A three-axis coil analog magnetic field system orthogonality calibration device and calibration method

Abstract

The application discloses a three-axis coil analog magnetic field system orthogonality calibration device and a calibration method, which comprises a base, a cubic prism and a magnetometer, the base is made of glass and is in the shape of a cuboid, a non-magnetic column which is perpendicular to the surface of the base is arranged at the center of the base, the cubic prism is made of glass and is in the shape of a square, three adjacent surfaces of the cubic prism are provided with holes which are matched with the non-magnetic column, a recess in the shape of a cubic column is arranged at the center of the surface of the cubic prism which is not provided with the holes, and the recess is matched with the magnetometer. The device can be calibrated at any time, the whole calibration method is simple and reliable, the calibration precision is high, the position relationship between the three-axis coil magnetic field and the surrounding objects can be determined, the whole device is designed without magnetism, the measuring system and method are simple, the measuring efficiency is high, the time cost is short, the absolute orthogonality of the device is ensured by the optical prism, and the orthogonality can be self-calibrated in a natural environment.

Description

Technical Field

[0001] This invention relates to the field of magnetic field measurement technology, and in particular to an orthogonality calibration device and calibration method for a triaxial coil simulated magnetic field system. Background Technology

[0002] A triaxial coil magnetic field simulation system is a device that uses an energized coil to generate a magnetic field. These coils come in various shapes and can produce magnetic fields in three directions when energized. A uniform region can be generated at the center of the coil. Common triaxial coil magnetic field simulation systems include Helmholtz coils, Wedrich coils, and Braunbeck coils. This system can be used to counteract the Earth's magnetic field, create a region with a near-zero magnetic field, and simulate any magnetic field environment. It has significant practical value in production and scientific research in aerospace, aviation, and electronics fields, and is also commonly used for metrological standards for weak magnetic fields. Therefore, the orthogonality of the magnetic field generated by its three axes is required to be very high.

[0003] Currently, the orthogonality of triaxial coil magnetic field simulation systems mainly relies on the initial calibration of the triaxial coil using various instruments, followed by support and maintenance using rigid structures. During use, these structures undergo slight deformations. In addition, the Earth's magnetic field changes annually. These factors affect the orthogonality of the magnetic field generated by the triaxial coil. With the advancement of science and technology, the requirements for the orthogonality of the magnetic field generated by the triaxial coil in production, research, and metrology are becoming increasingly stringent. This necessitates the measurement and calibration of the orthogonality of the triaxial coil magnetic field before use. However, there is currently no mature device or instrument in the field for the orthogonality calibration of triaxial coil magnetic field simulation systems. Therefore, there is an urgent need for an orthogonality calibration device and method for triaxial coil simulated magnetic field systems. Summary of the Invention

[0004] The purpose of this invention is to provide an orthogonality calibration device and calibration method for a triaxial coil simulated magnetic field system in order to solve the above-mentioned problems.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A triaxial coil simulated magnetic field system orthogonality calibration device includes a base, a cubic prism, and a magnetometer. The base is a cuboid made of glass, with a non-magnetic column perpendicular to the base surface at its center. The cubic prism is a cube made of glass, with slots matching the non-magnetic column at the center of three adjacent faces. A cubic prism-shaped groove matching the magnetometer is formed at the center of the face without slots.

[0007] Preferably, the surface of the base is optically treated to be nearly perfectly horizontal, and the base is provided with at least four non-magnetic screws that can be screwed downwards for adjusting the horizontal plane of the base.

[0008] Preferably, the surface and corners of the cubic prism are optically processed to be nearly horizontal and vertical.

[0009] Preferably, the four sides of the groove in the depth direction are parallel to the four sides of the cubic prism.

[0010] Preferably, the magnetometer is a triaxial magnetometer located in the groove, and the center positions of the magnetometer in the three directions coincide with the positions of the three opening slots of the cubic prism.

[0011] Preferably, a calibration method for an orthogonality calibration device for a triaxial coil simulated magnetic field system includes the following steps:

[0012] S1. Place the entire device at the center of the area to be tested;

[0013] S2. Align and connect one face of the cubic prism with a slotted hole to the non-magnetic column on the base.

[0014] S3. Rotate the cube prism to observe the change in magnetic field of the magnetometer along the rotation axis. If the reading remains unchanged, it indicates that the rotation axis and the magnetometer axis coincide. If the reading changes, observe and record the positive and negative magnetic field extremes in the horizontal direction and calculate the coincidence correction coefficient of the rotation axis and the magnetometer axis in that direction.

[0015] S4. Based on step S3, complete the coincidence correction coefficient of the other two rotating axes and the magnetometer axis in that direction;

[0016] S5. Obtain the correction matrix so that the three rotation axes of the cube prism and the three axes of the magnetometer are completely coincident, making the three axes of the magnetometer completely orthogonal.

[0017] S6. All three-axis coils are turned on, making the three-axis output of the magnetometer zero;

[0018] S7. In the vertical direction, apply a magnetic field value using the coil, rotate the cube prism, and observe whether the value of the magnetometer after vertical correction changes. If it changes, adjust the four non-magnetic screws on the base and rotate the cube prism until the magnetic field reading remains unchanged. At this time, the vertical axis of the magnetometer, the rotation axis of the cube prism, and the direction axis of the magnetic field applied by the coil coincide.

[0019] S8. Turn off the magnetic field applied in the vertical direction of the coil to make the three-axis output of the magnetometer zero. Apply a magnetic field value to the coil in a horizontal direction. Then rotate the cube prism to maximize the corrected value of the magnetometer in the horizontal direction. Observe the corrected values ​​of the magnetometer in the vertical direction and the other horizontal direction.

[0020] S9. The calibration of the other horizontal axis of the coil is also performed according to step S3, resulting in a correction matrix, which is the orthogonality repair matrix of the triaxial coil magnetic field simulation system.

[0021] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0022] 1. The calibration device of this application is simple and practical, and can be self-calibrated at any time. The entire calibration method is simple and reliable with high calibration accuracy. It can also determine the positional relationship between the magnetic field of the triaxial coil and the surrounding objects. The entire device adopts a non-magnetic design, the measurement system and method are simple, the measurement efficiency is high, and the time spent is short. The optical prism ensures the absolute orthogonality of the device. The entire device is formed in one piece and does not require subsequent modification. It can perform orthogonal self-calibration in natural environment. Attached Figure Description

[0023] Figure 1 A schematic diagram of the main structure of an orthogonality calibration device for a triaxial coil simulated magnetic field system provided according to an embodiment of the present invention is shown.

[0024] Legend:

[0025] 1. Base; 2. Cubic prism; 3. Magnetometer; 4. Non-magnetic column; 5. Hole and slot; 6. Groove. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Please see Figure 1 The present invention provides a technical solution:

[0028] A triaxial coil simulated magnetic field system orthogonality calibration device includes a base 1, a cubic prism 2, and a magnetometer 3. The base 1 is a cuboid made of glass, and a non-magnetic column 4 perpendicular to the surface of the base 1 is provided at the center of the base 1. The cubic prism 2 is a cube made of glass, and the center of each of the three adjacent faces of the cubic prism 2 is provided with a slot 5 that matches the non-magnetic column 4, allowing the cubic prism 2 to rotate around the non-magnetic column 4. The center of the face of the cubic prism 2 without the slot 5 is provided with a cubic prism-shaped groove 6, which matches the magnetometer 3.

[0029] Specifically, such as Figure 1As shown, the surface of the base 1 is optically treated to be nearly perfectly horizontal. The base 1 is provided with at least four non-magnetic screws that can be screwed downwards for adjusting the horizontal plane of the base 1. The surface and each edge of the cubic prism 2 are optically treated to be nearly horizontal and vertical. The four sides of the groove 6 in the depth direction are parallel to the four sides of the cubic prism 2. The magnetometer 3 is a triaxial magnetometer located in the groove 6. The center position of the magnetometer 3 in the three directions coincides with the position of the three-sided opening groove 5 of the cubic prism 2.

[0030] Specifically, such as Figure 1 As shown, a calibration method for an orthogonality calibration device for a triaxial coil simulated magnetic field system includes the following steps:

[0031] S1. Place the entire device at the center of the area to be tested;

[0032] S2. Align and connect one face of the cubic prism 2 with a slot 5 and the non-magnetic column 4 on the base 1.

[0033] S3. Rotate the cube prism 2 to observe the change in magnetic field of magnetometer 3 in the direction of rotation axis. If the reading remains unchanged, it means that the rotation axis and the direction axis of magnetometer 3 coincide. If the reading changes, observe and record the positive and negative magnetic field extreme values ​​in the horizontal direction and calculate the coincidence correction coefficient of the rotation axis and the direction axis of magnetometer 3.

[0034] S4. Based on step S3, complete the overlap correction coefficient of the other two rotating axes and the magnetometer 3 in this direction.

[0035] S5. Obtain the correction matrix so that the three rotation axes of the cube prism 2 and the three axes of the magnetometer 3 are completely coincident, making the three axes of the magnetometer 3 completely orthogonal.

[0036] S6. All three-axis coils are turned on, making the three-axis output of magnetometer 3 zero;

[0037] S7. In the vertical direction, apply a magnetic field value using the coil, rotate the cube prism 2, and observe whether the value of the magnetometer 3 after vertical correction changes. If it changes, adjust the four non-magnetic screws on the base 1 and rotate the cube prism 2 until the magnetic field reading remains unchanged. At this time, the vertical axis of the magnetometer 3, the rotation axis of the cube prism 2, and the direction axis of the magnetic field applied by the coil coincide.

[0038] S8. Turn off the magnetic field applied vertically to the coil, making the three-axis output of magnetometer 3 zero. Apply a magnetic field value to the coil in a horizontal direction, and then rotate the cube prism 2 to maximize the corrected value of magnetometer 3 in that horizontal direction. Observe the corrected values ​​of magnetometer 3 in the vertical and other horizontal directions. If the output is zero, it means that the direction of the magnetic field applied to the coil in a horizontal direction is consistent with the direction of the maximum value reading axis of the corrected magnetometer 3, indicating that the three-axis coils are orthogonal. If there is an output of the corrected value of magnetometer 3 in the vertical and other horizontal directions, then it is necessary to add appropriate magnetic fields in these two directions to cancel the components of the coil in the vertical and other horizontal directions in a certain horizontal axis direction.

[0039] S9. The calibration of the other horizontal axis of the coil is also performed according to step S3, resulting in a correction matrix, which is the orthogonality repair matrix of the triaxial coil magnetic field simulation system.

[0040] The calibration device proposed in this application is simple and practical, and can perform self-calibration at any time. The entire calibration method is simple and reliable with high calibration accuracy. It can also determine the positional relationship between the three-axis coil magnetic field and surrounding objects. Furthermore, the entire device adopts a non-magnetic design, and the measurement system and method are simple, with high measurement efficiency and short time consumption. The optical prism ensures the absolute orthogonality of the device. The entire device is molded in one piece and requires no later modification. It can perform orthogonal self-calibration in natural environments.

[0041] The above description of the embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A calibration method for a three-axis coil analog magnetic field system orthogonality calibration device, characterized in that, The utility model relates to a kind of three-axis magnetometer magnetic field simulation system, including base (1), cubic prism (2) and magnetometer (3), the base (1) is glass rectangular parallelepiped shape, the base (1) center position is equipped with the non-magnetic column (4) perpendicular to base (1) surface, the cubic prism (2) is glass square shape, the cubic prism (2) adjacent three face center position is equipped with the hole slot (5) matching with the non-magnetic column (4), the cubic prism (2) is not the hole slot (5) one face center is equipped with cubic recess (6), the recess (6) is matched with the magnetometer (3). It comprises the following steps: S1, the whole device is placed in the center position of the area to be measured; S2, the face of the cubic prism (2) with the hole slot (5) is connected with the non-magnetic column (4) on the base (1) in alignment; S3, rotate the cubic prism (2) to observe the magnetic field change value of the magnetometer (3) in the rotation axis direction. If the reading does not change, it means that the rotation axis and the direction axis of the magnetometer (3) coincide. If the reading changes, observe and record the positive and negative magnetic field extreme values in the horizontal two direction axes, and calculate the coincidence degree repair coefficient of the rotation axis and the direction axis of the magnetometer (3); S4, according to step S3, complete the coincidence degree repair coefficient of the other two rotation axes and the direction axis of the magnetometer (3); S5, obtain the correction matrix of the complete coincidence of the three rotation axes of the cubic prism (2) and the three axes of the magnetometer (3), so that the three axes of the magnetometer (3) are completely orthogonal; S6, turn on all the coils to make the three-axis output of the magnetometer (3) zero; S7, in the vertical direction, apply a magnetic field value using the coil, rotate the cubic prism (2), and observe whether the corrected value of the magnetometer (3) in the vertical direction changes. If it changes, adjust the four non-magnetic screws on the base (1), rotate the cubic prism (2), until the magnetic field reading does not change. At this time, the vertical direction axis of the magnetometer (3), the rotation axis of the cubic prism (2), and the direction axis of the coil applied magnetic field coincide; S8, turn off the magnetic field applied by the coil in the vertical direction to make the three-axis output of the magnetometer (3) zero. Then apply a magnetic field value to the coil in a certain horizontal direction, and then rotate the cubic prism (2) to make the corrected value of the magnetometer (3) in a certain horizontal direction maximum. Observe the corrected values of the magnetometer (3) in the vertical direction and the other horizontal direction; S9, the calibration of the coil in the other horizontal direction is also carried out according to step S3 to obtain a correction matrix, which is the repair matrix of the orthogonality of the three-axis coil magnetic field simulation system.

2. The calibration method of the three-axis coil analog magnetic field system orthogonality calibration device according to claim 1, characterized in that, The four edges of the recess (6) in the depth direction are parallel to the four edges of the cubic prism (2).

3. The calibration method of the three-axis coil analog magnetic field system orthogonality calibration device according to claim 1, characterized in that, The magnetometer (3) is a three-axis magnetometer located in the recess (6), and the center positions of the three directions of the magnetometer (3) coincide with the positions of the three hole slots (5) of the cubic prism (2).

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