Compensation method for reducing cross coupling angle of biaxial optical fiber gyroscope

Abstract

The invention relates to a double-axis optical fiber gyroscope, and provides a compensation method for reducing a cross coupling angle of a double-axis optical fiber gyroscope in order to solve the problems of time and labor waste, high risk, poor compensation effect and the like in an operation process of an existing mode for reducing the cross coupling angle. Comprising the following steps: mounting a hexahedron tool and a double-shaft optical fiber gyroscope on a rate turntable; adjusting the relative position relationship between the X-axis optical fiber ring mounting surface on the hexahedron tool and the rate turntable, recording the average value of the X-axis output values and the average value of the Y-axis output values of the double-axis optical fiber gyroscope when each rotation is completed, and calculating the Y-axis cross coupling angle of the double-axis optical fiber gyroscope; adjusting a relative position relation between a Y-axis optical fiber ring mounting surface on the hexahedron tool and the rate turntable, recording an average value of X-axis output values and an average value of Y-axis output values of the double-axis optical fiber gyroscope when each rotation is completed, and calculating an X-axis cross coupling angle of the double-axis optical fiber gyroscope; the X-axis output value and the Y-axis output value of the double-axis optical fiber gyroscope are compensated in real time.

Description

Technical Field

[0001] The invention relates to a dual-axis fiber optic gyroscope, and in particular to a compensation method for reducing a cross-coupling angle of the dual-axis fiber optic gyroscope. Background Art

[0002] The fiber optic gyroscope (FOG) is an interference type angular velocity measurement device based on the Sagnac effect and composed of a fiber optic loop. When the fiber optic coil rotates around the normal of the equivalent plane, a phase difference is generated between the two coherent light beams transmitted in opposite directions in the coil. The phase difference is proportional to the angular velocity of the device relative to the inertial space. The change in angular velocity can be obtained by detecting the interference intensity of the output light.

[0003] A dual-axis fiber optic gyroscope is a gyroscope that has two orthogonal fiber optic rings installed on the gyroscope body, namely the X-axis fiber optic ring and the Y-axis fiber optic ring, which can test the angular velocity of the two axes; Figure 2 As shown, IAx is the component of the sensitive axis of the X-axis fiber optic ring in the xoy plane, IRAx is the direction perpendicular to the mounting surface of the X-axis fiber optic ring, IAy is the component of the sensitive axis of the Y-axis fiber optic ring in the xoy plane, and IRAy is the direction perpendicular to the mounting surface of the Y-axis fiber optic ring. Due to the limitations of the processing and assembly accuracy of the fiber optic ring frame and the gyro table, as well as the different material expansion coefficients of the optical fiber and the fiber optic surrounding glue, there is a slight angle difference between IRAx and IAx. When the gyro rotates around the IRAy direction, the IAx axis direction will be sensitive to the angular velocity of the rotation in the IRAy direction, resulting in an angular velocity error; there is a slight angle difference between IRAy and IAy, resulting in the IAy axis direction being sensitive to the angular velocity of the rotation in the IRAx direction when the gyro rotates around the IRAx direction, resulting in an angular velocity error. The angle θx between IAx and IRAx is called the cross-coupling angle of the X-axis, and the angle θy between IAy and IRAy is called the cross-coupling angle of the Y-axis. The unit of the cross-coupling angle is radian or angle minute.

[0004] When there is a cross-coupling angle between two axes, the input of one axis is coupled to the other axis, which will cause an angular rate error in the output of the other axis. In order to reduce the cross-coupling error, the commonly used method is to reduce the cross-coupling angle.

[0005] At present, the method to reduce the cross-coupling angle is as follows: in the fiber optic ring winding stage, the cross-coupling angle is reduced by improving the winding process of the fiber optic ring, such as using optical fiber with a lower expansion coefficient and fiber optic ring glue, but the experimental effect of this method is not obvious; secondly, when the gyroscope is assembled, the cross-coupling angle is reduced by padding a thin copper sheet under the fiber optic ring mounting surface, but because the thickness of the copper sheet used cannot be determined in advance, it is necessary to continuously try to adjust it until it can meet the compensation requirements; at the same time, due to the small mounting surface of the fiber optic ring, this method has high requirements on the operator, the operation process is time-consuming and labor-intensive, and the operation risk is high, the work efficiency is low, the engineering performance and compensation effect are poor, and it cannot meet the actual production needs. Summary of the invention

[0006] The purpose of the present invention is to solve the technical problems that the existing methods of reducing the cross-coupling angle have no obvious experimental effect, the operation process is time-consuming and labor-intensive, the operation risk is high, the work efficiency is low, the engineering performance and compensation effect are poor, and a compensation method for reducing the cross-coupling angle of a dual-axis fiber optic gyroscope is proposed.

[0007] The design idea of ​​the present invention is: to test the cross-coupling angle of the two axes of the dual-axis gyroscope through a test platform, calculate the error compensation amount about the cross-coupling angle, and then subtract the error compensation amount from the corresponding output of the gyroscope, so as to achieve the purpose of reducing the cross-coupling angle.

[0008] To achieve the above objectives, the technical solution proposed by the present invention is:

[0009] A compensation method for reducing the cross-coupling angle of a dual-axis fiber optic gyroscope is characterized in that it comprises the following steps:

[0010] S1. Install the dual-axis fiber optic gyroscope in a hexahedron fixture, then install the hexahedron fixture on the horizontal plane of the rate turntable, and set the angular rate and number of rotations of the rate turntable;

[0011] S2, make the IRAx axis perpendicular to the X-axis fiber optic ring mounting surface parallel to the rotation axis of the rate turntable, adjust the different positions between the X-axis fiber optic ring mounting surface and the rate turntable on the hexahedral tooling, start the rate turntable to rotate counterclockwise and clockwise in sequence, record and calculate the average value of the X-axis output value and the average value of the Y-axis output value of the dual-axis fiber optic gyroscope when each rotation is completed, and calculate the Y-axis cross-coupling angle of the dual-axis fiber optic gyroscope based on the average value of the X-axis output value and the average value of the Y-axis output value;

[0012] S3, make the IRAy axis perpendicular to the Y-axis fiber optic ring mounting surface parallel to the rotation axis of the rate turntable, adjust the different positions between the Y-axis fiber optic ring mounting surface and the rate turntable on the hexahedral tooling, start the rate turntable to rotate counterclockwise and clockwise in sequence, record and calculate the average value of the X-axis output value and the average value of the Y-axis output value of the dual-axis fiber optic gyroscope when each rotation is completed, and calculate the X-axis cross-coupling angle of the dual-axis fiber optic gyroscope based on the average value of the X-axis output value and the average value of the Y-axis output value;

[0013] S4. Performing real-time compensation for the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope according to the X-axis cross-coupling angle and the Y-axis cross-coupling angle.

[0014] Furthermore, in step S1, the hexahedral tooling is a hollow hexahedral frame, a mounting groove adapted to the dual-axis fiber optic gyroscope is provided inside the hexahedral tooling, and the dual-axis fiber optic gyroscope is installed in the mounting groove of the hexahedral tooling.

[0015] Furthermore, step S2 is specifically as follows:

[0016] S2.1. Adjust the installation position of the hexahedral tooling so that the X-axis fiber optic ring installation surface on the dual-axis fiber optic gyroscope is away from the horizontal plane of the rate turntable, and at the same time, the IRAx axis perpendicular to the X-axis fiber optic ring installation surface is parallel to the rotation axis of the rate turntable. This position is recorded as the first position output of the dual-axis fiber optic gyroscope.

[0017] S2.2, rotate the rate turntable counterclockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope when the rate turntable rotates the set number of circles, and calculate the average value F1x+ of the X-axis output value and the average value F1y+ of the Y-axis output value;

[0018] S2.3, rotate the rate turntable clockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope when the rate turntable rotates the set number of circles, and calculate the average value F1x- of the X-axis output value and the average value F1y- of the Y-axis output value;

[0019] S2.4. Adjust the installation position of the hexahedral tooling so that the X-axis fiber optic ring installation surface on the dual-axis fiber optic gyroscope is close to the horizontal plane of the rate turntable, and at the same time, the IRAx axis perpendicular to the X-axis fiber optic ring installation surface is parallel to the rotation axis of the rate turntable. This position is recorded as the second position output of the dual-axis fiber optic gyroscope.

[0020] S2.5, rotate the rate turntable counterclockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope when the rate turntable rotates the set number of circles, and calculate the average value F2x+ of the X-axis output value and the average value F2y+ of the Y-axis output value;

[0021] S2.6, rotate the rate turntable clockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope when the rate turntable rotates the set number of circles, and calculate the average value F2x- of the X-axis output value and the average value F2y- of the Y-axis output value;

[0022] S2.7. Calculate the Y-axis cross-coupling angle of the dual-axis fiber optic gyroscope based on the average value of the X-axis output value and the average value of the Y-axis output value output at the first position of the dual-axis fiber optic gyroscope, and the average value of the X-axis output value and the average value of the Y-axis output value output at the second position.

[0023] Furthermore, in step S2.7, the Y-axis cross-coupling angle θ y The specific calculation formula is:

[0024]

[0025] Where: K y is the scale factor of the Y axis, θ y1 is the Y-axis cross-coupling angle at the first position, θ y2 is the Y-axis cross-coupling angle of the second position.

[0026] Further, in step S2.4, the adjusting the installation position of the hexahedron fixture is specifically: rotating the hexahedron fixture 180° around the IRAy axis of the dual-axis fiber optic gyroscope.

[0027] Furthermore, step S3 is specifically as follows:

[0028] S3.1. Adjust the installation position of the hexahedral tooling so that the Y-axis fiber optic ring installation surface on the dual-axis fiber optic gyroscope is away from the horizontal plane of the rate turntable, and at the same time, the IRAy axis perpendicular to the Y-axis fiber optic ring installation surface is parallel to the rotation axis of the rate turntable. This position is recorded as the third position output of the dual-axis fiber optic gyroscope;

[0029] S3.2, rotate the rate turntable counterclockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope when the rate turntable rotates the set number of circles, and calculate the average value F3x+ of the X-axis output value and the average value F3y+ of the Y-axis output value;

[0030] S3.3, rotate the rate turntable clockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope when the rate turntable rotates the set number of circles, and calculate the average value F3x- of the X-axis output value and the average value F3y- of the Y-axis output value;

[0031] S3.4. Adjust the installation position of the hexahedral tooling so that the Y-axis fiber optic ring installation surface on the dual-axis fiber optic gyroscope is close to the horizontal plane of the rate turntable, and at the same time, the IRAy axis perpendicular to the Y-axis fiber optic ring installation surface is parallel to the rotation axis of the rate turntable. This position is recorded as the fourth position output of the dual-axis fiber optic gyroscope;

[0032] S3.5, rotate the rate turntable counterclockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope when the rate turntable rotates the set number of circles, and calculate the average value F4x+ of the X-axis output value and the average value F4y+ of the Y-axis output value;

[0033] S3.6, rotate the rate turntable clockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope when the rate turntable rotates the set number of circles, and calculate the average value F4x- of the X-axis output value and the average value F4y- of the Y-axis output value;

[0034] S3.7. Calculate the X-axis cross-coupling angle of the dual-axis fiber optic gyroscope based on the average value of the X-axis output value and the average value of the Y-axis output value output at the third position of the dual-axis fiber optic gyroscope, and the average value of the X-axis output value and the average value of the Y-axis output value output at the fourth position.

[0035] Furthermore, in step S3.7, the X-axis cross-coupling angle θ x The specific calculation formula is:

[0036]

[0037] Where: K X is the scale factor of the X-axis, θ x1 is the X-axis cross-coupling angle at the third position, θ x2 is the X-axis cross-coupling angle of the fourth position.

[0038] Further, in step S3.4, the adjusting the installation position of the hexahedron fixture is specifically: rotating the hexahedron fixture 180° around the IRAx axis of the dual-axis fiber optic gyroscope.

[0039] Further, in step S4, the formula for real-time compensation of the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope according to the X-axis cross-coupling angle and the Y-axis cross-coupling angle is:

[0040] F x ′=F x -F y *θ x

[0041] F y ′=F y -F x *θ y

[0042] Among them: F x is the output value of the X-axis of the dual-axis fiber optic gyroscope;

[0043] F x ′ is the output value of the dual-axis fiber optic gyroscope after X-axis compensation;

[0044] F y is the output value of the Y-axis of the dual-axis fiber optic gyroscope;

[0045] F y ′ is the output value of the dual-axis fiber optic gyroscope after Y-axis compensation.

[0046] Furthermore, in step S1, the angular velocity of the rate turntable is set to 5° / s.

[0047] Beneficial effects of the present invention:

[0048] [1] The present invention discloses a compensation method for reducing the cross-coupling angle of a dual-axis fiber optic gyroscope, which has a simple operation mode, is easy to implement, and has a good compensation effect.

[0049] [2] The present invention can compensate the output of the dual-axis fiber optic gyroscope in real time by using the X-axis cross-coupling angle and the Y-axis cross-coupling angle of the dual-axis fiber optic gyroscope, thereby effectively improving the compensation efficiency of the dual-axis fiber optic gyroscope, saving system compensation time, and realizing real-time and effective compensation of the dual-axis fiber optic gyroscope.

[0050] [3] The present invention adjusts the installation position of the hexahedron fixture by rotating 180° around the IRAx axis or the IRAy axis of the dual-axis fiber optic gyroscope, obtains the output of the dual-axis fiber optic gyroscope at multiple positions, and can effectively eliminate the error between the hexahedron fixture and the horizontal plane of the rate turntable, thereby improving the compensation accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A flow chart of a compensation method for reducing the cross-coupling angle of a dual-axis fiber optic gyroscope according to the present invention;

[0052] Figure 2 It is a structural schematic diagram of a dual-axis fiber optic gyroscope;

[0053] Figure 3 Schematic diagram of the installation of a dual-axis fiber optic gyroscope in an embodiment of the present invention;

[0054] Figure 4 is a principle block diagram of an embodiment of the present invention;

[0055] Reference numerals:

[0056] 1-Dual-axis fiber optic gyroscope, 2-Hexahedron tooling, 3-Rate turntable. DETAILED DESCRIPTION

[0057] like Figure 1 and Figure 4 As shown, a compensation method for reducing the cross-coupling angle of a dual-axis fiber optic gyroscope comprises the following steps:

[0058] S1, such as Figure 3 As shown, the dual-axis fiber optic gyroscope 1 is mounted on the hexahedron fixture 2, and then the hexahedron fixture 2 is fixed on the horizontal plane of the rate turntable 3 by a fixing fixture, and the angular velocity and number of rotations of the rate turntable 3 are set;

[0059] S2. Calculate the Y-axis cross-coupling angle of the dual-axis fiber optic gyroscope 1

[0060] S2.1. Adjust the installation position of the hexahedral tooling 2 so that the X-axis fiber optic ring installation surface on the dual-axis fiber optic gyroscope 1 is away from the horizontal plane of the rate turntable 3, and at the same time, the IRAx axis perpendicular to the X-axis fiber optic ring installation surface is parallel to the rotation axis of the rate turntable 3. This position is recorded as the first position output of the dual-axis fiber optic gyroscope 1, and the test is performed after preheating;

[0061] S2.2, rotate the rate turntable 3 counterclockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope 1 when the rate turntable 3 rotates the set number of circles, and calculate the average value F1x+ of the X-axis output value and the average value F1y+ of the Y-axis output value;

[0062] S2.3, rotate the rate turntable 3 clockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope 1 when the rate turntable 3 rotates the set number of circles, and calculate the average value F1x- of the X-axis output value and the average value F1y- of the Y-axis output value;

[0063] S2.4, in order to eliminate the error of the hexahedron fixture 2 and the turntable mounting surface, the hexahedron fixture 2 is rotated 180° around the IRAy axis of the dual-axis fiber optic gyroscope 1, so that the X-axis fiber optic ring mounting surface on the dual-axis fiber optic gyroscope 1 is close to the horizontal plane of the rate turntable 3, and at the same time, the IRAx axis perpendicular to the X-axis fiber optic ring mounting surface is parallel to the rotation axis of the rate turntable 3, and this position is recorded as the second position output of the dual-axis fiber optic gyroscope 1;

[0064] S2.5, rotate the rate turntable 3 counterclockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope 1 when the rate turntable 3 rotates the set number of circles, and calculate the average value F2x+ of the X-axis output value and the average value F2y+ of the Y-axis output value;

[0065] S2.6, rotate the rate turntable 3 clockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope 1 when the rate turntable 3 rotates the set number of circles, and calculate the average value F2x- of the X-axis output value and the average value F2y- of the Y-axis output value;

[0066] S2.7, calculating the Y-axis cross-coupling angle of the dual-axis fiber optic gyroscope 1 according to the average value of the X-axis output value and the average value of the Y-axis output value output at the first position of the dual-axis fiber optic gyroscope 1, and the average value of the X-axis output value and the average value of the Y-axis output value output at the second position;

[0067] θ y The specific calculation formula is:

[0068]

[0069] Where: K y is the scale factor of the Y axis, θ y1 is the Y-axis cross-coupling angle at the first position, θ y2 is the Y-axis cross-coupling angle of the second position.

[0070] S3. Calculate the X-axis cross-coupling angle of the dual-axis fiber optic gyroscope 1

[0071] S3.1, adjust the installation position of the hexahedral tooling 2, so that the Y-axis fiber optic ring installation surface on the dual-axis fiber optic gyroscope 1 is away from the horizontal plane of the rate turntable 3, and at the same time, the IRAy axis perpendicular to the Y-axis fiber optic ring installation surface is parallel to the rotation axis of the rate turntable 3, and record this position as the third position output of the dual-axis fiber optic gyroscope 1;

[0072] S3.2, rotate the rate turntable 3 counterclockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope 1 when the rate turntable 3 rotates the set number of circles, and calculate the average value F3x+ of the X-axis output value and the average value F3y+ of the Y-axis output value;

[0073] S3.3, rotate the rate turntable 3 clockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope 1 when the rate turntable 3 rotates the set number of circles, and calculate the average value F3x- of the X-axis output value and the average value F3y- of the Y-axis output value;

[0074] S3.4, in order to eliminate the error of the hexahedron fixture 2 and the turntable mounting surface, the hexahedron fixture 2 is rotated 180° around the IRAx axis of the dual-axis fiber optic gyroscope 1, so that the Y-axis fiber optic ring mounting surface on the dual-axis fiber optic gyroscope 1 is close to the horizontal plane of the rate turntable 3, and at the same time, the IRAy axis perpendicular to the Y-axis fiber optic ring mounting surface is parallel to the rotation axis of the rate turntable 3, and this position is recorded as the fourth position output of the dual-axis fiber optic gyroscope 1;

[0075] S3.5, rotate the rate turntable 3 counterclockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope 1 when the rate turntable 3 rotates the set number of circles, and calculate the average value F4x+ of the X-axis output value and the average value F4y+ of the Y-axis output value;

[0076] S3.6, rotate the rate turntable 3 clockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope 1 when the rate turntable 3 rotates the set number of circles, and calculate the average value F4x- of the X-axis output value and the average value F4y- of the Y-axis output value;

[0077] S3.7, calculating the X-axis cross-coupling angle of the dual-axis fiber optic gyroscope 1 according to the average value of the X-axis output value and the average value of the Y-axis output value output at the third position of the dual-axis fiber optic gyroscope 1, and the average value of the X-axis output value and the average value of the Y-axis output value output at the fourth position;

[0078] θ x The specific calculation formula is:

[0079]

[0080] Where: K X is the scale factor of the X-axis, θ x1 is the X-axis cross-coupling angle at the third position, θ x2 is the X-axis cross-coupling angle of the fourth position.

[0081] S4, compensating the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope 1 according to the X-axis cross-coupling angle and the Y-axis cross-coupling angle, so that the output of the dual-axis fiber optic gyroscope 1 is the output value after the X-axis compensation and the output value after the Y-axis compensation, thereby completing the real-time compensation of the cross-coupling angle of the dual-axis fiber optic gyroscope 1;

[0082] The specific compensation formula is:

[0083] F x ′=F x -F y *θ x

[0084] F y ′=F y -F x *θ y

[0085] Among them: F x is the output value of the 1X axis of the dual-axis fiber optic gyroscope;

[0086] F x ′ is the output value of the dual-axis fiber optic gyroscope after 1X axis compensation;

[0087] F y is the output value of the Y axis of the dual-axis fiber optic gyroscope 1;

[0088] F y ′ is the output value of the dual-axis fiber optic gyroscope 1 after Y-axis compensation.

[0089] The rotation speed of the rate turntable 3 is set to 5° / s, and the scale factor of the dual-axis fiber optic gyroscope 1 is set to 7000. The cross-coupling data of the dual-axis fiber optic gyroscope 1 before compensation is obtained according to the experimental test, as shown in Table 1:

[0090] Table 1 Cross-coupling test data before compensation

[0091]

[0092] The X-axis cross-coupling angle θ of the dual-axis fiber optic gyroscope 1 before compensation is calculated through steps S2 and S3. x =0.002826 (rad) = 9.71′, Y-axis cross coupling angle θ y =0.002516 (rad) =8.65′.

[0093] After the compensation in step S4, the cross-coupling test data of the dual-axis fiber optic gyroscope 1 is shown in Table 2:

[0094] Table 2 Compensated cross-coupling test data

[0095]

[0096]

[0097] The X-axis cross-coupling angle θ of the compensated dual-axis fiber optic gyroscope 1 is calculated through steps S2 and S3. x =0.000126 (rad) = 0.43', Y-axis cross coupling angle θ y =0.000115 (rad) = 0.40′;

[0098] Table 3 shows the comparison before and after cross-coupling angle compensation

[0099] Gyro indicator Before compensation After compensation <![CDATA[X-axis cross-coupling angle θ x (′)]]> 9.71 0.43 <![CDATA[Y-axis cross-coupling angle θ y (′)]]> 8.65 0.40

[0100] It can be seen from Table 3 that after the compensation method is used, the cross-coupling angle of the two axes on the dual-axis fiber optic gyroscope 1 is reduced to within 1′, which shows that the compensation method is effective.

Claims

1. A compensation method for reducing the cross-coupling angle of a dual-axis fiber optic gyroscope, characterized in that: The following steps are involved: S1. Install the dual-axis fiber optic gyroscope in a hexahedral fixture (2), then install the hexahedral fixture (2) on a horizontal plane of a rate turntable (3), and set the angular velocity and number of rotations of the rate turntable (3); S2, making the IRAx axis perpendicular to the X-axis fiber optic ring mounting surface parallel to the rotation axis of the rate turntable (3), adjusting the different positions between the X-axis fiber optic ring mounting surface on the hexahedral tooling (2) and the rate turntable (3), starting the rate turntable (3) to rotate counterclockwise and clockwise in sequence, recording and calculating the average value of the X-axis output value and the average value of the Y-axis output value of the dual-axis fiber optic gyroscope (1) at the completion of each rotation, and calculating the Y-axis cross-coupling angle of the dual-axis fiber optic gyroscope (1) based on the average value of the X-axis output value and the average value of the Y-axis output value; S3, making the IRAy axis perpendicular to the Y-axis optical fiber ring installation surface parallel to the rotation axis of the rate turntable (3), adjusting the different positions between the Y-axis optical fiber ring installation surface on the hexahedral tooling (2) and the rate turntable (3), starting the rate turntable (3) to rotate counterclockwise and clockwise in sequence, recording and calculating the average value of the X-axis output value and the average value of the Y-axis output value of the dual-axis optical fiber gyroscope (1) when each rotation is completed, and calculating the X-axis cross-coupling angle of the dual-axis optical fiber gyroscope (1) based on the average value of the X-axis output value and the average value of the Y-axis output value; S4. Performing real-time compensation for the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope (1) according to the X-axis cross-coupling angle and the Y-axis cross-coupling angle.

2. A compensation method for reducing the cross-coupling angle of a dual-axis fiber optic gyroscope according to claim 1, characterized in that: In step S1, the hexahedral tooling (2) is a hollow hexahedral frame, and a mounting groove adapted to the dual-axis fiber optic gyroscope (1) is provided inside the hexahedral tooling (2). The dual-axis fiber optic gyroscope (1) is mounted in the mounting groove of the hexahedral tooling (2).

3. A compensation method for reducing the cross-coupling angle of a dual-axis fiber optic gyroscope according to claim 2, characterized in that: Step S2 is specifically as follows: S2.

1. Adjust the installation position of the hexahedral tooling (2) so that the X-axis fiber optic ring installation surface on the dual-axis fiber optic gyroscope (1) is away from the horizontal plane of the rate turntable (3), and at the same time, the IRAx axis perpendicular to the X-axis fiber optic ring installation surface is parallel to the rotation axis of the rate turntable (3). This position is recorded as the first position output of the dual-axis fiber optic gyroscope (1); S2.2, rotate the rate turntable (3) counterclockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope (1) when the rate turntable (3) rotates the set number of circles, and calculate the average value F1x+ of the X-axis output value and the average value F1y+ of the Y-axis output value; S2.3, rotate the rate turntable (3) clockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope (1) when the rate turntable (3) rotates the set number of circles, and calculate the average value F1x- of the X-axis output value and the average value F1y- of the Y-axis output value; S2.4, adjust the installation position of the hexahedral tooling (2) so that the X-axis fiber optic ring installation surface on the dual-axis fiber optic gyroscope (1) is close to the horizontal plane of the rate turntable (3), and at the same time, the IRAx axis perpendicular to the X-axis fiber optic ring installation surface is parallel to the rotation axis of the rate turntable (3). This position is recorded as the second position output of the dual-axis fiber optic gyroscope (1); S2.5, rotate the rate turntable (3) counterclockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope (1) when the rate turntable (3) rotates the set number of circles, and calculate the average value F2x+ of the X-axis output value and the average value F2y+ of the Y-axis output value; S2.6, rotate the rate turntable (3) clockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope (1) when the rate turntable (3) rotates the set number of circles, and calculate the average value F2x- of the X-axis output value and the average value F2y- of the Y-axis output value; S2.

7. Calculate the Y-axis cross-coupling angle of the dual-axis fiber optic gyroscope (1) based on the average value of the X-axis output value and the average value of the Y-axis output value output at the first position of the dual-axis fiber optic gyroscope (1), and the average value of the X-axis output value and the average value of the Y-axis output value output at the second position.

4. A compensation method for reducing the cross-coupling angle of a dual-axis fiber optic gyroscope according to claim 3, characterized in that: The Y-axis cross-coupling angle θ in step S2.7 y The specific calculation formula is: Where: K y is the scale factor of the Y axis, θ y1 is the Y-axis cross-coupling angle at the first position, θ y2 is the Y-axis cross-coupling angle of the second position.

5. A compensation method for reducing the cross-coupling angle of a dual-axis fiber optic gyroscope according to claim 4, characterized in that: In step S2.4, the adjustment of the installation position of the hexahedral fixture (2) is specifically performed by rotating the hexahedral fixture (2) by 180° around the IRAy axis of the dual-axis fiber optic gyroscope (1).

6. A compensation method for reducing the cross-coupling angle of a dual-axis fiber optic gyroscope according to claim 2, characterized in that: Step S3 is specifically as follows: S3.

1. Adjust the installation position of the hexahedral tooling (2) so that the Y-axis fiber optic ring installation surface on the dual-axis fiber optic gyroscope (1) is away from the horizontal plane of the rate turntable (3), and at the same time, the IRAy axis perpendicular to the Y-axis fiber optic ring installation surface is parallel to the rotation axis of the rate turntable (3). This position is recorded as the third position output of the dual-axis fiber optic gyroscope (1); S3.2, rotate the rate turntable (3) counterclockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope (1) when the rate turntable (3) rotates the set number of circles, and calculate the average value F3x+ of the X-axis output value and the average value F3y+ of the Y-axis output value; S3.3, rotate the rate turntable (3) clockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope (1) when the rate turntable (3) rotates the set number of circles, and calculate the average value F3x- of the X-axis output value and the average value F3y- of the Y-axis output value; S3.4, adjust the installation position of the hexahedral tooling (2) so that the Y-axis fiber optic ring installation surface on the dual-axis fiber optic gyroscope (1) is close to the horizontal plane of the rate turntable (3), and at the same time, the IRAy axis perpendicular to the Y-axis fiber optic ring installation surface is parallel to the rotation axis of the rate turntable (3). This position is recorded as the fourth position output of the dual-axis fiber optic gyroscope (1); S3.5, rotate the rate turntable (3) counterclockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope (1) when the rate turntable (3) rotates the set number of circles, and calculate the average value F4x+ of the X-axis output value and the average value F4y+ of the Y-axis output value; S3.6, rotate the rate turntable (3) clockwise at a set angular rate Ω, record the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope (1) when the rate turntable (3) rotates the set number of circles, and calculate the average value F4x- of the X-axis output value and the average value F4y- of the Y-axis output value; S3.

7. Calculate the X-axis cross-coupling angle of the dual-axis fiber optic gyroscope (1) based on the average value of the X-axis output value and the average value of the Y-axis output value output at the third position of the dual-axis fiber optic gyroscope (1), and the average value of the X-axis output value and the average value of the Y-axis output value output at the fourth position.

7. A compensation method for reducing the cross-coupling angle of a dual-axis fiber optic gyroscope according to claim 6, characterized in that: The X-axis cross-coupling angle θ in step S3.7 x The specific calculation formula is: Where: K X is the scale factor of the X-axis, θ x1 is the X-axis cross-coupling angle at the third position, θ x2 is the X-axis cross-coupling angle of the fourth position.

8. A compensation method for reducing the cross-coupling angle of a dual-axis fiber optic gyroscope according to claim 7, characterized in that: In step S3.4, the adjustment of the installation position of the hexahedral fixture (2) is specifically performed by rotating the hexahedral fixture (2) by 180° around the IRAx axis of the dual-axis fiber optic gyroscope (1).

9. A compensation method for reducing the cross-coupling angle of a dual-axis fiber optic gyroscope according to claim 8, characterized in that: In step S4, the formula for real-time compensation of the X-axis output value and the Y-axis output value of the dual-axis fiber optic gyroscope (1) according to the X-axis cross-coupling angle and the Y-axis cross-coupling angle is: F x ′=F x -F y *θ x F y ′=F y -F x *θ y Among them: F x is the output value of the X-axis of the dual-axis fiber optic gyroscope (1); F x ' is the output value of the dual-axis fiber optic gyroscope (1) after X-axis compensation; F y is the output value of the Y axis of the dual-axis fiber optic gyroscope (1); F y ' is the output value of the dual-axis fiber optic gyroscope (1) after Y-axis compensation.

10. A compensation method for reducing the cross-coupling angle of a dual-axis fiber optic gyroscope according to claim 1, characterized in that: In step S1, the angular velocity of the rate turntable (3) is set to 5° / s.

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