A method for testing and compensating installation error angle of fiber-optic gyroscope inertial platform gyro

Abstract

A kind of optical fiber gyro inertial platform gyro installation error angle test and compensation method, for testing optical fiber gyro platform optical fiber gyro is installed in platform body after the installation error angle relative to hexahedral coordinate system, using based on instrument installation and instrument error model, error coefficient calibration when gyro installation error is coupled with ground speed in gyroscope output, so as to influence the true value of the calibration result of instrument error coefficient, calibration is carried out in different azimuth, and the ground speed coupled with gyro installation error is different, so the calibration results of four orthogonal azimuths are combined, to realize the gyro installation error angle solution in analytical way.The gyro installation error angle obtained is compensated to error model, to solve the test problem of high-precision optical fiber gyro platform gyro precision.

Description

Technical Field

[0001] This invention relates to a method for testing and compensating for the installation error angle of a fiber optic gyroscope inertial platform, belonging to the technical field of inertial platform installation error angle testing. Background Technology

[0002] A fiber optic gyroscope inertial platform is an inertial navigation and measurement device that uses inertial sensors to measure the linear and angular motion parameters of a carrier relative to inertial space. The platform consists of a fiber optic gyroscope, an accelerometer, a platform body, a support frame, and a stabilization control loop. The stabilization control loop stabilizes the platform in inertial space, the fiber optic gyroscope measures the carrier's angular velocity, the accelerometer measures the carrier's linear acceleration, and Newton's second law is used to calculate the carrier's velocity and position.

[0003] Currently, analytical methods lack the ability to automatically calibrate gyroscope installation errors, which slightly affects the zero bias of the gyroscope during self-calibration when the platform is tilted to different orientations. Since fiber optic gyroscopes have no trend term for zero bias, it is determined that this is an error inherent to the non-inertial instrument itself. Through error analysis of the calibration method, the error mechanism is obtained, and therefore, research on compensation methods is carried out.

[0004] Inertial systems always have errors during manufacturing and assembly, so errors such as instrument installation errors can affect the platform's accuracy. The six-position analytical calibration method uses six orthogonal rotations to obtain calibration results from the positive and negative inverted data of the instruments. Due to installation errors, the gyroscope installation error angle is coupled with the ground speed in the gyroscope output, resulting in significant differences in calibration results at different orientations, which is one of the factors contributing to the low accuracy of the gyroscope. Summary of the Invention

[0005] The technical problem solved by this invention is that, in the existing technology, the installation error angle is difficult to avoid in the traditional inertial platform calibration method, which easily leads to the low accuracy level of the gyroscope. Therefore, a method for testing and compensating the installation error angle of the gyroscope inertial platform with fiber optic gyroscope is proposed.

[0006] The present invention solves the above-mentioned technical problem through the following technical solution:

[0007] A method for testing and compensating for the gyroscope installation error angle of a fiber optic gyroscope inertial platform, comprising:

[0008] Set the fiber optic gyroscope inertial platform at a preset position, and set four azimuth angles for the fiber optic gyroscope inertial platform in the preset position plane for fiber optic gyroscope calibration.

[0009] The fiber optic gyroscope inertial platform is self-aiming and self-calibrated at four azimuth angles to obtain calibration results at each azimuth angle.

[0010] A fiber optic gyroscope installation error model is established, using the calibration results of angles in each direction as model input, and the installation error angles of each fiber optic gyroscope are calculated.

[0011] The calculated gyroscope installation error angle is compensated to the output of each fiber optic gyroscope.

[0012] The azimuth angles are four orthogonal angles under the geographical level. Under the four orthogonal angles, the fiber optic gyroscope inertial platform sends a self-aiming command through the external control system. After completing the self-aiming, a calibration command is sent to obtain the zero bias calibrated under each orthogonal angle, which is used as the model input for the fiber optic gyroscope installation error model. The fiber optic gyroscope inertial platform has three gyroscopes.

[0013] The fiber optic gyroscope inertial platform is mounted on a marble plate that serves as an isolated foundation. The levelness of the marble plate is determined according to the calibration requirements of the fiber optic gyroscope inertial platform's operation.

[0014] The method for setting the angle of the fiber optic gyroscope inertial platform at the preset position is as follows:

[0015] The azimuth angle of the fiber optic gyroscope inertial platform is defined as the angle between the X-axis direction and the north direction. With the northwest direction as the positive direction, the X-axis of the fiber optic gyroscope inertial platform is manually or via an external turntable directed to four orthogonal angles, including the azimuth angle. , , , The positive and negative deviations of each orthogonal angle shall not exceed 2°.

[0016] After the external control system sends the self-aiming command to the fiber optic gyroscope inertial platform, the four orthogonal angles of the fiber optic gyroscope inertial platform... , , , The measured value is , , , The measured values ​​of gyroscope zero bias corresponding to each measured value are recorded as follows:

[0017] When the measured value is At that time, the measured value of the zero bias of the self-calibrated gyroscope is recorded as , , ;

[0018] When the measured value is At that time, the measured value of the zero bias of the self-calibrated gyroscope is recorded as , , ;

[0019] When the measured value is At that time, the measured value of the zero bias of the self-calibrated gyroscope is recorded as , , ;

[0020] When the measured value is At that time, the measured value of the zero bias of the self-calibrated gyroscope is recorded as , , .

[0021] The fiber optic gyroscope installation error model is as follows:

[0022]

[0023]

[0024]

[0025] In the formula, These are the measured zero-bias values ​​of the X, Y, and Z gyroscopes, in units of... ,in, ;

[0026] This represents a true gyroscope with zero bias, measured in units of... ,in, ;

[0027] To measure the local northward ground velocity, the unit is... ;

[0028] The X-axis azimuth of the platform is taken as the positive direction, with north-northwest as the positive direction, and the unit is rad.

[0029] , , This represents the installation error angle of the gyroscope, expressed in rad.

[0030] Based on the fiber optic gyroscope installation error model, the measured zero-bias values ​​of the calibrated fiber optic gyroscopes at various azimuth angles and the measured local northward ground velocity are used as model inputs to calculate the installation error angles of each fiber optic gyroscope. , , The method is as follows:

[0031]

[0032]

[0033] .

[0034] The calculated gyroscope installation error angle ( , , The compensation to the output of each fiber optic gyroscope is achieved through a gyroscope output error compensation model, which is as follows:

[0035]

[0036]

[0037]

[0038] In the formula, These are the measured zero-bias values ​​of the X, Y, and Z gyroscopes, in units of... ,in, ;

[0039] This represents a true gyroscope with zero bias, measured in units of... ,in, ;

[0040] To measure the local northward ground velocity, the unit is... ;

[0041] The X-axis azimuth of the platform is taken as the positive direction, with north-northwest as the positive direction, and the unit is rad.

[0042] , , This represents the installation error angle of the gyroscope, expressed in rad.

[0043] The fiber optic gyroscope inertial platform is mounted on a marble slab serving as an isolated foundation or directly on a positioning turntable; the initial position of the fiber optic gyroscope inertial platform is used for self-calibration, and the X-axis and Y-axis gyroscope installation error angles of each fiber optic gyroscope are (…). , ), Z-axis gyroscope installation error angle for each fiber optic gyroscope ( The calibration is determined at different initial positions.

[0044] After the compensation output for the installation error angle of each fiber optic gyroscope is calculated, it is bound to the external main control system through parameter binding, and the zero bias of the gyroscope is continuously updated and compensated during the subsequent calibration process of the fiber optic gyroscope inertial platform.

[0045] The advantages of this invention compared to the prior art are:

[0046] (1) The present invention provides a method for testing and compensating the installation error angle of a fiber optic gyroscope inertial platform. This method overcomes the shortcomings of existing discrete analytical calibration techniques for platforms, which cannot compensate for gyroscope installation errors. It utilizes the coupling between the ground velocity component and the gyroscope installation angle, and adopts a traditional calibration method under orthogonal orientation. By incorporating the calibration results of coupled gyroscope installation error angles in different orientations into the gyroscope installation error model, the installation error angle value of the gyroscope relative to the platform is finally obtained. Subsequently, the gyroscope installation error is eliminated mathematically in the form of compensation. This method overcomes the influence of the coupling between the gyroscope installation error and the ground velocity, solves the testing problem of gyroscope accuracy exceeding the tolerance in different orientations using the 6-position analytical calibration method, and achieves the goal of making the system value of the gyroscope calibration closer to the true value.

[0047] (2) This invention adopts the original calibration method and error model. Without modifying the scheme, it uses the ground velocity component information and adds a calibration process at a special position to increase the scalable gyroscope installation error angle parameter. At the same time, it solves the problem that the calibration result is related to the platform placement angle. By compensating for the gyroscope installation error angle, the accuracy of the calibration result is improved. Moreover, it does not require the use of a special high-precision turntable to test the gyroscope installation error angle, thus reducing testing costs and labor costs. It has been successfully applied to the installation error angle test of the fiber optic gyroscope platform calibration table and provides technical practice for the high-precision test of the new fiber optic gyroscope inertial platform. Attached Figure Description

[0048] Figure 1 A schematic diagram illustrating the testing and compensation of the gyroscope installation error angle for the fiber optic gyroscope inertial platform provided by this invention;

[0049] Figure 2 A schematic diagram illustrating the installation error of the angular gyroscope on the fiber optic gyroscope platform provided by this invention. Detailed Implementation

[0050] A method for testing and compensating the installation error angle of a fiber optic gyroscope inertial platform is disclosed. This method uses preset orthogonal angles to replace the position turntable, providing the fiber optic gyroscope inertial platform with four self-aiming and self-calibrating commands for the horizontal direction (geographical level) and four orthogonal angles for the azimuth direction. This achieves output error calibration and compensation for each fiber optic gyroscope. The method uses the measured zero-bias values ​​of the fiber optic gyroscopes obtained from the four orthogonal angles and the measured local north-facing ground velocity as inputs. Based on the mathematical model of gyroscope installation error, discrete analytical calculations are performed to test the installation error angles of the three gyroscopes. The obtained gyroscope installation error angles are then compensated to the gyroscope output, thus achieving compensation for the gyroscope installation error coefficient.

[0051] The testing and compensation method for the gyroscope installation error angle of a fiber optic gyroscope inertial platform includes the following steps:

[0052] The fiber optic gyroscope inertial platform is set at a preset position, and four azimuth angles are set for the fiber optic gyroscope inertial platform in the preset position plane for zero bias calibration of the fiber optic gyroscope.

[0053] The fiber optic gyroscope inertial platform is self-aiming and self-calibrated at four azimuth angles to obtain calibration results at each azimuth angle.

[0054] A fiber optic gyroscope installation error model was established, using the measured zero-bias values ​​of the fiber optic gyroscopes at various angles and the measured local northward ground velocity as model inputs, and the installation error angles of each fiber optic gyroscope were calculated.

[0055] The calculated gyroscope installation error angle is compensated to the output of each fiber optic gyroscope.

[0056] The azimuth angles are four orthogonal angles under the geographical level. At the four orthogonal angles, the fiber optic gyroscope inertial platform sends self-aiming commands through the external control system. After aiming is completed, calibration commands are sent to obtain the measured zero-bias values ​​of the fiber optic gyroscope at each orthogonal angle and measure the local northward ground velocity, which are used as model inputs for the fiber optic gyroscope installation error model. The fiber optic gyroscope inertial platform has 3 gyroscopes.

[0057] The fiber optic gyroscope inertial platform is mounted on a marble plate that serves as an isolated foundation. The levelness of the marble plate is determined according to the calibration requirements of the fiber optic gyroscope inertial platform's operation.

[0058] The method for setting the angle of the fiber optic gyroscope inertial platform at the preset position is as follows:

[0059] The azimuth angle of the fiber optic gyroscope inertial platform is defined as the angle between the X-axis direction and the north direction. With the northwest direction as the positive direction, the X-axis of the fiber optic gyroscope inertial platform is manually or via an external turntable directed to four orthogonal angles, including the azimuth angle. , , , The positive and negative deviations of each orthogonal angle shall not exceed 2°.

[0060] After the external control system sends the self-aiming command to the fiber optic gyroscope inertial platform, the four orthogonal angles of the fiber optic gyroscope inertial platform... , , , The measured value is , , , The measured values ​​of the gyroscope zero bias corresponding to each measured value are as follows:

[0061] When the measured value is At that time, the measured value of the zero bias of the self-calibrated gyroscope is recorded as , , ;

[0062] When the measured value is At that time, the measured value of the zero bias of the self-calibrated gyroscope is recorded as , , ;

[0063] When the measured value is At that time, the measured value of the zero bias of the self-calibrated gyroscope is recorded as , , ;

[0064] When the measured value is At that time, the measured value of the zero bias of the self-calibrated gyroscope is recorded as , , .

[0065] The fiber optic gyroscope installation error model is as follows:

[0066]

[0067]

[0068]

[0069] In the formula, These are the measured zero-bias values ​​of the X, Y, and Z gyroscopes, in units of... ,in, ;

[0070] This represents a true gyroscope with zero bias, measured in units of... ,in, ;

[0071] To measure the local northward ground velocity, the unit is... ;

[0072] The X-axis azimuth of the platform is taken as the positive direction, with north-northwest as the positive direction, and the unit is rad.

[0073] , , This represents the installation error angle of the gyroscope, expressed in rad.

[0074] Based on the fiber optic gyroscope installation error model, the measured zero-bias values ​​of the calibrated fiber optic gyroscopes at various azimuth angles and the measured local northward ground velocity are used as model inputs to calculate the installation error angles of each fiber optic gyroscope. , , The method is as follows:

[0075]

[0076]

[0077] .

[0078] The calculated gyroscope installation error angle ( , , The compensation to the output of each fiber optic gyroscope is achieved through a gyroscope output error compensation model, which is as follows:

[0079]

[0080]

[0081]

[0082] In the formula, These are the measured zero-bias values ​​of the X, Y, and Z gyroscopes, in units of... ,in, ;

[0083] This represents a true gyroscope with zero bias, measured in units of... ,in, ;

[0084] To measure the local northward ground velocity, the unit is... ;

[0085] The X-axis azimuth of the platform is taken as the positive direction, with north-northwest as the positive direction, and the unit is rad.

[0086] , , This represents the installation error angle of the gyroscope, expressed in rad.

[0087] The fiber optic gyroscope inertial platform is mounted on a marble slab serving as an isolated foundation or directly on a positioning turntable; the initial position of the fiber optic gyroscope inertial platform is used for self-calibration, and the X-axis and Y-axis gyroscope installation error angles of each fiber optic gyroscope are (…). , ), Z-axis gyroscope installation error angle for each fiber optic gyroscope ( The calibration is determined at different initial positions.

[0088] After the compensation output for the installation error angle of each fiber optic gyroscope is calculated, it is bound to the external main control system through parameter binding, and the zero bias of the gyroscope is continuously updated and compensated during the subsequent calibration process of the fiber optic gyroscope inertial platform.

[0089] The following description, in conjunction with the accompanying drawings and preferred embodiments, provides further details:

[0090] In the current embodiment, such as Figure 1 The diagram shows a hardware schematic for testing and compensating for the gyroscope installation error angle of a fiber optic gyroscope inertial platform. The platform is placed on a marble plate (with a levelness better than 1') on an isolated foundation or mounted on a turntable.

[0091] The angle between the X-axis of the platform and the north direction is defined as the azimuth angle of the fiber optic gyroscope inertial platform. Northwest is considered positive. The X-axis of the platform is oriented to four orthogonal directions manually or using a turntable. It is 0° ± 5°. The other three azimuth angles are respectively , , The positive and negative deviations of the four angles shall not exceed 2°.

[0092] Platform pointing The measured value of the self-aiming angle at that time is The measured value of the calibrated gyroscope zero bias is recorded as The platform is oriented towards , , In respectively Based on this, add 90 degrees sequentially (right-hand rule), the platform points to , , The measured aiming angles at the three positions are , , The platform points to Its measured zero bias value for the gyroscope is recorded as The platform points to Its measured zero bias value for the gyroscope is recorded as The platform points to Its measured zero bias value for the gyroscope is recorded as .

[0093] Based on the mathematical model of gyroscope installation error, the gyroscope installation error angle is obtained. The calibrated gyroscope zero bias value includes the angular velocity projection component caused by the installation error angle.

[0094] The discrete analytical solution is used to test the installation error angle of the three gyroscopes. The aiming angle and the zero bias value of the gyroscope in the four directions are obtained through calculation. The obtained installation error angle of the gyroscope is compensated to the gyroscope output to realize the compensation of the gyroscope installation error coefficient.

[0095] In this embodiment, in order to maximize the observed value of the installation error angle of the excitation gyroscope, the calibration time is made to be close to the north direction (the ground velocity component is large in the north direction). Based on this, the calibration scheme is designed as follows:

[0096] (1) The platform is calibrated at initial positions of 5° and 185°, and the installation error angle of the Z-gyroscope is calculated.

[0097] (2) Calibrate the platform at initial positions of 95° and 275°, and calculate the installation errors of the X and Y gyroscopes. , .

[0098] The gyroscope installation error was calculated using the self-calibration results at self-aiming angles of 5°, 95°, 185°, and 275°, and the calculated installation error was used to compensate for the calibration results in other orientations. The results are shown in the table below.

[0099] During platform debugging, aiming and calibration were performed near the initial position at 5°, 185°, 95°, and 275° azimuths, and the installation error angle was calculated offline. , , The installation error angle is bound to the main control computer through parameter binding (the original parameter binding function of the platform has reserved the position of the gyroscope installation error angle), and the zero bias of the gyroscope is compensated during the subsequent platform calibration process.

[0100] During the platform calibration process, the Earth's rotational angular velocity is used to excite the gyroscope output. During the gyroscope calibration process, the instrument input axis is in the sky and ground directions, and the sky-ground speed component is mainly used to excite the instrument output.

[0101] During calibration, the platform operates in locked mode and is in a non-isolated angular motion state. In this state, both the northward ground speed and the gyroscope installation error affect the output of the gyroscope being calibrated. A simplified diagram is shown below. Figure 2 As shown.

[0102] In the traditional six-position analytical method for calibrating gyroscope zero bias, the angular velocity component caused by the gyroscope installation error is related to the installation error angle and the initial orientation of the platform. The installation error angle is a constant value, and the initial orientation can be adjusted by changing the orientation of the platform base.

[0103] The zero deviation of the gyroscope calibrated at the initial positions of 5°, 185°, 95°, and 275° were statistically analyzed.

[0104]

[0105]

[0106]

[0107] in , For the results of two calibrations, Northbound ground speed, , The platform's self-aiming azimuth angle is a known quantity, from which the gyroscope installation error angle can be calculated. Similarly, we can obtain , Substituting the zero-bias values ​​of the gyroscope in the four directions, the gyroscope installation error angle values ​​are obtained as follows:

[0108] , ,

[0109] To verify the correctness of the gyroscope installation error angle calibration, the platform was placed on marble and started normally. Calibration was performed at different initial azimuth angles of 5°, 10°, 30°, 60°, 80°, 95°, 120°, 145°, 150°, 170°, 185°, and 275°. Two sets of calibrations were performed at each position, and the average zero bias of the gyroscope was obtained. The verification results should reach the actual accuracy level of the instrument.

[0110] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0111] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for testing and compensating for the installation error angle of a fiber optic gyroscope inertial platform, characterized in that... include: The fiber optic gyroscope inertial platform is set at a preset position, and four azimuth angles are preset in the preset position plane. The self-aiming and calibration of each fiber optic gyroscope on the fiber optic gyroscope inertial platform are performed according to the preset azimuth angles, and the calibration results of each fiber optic gyroscope at each azimuth angle are obtained. A fiber optic gyroscope installation error model is established, using the calibration results of angles in each direction as model input, and the installation error angles of each fiber optic gyroscope are calculated. The calculated gyroscope installation error angle is compensated to the output of the fiber optic gyroscope inertial platform; The azimuth angles are four orthogonal angles at the geographical level; The self-aiming and calibration method for fiber optic gyroscope inertial platforms is as follows: At four orthogonal angles, the external control system sends self-aiming commands to the fiber optic gyroscope inertial platform. After the fiber optic gyroscope inertial platform completes self-aiming, it sends self-calibration commands through the external control system to obtain the calibration results of any fiber optic gyroscope at each orthogonal angle. The fiber optic gyroscope inertial platform has three fiber optic gyroscopes, which are self-aimed and calibrated in any order. After the external control system sends the self-aiming command to the fiber optic gyroscope inertial platform, it measures the four orthogonal angles of the fiber optic gyroscope inertial platform. , , , Obtain the measured value. , , , Then, determine the gyroscope zero bias corresponding to the measured value: When the measured value is At that time, the self-calibrated gyroscope is recorded as zero bias. ; When the measured value is At that time, the self-calibrated gyroscope is recorded as zero bias. ; When the measured value is At that time, the self-calibrated gyroscope is recorded as zero bias. ; When the measured value is At that time, the self-calibrated gyroscope is recorded as zero bias. ; The fiber optic gyroscope installation error model is as follows: In the formula, These are the measured zero-bias values ​​of the X, Y, and Z gyroscopes, in units of... ,in, ; This represents a true gyroscope with zero bias, measured in units of... ,in, ; To measure the local northward ground velocity, the unit is... ; The X-axis azimuth of the platform is taken as the positive direction, with north-northwest as the positive direction, and the unit is rad. , , This represents the installation error angle of the gyroscope, expressed in rad.

2. The method for testing and compensating the gyroscope installation error angle of a fiber optic gyroscope inertial platform according to claim 1, characterized in that: The fiber optic gyroscope inertial platform is mounted on a marble plate that serves as an isolated foundation. The levelness of the marble plate is determined according to the calibration requirements of the fiber optic gyroscope inertial platform.

3. The method for testing and compensating for the gyroscope installation error angle of a fiber optic gyroscope inertial platform according to claim 2, characterized in that: The method for setting the angle of the fiber optic gyroscope inertial platform at the preset position is as follows: The angle between the X-axis direction of the fiber optic gyroscope inertial platform and the north direction is set as follows: With the northwest direction as the positive direction, the X-axis of the fiber optic gyroscope inertial platform is manually or via an external turntable directed to four orthogonal angles, including the azimuth angle. , , , The positive and negative deviations of each orthogonal angle shall not exceed 2°.

4. The method for testing and compensating the gyroscope installation error angle of a fiber optic gyroscope inertial platform according to claim 3, characterized in that: Based on the fiber optic gyroscope installation error model, the calibration results of each azimuth angle are used as model input to calculate the installation error angle of each fiber optic gyroscope. , , The method is as follows: 。 5. The method for testing and compensating for the gyroscope installation error angle of a fiber optic gyroscope inertial platform according to claim 4, characterized in that: The calculated gyroscope installation error angle ( , , The method for compensating the output of each fiber optic gyroscope is as follows: This is achieved through a gyroscope output error compensation model, which is as follows: In the formula, These are the measured zero-bias values ​​of the X, Y, and Z gyroscopes, in units of... ,in, ; This represents a true gyroscope with zero bias, measured in units of... ,in, ; To measure the local northward ground velocity, the unit is... ; The X-axis azimuth of the platform is radian, with the north-northwest direction as the positive direction.

6. The method for testing and compensating for the gyroscope installation error angle of a fiber optic gyroscope inertial platform according to claim 5, characterized in that: The installation error angles of each fiber optic gyroscope along the X and Y axes are ( ). , ), Z-axis gyroscope installation error angle for each fiber optic gyroscope ( The calibration is determined at different initial positions.

7. The method for testing and compensating the gyroscope installation error angle of a fiber optic gyroscope inertial platform according to claim 1, characterized in that: After the compensation output for the installation error angle of each fiber optic gyroscope is calculated, it is bound to the external main control system through parameter binding. During the subsequent self-calibration process of the fiber optic gyroscope inertial platform, the zero bias of the gyroscope is continuously updated and compensated.

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