A method, device, equipment and medium for calibrating orthogonality of a magnetic shaft and a mechanical shaft

Abstract

The application provides a magnetic axis and mechanical axis orthogonality calibration method and device, electronic equipment and medium, the device comprises: a Helmholtz coil, a non-magnetic turntable, two non-magnetic theodolites, a reference cube mirror and an electronics box, the non-magnetic turntable is placed in the center of the Helmholtz coil, and the two non-magnetic theodolites establish a rectangular coordinate system for the Helmholtz coil;The to-be-measured magnetometer is placed on the non-magnetic turntable, and the shell top of the probe of the to-be-measured magnetometer is fixed with the reference cube mirror;Adjust the two non-magnetic theodolites to align the cube mirror, input the first rotating field value to the Helmholtz coil, rotate the non-magnetic turntable to measure the probe measurement value of the to-be-measured magnetometer at three positions, combine the calibration result of the Helmholtz coil to obtain the calibrated first rotating field value, thereby obtaining the rotation matrix of the three positions, solve the two vertical normal directions of the cube mirror in the sensor coordinate system, determine the orthogonality calibration result, thereby improving the orthogonality calibration precision.

Description

Technical Field

[0001] This application relates to the field of vector magnetometers, and more specifically, to a method, apparatus, device, and medium for calibrating the orthogonality of magnetic and mechanical axes. Background Technology

[0002] Vector magnetometers are crucial components in drones, navigation systems, and other devices requiring precise orientation detection, making their accuracy paramount. Ideally, the magnetic axis and mechanical axis of the magnetometer should be perfectly aligned. Misalignment between these axes will lead to errors in orientation measurement, impacting overall performance. Therefore, calibrating the magnetic axis and mechanical axis of the magnetic sensor (i.e., the magnetometer) is a critical step in ensuring sensor measurement accuracy. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a method, apparatus, device and medium for calibrating the orthogonality of magnetic and mechanical axes, which can more accurately calibrate the orthogonality of magnetic and mechanical axes and improve the overall measurement accuracy of vector magnetometers.

[0004] This application provides a method for calibrating the orthogonality of magnetic and mechanical axes, applied to an orthogonality calibration device for magnetic and mechanical axes. The device includes: a Helmholtz coil, a non-magnetic turntable, two non-magnetic theodolites, a reference cubic mirror, and an electronics box. The non-magnetic turntable is placed at the center of the Helmholtz coil, and the two non-magnetic theodolites establish a rectangular coordinate system relative to the Helmholtz coil. The two non-magnetic theodolites include a first non-magnetic theodolite and a second non-magnetic theodolite.

[0005] The calibration method includes the following steps:

[0006] The Helmholtz coil is calibrated, and its linearity, orthogonality, and zero bias are calculated.

[0007] The magnetometer to be tested is placed on the non-magnetic turntable; wherein, a reference cubic mirror is fixed on the top of the probe housing of the magnetometer to be tested, and the three cubic faces of the reference cubic mirror represent the normals of the three mechanical axes respectively; the probe of the magnetometer to be tested is connected to the electronics box.

[0008] Adjust the two non-magnetic theodolites so that the first and second cubic normals of the cube mirror are aligned with the two non-magnetic theodolites respectively and meet the preset alignment accuracy; set the first position after alignment as the alignment of the first non-magnetic theodolite and the first cubic normal of the cube mirror.

[0009] A first rotational field value is input to the Helmholtz coil, and the non-magnetic turntable is rotated to measure the probe values ​​of the magnetometer under test in three positions. The three positions are the first position, the second position where the second non-magnetic theodolite and the second cubic normal of the cubic mirror are aligned, and the third position where the first theodolite and the second cubic normal of the cubic mirror are aligned.

[0010] The first rotating field value is calibrated based on the linearity factor, orthogonality, and zero bias of the Helmholtz coil. The calibrated first rotating field value is obtained, and the rotation matrix at the three positions is obtained based on the calibrated first rotating field value and the probe measurement values ​​at the three positions.

[0011] The first and second cubic normals of the cubic mirror in the sensor coordinate system are solved by the transformation matrix of the three positions, and the orthogonality calibration result is determined based on the first and second cubic normals; the orthogonality calibration result includes: the angular deviation between the first and second cubic normals, and the transformation matrix between the orthogonality matrix based on the magnetic axis and the mechanical axis.

[0012] In some embodiments, the orthogonality calibration method for the magnetic and mechanical axes, wherein calibrating the Helmholtz coil and calculating its linearity factor, orthogonality, and zero bias, includes:

[0013] A proton magnetometer is placed at the center of the Helmholtz coil, and a second rotating field value is input to the Helmholtz coil system; the total field of the second rotating field value is 50000 nT, and the vector direction is uniformly distributed on a sphere;

[0014] Data from the proton magnetometer is collected, the coil is calibrated, and the linearity factor, orthogonality, and zero bias of the coil are calculated.

[0015] In some embodiments, the orthogonality calibration method for the magnetic axis and mechanical axis, wherein adjusting the two non-magnetic theodolites so that the first and second cubic normals of the cube mirror are respectively aligned with the two non-magnetic theodolites and meet a preset alignment accuracy, includes:

[0016] Laser was used to initially align the first and second cubic normals of the cube mirror with the two non-magnetic theodolites, respectively.

[0017] Fine-tune the position of the non-magnetic turntable until the alignment accuracy between the cube mirror and the two non-magnetic theodolites matches the preset alignment accuracy; the preset alignment accuracy is 2 arcseconds.

[0018] In some embodiments, the orthogonality calibration method for the magnetic axis and mechanical axis, wherein inputting a first rotational applied field value to the Helmholtz coil, rotating the non-magnetic turntable, and measuring the probe measurement values ​​of the magnetometer under test at three positions respectively includes:

[0019] A first rotating field value is input to the Helmholtz coil system to obtain the probe measurement value of the magnetometer under test at the first position. ;

[0020] Rotate the non-magnetic turntable to bring the cube mirror to the second position, and fine-tune the horizontal plane of the non-magnetic turntable to align the second non-magnetic theodolite with the normal of the second cubic surface of the cube mirror;

[0021] A first rotational field value is input to the Helmholtz coil system to obtain the probe measurement value of the magnetometer under test in the second position. ;

[0022] Rotate the non-magnetic turntable to bring the cube mirror to the third position, and fine-tune the horizontal plane of the non-magnetic turntable to align the first non-magnetic theodolite with the normal of the second cubic surface of the cube mirror.

[0023] A first rotational field value is input to the Helmholtz coil system to obtain the probe measurement value of the magnetometer under test in the second position. .

[0024] In some embodiments, the orthogonality calibration method for the magnetic axis and mechanical axis, wherein calibrating the first rotating applied field value based on the linearity factor, orthogonality, and zero bias of the Helmholtz coil to obtain the calibrated first rotating applied field value includes:

[0025] The calibrated first rotational field value is calculated based on the following formula (1): ...(1);

[0026] Among them, the The first rotational field value representing the input; The first rotational applied field value is characterized by its calibration. Characterizing linear factors, Characterizes the degree of orthogonality; Characterizes zero bias.

[0027] In some embodiments, the orthogonality calibration method for the magnetic axis and the mechanical axis, wherein obtaining the rotation matrix at three positions based on the calibrated first rotational applied field value and the probe measurements at three positions includes:

[0028] The first rotation matrix between the probe measurement value at the first position and the calibrated first rotation field value is calculated using the following formula (2). R 1;

[0029] ...(2);

[0030] Among them, the The probe measurement value characterizing the first position;R 1. First rotation matrix;

[0031] The second rotation matrix between the probe measurement value at the second position and the calibrated first rotation field value is calculated using the following formula (3). R 2;

[0032] ... (3);

[0033] in, The probe measurement value characterizing the second position; R 2. Second rotation matrix;

[0034] The third rotation matrix, which is the probe measurement value at the third position and the calibrated first rotation field value, is calculated using the following formula (4). R 3;

[0035] ... (4);

[0036] in, The probe measurement value characterizing the third position; R 3. Third rotation matrix.

[0037] In some embodiments, the orthogonality calibration method for the magnetic axis and mechanical axis involves solving for the first and second cubic normals of the cubic mirror in the sensor coordinate system using transformation matrices at three positions, and determining the orthogonality calibration result based on the first and second cubic normals, including:

[0038] Calculate the fourth rotation matrix of the magnetometer under test from the first position to the second position, and calculate the eigenvectors of the fourth rotation matrix; the eigenvectors of the fourth rotation matrix are the first cubic normal of the cubic mirror in the sensor coordinate system;

[0039] Based on the fourth rotation matrix and the first cubic normal, calculate the direction of the optical rotation axis in the coil coordinate system;

[0040] Based on the third rotation matrix corresponding to the third position and the direction of the optical rotation axis, calculate the second cubic normal of the cubic mirror in the sensor coordinate system;

[0041] Calculate the angular deviation between the normals of the first and second cubic surfaces;

[0042] Based on the first and second cubic normals, the target transformation matrix between the magnetic field of the cubic mirror mechanical coordinate system and the magnetic field of the sensor coordinate system is determined. The target transformation matrix represents the transformation matrix between the orthogonal matrix based on the magnetic axis and the mechanical axis.

[0043] In some embodiments, an orthogonality calibration device for magnetic and mechanical axes is also provided. The device includes: a Helmholtz coil, a non-magnetic turntable, two non-magnetic theodolites, a reference cubic mirror, an electronics box, and a processor. The non-magnetic turntable is placed at the center of the Helmholtz coil, and the two non-magnetic theodolites establish a rectangular coordinate system relative to the Helmholtz coil. The two non-magnetic theodolites include a first non-magnetic theodolite and a second non-magnetic theodolite.

[0044] During calibration, the magnetometer to be tested is placed on the non-magnetic turntable; wherein, a reference cubic mirror is fixed on the top of the probe housing of the magnetometer to be tested, and the three cubic faces of the reference cubic mirror represent the normals of the three mechanical axes respectively; the probe of the magnetometer to be tested is connected to the electronics box, and the electronics box is connected to the processor;

[0045] Adjust the two non-magnetic theodolites so that the first and second cubic normals of the cube mirror are aligned with the two non-magnetic theodolites respectively and meet the preset alignment accuracy; set the first position after alignment as the alignment of the first non-magnetic theodolite and the first cubic normal of the cube mirror.

[0046] A first rotational field value is input to the Helmholtz coil, and the non-magnetic turntable is rotated to measure the probe values ​​of the magnetometer under test in three positions. The three positions are the first position, the second position where the second non-magnetic theodolite and the second cubic normal of the cubic mirror are aligned, and the third position where the first theodolite and the second cubic normal of the cubic mirror are aligned.

[0047] The processor is used to calibrate the first rotation field value based on the linearity factor, orthogonality, and zero bias of the calibrated Helmholtz coil, obtain the calibrated first rotation field value, and obtain the rotation matrix for the three positions based on the calibrated first rotation field value and the probe measurement values ​​at the three positions; solve for the first and second cubic normals of the cubic mirror in the sensor coordinate system through the transformation matrix of the three positions, and determine the orthogonality calibration result based on the first and second cubic normals; the orthogonality calibration result includes: the angular deviation between the first and second cubic normals, and the magnetic field of the magnetic axis coordinate system and the magnetic field of the mechanical axis coordinate system.

[0048] In some embodiments, an electronic device is also provided, comprising: a processor, a memory, and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor communicates with the memory via the bus, and when the machine-readable instructions are executed by the processor, the steps of the orthogonality calibration method for the magnetic axis and mechanical axis are performed.

[0049] In some embodiments, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor, performs the steps of the orthogonality calibration method for the magnetic and mechanical axes.

[0050] The orthogonality calibration method, apparatus, electronic device, and medium for magnetic and mechanical axes described in this application calibrate Helmholtz coils to reduce errors in the applied known magnetic field. Furthermore, it utilizes two non-magnetic theodolites to establish a precise rectangular coordinate system, and employs a non-magnetic turntable, laser, and cubic mirror to improve the alignment accuracy of the mechanical axis, reducing experimental operation errors and thereby improving the accuracy of the conversion matrix between the vector magnetometer's measured values ​​and the actual magnetic field measurements. Based on this, the non-orthogonality between the magnetic and mechanical axes is effectively corrected, improving the overall measurement accuracy of the vector magnetometer. Attached Figure Description

[0051] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 A flowchart of the orthogonality calibration method for magnetic and mechanical axes described in an embodiment of this application is shown;

[0053] Figure 2 A flowchart illustrating the method for calculating the linearity factor, orthogonality, and zero bias of the Helmholtz coil according to an embodiment of this application is shown.

[0054] Figure 3 This illustration shows a schematic diagram of the rotational positions of the theodolite and vector magnetometer described in an embodiment of this application;

[0055] Figure 4 A flowchart of the method for determining orthogonality calibration results according to an embodiment of this application is shown;

[0056] Figure 5 A schematic diagram showing the measurement results of the calibration magnetic field of the Helmholtz coil described in an embodiment of this application is illustrated.

[0057] Figure 6 An example diagram of Helmholtz coil calibration according to an embodiment of this application is shown;

[0058] Figure 7 This paper illustrates an example diagram of the conversion matrix calculation between the measured values ​​of the magnetometer under test and the actual magnetic field measured values ​​according to an embodiment of this application.

[0059] Figure 8A schematic diagram of the coordinate systems of the sensor coordinate system and the cubic mirror coordinate system described in the embodiments of this application is shown;

[0060] Figure 9 A schematic diagram of the structure of the electronic device described in an embodiment of this application is shown. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the accompanying drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0062] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0063] It should be noted that the term "comprising" will be used in the embodiments of this application to indicate the presence of the features declared thereafter, but does not exclude the addition of other features.

[0064] Vector magnetometers are crucial components in drones, navigation systems, and other devices requiring precise orientation detection, making their accuracy paramount. Ideally, the magnetic axis and mechanical axis of the magnetometer should be perfectly aligned. Misalignment between these axes will lead to errors in orientation measurement, impacting overall performance. Therefore, calibrating the magnetic axis and mechanical axis of the magnetic sensor (i.e., the magnetometer) is a critical step in ensuring sensor measurement accuracy.

[0065] Based on this, this application provides a method, apparatus, electronic device, and medium for calibrating the orthogonality of magnetic and mechanical axes. The apparatus, applied to the orthogonality calibration of magnetic and mechanical axes, includes: a Helmholtz coil, a non-magnetic turntable, two non-magnetic theodolites, a reference cubic mirror, and an electronics box. The non-magnetic turntable is placed at the center of the Helmholtz coil, and the two non-magnetic theodolites establish a rectangular coordinate system relative to the Helmholtz coil. The two non-magnetic theodolites include a first non-magnetic theodolite and a second non-magnetic theodolite. The calibration method includes the following steps: calibrating the Helmholtz coil, and calculating the linearity factor, orthogonality, and zero of the Helmholtz coil. The magnetometer to be tested is placed on the non-magnetic turntable. A reference cubic mirror is fixed to the top of the probe housing of the magnetometer to be tested, and the three faces of the reference cubic mirror represent the normals of the three mechanical axes. The probe of the magnetometer to be tested is connected to the electronics box. Two non-magnetic theodolites are adjusted so that the normals of the first and second faces of the cubic mirror are aligned with the two non-magnetic theodolites and meet the preset alignment accuracy. The first aligned position is set as the alignment of the first non-magnetic theodolite and the first face of the cubic mirror. A first rotational applied field value is input to the Helmholtz coil, the non-magnetic turntable is rotated, and the probe of the magnetometer to be tested is measured at the three positions. The probe measurements are taken at the following positions: the first position, the second position where the second non-magnetic theodolite and the second cubic normal of the cube mirror are aligned, and the third position where the first theodolite and the second cubic normal of the cube mirror are aligned; the first rotation field value is calibrated based on the linearity factor, orthogonality, and zero bias of the Helmholtz coil, and the calibrated first rotation field value is obtained; based on the calibrated first rotation field value and the probe measurements at the three positions, the rotation matrices of the three positions are obtained; the first cubic normal and the second cubic normal of the cube mirror in the sensor coordinate system are solved by the transformation matrices of the three positions, and the rotation matrices of the first cubic normal and the second cubic normal of the cube mirror in the sensor coordinate system are solved by the transformation matrices of the three positions. The orthogonality calibration result is determined by the two-dimensional normal direction; the orthogonality calibration result includes: the angular deviation between the first and second dimensional normal directions, and the transformation matrix between the magnetic axis-based orthogonality matrix and the mechanical axis; the method calibrates the Helmholtz coil to reduce the error of the applied known magnetic field; it also uses two non-magnetic theodolites to establish a precise rectangular coordinate system, and uses a non-magnetic turntable, laser, and cubic mirror to improve the alignment accuracy of the mechanical axis, reduce experimental operation errors, and thus improve the accuracy of the transformation matrix between the vector magnetometer measurement value and the actual magnetic field measurement value; based on this, the non-orthogonality between the magnetic axis and the mechanical axis is effectively corrected, and the overall measurement accuracy of the vector magnetometer is improved.

[0066] Please refer to Figure 1 , Figure 1The steps of the orthogonality calibration method for magnetic and mechanical axes described in this application embodiment are illustrated; the apparatus includes: a Helmholtz coil, a non-magnetic turntable, two non-magnetic theodolites, a reference cubic mirror, and an electronics box. The non-magnetic turntable is placed at the center of the Helmholtz coil, and the two non-magnetic theodolites establish a rectangular coordinate system relative to the Helmholtz coil; the two non-magnetic theodolites include a first non-magnetic theodolite and a second non-magnetic theodolite.

[0067] like Figure 1 As shown, the calibration method includes the following steps S101-S106:

[0068] S101. Calibrate the Helmholtz coil and calculate its linearity factor, orthogonality, and zero bias.

[0069] S102. Place the magnetometer to be tested on the non-magnetic turntable; wherein, a reference cubic mirror is fixed on the top of the probe housing of the magnetometer to be tested, and the three cubic faces of the reference cubic mirror represent the normals of the three mechanical axes respectively; the probe of the magnetometer to be tested is connected to the electronics box.

[0070] S103. Adjust the two non-magnetic theodolites so that the first and second cubic normals of the cube mirror are aligned with the two non-magnetic theodolites respectively and meet the preset alignment accuracy; set the first position after alignment as the alignment of the first non-magnetic theodolite and the first cubic normal of the cube mirror.

[0071] S104. Input the first rotation field value to the Helmholtz coil, rotate the non-magnetic turntable and measure the probe measurement values ​​of the magnetometer under test in three positions respectively; the three positions are the first position, the second position where the second non-magnetic theodolite and the second cubic normal of the cubic mirror are aligned, and the third position where the first theodolite and the second cubic normal of the cubic mirror are aligned.

[0072] S105. Based on the linearity factor, orthogonality and zero bias of the Helmholtz coil, calibrate the first rotating field value to obtain the calibrated first rotating field value, and based on the calibrated first rotating field value and the probe measurement values ​​at three positions, obtain the rotation matrix at the three positions.

[0073] S106. Solve for the first and second cubic normals of the cubic mirror in the sensor coordinate system using the transformation matrices of the three positions, and determine the orthogonality calibration result based on the first and second cubic normals; the orthogonality calibration result includes: the angular deviation between the first and second cubic normals, and the transformation matrix between the orthogonality matrix based on the magnetic axis and the mechanical axis.

[0074] In other words, the orthogonality calibration method for magnetic and mechanical axes described in this application involves placing the fluxgate magnetometer to be tested at the center of a Helmholtz field coil and applying a stable and uniform magnetic field; attaching a cubic mirror to the top of the magnetometer and using the cubic mirror as a reference for the mechanical axis; determining the relationship between the mechanical axis and the magnetic axis through a rotation method; and obtaining the transformation relationship between the orthogonal matrix based on the magnetic axis and the mechanical axis.

[0075] In step S101, the Helmholtz coil is calibrated, and the linearity factor, orthogonality, and zero bias of the Helmholtz coil are calculated.

[0076] The Helmholtz coil can also be called a Helmholtz field coil or a Helmholtz coil mechanism.

[0077] Please refer to Figure 2 The calibration of the Helmholtz coil, including the calculation of its linearity factor, orthogonality, and zero bias, comprises the following steps S201-S202:

[0078] S201. Place the proton magnetometer at the center of the Helmholtz coil and input a second rotating field value to the Helmholtz coil system; the total field of the second rotating field value is 50000nT, and the vector direction is uniformly distributed on a spherical surface;

[0079] S202. Collect the data from the proton magnetometer, calibrate the coil, and calculate the linearity factor, orthogonality, and zero bias of the coil.

[0080] The proton magnetometer is an Overhauser proton magnetometer.

[0081] The Helmholtz coil is calibrated, and its linearity factor is calculated. orthogonality and zero bias The calibrated coil field value can be approximated as the actual geomagnetic field value in the coil coordinate system. Through calibration, the coil can represent the current actual geomagnetic field value, reducing the error of the applied known magnetic field.

[0082] Specifically, please refer to the following formula (5): ... (5);

[0083] in, This is the applied field value of the calibrated coil; It is the linearity factor of the coil; It is the orthogonality of the coils and It is the zero bias of the coil, and also the zero bias of the calibrated magnetometer.

[0084] In step S102, the magnetometer to be tested is placed on the non-magnetic turntable; wherein, a reference cubic mirror is fixed on the top of the probe housing of the magnetometer to be tested, and the three cubic faces of the reference cubic mirror represent the normals of the three mechanical axes respectively; the probe of the magnetometer to be tested is connected to the electronics box.

[0085] Specifically, a non-magnetic turntable is placed at the center of the Helmholtz field coil. The reference cubic mirror is attached to the top of the probe housing of the magnetometer to be tested. The magnetometer probe and the electronics box are connected and placed on the non-magnetic turntable. The host is turned on and the equipment status is checked, and it is preheated for 60 minutes.

[0086] In step S103, the two non-magnetic theodolites are adjusted so that the first and second cubic normals of the cube mirror are aligned with the two non-magnetic theodolites and meet the preset alignment accuracy; the first position after alignment is set as the alignment of the first non-magnetic theodolite and the first cubic normal of the cube mirror.

[0087] The adjustment of the two non-magnetic theodolites to align the first and second cubic normals of the cube mirror with the two non-magnetic theodolites respectively and meet the preset alignment accuracy includes:

[0088] Laser was used to initially align the first and second cubic normals of the cube mirror with the two non-magnetic theodolites, respectively.

[0089] Fine-tune the position of the non-magnetic turntable until the alignment accuracy between the cube mirror and the two non-magnetic theodolites matches the preset alignment accuracy; the preset alignment accuracy is 2 arcseconds.

[0090] Please refer to Figure 3 Set up a non-magnetic theodolite so that the two theodolites establish a rectangular coordinate system (e.g., Figure 3 (The coordinate system in the image); a laser is used to roughly align the two normal planes of the cube mirror with the two theodolites, and then fine-tuning is performed until the alignment accuracy between the cube mirror and the two theodolites is 2 arcseconds, so that the second theodolite is aligned with the normal plane of the first cube mirror. The position at this time is recorded as the first position. Figure 3 (#1 in the text); After the non-magnetic turntable rotates, it can rotate to the second position ( Figure 3 #2 in the middle) and the third position ( Figure 3 (#3 in the middle).

[0091] In step S104, a first rotational field value is input to the Helmholtz coil, the non-magnetic turntable is rotated, and the probe measurement values ​​of the magnetometer under test are measured at three positions. The three positions are the first position, the second position where the second non-magnetic theodolite and the second cubic normal of the cubic mirror are aligned, and the third position where the first theodolite and the second cubic normal of the cubic mirror are aligned.

[0092] Specifically, the step of inputting a first rotational applied field value to the Helmholtz coil, rotating the non-magnetic turntable, and measuring the probe values ​​of the magnetometer under test at three positions includes:

[0093] A first rotating field value is input to the Helmholtz coil system to obtain the probe measurement value of the magnetometer under test at the first position. ;

[0094] Rotate the non-magnetic turntable to bring the cube mirror to the second position, and fine-tune the horizontal plane of the non-magnetic turntable to align the second non-magnetic theodolite with the normal of the second cubic surface of the cube mirror;

[0095] A first rotational field value is input to the Helmholtz coil system to obtain the probe measurement value of the magnetometer under test in the second position. ;

[0096] Rotate the non-magnetic turntable to bring the cube mirror to the third position, and fine-tune the horizontal plane of the non-magnetic turntable to align the first non-magnetic theodolite with the normal of the second cubic surface of the cube mirror.

[0097] A first rotational field value is input to the Helmholtz coil system to obtain the probe measurement value of the magnetometer under test in the second position. .

[0098] The first rotational field value is the same as the second rotational field value input when calibrating the coil, with a total field of 50000nT and a vector direction uniformly distributed on a spherical surface.

[0099] In some embodiments, specifically, a rotating applied field value (total field of 50,000 nT, vector direction uniformly distributed on a sphere) is input to the Helmholtz coil system, and the vector magnetometer stores the measurement data to obtain the probe measurement value through calculation. Field value applied to the coil Transformation matrix R 1.

[0100] Rotate the non-magnetic turntable to the second position (rotate around the optical axis of the theodolite), and fine-tune the horizontal plane of the non-magnetic turntable to align the theodolite 2 with the normal of the vertical plane 1.

[0101] A rotating field value (total field of 50,000 nT, vector direction uniformly distributed on a sphere) is input to the Helmholtz coil system. The vector magnetometer stores the measurement data and calculates the probe measurement value. Field value applied to the coil Transformation matrix R 2.

[0102] Rotate the non-magnetic turntable to the third position and fine-tune the horizontal plane of the non-magnetic turntable to align the first theodolite with the normal of the second vertical plane.

[0103] A rotating field value (total field of 50,000 nT, vector direction uniformly distributed on a sphere) is input to the Helmholtz coil system. The vector magnetometer stores the measurement data and calculates the probe measurement value. Field value applied to the coil Transformation matrix R 3.

[0104] The main unit is shut down, the test is over, and the stored data is organized and processed.

[0105] In step S105, the first rotation field value is calibrated based on the linearity factor, orthogonality, and zero bias of the Helmholtz coil to obtain the calibrated first rotation field value. Based on the calibrated first rotation field value and the probe measurements at the three positions, the rotation matrix at the three positions is obtained.

[0106] In some embodiments, the step of calibrating the first rotating field value based on the linearity factor, orthogonality, and zero bias of the Helmholtz coil to obtain the calibrated first rotating field value includes:

[0107] The calibrated first rotational field value is calculated based on the following formula (1): ...(1);

[0108] Among them, the The first rotational field value representing the input; The first rotational applied field value is characterized by its calibration. Characterizing linear factors, Characterizes the degree of orthogonality; Characterizes zero bias.

[0109] Based on the calibrated first rotation field value and the probe measurements at three positions, a rotation matrix is ​​obtained at three positions, including:

[0110] The first rotation matrix between the probe measurement value at the first position and the calibrated first rotation field value is calculated using the following formula (2). R 1;

[0111] ...(2);

[0112] Among them, the The probe measurement value characterizing the first position; R 1. First rotation matrix.

[0113] The second rotation matrix between the probe measurement value at the second position and the calibrated first rotation field value is calculated using the following formula (3). R 2;

[0114] ... (3);

[0115] in, The probe measurement value characterizing the second position; R 2. Second rotation matrix.

[0116] The third rotation matrix, which is the probe measurement value at the third position and the calibrated first rotation field value, is calculated using the following formula (4). R 3;

[0117] ... (4);

[0118] in, The probe measurement value characterizing the third position; R 3. Third rotation matrix.

[0119] In step S106, the first and second cubic normals of the cubic mirror in the sensor coordinate system are solved by the transformation matrix of the three positions, and the orthogonality calibration result is determined based on the first and second cubic normals.

[0120] Please refer to Figure 4 The first and second cubic normals of the cubic mirror in the sensor coordinate system are solved by the transformation matrix of the three positions, and the orthogonality calibration result is determined based on the first and second cubic normals, including the following steps S401-S405:

[0121] S401. Calculate the fourth rotation matrix of the magnetometer to be measured from the first position to the second position, and calculate the eigenvectors of the fourth rotation matrix; the eigenvectors of the fourth rotation matrix are the first cubic normal of the cubic mirror in the sensor coordinate system.

[0122] S402. Based on the fourth rotation matrix and the first cubic normal, calculate the direction of the optical rotation axis in the coil coordinate system;

[0123] S403. Based on the third rotation matrix corresponding to the third position and the direction of the optical rotation axis, calculate the second cubic normal of the cubic mirror in the sensor coordinate system;

[0124] S404. Calculate the angle deviation between the normals of the first and second cubic surfaces;

[0125] S405. Based on the first cubic normal and the second cubic normal, determine the target transformation matrix between the magnetic field of the cubic mirror mechanical coordinate system and the magnetic field of the sensor coordinate system. The target transformation matrix represents the transformation matrix between the orthogonal matrix based on the magnetic axis and the mechanical axis.

[0126] The magnetic field of the cubic mirror mechanical coordinate system is the magnetic field of the coordinate system established based on the cubic mirror.

[0127] The following analysis explains the principle of the orthogonality calibration method for magnetic and mechanical axes described in the embodiments of this application.

[0128] The conversion matrix between vector magnetometer measurements and actual magnetic field measurements is calculated as follows:

[0129] The relationship between the measured value of the vector magnetometer and the true value of the magnetic field can be expressed by the following formulas (6) and (7): ... (6);

[0130] ... (7);

[0131] Among them, the calibration matrix It is a 3×3 matrix, where b is the zero bias of the magnetometer, also known as the offset, which can be calculated by the magnetometer calibration method; It is the linearity factor of the coil; It refers to the orthogonality of the coils; These are measurements from a vector magnetometer. These are actual magnetic field measurements.

[0132] Due to the applied field value of the coil The values ​​measured by the vector magnetometer can be approximated as actual magnetic field measurements. (First position) and coil applied field value The transformation matrix is ​​given by the following formula (8):

[0133] ... (8);

[0134] in, .

[0135] Vector magnetometer measurements (Second position) and the applied field value of the coil The transformation matrix is ​​given by the following formula (9):

[0136] ... (9);

[0137] in, .

[0138] Vector magnetometer measurements (Position #3) and the applied field value of the coil The transformation matrix is ​​given by the following formula (10):

[0139] ... (10)

[0140] in, .

[0141] The transformation matrix between the magnetic sensing axis and the mechanical axis of the cubic mirror is calculated as follows:

[0142] First, we can obtain the following formulas (11) and (12);

[0143] ... (11);

[0144] = ... (12);

[0145] in This is the transformation matrix of the magnetometer from the first position to the second position. eigenvectors Defined as follows (13);

[0146] ... (13);

[0147] Since the rotation from position #1 to position #2 is around the optical axis of the theodolite 1 for automatic alignment, The direction is the axis of automatic alignment of the first non-magnetic theodolite in the sensor coordinate system, i.e., the normal direction of the first cubic aspect, which is transformed into the Helmholtz coil coordinate system. Due to the rotation vector It has three eigenvalues:

[0148] ,

[0149] That is The rotation angle from position 1 to position 2.

[0150] When the sensor moves to the third position, the normal to the second cubic surface in the sensor coordinate system can be calculated using the following formula (14):

[0151] ... (14);

[0152] The angle between the normals of the first and second cubic surfaces is given by the following formula (15):

[0153] ... (15);

[0154] Therefore, a system based on an optical reference axis can be established. and The orthogonal coordinate system, the cubic mirror machine coordinate system, has three coordinate axes as follows: , , Magnetic field in this coordinate system magnetic field relative to the magnetic sensitive axis coordinate system The transformation matrix is ​​given by the following formula (16):

[0155] ... (16);

[0156] in

[0157]

[0158]

[0159] 。

[0160] Based on this, after calculating the three rotation matrices corresponding to the three positions, the first and second cubic normals of the cubic mirror in the sensor coordinate system are solved using the transformation matrices of the three positions, and the orthogonality calibration result is determined based on the first and second cubic normals, as follows:

[0161] (1) Calculate the rotation matrix of the magnetometer to be measured from the first position to the second position. ;

[0162] (2) Calculation eigenvector of That is, the normal to the first cubic surface in the sensor coordinate system, such that ; Calculate the direction of the optical rotation axis in the coil coordinate system , The eigenvalues ​​are then , for The rotation angle from position 1 to position 2;

[0163] (3) Calculate the normal of the vertical aspect 2 in the sensor coordinate system The angle between the normals of the two cubic surfaces. for:

[0164] ；

[0165] (4) Therefore, an orthogonal coordinate system based on the mechanical axes of the cubic mirror can be established, with the three coordinate axes being respectively... , , The magnetic field in this coordinate system is:

[0166] ；

[0167] in

[0168] ，

[0169] ，

[0170] 。

[0171] The following is a test example of a calibration method for the orthogonality of the magnetic axis and mechanical axis of a magnetometer under test.

[0172] Please refer to Figure 5 , Figure 5 This diagram illustrates the measurement results of the calibration magnetic field of the Helmholtz coil according to an embodiment of this application; during the calibration process of the Helmholtz coil, as... Figure 5 As shown, from top to bottom, the three components of the coil field and the scalar measurement value of the proton magnetometer are displayed.

[0173] Please refer to Figure 6 , Figure 6 An example diagram of Helmholtz coil calibration according to an embodiment of this application is shown; Figure 6 A grouped scatter plot of multiple subplots, such as Figure 6 As shown, from top to bottom, the magnetic field of the coil consists of the three components x, y, and z. Figure 6 sub Figure 1 ,son Figure 2 Kazuko Figure 3 ); General Farm (Sub-farm) Figure 4 Where blue dots represent uncalibrated values, green dots represent Overhauser measurements, and red dots represent calibrated total field values; total field residuals (sub-) Figure 5 ).

[0174] The coil calibration parameters are shown in Table 1 below:

[0175] Table 1

[0176] Sensitivities, in nT / EU:1.00149391.00058940.99974595

[0177] offset, in nT:-14.525832-1.87698650.58799202

[0178] Misalignment Angle (xy), (xz), (yz), in deg: 0.0123600380.18785198-0.046998853

[0179] The following is an example of calculating the transformation matrix between the magnetic sensing axis and the cubic mirror mechanical axis.

[0180] Please refer to Figure 7 , Figure 7 This illustrates an example of calculating the conversion matrix between the measured values ​​of the magnetometer and the actual magnetic field measurements; for example... Figure 7 As shown, from top to bottom, the measured magnetic field components are x, y, and z. Figure 7 sub Figure 1 ,son Figure 2 Kazuko Figure 3 ); General Field ( Figure 7 sub Figure 4 Where, blue dots represent uncalibrated values, green dots represent scalar values ​​of the magnetic field after coil calibration, and red dots represent the total field value after vector magnetometer calibration; total field residual ( Figure 7 sub Figure 5 ).

[0181] Using the orthogonality calibration method mentioned in the embodiments of this application, three transformation matrices relative to the coil coordinate system at the first, second, and third positions are calculated. , , The specific calculation results are as follows:

[0182]

[0183]

[0184] ,

[0185] satisfy = , in, , The measured values ​​are obtained from the sensor coordinate system at three locations. The magnetic field measurement value is obtained in the coil coordinate system.

[0186] , eigenvector of That is, the first cubic normal in the sensor coordinate system (the theodolite automatically aligns to the axis) is:

[0187] ;

[0188] Transform to optical axis direction in coil coordinate system:

[0189] ;

[0190] The eigenvalues ​​are It can be calculated that =90.016°, which is the rotation angle from position 1 to position 2, with a rotation error of 0.016°.

[0191] Normal direction of sensor coordinate system in vertical direction 2

[0192] ;

[0193] To assess the error in the direction of the cubic normal, the angle between the two cubic normals was calculated.

[0194] =89.968°;

[0195] Therefore, the angular deviation between the normals of the first and second cubic surfaces is approximately 0.032°, with the main sources of error being the alignment error of the theodolite and the calibration algorithm error.

[0196] A magnetic field can be established in the mechanical coordinate system of a cubic mirror. magnetic field relative to the magnetic sensitive axis coordinate system Conversion relationship: ；

[0197] Magnetic field in cubic mirror mechanical coordinate system magnetic field relative to the magnetic sensitive axis coordinate system Transformation matrix for:

[0198] ;

[0199] Please refer to Figure 8 , Figure 8 The diagram shows the coordinate systems of the sensor coordinate system and the cubic mirror coordinate system; to align with the three axes of the sensor coordinate system, further transformation is needed to obtain:

[0200] ;

[0201] in, This is the transformation matrix that aligns the three axes between the sensor coordinate system and the cubic mirror coordinate system.

[0202] In other words, the transformation matrix between the orthogonal matrix based on the magnetic axis and the mechanical axis. Three components of the magnetic field in the magnetic sensitive axis coordinate system Three components of the magnetic field in the mechanical coordinate system of the cubic mirror The conversion relationship is ;

[0203] .

[0204] Based on the same inventive concept, this application also provides an orthogonality calibration device for magnetic and mechanical axes corresponding to the orthogonality calibration method for magnetic and mechanical axes. Since the principle of the device in this application is similar to the orthogonality calibration method for magnetic and mechanical axes described above in this application, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be described again.

[0205] In some embodiments, an orthogonality calibration device for magnetic and mechanical axes is also provided. The device includes: a Helmholtz coil, a non-magnetic turntable, two non-magnetic theodolites, a reference cubic mirror, an electronics box, and a processor. The non-magnetic turntable is placed at the center of the Helmholtz coil, and the two non-magnetic theodolites establish a rectangular coordinate system relative to the Helmholtz coil. The two non-magnetic theodolites include a first non-magnetic theodolite and a second non-magnetic theodolite.

[0206] During calibration, the magnetometer to be tested is placed on the non-magnetic turntable; wherein, a reference cubic mirror is fixed on the top of the probe housing of the magnetometer to be tested, and the three cubic faces of the reference cubic mirror represent the normals of the three mechanical axes respectively; the probe of the magnetometer to be tested is connected to the electronics box, and the electronics box is connected to the processor;

[0207] Adjust the two non-magnetic theodolites so that the first and second cubic normals of the cube mirror are aligned with the two non-magnetic theodolites respectively and meet the preset alignment accuracy; set the first position after alignment as the alignment of the first non-magnetic theodolite and the first cubic normal of the cube mirror.

[0208] A first rotational field value is input to the Helmholtz coil, and the non-magnetic turntable is rotated to measure the probe values ​​of the magnetometer under test in three positions. The three positions are the first position, the second position where the second non-magnetic theodolite and the second cubic normal of the cubic mirror are aligned, and the third position where the first theodolite and the second cubic normal of the cubic mirror are aligned.

[0209] The processor is used to calibrate the first rotation field value based on the linearity factor, orthogonality, and zero bias of the calibrated Helmholtz coil, obtain the calibrated first rotation field value, and obtain the rotation matrix for the three positions based on the calibrated first rotation field value and the probe measurement values ​​at the three positions; solve for the first and second cubic normals of the cubic mirror in the sensor coordinate system through the transformation matrix of the three positions, and determine the orthogonality calibration result based on the first and second cubic normals; the orthogonality calibration result includes: the angular deviation between the first and second cubic normals, and the magnetic field of the magnetic axis coordinate system and the magnetic field of the mechanical axis coordinate system.

[0210] Based on the same inventive concept, this application also provides an electronic device corresponding to the orthogonality calibration method for magnetic and mechanical axes. Since the principle of solving the problem by the electronic device in this application is similar to the orthogonality calibration method for magnetic and mechanical axes described above in this application, the implementation of the electronic device can refer to the implementation of the method, and the repeated parts will not be described again.

[0211] Please refer to Figure 9 , Figure 9A schematic diagram of the structure of the electronic device 900 according to an embodiment of this application is shown. The electronic device 900 includes a processor 901, a memory 902, and a bus. The memory 902 stores machine-readable instructions executable by the processor 901. When the electronic device 900 is running, the processor 901 communicates with the memory 902 via the bus. When the machine-readable instructions are executed by the processor 901, the steps of the orthogonality calibration method for magnetic and mechanical axes described in any one of the embodiments are executed, as follows:

[0212] Based on the calibrated linearity factor, orthogonality, and zero bias of the Helmholtz coil, the first rotating field value is calibrated to obtain the calibrated first rotating field value. Based on the calibrated first rotating field value and the probe measurements at three positions, the rotation matrices at the three positions are obtained. The first and second cubic normals of the cubic mirror in the sensor coordinate system are solved using the transformation matrices at the three positions. Based on the first and second cubic normals, the orthogonality calibration result is determined. The orthogonality calibration result includes: the angular deviation between the first and second cubic normals, and the magnetic field of the magnetic axis coordinate system and the magnetic field of the mechanical axis coordinate system.

[0213] In other words, the processor of the electronic device executes the software portion (i.e. the calculation portion) of the orthogonality calibration method for the magnetic axis and the mechanical axis.

[0214] Based on the same inventive concept, this application also provides a computer-readable storage medium corresponding to the orthogonality calibration method for magnetic and mechanical axes. Since the principle of the computer-readable storage medium in this application is similar to the orthogonality calibration method for magnetic and mechanical axes described above in this application, the implementation of the computer-readable storage medium can refer to the implementation of the method, and the repeated parts will not be described again.

[0215] A computer-readable storage medium storing a computer program, which, when executed by a processor, performs the steps of the orthogonality calibration method for magnetic and mechanical axes, as follows:

[0216] Based on the calibrated linearity factor, orthogonality, and zero bias of the Helmholtz coil, the first rotating field value is calibrated to obtain the calibrated first rotating field value. Based on the calibrated first rotating field value and the probe measurements at three positions, the rotation matrices at the three positions are obtained. The first and second cubic normals of the cubic mirror in the sensor coordinate system are solved using the transformation matrices at the three positions. Based on the first and second cubic normals, the orthogonality calibration result is determined. The orthogonality calibration result includes: the angular deviation between the first and second cubic normals, and the magnetic field of the magnetic axis coordinate system and the magnetic field of the mechanical axis coordinate system.

[0217] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems and devices described above can be referred to the corresponding processes in the method embodiments, and will not be repeated here. In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection can be through some communication interfaces; the indirect coupling or communication connection of devices or modules can be electrical, mechanical, or other forms.

[0218] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0219] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0220] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a platform server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0221] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for calibrating the orthogonality of a magnetic shaft and a mechanical shaft, characterized in that, An orthogonality calibration device for magnetic and mechanical axes, comprising: a Helmholtz coil, a non-magnetic turntable, two non-magnetic theodolites, a reference cubic mirror, and an electronics box; the non-magnetic turntable is placed at the center of the Helmholtz coil, and the two non-magnetic theodolites establish a rectangular coordinate system relative to the Helmholtz coil; the two non-magnetic theodolites include a first non-magnetic theodolite and a second non-magnetic theodolite. The calibration method includes the following steps: The Helmholtz coil is calibrated, and its linearity, orthogonality, and zero bias are calculated. The magnetometer to be tested is placed on the non-magnetic turntable; wherein, a reference cubic mirror is fixed on the top of the probe housing of the magnetometer to be tested, and the three cubic faces of the reference cubic mirror represent the normals of the three mechanical axes respectively; the probe of the magnetometer to be tested is connected to the electronics box. Adjust the two non-magnetic theodolites so that the first and second cubic normals of the cube mirror are aligned with the two non-magnetic theodolites respectively and meet the preset alignment accuracy; set the first position after alignment as the alignment of the first non-magnetic theodolite and the first cubic normal of the cube mirror. A first rotational field value is input to the Helmholtz coil, and the non-magnetic turntable is rotated to measure the probe values ​​of the magnetometer under test in three positions. The three positions are the first position, the second position where the second non-magnetic theodolite and the second cubic normal of the cubic mirror are aligned, and the third position where the first theodolite and the second cubic normal of the cubic mirror are aligned. The first rotating field value is calibrated based on the linearity factor, orthogonality, and zero bias of the Helmholtz coil. The calibrated first rotating field value is obtained, and the rotation matrix at the three positions is obtained based on the calibrated first rotating field value and the probe measurement values ​​at the three positions. The first and second cubic normals of the cubic mirror in the sensor coordinate system are solved by the transformation matrix of the three positions, and the orthogonality calibration result is determined based on the first and second cubic normals; the orthogonality calibration result includes: the angular deviation between the first and second cubic normals, and the transformation matrix between the orthogonality matrix based on the magnetic axis and the mechanical axis.

2. The orthogonality calibration method for magnetic and mechanical axes according to claim 1, characterized in that, The calibration of the Helmholtz coil, including the calculation of its linearity factor, orthogonality, and zero bias, includes: A proton magnetometer is placed at the center of the Helmholtz coil, and a second rotating field value is input to the Helmholtz coil system; the total field of the second rotating field value is 50000 nT, and the vector direction is uniformly distributed on a sphere; Data from the proton magnetometer is collected, the coil is calibrated, and the linearity factor, orthogonality, and zero bias of the coil are calculated.

3. The orthogonality calibration method for magnetic and mechanical axes according to claim 1, characterized in that, The adjustment of the two non-magnetic theodolites to align the first and second cubic normals of the cube mirror with the two non-magnetic theodolites respectively and meet the preset alignment accuracy includes: Laser was used to initially align the first and second cubic normals of the cube mirror with the two non-magnetic theodolites, respectively. Fine-tune the position of the non-magnetic turntable until the alignment accuracy between the cube mirror and the two non-magnetic theodolites matches the preset alignment accuracy; the preset alignment accuracy is 2 arcseconds.

4. The orthogonality calibration method for magnetic and mechanical axes according to claim 1, characterized in that, The process of inputting a first rotational applied field value to the Helmholtz coil, rotating the non-magnetic turntable, and measuring the probe values ​​of the magnetometer under test at three positions includes: A first rotating field value is input to the Helmholtz coil system to obtain the probe measurement value of the magnetometer under test at the first position. ; Rotate the non-magnetic turntable to bring the cube mirror to the second position, and fine-tune the horizontal plane of the non-magnetic turntable to align the second non-magnetic theodolite with the normal of the second cubic surface of the cube mirror; A first rotational field value is input to the Helmholtz coil system to obtain the probe measurement value of the magnetometer under test in the second position. ; Rotate the non-magnetic turntable to bring the cube mirror to the third position, and fine-tune the horizontal plane of the non-magnetic turntable to align the first non-magnetic theodolite with the normal of the second cubic surface of the cube mirror. A first rotational field value is input to the Helmholtz coil system to obtain the probe measurement value of the magnetometer under test in the second position. .

5. The orthogonality calibration method for magnetic and mechanical axes according to claim 1, characterized in that, The calibration of the first rotating field value based on the linearity factor, orthogonality, and zero bias of the Helmholtz coil, to obtain the calibrated first rotating field value, includes: The calibrated first rotational field value is calculated based on the following formula (1): ...(1); Among them, the The first rotational field value representing the input; The first rotational applied field value is characterized by its calibration. Characterizing linear factors, Characterizes the degree of orthogonality; Characterizes zero bias.

6. The orthogonality calibration method for magnetic and mechanical axes according to claim 5, characterized in that, Based on the calibrated first rotation field value and the probe measurements at three positions, a rotation matrix is ​​obtained at three positions, including: The first rotation matrix between the probe measurement value at the first position and the calibrated first rotation field value is calculated using the following formula (2). R 1; ……（2）； Among them, the The probe measurement value characterizing the first position; R 1. First rotation matrix; The second rotation matrix between the probe measurement value at the second position and the calibrated first rotation field value is calculated using the following formula (3). R 2; ……（3）； in, The probe measurement value characterizing the second position; R 2. Second rotation matrix; The third rotation matrix, which is the probe measurement value at the third position and the calibrated first rotation field value, is calculated using the following formula (4). R 3; ……（4）； in, The probe measurement value characterizing the third position; R 3. Third rotation matrix.

7. The orthogonality calibration method for magnetic and mechanical axes according to claim 6, characterized in that, The first and second cubic normals of the cubic mirror in the sensor coordinate system are solved using transformation matrices at three positions. Based on these first and second cubic normals, the orthogonality calibration results are determined, including: Calculate the fourth rotation matrix of the magnetometer under test from the first position to the second position, and calculate the eigenvectors of the fourth rotation matrix; the eigenvectors of the fourth rotation matrix are the first cubic normal of the cubic mirror in the sensor coordinate system; Based on the fourth rotation matrix and the first cubic normal, calculate the direction of the optical rotation axis in the coil coordinate system; Based on the third rotation matrix corresponding to the third position and the direction of the optical rotation axis, calculate the second cubic normal of the cubic mirror in the sensor coordinate system; Calculate the angular deviation between the normals of the first and second cubic surfaces; Based on the first and second cubic normals, the target transformation matrix between the magnetic field of the cubic mirror mechanical coordinate system and the magnetic field of the sensor coordinate system is determined. The target transformation matrix represents the transformation matrix between the orthogonal matrix based on the magnetic axis and the mechanical axis.

8. A device for calibrating the orthogonality of a magnetic shaft and a mechanical shaft, characterized in that, The device includes: a Helmholtz coil, a non-magnetic turntable, two non-magnetic theodolites, a reference cube mirror, an electronics box, and a processor. The non-magnetic turntable is placed at the center of the Helmholtz coil, and the two non-magnetic theodolites establish a rectangular coordinate system relative to the Helmholtz coil. The two non-magnetic theodolites include a first non-magnetic theodolite and a second non-magnetic theodolite. During calibration, the magnetometer to be tested is placed on the non-magnetic turntable; wherein, a reference cubic mirror is fixed on the top of the probe housing of the magnetometer to be tested, and the three cubic faces of the reference cubic mirror represent the normals of the three mechanical axes respectively; the probe of the magnetometer to be tested is connected to the electronics box, and the electronics box is connected to the processor; Adjust the two non-magnetic theodolites so that the first and second cubic normals of the cube mirror are aligned with the two non-magnetic theodolites respectively and meet the preset alignment accuracy; set the first position after alignment as the alignment of the first non-magnetic theodolite and the first cubic normal of the cube mirror. A first rotational field value is input to the Helmholtz coil, and the non-magnetic turntable is rotated to measure the probe values ​​of the magnetometer under test in three positions. The three positions are the first position, the second position where the second non-magnetic theodolite and the second cubic normal of the cubic mirror are aligned, and the third position where the first theodolite and the second cubic normal of the cubic mirror are aligned. The processor is used to calibrate the first rotation field value based on the linearity factor, orthogonality, and zero bias of the calibrated Helmholtz coil, obtain the calibrated first rotation field value, and obtain the rotation matrix for the three positions based on the calibrated first rotation field value and the probe measurement values ​​at the three positions; solve for the first and second cubic normals of the cubic mirror in the sensor coordinate system through the transformation matrix of the three positions, and determine the orthogonality calibration result based on the first and second cubic normals; the orthogonality calibration result includes: the angular deviation between the first and second cubic normals, and the magnetic field of the magnetic axis coordinate system and the magnetic field of the mechanical axis coordinate system.

9. An electronic device, characterized in that, include: The device includes a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the memory via the bus. When the machine-readable instructions are executed by the processor, they perform the steps of the orthogonality calibration method for magnetic and mechanical axes as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, performs the steps of the orthogonality calibration method for magnetic and mechanical axes as described in any one of claims 1 to 7.

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