circuit 6 compensates the temperature of the first optical fiber pigtail or the second optical fiber pigtail wound on the hub 8 in real time through the temperature control box 7 according to the sensitive angular rate information and temperature information of the fiber optic gyro, thereby generating an error effect opposite to the temperature effect of the fiber optic loop 4 and compensating the zero-offset drift of the fiber optic gyro caused by the start-up heat.

[0068] The fiber optic gyro for suppressing start-up drift in some embodiments

[0069] The hub 8 is fixed in the temperature control box 7 through a metal connecting piece.

[0070] The hub 8 is fixedly connected to the temperature control box through a metal connecting piece, and the temperature control is faster.

[0071] The fiber optic gyro for suppressing start-up drift in some embodiments

[0072] A semiconductor control device is provided in the temperature control box 7.

[0073] Semiconductor temperature control is a mature temperature control technology. In this embodiment, the optical fiber pigtail wound around the hub 8 is mainly cooled through the semiconductor temperature control device.

[0074] The fiber optic gyro for suppressing start-up drift in some embodiments

[0075] The hub 8 is a metal hub 8.

[0076] The metal hub 8 is adopted for the hub 8, enabling faster temperature control.

[0077] The fiber optic gyroscope for suppressing startup drift in some embodiments is referred to Figure 2 ,

[0078] The signal processing circuit 6 includes: a signal control circuit 61 and a temperature control circuit 62;

[0079] The signal control circuit 61 is respectively connected to the detector 5, the temperature sensor 9, the Y waveguide 3 and the temperature control circuit 62;

[0080] The temperature control circuit 62 is connected to the temperature control box.

[0081] The signal control circuit 61 is mainly used to receive the sensitive angular rate information of the fiber optic gyroscope sent by the detector 5 and the temperature information sent by the temperature sensor 9, and calculate the temperature information to be controlled based on the sensitive angular rate information and temperature information of the fiber optic gyroscope. The temperature control circuit 62 is mainly used to control the temperature inside the temperature control box.

[0082] It can be understood that the same or similar parts in the above embodiments can be referred to each other, and the content not detailed in some embodiments can be seen in the same or similar content of other embodiments.

[0083] It should be noted that in the description of the present application, terms such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present application, unless otherwise specified, the meaning of "a plurality" refers to at least two.

[0084] Any process or method description in the flowchart or described in other ways herein can be understood as representing a module, segment or part of code including one or more executable instructions for implementing a specific logical function or process, and the scope of the preferred embodiments of the present application includes additional implementations, where the functions can be executed in a way that is not shown or discussed, including in a substantially simultaneous manner according to the involved functions or in a reverse order, which should be understood by those skilled in the technical field to which the embodiments of the present application belong.

[0085] It should be understood that various parts of the present application can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0086] Those of ordinary skill in the art can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing relevant hardware through a program. The program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0087] In addition, in each embodiment of the present application, each functional unit can be integrated into a processing module, or each unit can exist physically alone, or two or more units can be integrated into one module. The above integrated module can be implemented in the form of hardware or in the form of a software functional module. When the above integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0088] The above-mentioned storage medium can be a read-only memory, a magnetic disk, an optical disk, etc.

[0089] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0090] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. An optical fiber gyroscope for suppressing startup drift, characterized in that, Comprising: A light source, a coupler, a Y waveguide, an optical fiber loop, a detector, a temperature sensor, a signal processing circuit, a temperature control box, and a hub; The signal processing circuit includes: a signal control circuit and a temperature control circuit; The signal control circuit is respectively connected to the detector, the temperature sensor, the Y waveguide, and the temperature control circuit; The temperature control circuit is connected to the temperature control box; The coupler is respectively connected to the light source, the detector, and the Y waveguide; The signal control circuit is respectively connected to the detector, the temperature sensor, the Y waveguide, and the temperature control box; The optical fiber loop is wound with a first optical fiber and a second optical fiber; The Y waveguide and the optical fiber loop are connected through a first optical fiber pigtail and a second optical fiber pigtail; The hub is arranged inside the temperature control box; The first optical fiber pigtail or the second optical fiber pigtail is further wound on the hub; The detector is used for detecting the sensitive angular rate information of the fiber optic gyroscope and sending it to the signal processing circuit; The temperature sensor is used for detecting the temperature information of the fiber optic gyroscope and sending it to the signal processing circuit; The signal processing circuit is used for performing temperature compensation on the first optical fiber pigtail or the second optical fiber pigtail wound on the hub through the temperature control box according to the sensitive angular rate information and the temperature information; The optical fiber pigtail wound on the hub is the optical fiber pigtail with a lower equivalent temperature among the optical fiber temperature deviations of the first optical fiber and the second optical fiber obtained through simulation calculation; The winding length of the first optical fiber pigtail or the second optical fiber pigtail on the hub is 50 cm - 100 cm; The winding length of the first optical fiber pigtail or the second optical fiber pigtail on the hub is determined by the optical fiber temperature deviation between the first optical fiber and the second optical fiber.

2. The fiber optic gyroscope for suppressing startup drift according to claim 1, wherein The hub is fixed inside the temperature control box through a metal connecting piece.

3. The fiber optic gyroscope for suppressing startup drift according to claim 1, wherein The first optical fiber and the second optical fiber are wound on the optical fiber loop in opposite directions.

4. The fiber optic gyroscope for suppressing startup drift according to claim 1, wherein A semiconductor temperature control device is arranged inside the temperature control box.

5. The fiber optic gyroscope for suppressing startup drift according to claim 1, wherein The hub is a metal hub.

6. The fiber optic gyroscope for suppressing startup drift according to claim 1, wherein The first optical fiber and the second optical fiber are wound on the optical fiber loop in a quadrupole symmetric manner.

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