A magnetic sphere calibration method and a magnetic sphere calibration device

Abstract

The present invention discloses a magnetic sphere calibration method and a magnetic sphere calibration device. The magnetic sphere calibration method of the present invention includes rotating the magnetic sphere around a first axis and a second axis, and acquiring detection data of three-axis magnetic field components at a detection position during the rotation process; obtaining a calibration position of the magnetic sphere according to the detection data; calibrating the magnetic sphere according to the calibration position of the magnetic sphere; wherein, when the magnetic sphere is located at the calibration position, the magnetic polarization direction of the magnetic sphere coincides with the second axis; the first axis is perpendicular to the second axis; the three-axis magnetic field components include an X-axis magnetic field component, a Y-axis magnetic field component and a Z-axis magnetic field component; the direction of the Z-axis magnetic field component coincides with the direction of the second axis; the Y-axis magnetic field component coincides with the direction of the first axis. According to the magnetic sphere calibration method and the magnetic sphere calibration device of the present invention, the magnetic sphere can be calibrated conveniently, quickly and accurately.

Description

Technical Field

[0001] The present invention relates to the technical fields of magnetic control technology and capsule endoscope technology, and particularly relates to a magnetic sphere calibration method and a magnetic sphere calibration device. Background Art

[0002] A capsule endoscope can perform a detailed and comprehensive examination under the active control of an external magnetic control device. Compared with an intubation endoscope, the capsule endoscope has advantages such as good comfort and low risk of cross-infection, resulting in an increasing popularity in clinical applications.

[0003] For a magnetic control capsule endoscope system, the permanent magnet (usually a magnetic sphere, i.e., a magnetic ball) on the external magnetic control device is the core component for controlling the movement of the capsule endoscope. By controlling the attitude and / or position of the magnetic ball, etc., to achieve a magnetic field change, the capsule endoscope can perform corresponding translational, rotational, and flipping movements according to the transformed magnetic field. Moreover, the magnetic ball affects the attitude of the capsule endoscope through the magnetic field direction. In actual use, the uncertainty of the magnetic field direction of the permanent magnet or the deviation of the magnetic pole position will cause a large attitude angle error of the capsule endoscope, affecting the accuracy of the capsule endoscope attitude, and further affecting the accuracy of information collection of the capsule endoscope. For the external magnetic control device of the capsule endoscope, when in use, it is necessary to calibrate the direction of the magnetic ball therein.

[0004] In the prior art, multiple sensors are usually used to obtain magnetic field data to determine the magnetic field direction of the magnetic ball. Although this method can accurately determine the magnetic ball direction, the process is cumbersome and the operation is complex, which is not conducive to wide application.

[0005] Therefore, there is a need for a more simple, convenient, and accurate magnetic ball calibration method and magnetic ball calibration device. Summary of the Invention

[0006] In view of the above problems, the purpose of the present invention is to provide a magnetic ball calibration method and a magnetic ball calibration device, so as to accurately, conveniently, and quickly calibrate the magnetic ball.

[0007] According to one aspect of the present invention, there is provided a magnetic ball calibration method, including the following steps:

[0008] The magnetic ball rotates around a first axis and a second axis, and detection data of triaxial magnetic field components at a detection position during the rotation process is obtained;

[0009] According to the detection data, the calibration position of the magnetic ball is obtained;

[0010] According to the calibration position of the magnetic ball, the magnetic ball is calibrated;

[0011] Wherein, when the magnetic ball is located at the calibration position, the magnetic polarization direction of the magnetic ball coincides with the second axis;

[0012] The first axis is perpendicular to the second axis;

[0013] The three-axis magnetic field components include an X-axis magnetic field component, a Y-axis magnetic field component, and a Z-axis magnetic field component;

[0014] The direction of the Z-axis magnetic field component coincides with the direction of the second axis; the Y-axis magnetic field component coincides with the direction of the first axis.

[0015] Optionally, the magnetic sphere rotates by a first angle around the first axis, and detection data of the three-axis magnetic field components at the detection position during the rotation is obtained;

[0016] According to the detection data of the three-axis magnetic field components and the corresponding rotation angles during the rotation of the magnetic sphere by the first angle around the first axis, a first calibration position V0 of the magnetic sphere rotating around the first axis is obtained;

[0017] The magnetic sphere is rotated to the first calibration position V0, and then the magnetic sphere is rotated by a second angle around the first axis;

[0018] The magnetic sphere rotates by a third angle around the second axis, and detection data of the three-axis magnetic field components at the detection position during the rotation is obtained;

[0019] According to the detection data of the three-axis magnetic field components and the corresponding rotation angles during the rotation of the magnetic sphere by the third angle around the second axis, a second calibration position H0 when the magnetic sphere rotates around the second axis is obtained.

[0020] Optionally, the first angle is greater than 360°, or is 540°;

[0021] The second angle is greater than or equal to 10° and less than or equal to 80°, or is 45°;

[0022] The third angle is greater than 360°, or is 540°.

[0023] Optionally, obtaining the first calibration position V0 of the magnetic sphere rotating around the first axis includes:

[0024] According to the detection data of the three-axis magnetic field components and the corresponding rotation angles during the rotation of the magnetic sphere by the first angle around the first axis, determining that the position of the magnetic sphere corresponding to the maximum or minimum value of the magnetic field intensity component in the Z-axis direction is the first calibration position V0;

[0025] Obtaining the second calibration position H0 of the magnetic sphere rotating around the second axis includes:

[0026] Based on the detection data of the three-axis magnetic field components and the corresponding rotation angles during the rotation of the magnetic sphere around the second axis by a third angle, determine that the rotation angle corresponding to the maximum or minimum value of the magnetic field intensity component in the Y-axis direction is the second calibration position H0;

[0027] Or, based on the detection data of the three-axis magnetic field components and the corresponding rotation angles during the rotation of the magnetic sphere around the second axis by a third angle, determine that the rotation angle corresponding to the maximum or minimum value of the magnetic field intensity component in the X-axis direction is the second calibration position H0.

[0028] Optionally, obtaining the first calibration position V0 of the magnetic sphere rotating around the first axis includes:

[0029] During the rotation of the magnetic sphere around the first axis by a first angle, obtain the curve of the magnetic field intensity component in the Z-axis direction with respect to the rotation angle of the magnetic sphere according to the detection data, and the rotation angle of the magnetic sphere corresponding to the maximum or minimum value on the curve is the first calibration position V0;

[0030] Obtaining the second calibration position H0 of the magnetic sphere rotating around the second axis includes:

[0031] During the rotation of the magnetic sphere around the second axis by a third angle, obtain the curve of the magnetic field intensity component in the Y-axis direction with respect to the rotation angle of the magnetic sphere according to the detection data, and determine that the rotation angle corresponding to the maximum or minimum value of the magnetic field intensity component in the Y-axis direction is the second calibration position H0;

[0032] Or, based on the detection data of the magnetic field intensity components and the corresponding rotation angles during the rotation of the magnetic sphere by the third angle, determine that the rotation angle corresponding to the maximum or minimum value of the magnetic field intensity component in the X-axis direction is the second calibration position H0.

[0033] According to another aspect of the present invention, there is provided a magnetic sphere calibration device, the magnetic sphere having magnetic poles along the main axis direction, including:

[0034] A driving unit for driving the magnetic sphere to rotate, including a first driving unit and a second driving unit, the first driving unit for driving the magnetic sphere to rotate around the first axis, the second driving unit for driving the magnetic sphere to rotate around the second axis, and calibrating the magnetic sphere according to the calibration position;

[0035] A three-axis magnetic field sensor disposed adjacent to the magnetic sphere to obtain detection data of the three-axis magnetic field components during the rotation of the magnetic sphere; and

[0036] A data processing unit connected to the three-axis magnetic field sensor to receive the detection data of the three-axis magnetic field components, and obtain the calibration position of the magnetic sphere according to the change of the detection data with the rotation angle of the magnetic sphere during the rotation process,

[0037] When the magnetic sphere is located at the calibration position, the main axis coincides with the second axis;

[0038] The first axis is perpendicular to the second axis;

[0039] The three-axis magnetic field components include an X-axis magnetic field component, a Y-axis magnetic field component, and a Z-axis magnetic field component;

[0040] The direction of the Z-axis magnetic field component coincides with the direction of the second axis; the Y-axis magnetic field component coincides with the direction of the first axis.

[0041] Optionally, the first driving unit is configured to drive the magnetic sphere to rotate by a first angle around the first axis;

[0042] The data processing unit includes a third processing unit, and the third processing unit is configured to obtain a first calibration position V0 of the magnetic sphere rotating around the first axis according to the detection data of the three-axis magnetic field components and the corresponding rotation angles during the process that the magnetic sphere rotates by the first angle around the first axis;

[0043] The first driving unit rotates the magnetic sphere to the first calibration position V0, and the first driving unit is further configured to rotate the magnetic sphere by a second angle around the first axis;

[0044] The second driving unit is configured to drive the magnetic sphere to rotate by a third angle around the second axis;

[0045] The data processing unit includes a fourth processing unit, and the fourth processing unit is configured to obtain a second calibration position H0 of the magnetic sphere rotating around the second axis according to the detection data of the three-axis magnetic field components and the corresponding rotation angles during the process that the magnetic sphere rotates by the third angle around the second axis.

[0046] Optionally, the first angle is greater than 360°, or is 540°;

[0047] The second angle is greater than or equal to 10° and less than or equal to 80°, or is 45°;

[0048] The third angle is greater than 360°, or is 540°.

[0049] Optionally, the third processing unit is further configured to

[0050] According to the detection data of the three-axis magnetic field components and the corresponding rotation angles during the process that the magnetic sphere rotates by the first angle around the first axis, determine that the position of the magnetic sphere corresponding to the maximum or minimum value of the magnetic field strength component in the Z-axis direction is the first calibration position V0;

[0051] The fourth processing unit is further configured to:

[0052] According to the detection data of the three-axis magnetic field components and the corresponding rotation angles during the rotation of the magnetic sphere around the second axis by a third angle, determine that the rotation angle corresponding to the maximum or minimum value of the magnetic field intensity component in the Y-axis direction is the second calibration position H0;

[0053] Alternatively, according to the detection data of the three-axis magnetic field components and the corresponding rotation angles during the rotation of the magnetic sphere around the second axis by a third angle, determine that the rotation angle corresponding to the maximum or minimum value of the magnetic field intensity component in the X-axis direction is the second calibration position H0.

[0054] Optionally, the third processing unit is further configured to:

[0055] During the rotation of the magnetic sphere around the first axis by a first angle, obtain a curve of the three-axis magnetic field component in the Z-axis direction with respect to the rotation angle of the magnetic sphere according to the detection data, and the rotation angle of the magnetic sphere corresponding to the maximum or minimum value on the curve is the first calibration position V0;

[0056] The fourth processing unit is further configured to:

[0057] During the rotation of the magnetic sphere around the second axis by a third angle, obtain a curve of the three-axis magnetic field component in the Y-axis direction with respect to the rotation angle of the magnetic sphere according to the detection data, and determine that the rotation angle corresponding to the maximum or minimum value of the magnetic field intensity component in the Y-axis direction is the second calibration position H0;

[0058] Alternatively, according to the detection data of the three-axis magnetic field components and the corresponding rotation angles during the rotation of the magnetic sphere by the third angle, determine that the rotation angle corresponding to the maximum or minimum value of the magnetic field intensity component in the X-axis direction is the second calibration position H0.

[0059] Optionally, the first axis or the second axis passes through the three-axis magnetic sensor;

[0060] The detection position includes the position where the three-axis magnetic sensor is located.

[0061] According to the magnetic sphere calibration device and the magnetic sphere calibration method of the embodiments of the present invention, using a three-axis magnetic sensor to determine the direction of the magnetic sphere has simple operation, can calibrate the magnetic sphere conveniently, quickly and accurately, and provides a precise basis for judging the attitude of the capsule endoscope.

[0062] According to the magnetic sphere calibration device of the embodiments of the present invention, the three-axis magnetic sensor and the two rotating shafts are fixed, which is convenient for the integrated design of the magnetic sphere calibration device.

[0063] According to the magnetic sphere calibration device and the magnetic sphere calibration method of the embodiments of the present invention, the magnetic sphere is rotated by different angles in sequence to complete the calibration of the magnetic sphere, and the calibration accuracy is high, which is beneficial to accurately controlling the attitude of the capsule. Brief Description of the Drawings

[0064] Through the following description of the embodiments of the present invention with reference to the accompanying drawings, the above and other objects, features, and advantages of the present invention will become more apparent. In the drawings:

[0065] Figure 1 A schematic diagram of the magnetic field distribution of the magnetic sphere according to an embodiment of the present invention is shown;

[0066] Figure 2 A three-dimensional schematic diagram of the magnetic sphere calibration device according to the first embodiment of the present invention is shown;

[0067] Figure 3 A flowchart of the magnetic sphere calibration method according to the first embodiment of the present invention is shown;

[0068] Figure 4 A flowchart of the magnetic sphere calibration method according to the second embodiment of the present invention is shown;

[0069] Figure 5 A schematic diagram after the magnetic sphere is calibrated according to an embodiment of the present invention is shown;

[0070] Figure 6 A flowchart of the magnetic sphere calibration method according to an alternative embodiment of the second embodiment of the present invention is shown;

[0071] Figure 7 A flowchart of the magnetic sphere calibration method according to the third embodiment of the present invention is shown;

[0072] Figure 8 A structural schematic diagram of the magnetic sphere calibration device according to the fourth embodiment of the present invention is shown;

[0073] Figure 9 A periodic change curve of the magnetic field value according to an embodiment of the present invention is shown. Detailed Embodiments

[0074] The various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. In each of the drawings, the same elements are denoted by the same or similar reference numerals. For the sake of clarity, the various parts in the drawings are not drawn to scale. In addition, some well-known parts may not be shown in the figures.

[0075] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings and embodiments. Many specific details of the present invention are described below, such as the structure, materials, dimensions, processing techniques, and technologies of components, in order to understand the present invention more clearly. However, as those skilled in the art can understand, the present invention can be implemented without these specific details.

[0076] It should be understood that when describing the structure of a component, when a layer or a region is referred to as being "above" or "over" another layer or another region, it may mean directly above the other layer or another region, or there may be other layers or regions between it and the other layer or another region. And if the component is flipped, this layer or region will be "below" or "beneath" the other layer or another region.

[0077] Figure 1 The schematic diagram of the magnetic field distribution of the magnetic sphere 10 according to an embodiment of the present invention is shown. As Figure 1 shown, the magnetic sphere 10 of the embodiment of the present invention has magnetic poles (magnetic fields in a specific direction) along the main axis direction. The main axis coincides with the line connecting the N magnetic pole and the S magnetic pole of the magnetic sphere and is a specific axis on the magnetic sphere. For the magnetic sphere 10 according to an embodiment of the present invention, the two ends of a certain diameter are respectively the N magnetic pole and the S magnetic pole. The magnetic field distribution of the magnetic sphere 10 is shown, for example, by Figure 1 the magnetic induction lines in.

[0078] Figure 2 The three-dimensional schematic diagram of the magnetic sphere calibration device according to the first embodiment of the present invention is shown. As Figure 2 shown, on the one hand, the embodiment of the present invention provides a magnetic sphere calibration device, including a three-axis magnetic field sensor 20, a driving unit, and a data processing unit 60. The magnetic sphere 10 includes a first direction and a second direction. Among them, the first direction is the direction in which the magnetic sphere 10 rotates around the first axis 110, and the second direction is the direction in which the magnetic sphere 10 rotates around the second axis.

[0079] The driving unit includes a first driving unit 40 and a second driving unit 50;

[0080] The first driving unit 40 is used to drive the magnetic sphere 10 to rotate in the first direction;

[0081] The second driving unit 50 is used to drive the magnetic sphere 10 to rotate in the second direction;

[0082] The three-axis magnetic field sensor 20 is arranged adjacent to the magnetic sphere 10 to obtain the detection data of the three-axis magnetic field components during the rotation of the magnetic sphere 10; and

[0083] The data processing unit 60 is connected to the three-axis magnetic field sensor 20 to receive the detection data of the three-axis magnetic field components, and obtain the calibration position of the magnetic sphere 10 according to the change of the detection data with the rotation angle of the magnetic sphere 10 during the rotation process.

[0084] Among them, when the magnetic sphere 10 is in the calibration position, the main axis coincides with the second axis direction; the first axis is perpendicular to the second axis; the three-axis magnetic field components include the X-axis magnetic field component, the Y-axis magnetic field component, and the Z-axis magnetic field component; the direction of the Z-axis magnetic field component coincides with the second axis direction; the Y-axis magnetic field component coincides with the direction of the first axis.

[0085] Specifically, the magnetic sphere 10 can rotate about the first axis 110 and / or the second axis 120 (i.e., rotate in the first direction and / or the second direction), and during the movement of the magnetic sphere 10, the first axis 110 maintains a fixed attitude (such as a fixed included angle) relative to the second axis 120. Optionally, the positions of the rotation axes of the first axis 110 and / or the second axis 120 are fixed, or the above rotation axes are fixedly installed in the capsule endoscope system. Preferably, both the first axis 110 and the second axis 120 pass through the center of the magnetic sphere 10, and the first axis 110 is perpendicular to the second axis 120. Based on this, a three-axis (three-dimensional rectangular coordinate system) is established. Optionally, in this coordinate system, the straight line where the first axis 110 is located is the Y-axis, and the center of the magnetic sphere 10 is the origin. The three-axis magnetic field components are the magnetic field components on the three axes of the three-dimensional rectangular coordinate system.

[0086] Optionally, the three-axis magnetic field components are determined by the direction of the three-axis magnetic field sensor 20 itself. Specifically, it is determined by the chip (not shown) of the sensor. The three-axis directions of the above three-axis magnetic field components are as follows: perpendicular to the chip plane and upward is the Z1 axis, and the X1 axis and the Y1 axis are parallel to the chip plane. Among them, the directions of the X1 axis, the Y1 axis, and the Z1 axis of the chip correspond to the directions of the X axis, the Y axis, and the Z axis in the three-dimensional rectangular coordinate system. In the following, the three axes of the three-axis magnetic field components are all described with the three axes of the three-dimensional rectangular coordinate system, that is, the three-axis magnetic field components include the X-axis magnetic field component, the Y-axis magnetic field component, and the Z-axis magnetic field component; the direction of the Z-axis magnetic field component coincides with the direction of the second axis 120; the Y-axis magnetic field component coincides with the direction of the first axis 110.

[0087] See Figure 3 As shown, the magnetic sphere calibration method according to the above device may include the following steps:

[0088] The magnetic sphere 10 rotates about the first axis 110 and the second axis 120, and the three-axis magnetic field sensor 20 acquires the detection data of the three-axis magnetic field components at the detection position during the rotation process.

[0089] According to the detection data, the calibration position of the magnetic sphere 10 is obtained.

[0090] According to the calibration position of the magnetic sphere 10, the magnetic sphere 10 is calibrated.

[0091] When calibration is performed, the first driving unit 40 drives the magnetic sphere 10 to rotate a preset angle around the first axis 110 (in the first direction), and the second driving unit 50 drives the magnetic sphere 10 to rotate a preset angle around the second axis 120 (in the second direction). Optionally, the first driving unit 40 drives the magnetic sphere 10 to rotate (a first angle) around the first axis 110, and the second driving unit 50 drives the magnetic sphere 10 to rotate (a third angle) around the second axis 120. Moreover, the magnetic sphere calibration device further includes a three-axis magnetic field sensor 20 placed adjacent to the magnetic sphere 10 for detecting the magnetic field intensity of the magnetic sphere 10, especially the change in magnetic field intensity during the rotation of the magnetic sphere 10.

[0092] In one embodiment, the first driving unit 40 may be located on the side of the magnetic sphere 10 (e.g., on both sides of the magnetic sphere 10) for driving the magnetic sphere 10 to rotate around the first axis 110.

[0093] More specifically, the three-axis magnetic field sensor 20 is located directly above the magnetic sphere 10 (as Figure 2 shown, i.e., at the top of the magnetic sphere 10 along the Z-axis) for detecting the magnetic field intensity of the magnetic sphere 10 in the three-axis directions (i.e., the magnetic field intensity in all directions of the three-dimensional space). In other embodiments of the present invention, the three-axis magnetic field sensor 20 may also be disposed at other positions as long as it can accurately obtain the magnetic field intensity data during the rotation of the magnetic sphere 10. In a specific embodiment, the detected data may include the three-axis magnetic field intensity components and the rotation angle of the magnetic sphere 10.

[0094] The three-axis magnetic field sensor 20 is placed adjacent to the magnetic sphere 10 to detect the detection data of the three-axis magnetic field components of the magnetic sphere 10 during rotation (e.g., detecting the magnetic field intensity of the magnetic sphere 10 in all directions within the three-dimensional space). In the embodiments of the present invention, the distance between the three-axis magnetic sensor 20 and the surface of the magnetic sphere 10 can be adjusted according to the magnetic field intensity of the magnetic sphere 10 and / or the sensitivity of the three-axis magnetic field sensor 20. The present invention does not further limit the distance between the three-axis magnetic field sensor 20 and the outer surface of the magnetic sphere 10 as long as the three-axis magnetic sensor 20 can accurately obtain the magnetic field intensity data of the magnetic sphere 10. In addition, the first driving unit 40 in this embodiment can directly control the rotation of the magnetic sphere 10 or control the rotation of the magnetic sphere 10 through a transmission component (not shown), which will not be elaborated here.

[0095] The data processing unit 60 is connected to the three-axis magnetic field sensor 20 to receive the detection data of the three-axis magnetic field components, and obtains the calibration position of the magnetic sphere 10 according to the changes of the detection data with the rotation of the magnetic sphere 10. Among them, the connection between the data processing unit 60 and the three-axis magnetic field sensor 20 can be a wired connection or a wireless connection. In a specific embodiment, after receiving the detection data, the data processing unit 60 obtains the calibration position of the magnetic sphere 10 according to the relationship between the three-axis magnetic field components and the rotation angle of the magnetic sphere 10. Then, the data processing unit 60 determines the angle that the magnetic sphere 10 needs to rotate according to the calibration position, and drives the magnetic sphere 10 to rotate by the driving unit, thereby completing the calibration.

[0096] For the convenience of installation and to improve the measurement accuracy, in an alternative embodiment, the first axis 110 or the second axis 120 passes through the three-axis magnetic field sensor 20. At this time, the position where the three-axis magnetic field sensor is located can be used as the detection position.

[0097] As Figure 2 shown, in a preferred embodiment of the present invention, the installation positions of the three-axis magnetic field sensor 20, the first driving unit 40, and the second driving unit 50 are relatively fixed, which is convenient for the integrated design of the magnetic sphere calibration device. In order to simplify the structure of the capsule endoscope system, in the embodiment of the present invention, the first driving unit 40 and the second driving unit 50 can be the driving components on the magnetic control device in the capsule endoscope system that drive the magnetic sphere 10 to rotate.

[0098] In an alternative embodiment of the present invention, in order to support the three-axis magnetic field sensor 20, a magnetic field plate 30 is provided at a position adjacent to the magnetic sphere 10, for example. The three-axis magnetic field sensor 20 is provided on the magnetic field plate 30. Among them, the magnetic field plate 30 is used to install the three-axis magnetic field sensor 20, and the overall structure of the magnetic field plate 30 is flat, occupying a small space, and can also fully cover the magnetic sphere 10, which is convenient for flexibly installing the three-axis magnetic field sensor 20 and is beneficial to reducing the volume of the overall device. In other embodiments of the present application, the magnetic field plate 30 can also be other structures for fixing the three-axis magnetic field sensor 20, which will not be elaborated here.

[0099] In an alternative embodiment of the present invention, the data processing unit 60 further includes a third processing unit (not shown) and a fourth processing unit (not shown). The magnetic sphere calibration device further includes a second driving unit 50. After the first driving unit 40 drives the magnetic sphere 10 to rotate by a first angle around the first axis 110, the first driving unit 40 drives the magnetic sphere 10 to rotate by a second angle around the first axis 10. After the magnetic sphere 10 rotates by the second angle, the second driving unit 50 is configured to drive the magnetic sphere 10 to rotate by a third angle around the second axis 120. The third processing unit is configured to obtain the calibration position in the first direction according to the detection data of the three-axis magnetic field components and the corresponding rotation angles during the process of the magnetic sphere 10 rotating by the first angle around the first axis. The fourth processing unit is configured to obtain the calibration position in the second direction according to the detection data of the magnetic field components and the corresponding rotation angles acquired by the three-axis magnetic field sensor 20 during the process of the magnetic sphere 10 rotating by the third angle around the second axis.

[0100] In an alternative embodiment of the present invention, the magnetic sphere calibration device further includes a readable storage medium for storing data, and the readable storage medium is connected to the data processing unit 60 and the three-axis magnetic field sensor 20 respectively, for example. Optionally, the readable storage medium is connected to the data processing unit 60 to store the data calculated by the data processing unit 60 and / or the data to be received by the data processing unit 60 (such as the detection data acquired by the three-axis magnetic field sensor 20 and / or the motion data of the magnetic sphere 10). Optionally, the readable storage medium is connected to the three-axis magnetic field sensor 20 to store the detection data acquired by the three-axis magnetic field sensor 20.

[0101] Figure 4 The flowchart of the magnetic sphere calibration method according to the second embodiment of the present invention is shown. According to the magnetic sphere calibration method of the second embodiment of the present invention, the calibration position is the position where the magnetic field intensity is the maximum or minimum value during the rotation of the magnetic sphere 10. The method of this embodiment includes the following steps:

[0102] In step S301, the magnetic sphere 10 is rotated uniformly by a first angle around the first axis 110, and the detection data of the three-axis magnetic field components during the rotation process are recorded, where the first angle is greater than 360°.

[0103] During the rotation of the magnetic sphere 10 around the first axis 110 in this step, the three-axis magnetic field sensor 20 acquires multiple sets of detection data of the three-axis magnetic field components at the detection positions (b x0 , b y0 , b z0 ), (b x1 , b y1 , b z1 ), …, (b xn , b yn , b zn ). Among them, the values of the detection data of the three-axis magnetic field components are positive and negative, and the positive and negative represent the direction of the magnetic field.

[0104] In step S302, according to the detection data of the three-axis magnetic field components recorded during the rotation of the magnetic sphere 10 by the first angle and the corresponding rotation angle, the first calibration position V0 is determined.

[0105] According to the detection data of the three-axis magnetic field components during the rotation of the magnetic sphere 10 by the first angle, find the rotation angle of the magnetic sphere 10 corresponding to the maximum magnetic field intensity in the Z-axis direction during the measurement process, and set this position as the first calibration position V0.

[0106] In step S303, the magnetic sphere 10 is rotated by a second angle around the first axis 110.

[0107] Optionally, the second angle is greater than or equal to 30° and less than or equal to 150°. Optionally, the second angle is greater than or equal to 10° and less than or equal to 80°. It should be noted that after the magnetic sphere 10 is calibrated in the first direction, the magnetic field values measured by the three-axis magnetic field sensor 20 in the X-axis direction and the Y-axis direction are very small and cannot be calibrated in the second direction. Therefore, the magnetic sphere 10 is rotated by a certain angle (the second angle) around the first axis 110. In the above optional embodiment, the second angle is greater than or equal to 10° and less than or equal to 80° (this rotation angle is determined by the accuracy of the magnetic sensor). Among them, the higher the accuracy of the magnetic sensor, the smaller the minimum rotation angle of the magnetic sphere 10 can be.

[0108] In an optional embodiment of the present invention, the rotation of the magnetic sphere 10 by the second angle is performed after the first calibration position V0 is determined. After the magnetic sphere 10 is rotated to the first calibration position V0, the magnetic sphere 10 is rotated by the second angle around the first axis 110 (that is, the rotation of the second angle starts based on the calibration position of the magnetic sphere 10 in the first direction).

[0109] In step S304, the magnetic sphere 10 is rotated uniformly by a third angle around the second axis 120, and the detection data of the three-axis magnetic field components during the rotation process are recorded, where the third angle is greater than 360°.

[0110] The magnetic sphere 10 is rotated uniformly by a third angle around the second axis 120, where the third angle is greater than 360°. Record the detection data of the three-axis magnetic field components at the detection position during the rotation process (b x0 , b y0 , b z0 ), (b x1 , b y1 , b z1 ), …, (b xn , b yn , b zn ).

[0111] In step S305, according to the detection data of the three-axis magnetic field components recorded during the rotation of the magnetic sphere 10 by a third angle and the corresponding rotation angle, the second calibration position H0 is determined.

[0112] According to the detection data of the three-axis magnetic field components during the rotation of the magnetic sphere 10 by a third angle, find the rotation angle of the magnetic sphere 10 corresponding to the maximum magnetic field intensity in the Y-axis direction, and set the position of the magnetic sphere 10 corresponding to the maximum magnetic field intensity in the Y-axis direction as the second calibration position H0. Optionally, set the position of the magnetic sphere 10 corresponding to the maximum magnetic field intensity in the X-axis direction as the second calibration position H0.

[0113] In an alternative embodiment of the present invention, after step S305, step S306 is further included. In step S306, the magnetic sphere 10 is calibrated according to the first calibration position V0 and the second calibration position H0.

[0114] The magnetic sphere 10 is calibrated according to the first calibration position V0 and the second calibration position H0. Among them, calibrating the magnetic sphere 10 means rotating the N and S magnetic poles of the magnetic sphere 10 onto the second axis 120 or the first axis 110.

[0115] Figure 5 Shows a schematic diagram of the magnetic sphere after calibration according to an embodiment of the present invention. As Figure 5 shown, after the magnetic sphere 10 according to the embodiment of the present invention is calibrated, the main axis of the magnetic sphere (i.e., the straight line where the N and S magnetic poles are located) coincides with the second axis 120.

[0116] Figure 6 Shows a flowchart of a magnetic sphere calibration method according to an alternative embodiment of the second embodiment of the present invention. In order to balance the integrity of the detection data and the simplicity of control, this alternative embodiment determines an appropriate rotation angle of the magnetic sphere. The magnetic sphere calibration method of this alternative embodiment specifically includes the following steps:

[0117] In step S401, the magnetic sphere 10 is rotated 540° around the first axis (in the first direction).

[0118] In step S402, the first calibration position V0 is found.

[0119] Record the change in the magnetic field intensity at the detection position (such as directly above the magnetic sphere 10) during the rotation of the magnetic sphere 10 around the first axis 110, and set the position of the magnetic sphere 10 corresponding to the maximum magnetic field intensity in the Z-axis direction at the detection position (such as directly above the magnetic sphere 10) as the first calibration position V0.

[0120] In step S403, the magnetic sphere 10 is rotated 45° around the first axis 110.

[0121] In step S404, rotate the magnetic sphere 10 by 540° about the second axis (in the second direction).

[0122] In step S405, find the second calibration position H0.

[0123] Record the change in the magnetic field intensity at the detection positions during the rotation of the magnetic sphere 10 about the first axis 110, and set the position of the magnetic sphere 10 corresponding to the maximum magnetic field intensity in the Y-axis direction at the detection position (e.g., directly above the magnetic sphere 10) as the second calibration position H0. Alternatively, set the position of the magnetic sphere 10 corresponding to the maximum magnetic field intensity in the X-axis direction (the direction perpendicular to both the first axis 110 and the second axis 120) at the detection position as the second calibration position H0.

[0124] Figure 7 The flowchart of the magnetic sphere calibration method according to the third embodiment of the present invention is shown. In order to further improve the data accuracy and thus the calibration accuracy of the magnetic sphere 10, the magnetic sphere calibration method according to the third embodiment of the present invention is a further improvement on the magnetic sphere calibration method in the above embodiment. For the convenience of description, the directions of the X-axis, Y-axis, and Z-axis of the three-axis magnetic field sensor 20 in this embodiment are the same as those in the above embodiment. The method of this embodiment specifically includes the following steps:

[0125] In step S501, rotate the magnetic sphere 10 by a first angle about the first axis 110, and record the detection data of the three-axis magnetic field components at the detection positions around the magnetic sphere 10 during the rotation of the magnetic sphere 10, where the first angle is greater than 360°;

[0126] In the above step, the three-axis magnetic field sensor 20 can record the detection data readings of the three-axis magnetic field components at the detection positions when the magnetic sphere 10 rotates to different angles. Optionally, according to the detection data of the three-axis magnetic field components in the Z-axis direction at the external detection position, with the rotation angle of the magnetic sphere 10 as the independent variable and the magnetic field value as the dependent variable, process to obtain the magnetic field value change curve in the selected direction (Z-axis direction) at the detection position. The magnetic field value readings are positive and negative, and the positive and negative represent the direction of the magnetic field.

[0127] In an alternative embodiment of the present invention, the data processing unit of the magnetic sphere calibration device further includes a fifth processing unit. This fifth processing unit takes the rotation angle of the magnetic sphere 10 as the independent variable and the measured magnetic field value at the detection position as the dependent variable, obtains the change in the measured magnetic field value in the Z-axis direction at the detection position with respect to the rotation angle of the magnetic sphere 10, and plots the magnetic field value change curve in the Z-axis direction measured at the detection position.

[0128] In step S502, determine the calibration position of the magnetic sphere 10 in the second direction according to the detection data of the three-axis magnetic field components recorded during the rotation of the magnetic sphere 10 by the first angle and the corresponding rotation angle.

[0129] Find the extreme values (maximum and minimum values) in the Z-axis direction in the detection data of the three-axis magnetic field components during the rotation of the magnetic sphere 10 by the first angle. According to the extreme values and the corresponding rotation angles of the magnetic sphere, determine the calibration position of the magnetic sphere 10 in the second direction. Specifically, in the detection data of the three-axis magnetic field components, the positions of the magnetic sphere 10 corresponding to the extreme values in the Z-axis direction can all be used as the calibration positions of the magnetic sphere 10 in the second direction, and the unique first calibration position V0 can be determined according to actual needs.

[0130] It should be noted that if the Z-axis direction in the recorded detection data of the three-axis magnetic field components is all zero during the rotation of the magnetic sphere 10 by the first angle, it means that both the N pole and the S pole of the magnetic sphere 10 are located on the first axis 110 (i.e., the magnetic polarization direction of the magnetic sphere 10 coincides with the first axis 110). In this case, the N pole and / or the S pole can be used as the calibration reference to calibrate the magnetic sphere 10.

[0131] In step S503, rotate the magnetic sphere 10 around the first axis 110 by the second angle.

[0132] Among them, the second angle is greater than or equal to 30° and less than or equal to 150°.

[0133] In step S504, rotate the magnetic sphere 10 around the second axis 120 by the third angle, and record the detection data of the three-axis magnetic field components at the external detection position during the rotation of the magnetic sphere 10, where the third angle is greater than 360°.

[0134] Rotate the magnetic sphere 10 around the second axis 120 by the third angle, where the third angle is greater than 360°. Record the detection data readings of the three-axis magnetic field components at the detection position when the magnetic sphere 10 rotates to different angles. Optionally, record the magnetic field data at the detection position, take the rotation angle of the magnetic sphere 10 as the independent variable and the magnetic field value as the dependent variable, and process to obtain the magnetic field value change curve in the Y-axis direction or the X-axis direction at the detection position. The magnetic field value readings are positive and negative, and the positive and negative represent the direction of the magnetic field.

[0135] Optionally, in one embodiment, the obtained magnetic field values and the corresponding angles are represented as discrete points on a graph. For example, by methods such as directly connecting the points or the difference method, connect the discrete points to draw a curve, and the corresponding magnetic field value at any angle can be obtained through the curve.

[0136] In addition, in another embodiment, the obtained magnetic field values and the corresponding angles are represented as discrete points on a graph. Fit these discrete points to a sine curve to obtain a sine curve, and the corresponding magnetic field value at any angle can be obtained through the sine curve.

[0137] In other embodiments, based on the measured magnetic field values, other methods can also be used to obtain a curve expressing the relationship between the magnetic field values and the rotation angle of the magnetic sphere 10, so as to obtain the calibration position of the magnetic sphere 10 according to the curve. In some other embodiments, if the relationship between the rotation of the magnetic sphere 10 and time is consistent, the calibration position of the magnetic sphere 10 can also be obtained through the curve of the magnetic field value and the rotation time of the magnetic sphere 10.

[0138] In step S505, according to the detection data of the three-axis magnetic field components recorded during the rotation of the magnetic sphere 10 by the third angle and the corresponding rotation angle, the calibration position of the magnetic sphere 10 in the first direction is determined.

[0139] Find the extreme values (maximum and minimum values) in the Y-axis direction in the detection data of the three-axis magnetic field components during the rotation of the magnetic sphere 10 by the third angle. According to the rotation angle of the magnetic sphere corresponding to the extreme values, determine the calibration position of the magnetic sphere 10 in the Y-axis direction. Or find the extreme values in the X-axis direction in the detection data of the three-axis magnetic field components during the rotation of the magnetic sphere 10 by the third angle. According to the extreme values and the rotation angle of the magnetic sphere corresponding to the extreme values, determine the calibration position of the magnetic sphere 10 in the X-axis direction. Specifically, the rotation angle of the magnetic sphere corresponding to the extreme values in the Y-axis direction or the X-axis direction in the detection data of the three-axis magnetic field components can be used as the calibration position of the magnetic sphere 10 in the Y-axis direction or the X-axis direction, and the unique second calibration position H0 can be determined according to actual needs.

[0140] In an alternative embodiment of the present invention, after step S505, step S506 is further included. In step S506, the magnetic sphere 10 is calibrated according to the calibration position in the first direction and the calibration position in the second direction.

[0141] Calibrate the magnetic sphere 10 according to the second calibration position H0 in the second direction and the first calibration position V0 in the first direction. Optionally, calibrating the magnetic sphere 10 means rotating the N and S magnetic poles of the magnetic sphere 10 onto the second axis 120 or the first axis 110.

[0142] In an alternative embodiment of the present invention, between step S502 and step S503, the following steps are further included:

[0143] Rotate the magnetic sphere 10 to the second calibration position H0 in the second direction.

[0144] In an alternative embodiment of the present invention, the magnetic sphere 10 rotates at a constant speed during the rotation of the first angle and / or the second angle and / or the third angle.

[0145] In the above embodiments of the present invention, taking the rotation angle of the magnetic sphere 10 as the independent variable and the detected data (magnetic field values) of the three-axis magnetic field components obtained as the dependent variable, the measured values obtained are plotted as curves, so that the magnetic field values corresponding to any angle can be obtained, improving the accuracy of the data, and further improving the calibration (adjustment) accuracy of the magnetic sphere 10.

[0146] Figure 8 FIG. shows a schematic structural diagram of a magnetic sphere calibration device according to a fourth embodiment of the present invention. As Figure 8 shown, the magnetic sphere calibration device according to the fourth embodiment of the present invention includes a three-axis magnetic field sensor 20 and a data processing unit 60. The magnetic sphere 10 rotates around the first axis 110 and / or the second axis 120.

[0147] The magnetic sphere 10 is in the three-dimensional rectangular coordinate system as shown in the figure and can rotate around the first axis 110 (Y axis) and the second axis 120 (Z axis) to realize the rotation of the magnetic sphere 10 in any direction.

[0148] The three-axis magnetic field sensor 20 is located directly above the magnetic sphere 10 (above the magnetic sphere 10 in the Z-axis direction) and is used to detect the magnetic field intensity of the magnetic sphere 10 in three-dimensional space.

[0149] The data processing unit 60 is connected to the three-axis magnetic field sensor 20 to receive the detected magnetic field intensity and perform data processing.

[0150] Figure 9 FIG. shows a periodic change curve of the magnetic field value according to an embodiment of the present invention. As Figure 9 shown, the abscissa represents the rotation angle of the magnetic sphere, and the ordinate represents the detected magnetic field value (for example, the data in any direction in the detected data of the three-axis magnetic field components). The detected magnetic field value changes periodically with the rotation angle of the magnetic sphere. According to the calibration method of the embodiment of the present invention, during the rotation of the magnetic sphere 10 (around the first axis or the second axis), the magnetic field value readings and the corresponding angles (in the Z-axis direction or the Y-axis direction) are recorded, and a periodic change curve of the magnetic field value is drawn, as Figure 9 shown. The curve has two types of vertices, one is the maximum value and the other is the minimum value. The magnetic sphere 10 rotates 180° between the positions corresponding to these two adjacent extreme values. The positions corresponding to the maximum and minimum values of the magnetic field value can both be used as the calibration positions of the magnetic sphere 10 (in the first direction or the second direction), which can be determined according to actual needs.

[0151] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising said element.

[0152] As described above with reference to the embodiments of the present invention, these embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the above description. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and its modifications based on the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A magnetic sphere calibration method, characterized in that, Applied to a magnetically controlled capsule endoscope system, it includes the following steps: The magnetic sphere rotates around the first axis and the second axis, and obtains the detection data of the three-axis magnetic field components at the detection position during the rotation process; According to the detection data, the calibration position of the magnetic sphere is obtained; According to the calibration position of the magnetic sphere, the magnetic sphere is calibrated; Among them, according to the detection data of the three-axis magnetic field components during the process of the magnetic sphere rotating around the first axis by a first angle and the corresponding rotation angle, it is determined that the position of the magnetic sphere corresponding to the maximum or minimum value of the magnetic field intensity component in the Z-axis direction is the first calibration position V0; According to the detection data of the three-axis magnetic field components during the process of the magnetic sphere rotating around the second axis by a third angle and the corresponding rotation angle, it is determined that the rotation angle corresponding to the maximum or minimum value of the magnetic field intensity component in the Y-axis direction is the second calibration position H0; Or, according to the detection data of the three-axis magnetic field components during the process of the magnetic sphere rotating around the second axis by a third angle and the corresponding rotation angle, it is determined that the rotation angle corresponding to the maximum or minimum value of the magnetic field intensity component in the X-axis direction is the second calibration position H0; When the magnetic sphere is located at the calibration position, the magnetic polarization direction of the magnetic sphere coincides with the second axis; The first axis and the second axis are perpendicular to each other; The three-axis magnetic field components include the X-axis magnetic field component, the Y-axis magnetic field component and the Z-axis magnetic field component; The direction of the Z-axis magnetic field component coincides with the direction of the second axis; the Y-axis magnetic field component coincides with the direction of the first axis.

2. The magnetic sphere calibration method according to claim 1, characterized in that The magnetic sphere rotates around the first axis by a first angle, and obtains the detection data of the three-axis magnetic field components at the detection position during the rotation process; According to the detection data of the three-axis magnetic field components during the process of the magnetic sphere rotating around the first axis by a first angle and the corresponding rotation angle, the first calibration position V0 of the magnetic sphere rotating around the first axis is obtained; The magnetic sphere is rotated to the first calibration position V0, and then the magnetic sphere is rotated around the first axis by a second angle; The magnetic sphere rotates around the second axis by a third angle, and obtains the detection data of the three-axis magnetic field components at the detection position during the rotation process; According to the detection data of the three-axis magnetic field components during the process of the magnetic sphere rotating around the second axis by a third angle and the corresponding rotation angle, the second calibration position H0 of the magnetic sphere rotating around the second axis is obtained.

3. The magnetic sphere calibration method according to claim 2, characterized in that The first angle is greater than 360°, or is 540°; The second angle is greater than or equal to 10°, and the second angle is less than or equal to 80°, or is 45°; The third angle is greater than 360°, or is 540°.

4. The magnetic sphere calibration method according to claim 2 or 3, characterized in that, Obtaining the first calibration position V0 of the magnetic sphere rotating around the first axis includes: During the process of the magnetic sphere rotating around the first axis by a first angle, according to the detection data, a curve of the magnetic field intensity component in the Z-axis direction with respect to the rotation angle of the magnetic sphere is obtained, and the rotation angle of the magnetic sphere corresponding to the maximum or minimum value on the curve is the first calibration position V0; Obtaining the second calibration position H0 of the magnetic sphere rotating around the second axis includes: During the rotation of the magnetic sphere around the second axis by a third angle, a curve of the magnetic field strength component in the Y-axis direction with respect to the rotation angle of the magnetic sphere is obtained based on the detection data, and the rotation angle corresponding to the maximum or minimum value of the magnetic field strength component in the Y-axis direction is determined as the second calibration position H0; Alternatively, based on the detection data of the magnetic field strength components and the corresponding rotation angles during the rotation of the magnetic sphere by the third angle, the rotation angle corresponding to the maximum or minimum value of the magnetic field strength component in the X-axis direction is determined as the second calibration position H0.

5. A magnetic sphere calibration device, wherein the magnetic sphere has magnetic poles along the main axis direction, characterized in that, Applied to a magnetic control capsule endoscope system, it includes: A driving unit for driving the rotation of the magnetic sphere, including a first driving unit and a second driving unit. The first driving unit is used to drive the magnetic sphere to rotate around the first axis, and the second driving unit is used to drive the magnetic sphere to rotate around the second axis and calibrate the magnetic sphere according to the calibration position; A three-axis magnetic field sensor disposed adjacent to the magnetic sphere to obtain detection data of the three-axis magnetic field components during the rotation of the magnetic sphere; and A data processing unit connected to the three-axis magnetic field sensor to receive the detection data of the three-axis magnetic field components, and obtain the calibration position of the magnetic sphere according to the change of the detection data with the rotation angle of the magnetic sphere during the rotation process, wherein, based on the detection data of the three-axis magnetic field components and the corresponding rotation angles during the rotation of the magnetic sphere around the first axis by a first angle, the position of the magnetic sphere corresponding to the maximum or minimum value of the magnetic field strength component in the Z-axis direction is determined as the first calibration position V0; Based on the detection data of the three-axis magnetic field components and the corresponding rotation angles during the rotation of the magnetic sphere around the second axis by a third angle, the rotation angle corresponding to the maximum or minimum value of the magnetic field strength component in the Y-axis direction is determined as the second calibration position H0; Alternatively, based on the detection data of the three-axis magnetic field components and the corresponding rotation angles during the rotation of the magnetic sphere around the second axis by a third angle, the rotation angle corresponding to the maximum or minimum value of the magnetic field strength component in the X-axis direction is determined as the second calibration position H0; When the magnetic sphere is at the calibration position, the main axis coincides with the second axis; The first axis and the second axis are perpendicular to each other; The three-axis magnetic field components include an X-axis magnetic field component, a Y-axis magnetic field component, and a Z-axis magnetic field component; The direction of the Z-axis magnetic field component coincides with the direction of the second axis; the Y-axis magnetic field component coincides with the direction of the first axis.

6. The magnetic sphere calibration device according to claim 5, characterized in that The first driving unit is used to drive the magnetic sphere to rotate around the first axis by a first angle; The data processing unit includes a third processing unit, and the third processing unit is used to obtain the first calibration position V0 of the magnetic sphere rotating around the first axis based on the detection data of the three-axis magnetic field components and the corresponding rotation angles during the rotation of the magnetic sphere around the first axis by a first angle; The first driving unit rotates the magnetic sphere to the first calibration position V0, and the first driving unit is also used to rotate the magnetic sphere around the first axis by a second angle; The second driving unit is used to drive the magnetic sphere to rotate around the second axis by a third angle; The data processing unit includes a fourth processing unit, and the fourth processing unit is configured to obtain a second calibration position H0 when the magnetic sphere rotates about the second axis according to the detection data of the three-axis magnetic field components and the corresponding rotation angles during the process that the magnetic sphere rotates about the second axis by a third angle.

7. The magnetic sphere calibration device according to claim 6, characterized in that, The first angle is greater than 360°, or is 540°; The second angle is greater than or equal to 10° and less than or equal to 80°, or is 45°; The third angle is greater than 360°, or is 540°.

8. The magnetic sphere calibration device according to claim 6 or 7, characterized in that, The third processing unit is further configured to: During the process that the magnetic sphere rotates about the first axis by a first angle, obtain a curve of the three-axis magnetic field component in the Z-axis direction with respect to the rotation angle of the magnetic sphere according to the detection data, and the rotation angle of the magnetic sphere corresponding to the maximum or minimum value on the curve is the first calibration position V0; The fourth processing unit is further configured to: During the process that the magnetic sphere rotates about the second axis by a third angle, obtain a curve of the three-axis magnetic field component in the Y-axis direction with respect to the rotation angle of the magnetic sphere according to the detection data, and determine that the rotation angle corresponding to the maximum or minimum value of the magnetic field intensity component in the Y-axis direction is the second calibration position H0; Or, according to the detection data of the three-axis magnetic field components and the corresponding rotation angles during the process that the magnetic sphere rotates by the third angle, determine that the rotation angle corresponding to the maximum or minimum value of the magnetic field intensity component in the X-axis direction is the second calibration position H0.

9. The magnetic sphere calibration device according to claim 5, wherein The first axis or the second axis passes through the three-axis magnetic field sensor; The detection position includes the position where the three-axis magnetic field sensor is located.

Images