Magnetic ball calibration method and magnetic ball calibration device

Abstract

A method and apparatus for calibrating a magnetic ball, comprising the steps of: rotating the magnetic ball 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 (S101); obtaining a calibration position of the magnetic ball from the detection data (S102); and calibrating the magnetic ball based on the calibration position of the magnetic ball (S103), where when the magnetic ball is in the calibration position, the magnetization direction of the magnetic ball overlaps 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 overlaps with the direction of the second axis, and the direction of the Y-axis magnetic field component overlaps with the direction of the first axis. The method and apparatus for calibrating a magnetic ball can conveniently, quickly and accurately calibrate the magnetic ball.

Description

[Technical field]

[0001] This application claims priority to a Chinese patent application having a filing date of January 28, 2022, application number 202210104917.0 and entitled "Method and apparatus for calibrating magnetic balls", and incorporates herein by reference all of the specification, claims, drawings and abstract of the aforementioned Chinese patent application.

[0002] The present application relates to the technical fields of magnetic control and capsule endoscopy, and in particular to a method and device for calibrating a magnetic ball. [Background technology]

[0003] Capsule endoscopy can perform detailed and comprehensive examination under the active control of an external magnetic control device.Compared with intubation endoscopy, capsule endoscopy has the advantages of better comfort and lower risk of cross-infection, and its popularity in clinical applications is constantly increasing.

[0004] For a magnetically controlled capsule endoscope system, the permanent magnet (usually a magnetic sphere, i.e., a magnetic ball) in the external magnetic control device is the core component that controls the movement of the capsule endoscope. The magnetic field change is realized by controlling the attitude and / or position of the magnetic ball. The capsule endoscope can realize the corresponding translation, rotation, inversion, and other movements according to the transformed magnetic field. The magnetic ball then affects the attitude of the capsule endoscope through the direction of the magnetic field. In actual use, the uncertainty of the magnetic field direction of the permanent magnet or the variation in the magnetic pole position will increase the error of the attitude angle of the capsule endoscope, affecting the accuracy of the attitude of the capsule endoscope and further affecting the accuracy of information collection by the capsule endoscope. For the external magnetic control device of the capsule endoscope, the direction of the magnetic ball therein needs to be calibrated when in use.

[0005] 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 direction of the magnetic ball, the process is complicated and the operation is complex, which is disadvantageous for widespread application.

[0006] Therefore, there is a need for a simpler, more convenient and more accurate magnetic ball calibration method and magnetic ball calibration device. Summary of the Invention [Problem to be solved by the invention]

[0007] In view of the above problems, an object of the present application is to provide a method and apparatus for calibrating a magnetic ball, which can calibrate the magnetic ball accurately, conveniently and quickly. [Means for solving the problem]

[0008] A method for calibrating a magnetic ball according to one aspect of the present disclosure includes: A step of rotating the magnetic ball 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; obtaining a calibrated position of the magnetic ball from the detection data; calibrating the magnetic ball based on the calibrated position of the magnetic ball; When the magnetic ball is located at the calibration position, the magnetization direction of the magnetic ball overlaps with a 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 overlaps with the direction of the second axis, and the Y-axis magnetic field component overlaps with the direction of the first axis.

[0009] Optionally, the magnetic ball is rotated around a first axis by a first angle, and detection data of three-axis magnetic field components is obtained at a detection position during the rotation; Obtain a first calibration position V0 when the magnetic ball rotates around the first axis based on the detection data of the three-axis magnetic field components and the corresponding rotation angle during the process of the magnetic ball rotating around the first axis by a first angle; rotating the magnetic ball to the first calibration position V0, and then rotating the magnetic ball a second angle about the first axis; The magnetic ball rotates around the second axis by a third angle, and detection data of three-axis magnetic field components is obtained at a detection position during the rotation; Based on the detection data of the three-axis magnetic field components and the corresponding rotation angles during the process of the magnetic ball rotating a third angle around the second axis, a second calibration position H0 is obtained when the magnetic ball rotates around the second axis.

[0010] Optionally, the first angle is greater than 360° or 540°; the second angle is greater than or equal to 10°, and the second angle is less than or equal to 80° or 45°; The third angle is greater than 360° or is 540°.

[0011] Optionally, the step of obtaining a first calibration position V0 when the magnetic ball rotates around the first axis includes determining a position of the magnetic ball corresponding to a maximum or minimum value of a magnetic field strength component in a Z-axis direction as a first calibration position V0 based on the detection data of the three-axis magnetic field components and the corresponding rotation angles during the magnetic ball rotating around the first axis by a first angle; The step of obtaining a second calibration position H0 when the magnetic ball rotates about the second axis includes: According to the detection data of the three-axis magnetic field components and the corresponding rotation angles during the process of the magnetic ball rotating around the second axis by a third angle, determining the rotation angle corresponding to the maximum or minimum value of the magnetic field strength component in the Y-axis direction as the second calibration position H0; or This includes determining the rotation angle corresponding to the maximum or minimum value of the magnetic field strength component in the X-axis direction as the second calibration position H0 based on the detection data of the three-axis magnetic field components and the corresponding rotation angles during the process of the magnetic ball rotating a third angle around the second axis.

[0012] Optionally, the step of obtaining a first calibration position V0 of the magnetic ball as it rotates about the first axis comprises: In the process of the magnetic ball rotating around the first axis by a first angle, a curve according to the rotation angle of the magnetic ball of the magnetic field strength component in the Z-axis direction is obtained from the detection data, and the rotation angle of the magnetic ball corresponding to the maximum or minimum value of the curve is set as a first calibration position V0; The step of obtaining a second calibration position H0 when the magnetic ball rotates about the second axis includes: During the process of the magnetic ball rotating a third angle around the second axis, obtaining a curve of the magnetic field strength component in the Y-axis direction according to the rotation angle of the magnetic ball from the detection data, and determining the rotation angle corresponding to the maximum or minimum value of the magnetic field strength component in the Y-axis direction as a second calibration position H0; or This includes determining the rotation angle corresponding to the maximum or minimum value of the magnetic field strength component in the X-axis direction as the second calibration position H0 based on the detection data of the magnetic field strength component and the corresponding rotation angle during the process of the magnetic ball rotating through the third angle.

[0013] In a magnetic ball calibration device according to another aspect of the present application, the magnetic ball has a magnetic pole along a main axis direction, and the magnetic ball calibration device includes: a drive unit for driving the magnetic ball to rotate; a three-axis magnetic field sensor disposed adjacent to the magnetic ball for acquiring detection data of three-axis magnetic field components during rotation of the magnetic ball; a data processing unit connected to the three-axis magnetic field sensor to receive detection data of the three-axis magnetic field components and to obtain a calibration position of the magnetic ball according to a change in the detection data with a rotation angle of the magnetic ball during the rotation; The driving unit includes a first driving unit and a second driving unit, the first driving unit drives the magnetic ball to rotate around a first axis, and the second driving unit drives the magnetic ball to rotate around a second axis and calibrates the magnetic ball based on a calibration position; When the magnetic ball is located at the calibration position, the primary axis overlaps 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 overlaps with the direction of the second axis, and the Y-axis magnetic field component overlaps with the direction of the first axis.

[0014] Optionally, the first drive unit is for driving the magnetic ball to rotate through a first angle about a first axis; The data processing unit includes a third processing unit, which is used to obtain a first calibration position V0 of the magnetic ball rotating around the first axis based on the detection data of the three-axis magnetic field components and the corresponding rotation angle during the magnetic ball rotating around the first axis by a first angle; the first driving unit rotates the magnetic ball to a first calibration position V0, the first driving unit is also used to rotate the magnetic ball a second angle about the first axis; the second driving unit is for driving the magnetic ball to rotate about a second axis by a third angle; The data processing unit includes a fourth processing unit, which is used to obtain a second calibration position H0 when the magnetic ball rotates around the second axis based on the detection data of the three-axis magnetic field components and the corresponding rotation angle during the magnetic ball rotating a third angle around the second axis.

[0015] Optionally, 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 45°; The third angle is greater than 360° or is 540°.

[0016] Optionally, the third processing unit further comprises: According to the detection data of the three-axis magnetic field components and the corresponding rotation angles during the process of the magnetic ball rotating around the first axis by a first angle, the position of the magnetic ball corresponding to the maximum or minimum value of the magnetic field intensity component in the Z-axis direction is determined as a first calibration position V0; The fourth processing unit further comprises: According to the detection data of the three-axis magnetic field components and the corresponding rotation angles during the process of the magnetic ball rotating around the second axis by a third angle, determine the rotation angle corresponding to the maximum or minimum value of the magnetic field intensity component in the Y-axis direction as the second calibration position H0; or Based on the detection data of the three-axis magnetic field components and the corresponding rotation angles during the process of the magnetic ball rotating a third angle around the second axis, the rotation angle corresponding to the maximum or minimum value of the magnetic field strength component in the X-axis direction is used to determine the second calibration position H0.

[0017] Optionally, the third processing unit is further used to obtain a curve of the three-axis magnetic field components in the Z-axis direction according to the rotation angle of the magnetic ball from the detection data during the magnetic ball rotating around the first axis by a first angle; The rotation angle of the magnetic ball corresponding to the maximum or minimum value on the curve is the first calibration position V0; The fourth processing unit further obtains a curve according to the rotation angle of the magnetic ball of the three-axis magnetic field components in the Y-axis direction from the detection data during the process of the magnetic ball rotating a third angle around the second axis, and determines the rotation angle corresponding to the maximum value or minimum value of the magnetic field intensity component in the Y-axis direction as a second calibration position H0; or Based on the detection data of the three-axis magnetic field components and the corresponding rotation angles during the process of the magnetic ball rotating through 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 used to determine the second calibration position H0.

[0018] Optionally, the first axis or the second axis passes through the three-axis magnetic field sensor; The detection position includes a position where the three-axis magnetic field sensor is located.

[0019] According to the magnetic ball calibration device and magnetic ball calibration method of the embodiments of the present application, a three-axis magnetic sensor is used to determine the direction of the magnetic ball, the operation is simple, and the magnetic ball can be calibrated conveniently, quickly and accurately, providing an accurate basis for judging the posture of the capsule endoscope.

[0020] According to the magnetic ball calibration device of the embodiment of the present application, the three-axis magnetic sensor and the two rotating shafts are fixed and do not move, which facilitates the integrated design of the magnetic ball calibration device.

[0021] According to the magnetic ball calibration device and magnetic ball calibration method of the embodiments of the present application, the magnetic ball is rotated sequentially to different angles to complete the calibration of the magnetic ball, which has high calibration accuracy and is advantageous for accurately controlling the posture of the capsule. [Brief description of the drawings]

[0022] The above and other objects, features and advantages of the present application will become more apparent from the following description of the embodiments of the present application with reference to the following drawings. [Figure 1] 3A and 3B are schematic diagrams illustrating the magnetic field distribution of a magnetic ball according to an embodiment of the present application. [Diagram 2] 1 is a perspective view of a magnetic ball calibration device according to a first embodiment of the present application; [Diagram 3] FIG. 2 is a flowchart of a magnetic ball calibration method according to a first embodiment of the present invention. [Figure 4]FIG. 11 is a flowchart of a magnetic ball calibration method according to a second embodiment of the present application. [Diagram 5] FIG. 2 is a schematic diagram of a magnetic ball according to an embodiment of the present application after calibration. [Figure 6] FIG. 13 is a flowchart of a method for calibrating a magnetic ball according to an alternative embodiment of the second embodiment of the present application. [Figure 7] FIG. 11 is a flowchart of a magnetic ball calibration method according to a third embodiment of the present invention. [Figure 8] FIG. 11 is a schematic diagram of a magnetic ball calibration device according to a fourth embodiment of the present invention. [Figure 9] FIG. 2 is a curve diagram showing periodic changes in magnetic field values ​​according to an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Various embodiments of the present application will now be described in more detail with reference to the accompanying drawings, in which the same elements are represented by the same or similar reference numerals in the various drawings, and for clarity, the parts in the drawings are not drawn to scale, and some known parts may not be shown in the drawings.

[0024] In the following, specific embodiments of the present application will be further described in conjunction with the accompanying drawings and examples. In order to make the present application more clearly understandable, many specific details of the present application will be described below, such as the structure, materials, dimensions, processing processes and techniques of parts. However, as can be understood by those skilled in the art, the present application may not be realized according to these specific details.

[0025] Also, when describing the structure of a part, when a layer or region is referred to as being "on" or "above" another layer or region, it should be understood that it may be directly on top of the other layer or region, or may include additional layers or regions between the other layer or region, and when the part is inverted, the layer or region would be "on" or "below" the other layer or region.

[0026] FIG. 1 shows a schematic diagram of the magnetic field distribution of a magnetic ball 10 according to an embodiment of the present application. As shown in FIG. 1, the magnetic ball 10 according to the embodiment of the present application has magnetic poles (magnetic field in a specific direction) along the main axis. The main axis overlaps with the connecting line of the north and south magnetic poles of the magnetic ball, and is a specific axis of the magnetic ball. According to the magnetic ball 10 according to the embodiment of the present application, both ends of a certain diameter are the north and south magnetic poles, respectively. The magnetic field distribution of the magnetic ball 10 is shown, for example, by the magnetic induction lines in FIG. 1.

[0027] FIG. 2 is a schematic perspective view of a calibration device for a magnetic ball according to a first embodiment of the present application. As shown in FIG. 2, in one aspect, the calibration device for a magnetic ball provided by the embodiment of the present application includes a three-axis magnetic field sensor 20, a driving unit, and a data processing unit 60. The magnetic ball 10 includes a first direction and a second direction. Here, the first direction is the direction in which the magnetic ball 10 rotates around the first axis 110. The second direction is the direction in which the magnetic ball 10 rotates around the second axis 120.

[0028] The drive unit includes a first drive unit 40 and a second drive unit 50. The first drive unit 40 is for driving the magnetic ball 10 to rotate in a first direction. The second drive unit 50 is for driving the magnetic ball 10 to rotate in a second direction.

[0029] The three-axis magnetic field sensor 20 is disposed adjacent to the magnetic ball 10 to obtain detection data of the three-axis magnetic field components during the rotation of the magnetic ball 10. 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 calibrated position of the magnetic ball 10 according to the change in the detection data with the rotation angle of the magnetic ball 10 during the rotation.

[0030] Here, when the magnetic ball 10 is in the calibration position, the main axis overlaps with the direction of 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 overlaps with the direction of the second axis, and the direction of the Y-axis magnetic field component overlaps with the direction of the first axis.

[0031] Specifically, the magnetic ball 10 can rotate (i.e., rotate in a first direction and / or a second direction) around the first axis 110 and / or the second axis 120. Moreover, during the movement of the magnetic ball 10, the first axis 110 maintains a fixed attitude (e.g., a fixed angle) with respect to the second axis 120. Alternatively, the positions of the rotation axes of the first axis 110 and / or the second axis 120 are fixed, or the rotation axes are fixedly attached in the capsule endoscope system. Preferably, both the first axis 110 and the second axis 120 pass through the spherical center of the magnetic ball 10, and the first axis 110 is perpendicular to the second axis 120. Based on this, a three-axis (three-dimensional Cartesian coordinate system) is created. Optionally, in this coordinate system, the straight line on which the first axis 110 is located is the Y-axis, and the spherical center of the magnetic ball 10 is the origin. The three-axis magnetic field components refer to magnetic field components in the three axes of the three-dimensional Cartesian coordinate system.

[0032] Optionally, the three-axis magnetic field components are determined by the orientation of the three-axis magnetic field sensor 20 itself, specifically, the chip (not shown) of the sensor. Regarding the three axial directions of the above-mentioned three-axis magnetic field components, the Z1 axis is perpendicular to the plane of the chip, and the X1 axis and the Y1 axis are parallel to the plane of the chip. Here, 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 a three-dimensional Cartesian coordinate system. Of the three axes of the three-axis magnetic field components described later, all will be described in terms of the three axes of the three-dimensional Cartesian 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 overlaps with the direction of the second axis 120. The Y axis magnetic field component overlaps with the direction of the first axis 110.

[0033] As shown in FIG. 3, the method for calibrating the magnetic ball by the above-mentioned device includes the following steps:

[0034] The magnetic ball 10 rotates around a first axis 110 and a second axis 120, and the three-axis magnetic field sensor 20 obtains detection data of three-axis magnetic field components at a detection position during the rotation.

[0035] From the detection data, a calibrated position of the magnetic ball 10 is obtained.

[0036] Based on the calibration position of the magnetic ball 10, the magnetic ball 10 is calibrated.

[0037] During calibration, the first driving unit 40 drives the magnetic ball 10 to rotate around the first axis 110 (in a first direction) by a predetermined angle, and the second driving unit 50 drives the magnetic ball 10 to rotate around the second axis 120 (in a second direction) by a predetermined angle. Optionally, the first driving unit 40 rotates the magnetic ball 10 around the first axis 110 (a first angle), and the second driving unit 50 rotates the magnetic ball 10 around the second axis 120 (a third angle). In addition, the magnetic ball calibration device further includes a three-axis magnetic field sensor 20 disposed adjacent to the magnetic ball 10 to detect the magnetic field strength of the magnetic ball 10, in particular the change in the magnetic field strength during the rotation of the magnetic ball 10.

[0038] In one embodiment, the first driving unit 40 is located on the side of the magnetic ball 10 (eg, on both sides of the magnetic ball 10 ) and is used to drive the magnetic ball 10 to rotate around the first axis 110 .

[0039] More specifically, the three-axis magnetic field sensor 20 is located directly above the magnetic ball 10 (located at the tip of the magnetic ball 10 along the Z-axis as shown in FIG. 2) in order to detect the magnetic field strength in the three-axis directions of the magnetic ball 10 (i.e., the magnetic field strength in each direction in three-dimensional space). Meanwhile, in other embodiments of the present application, the three-axis magnetic field sensor 20 may be installed at other positions as long as data on the magnetic field strength during the rotation of the magnetic ball 10 can be accurately obtained. In one specific embodiment, the detection data may include three-axis magnetic field strength components and the rotation angle of the magnetic ball 10.

[0040] The three-axis magnetic field sensor 20 is disposed adjacent to the magnetic ball 10 to detect the detection data of the three-axis magnetic field components during the rotation of the magnetic ball 10 (for example, the magnetic field strength in each direction in the three-dimensional space of the magnetic ball 10). In the embodiment of the present application, the distance between the three-axis magnetic sensor 20 and the surface of the magnetic ball 10 is adjusted according to the magnetic field strength of the magnetic ball 10 and / or the sensitivity of the three-axis magnetic field sensor 20. In the present application, the distance of the three-axis magnetic field sensor 20 from the outer surface of the magnetic ball 10 is not further limited as long as the three-axis magnetic field sensor 20 can obtain the magnetic field strength data of the magnetic ball 10. It should be noted that the first driving unit 40 in this embodiment may directly control the rotation of the magnetic ball 10 or may control the rotation of the magnetic ball 10 via a transmission member (not shown), which will not be described further here.

[0041] 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 ball 10 according to the change of the detection data with the rotation of the magnetic ball 10. Here, the connection between the data processing unit 60 and the three-axis magnetic field sensor 20 may 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 ball 10 according to the relationship between the three-axis magnetic field components and the rotation angle of the magnetic ball 10. Then, the data processing unit 60 determines the angle that the magnetic ball 10 needs to rotate according to the calibration position, and drives the rotation of the magnetic ball 10 by the driving unit to complete the calibration.

[0042] In consideration of ease of installation and improved measurement accuracy, in one alternative embodiment, the first axis 110 or the second axis 120 passes through the three-axis magnetic field sensor 20, in which case the position where the three-axis magnetic field sensor is located can be the detection position.

[0043] 2, in a preferred embodiment of the present application, the mounting positions of the three-axis magnetic field sensor 20, the first driving unit 40 and the second driving unit 50 are relatively fixed, which facilitates the integrated design of the calibration device of the magnetic ball. In order to simplify the configuration of the capsule endoscope system, in the embodiment of the present application, the first driving unit 40 and the second driving unit 50 may be a driving assembly for driving and rotating the magnetic ball 10 in the magnetic control device in the capsule endoscope system.

[0044] In an optional embodiment of the present application, a magnetic field plate (not shown) is provided adjacent to the magnetic ball 10 to support the three-axis magnetic field sensor 20. The three-axis magnetic field sensor 20 is provided on the magnetic field plate. Here, the magnetic field plate is used to mount the three-axis magnetic field sensor 20, and the overall structure of the magnetic field plate is flat, occupies a small space, can cover the magnetic ball 10 completely, is convenient for flexibly mounting the three-axis magnetic field sensor 20, and is favorable for reducing the volume of the entire device. In other embodiments of the present application, the magnetic field plate may be other structures for fixing the three-axis magnetic field sensor 20. No further description is given here.

[0045] In an optional embodiment of the present application, the data processing unit 60 further includes a third processing unit (not shown) and a fourth processing unit (not shown). The magnetic ball calibration device further includes a second driving unit 50. The first driving unit 40 drives the magnetic ball 10 to rotate a first angle around the first axis 110, and then drives the magnetic ball 10 to rotate a second angle around the first axis 10. After the magnetic ball 10 rotates a second angle, the second driving unit 50 is used to drive the magnetic ball 10 to rotate a third angle around the second axis 120. The third processing unit obtains a calibration position in a first direction based on the detection data of the three-axis magnetic field components and the corresponding rotation angles during the magnetic ball 10 rotates a first angle around the first axis. The fourth processing unit obtains a calibration position in the second direction based on the detection data of the magnetic field components acquired by the three-axis magnetic field sensor 20 during the process of the magnetic ball 10 rotating a third angle around the second axis and the corresponding rotation angle.

[0046] In an alternative embodiment of the present application, the calibration device for the magnetic ball further includes a readable storage medium for storing data. The readable storage medium is, for example, connected to the data processing unit 60 and the three-axis magnetic field sensor 20, respectively. Alternatively, the readable storage medium is connected to the data processing unit 60 for storing data calculated by the data processing unit 60 and / or data received by the data processing unit 60 (for example, detection data acquired by the three-axis magnetic field sensor 20 and / or motion data of the magnetic ball 10). Alternatively, the readable storage medium is connected to the three-axis magnetic field sensor 20 for storing detection data acquired by the three-axis magnetic field sensor 20.

[0047] 4 shows a flow chart of the magnetic ball calibration method according to the second embodiment of the present application. According to the magnetic ball calibration method according to the second embodiment of the present application, the calibration position is the position where the magnetic field strength is maximum or minimum during the rotation of the magnetic ball 10. The method of this embodiment includes the following steps:

[0048] In step S301, the magnetic ball 10 is rotated around the first axis 110 at a uniform speed by a first angle, and detection data of the three-axis magnetic field components during the rotation are recorded. Here, the first angle is greater than 360°.

[0049] In this step, while the magnetic ball 10 rotates around the first axis 110, the three-axis magnetic field sensor 20 detects the three-axis magnetic field components at a plurality of sets of detection positions (b x0 ,b y0 ,b z0 ), (b x1 ,b y1 ,b z1 ),......,(b xn ,b yn ,b zn ) is obtained. The numerical values ​​of the detected data of the three-axis magnetic field components can be positive or negative, and the positive and negative values ​​represent the direction of the magnetic field.

[0050] In step S302, a first calibration position V0 is determined based on the detection data of the three-axis magnetic field components recorded during the process in which the magnetic ball 10 rotates through a first angle and the corresponding rotation angle.

[0051] Based on the detection data of the three-axis magnetic field components during the process of the magnetic ball 10 rotating through the first angle, the maximum value of the magnetic field strength in the Z-axis direction during the measurement process is found as the corresponding rotation angle of the magnetic ball 10, and this position is set as the first calibration position V0.

[0052] In step S303, the magnetic ball 10 is rotated around the first axis 110 by a second angle.

[0053] Optionally, the second angle is 30° or more and 150° or less. Optionally, the second angle is 10° or more and 80° or less. Note that after the magnetic ball 10 is calibrated in the first direction, the magnetic field values ​​measured by the three-axis magnetic field sensor 20 in the X-axis and Y-axis directions are too small to calibrate in the second direction. Therefore, the magnetic ball 10 is rotated around the first axis 110 by a certain angle (second angle). In the above alternative embodiment, the second angle is 10° or more and 80° or less (this rotation angle is determined by the accuracy of the magnetic sensor). Here, the higher the accuracy of the magnetic sensor, the smaller the minimum angle the magnetic ball 10 rotates.

[0054] In an optional embodiment of the present application, the magnetic ball 10 is rotated by the second angle after the first calibration position V0 is determined. After the magnetic ball 10 is rotated to the first calibration position V0, the magnetic ball 10 is rotated by the second angle about the first axis 110 (i.e., the rotation of the second angle is initiated while the magnetic ball 10 is in the calibration position in the first direction).

[0055] In step S304, the magnetic ball 10 is rotated around the second axis 120 at a uniform speed by a third angle, and the detection data of the three-axis magnetic field components during the rotation is recorded, where the third angle is greater than 360°.

[0056] The magnetic ball 10 is rotated around the second axis 120 at a uniform speed by a third angle. Here, the third angle is greater than 360°. The detection data (b x0 ,b y0 ,b z0 ), (b x1 ,b y1 ,b z1 ),......,(b xn ,b yn ,b zn ) is recorded.

[0057] In step S305, a second calibration position H0 is determined based on the detection data of the three-axis magnetic field components recorded during the process of the magnetic ball 10 rotating through a third angle and the corresponding rotation angles.

[0058] Based on the detection data of the three-axis magnetic field components during the process of the magnetic ball 10 rotating through the third angle, a rotation angle (of the magnetic ball 10) corresponding to the maximum value of the magnetic field strength in the Y-axis direction is found, and the position of the magnetic ball 10 corresponding to the maximum value of the magnetic field strength in the Y-axis direction is set as the second calibration position H0. Optionally, the position of the magnetic ball 10 corresponding to the maximum value of the magnetic field strength in the X-axis direction is set as the second calibration position H0.

[0059] In one alternative embodiment of the present application, after step S305, the method further includes step S306, in which the magnetic ball 10 is calibrated according to the first calibration position V0 and the second calibration position H0.

[0060] The magnetic ball 10 is calibrated based on the first calibration position V0 and the second calibration position H0. Here, calibrating the magnetic ball 10 means rotating the N pole and S pole of the magnetic ball 10 to the second axis 120 or the first axis 110.

[0061] 5 is a schematic diagram of the magnetic ball according to the embodiment of the present application after calibration. As shown in FIG. 5, after the magnetic ball 10 according to the embodiment of the present application is calibrated, the main axis of the magnetic ball (i.e., the straight line on which the N pole and the S pole are located) overlaps with the second axis 120.

[0062] 6 shows a flow chart of a magnetic ball calibration method according to an alternative embodiment of the second embodiment of the present application. In order to achieve both the completeness of the detection data and the simplicity of control, this alternative embodiment determines an appropriate rotation angle for the magnetic ball. The magnetic ball calibration method of this alternative embodiment specifically includes the following steps:

[0063] In step S401, the magnetic ball 10 is rotated 540° around the first axis (in the first direction).

[0064] In step S402, a first calibration position V0 is located.

[0065] The change in magnetic field strength at a detection position (e.g., directly above the magnetic ball 10) during the process of the magnetic ball 10 rotating around the first axis 110 is recorded, and the position of the magnetic ball 10 corresponding to the maximum value of the magnetic field strength in the Z-axis direction at the detection position (e.g., directly above the magnetic ball 10) is set as the first calibration position V0.

[0066] In step S403, the magnetic ball 10 is rotated around the first axis 110 by 45 degrees.

[0067] In step S404, the magnetic ball 10 is rotated 540° around the second axis (in the second direction).

[0068] In step S405, the second calibration position H0 is located.

[0069] The change in magnetic field strength at the detection position during the process of magnetic ball 10 rotating around first axis 110 is recorded, and the position of magnetic ball 10 corresponding to the maximum value of magnetic field strength in the Y-axis direction at the detection position (e.g., directly above magnetic ball 10) is set as the second calibration position H0. Alternatively, the position of magnetic ball 10 corresponding to the maximum value of magnetic field strength in the X-axis direction (direction perpendicular to first axis 110 and second axis 120 at the same time) at the detection position is set as the second calibration position H0.

[0070] 7 shows a flow chart of the magnetic ball calibration method according to the third embodiment of the present application. In order to further improve the accuracy of the data and further improve the calibration accuracy of the magnetic ball 10, the third embodiment of the present application further improves the above-mentioned magnetic ball calibration method. For convenience of explanation, the directions of the X-axis, Y-axis and Z-axis of the three-axis magnetic field sensor 20 in this embodiment are consistent with those in the above-mentioned embodiment, and the method of this embodiment specifically includes the following steps:

[0071] In step S501, the magnetic ball 10 is rotated around the first axis 110 by a first angle, and during the rotation, detection data of the three-axis magnetic field components at detection positions around the magnetic ball 10 are recorded, where the first angle is greater than 360°.

[0072] In the above steps, the three-axis magnetic field sensor 20 can record the detection data readings of the three-axis magnetic field components at the detection position when the magnetic ball 10 rotates at different angles. Alternatively, based on the detection data of the three-axis magnetic field components in the Z-axis direction at the external detection position, the change curve of the magnetic field value in the selected direction (Z-axis direction) at the detection position is obtained by processing the angle at which the magnetic ball 10 rotates as an argument and the magnetic field value as a causal variable. The magnetic field value readings can be positive or negative, and the positive and negative indicate the direction of the magnetic field.

[0073] In an optional embodiment of the present application, the data processing unit of the magnetic ball calibration device further includes a fifth processing unit, which takes the rotation angle of the magnetic ball 10 as an argument and the magnetic field value measured at the detection position as a cause variable, obtains the change in the magnetic field value in the Z-axis direction measured at the detection position with respect to the rotation angle of the magnetic ball 10, and plots a change curve of the magnetic field value in the Z-axis direction measured at the detection position.

[0074] In step S502, a calibration position of the magnetic ball 10 in the second direction is determined based on the detection data of the three-axis magnetic field components recorded during the process of the magnetic ball 10 rotating through the first angle and the corresponding rotation angle.

[0075] The extreme values ​​(maximum and minimum values) in the Z-axis direction of the detection data of the three-axis magnetic field components during the process of the magnetic ball 10 rotating through the first angle are found, and the calibration position of the magnetic ball 10 in the second direction is determined based on the extreme values ​​and the rotation angles of the magnetic ball corresponding to the extreme values. Specifically, in the detection data of the three-axis magnetic field components, any position of the magnetic ball 10 corresponding to the extreme values ​​in the Z-axis direction can be the calibration position of the magnetic ball 10 in the second direction. A unique first calibration position V0 can be determined based on actual needs.

[0076] In addition, in the process of magnetic ball 10 rotating by the first angle, if all of the detection data in the Z-axis direction among the detection data of the recorded three-axis magnetic field components is zero, it indicates that both the N magnetic pole and the S magnetic pole of magnetic ball 10 are located on the first axis 110 (i.e., the magnetization direction of magnetic ball 10 overlaps with the first axis 110). In this case, calibration can be performed on magnetic ball 10 using the N magnetic pole and / or the S magnetic pole as the calibration standard.

[0077] In step S503, the magnetic ball 10 is rotated around the first axis 110 by a second angle.

[0078] Here, the second angle is equal to or greater than 30° and equal to or less than 150°.

[0079] In step S504, the magnetic ball 10 is rotated around the second axis 120 by a third angle, and the detection data of the three-axis magnetic field components at the external detection position during the rotation of the magnetic ball 10 is recorded, where the third angle is greater than 360°.

[0080] The magnetic ball 10 is rotated around the second axis 120 through a third angle, where the third angle is greater than 360°. The detected data readings of the three-axis magnetic field components at the detection position when the magnetic ball 10 is rotated through different angles are recorded. Optionally, the magnetic field data at the detection position is recorded and the angle of rotation of the magnetic ball 10 is used as an argument and the magnetic field value is treated as a causal variable to obtain a variation curve of the magnetic field value in the Y-axis direction or the X-axis direction at this detection position. The magnetic field value readings can be positive or negative, which indicates the direction of the magnetic field.

[0081] Optionally, in one embodiment, the obtained magnetic field values ​​and corresponding angles are reflected as discrete points in a drawing, and a curve can be drawn by connecting each of the discrete points, for example by direct connection or differential method, and the corresponding magnetic field value at any angle can be obtained through the curve.

[0082] In another embodiment, the obtained magnetic field values ​​and corresponding angles are reflected as discrete points on a diagram, and a sine curve is obtained by fitting these discrete points to a sine curve, which gives the corresponding magnetic field values ​​at any angle.

[0083] In other embodiments, based on the measured magnetic field value, a curve representing the magnetic field value and the rotation angle of the magnetic ball 10 can be obtained by other methods, and the calibration position of the magnetic ball 10 can be obtained based on the curve. In some other embodiments, as long as the rotation situation of the magnetic ball 10 is consistent with the relationship with time, the calibration position of the magnetic ball 10 can also be obtained based on the curve of the magnetic field value and the rotation time of the magnetic ball 10.

[0084] In step S505, a calibration position of the magnetic ball 10 in the first direction is determined based on the detection data of the three-axis magnetic field components recorded during the process of the magnetic ball 10 rotating through the third angle and the corresponding rotation angle.

[0085] The extreme values ​​(maximum and minimum values) in the Y-axis direction of the detection data of the three-axis magnetic field components during the process of the magnetic ball 10 rotating at the third angle are found, and the calibration position of the magnetic ball 10 in the Y-axis direction is determined based on the rotation angle of the magnetic ball corresponding to the extreme value. Alternatively, the extreme values ​​in the X-axis direction of the detection data of the three-axis magnetic field components during the process of the magnetic ball 10 rotating at the third angle are found, and the calibration position of the magnetic ball 10 in the X-axis direction is determined based on the extreme value and the rotation angle of the magnetic ball corresponding to the extreme value. Specifically, the rotation angle of the magnetic ball corresponding to the extreme value in the Y-axis direction or the X-axis direction in the detection data of the three-axis magnetic field components can be the calibration position of the magnetic ball 10 in the Y-axis direction or the X-axis direction. Based on actual needs, only one second calibration position H0 can be determined.

[0086] In an alternative embodiment of the present application, the method further includes step S506 after step S505, in which the magnetic ball 10 is calibrated based on the calibration position in the first direction and the calibration position in the second direction.

[0087] The magnetic ball 10 is calibrated based on the second calibration position H0 in the second direction and the first calibration position V0 in the first direction. Optionally, the magnetic ball 10 is calibrated such that the north and south magnetic poles of the magnetic ball 10 rotate to the second axis 120 or the first axis 110.

[0088] In one alternative embodiment of the present application, between step S502 and step S503, the following step is further included:

[0089] The magnetic ball 10 is rotated in a second direction to a second calibration position H0.

[0090] In one alternative embodiment of the present application, the magnetic ball 10 rotates at a uniform speed while rotating through the first angle and / or the second angle and / or the third angle.

[0091] In the above-described embodiment of the present application, a curve is drawn using the rotation angle of the magnetic ball 10 as an argument and the acquired detection data (magnetic field values) of the three-axis magnetic field components as causal variables, and the acquired measurement values ​​are plotted on the curve, thereby making it possible to obtain magnetic field values ​​corresponding to any angle, thereby improving the accuracy of the data and further improving the calibration (adjustment) accuracy of the magnetic ball 10.

[0092] Fig. 8 shows a schematic configuration diagram of a magnetic ball calibration device according to a fourth embodiment of the present application. As shown in Fig. 8, the magnetic ball calibration device according to the fourth embodiment of the present application includes a three-axis magnetic field sensor 20 and a data processing unit 60. The magnetic ball 10 rotates around a first axis 110 and / or a second axis 120.

[0093] The magnetic ball 10 is located under a three-dimensional rectangular coordinate system as shown in the drawing, and can rotate in any direction by rotating around a first axis 110 (Y-axis) and a second axis 120 (Z-axis).

[0094] The three-axis magnetic field sensor 20 is positioned directly above the magnetic ball 10 (above the magnetic ball 10 in the Z-axis direction) in order to detect the magnetic field strength of the magnetic ball 10 in the three-dimensional space.

[0095] A data processing unit 60 is connected to the three-axis magnetic field sensor 20 to receive the detected magnetic field strength and to process the data.

[0096] FIG. 9 shows a curve of periodic change of magnetic field value according to an embodiment of the present application. As shown in FIG. 9, the horizontal axis indicates the rotation angle of the magnetic ball, and the vertical axis indicates the detected magnetic field value (for example, data in any direction among the detection data of the three-axis magnetic field components). The detected magnetic field value changes periodically according to the rotation angle of the magnetic ball. According to the calibration method of the embodiment of the present application, as shown in FIG. 9, while the magnetic ball 10 rotates (around the first axis or the second axis), the number of magnetic field value readings (in the Z-axis direction or the Y-axis direction) and the corresponding angle are recorded to draw a periodic change curve of the magnetic field value. There are two vertices on the curve, one is a maximum value and the other is a minimum value, and the magnetic ball 10 rotates 180° between the positions corresponding to the two adjacent extreme values. The positions corresponding to the maximum and minimum values ​​of the magnetic field value can both be the calibration positions of the magnetic ball 10 (in the first direction or the second direction), which can be determined according to actual needs.

[0097] It should be explained that, in this specification, relationship terms such as first and second are used only to distinguish one entity or operation from another entity or operation without necessarily requiring or implying that such an actual relationship or order exists between these entities or operations. Furthermore, the terms "comprise", "comprise", or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or device that includes a set of elements includes not only those elements, but also other elements not expressly listed, or includes elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "including one" does not exclude the presence of another identical element in the process, method, article, or device that includes the element.

[0098] According to the embodiments of the present application as described above, these embodiments are not detailed in all details, and the present disclosure is not limited to the specific embodiments described. Obviously, many modifications and variations are possible according to the above description. The present specification selects and specifically describes these embodiments in order to better interpret the principles and practical applications of the present application, and thereby enable those skilled in the art to make good use of the present application and to modify and use the present application. The present application is limited only by the claims and all scopes and equivalents thereof.

Claims

1. A method for calibrating a magnetic ball, comprising the steps of: Rotating the magnetic ball around a first axis and a second axis, and acquiring detection data of three-axis magnetic field components at a detection position during rotation; obtaining a calibrated position of the magnetic ball from the detection data; calibrating the magnetic ball based on the calibration position; When the magnetic ball is located at the calibration position, the magnetization direction of the magnetic ball overlaps 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 magnetic field component in the Z-axis direction overlaps with the direction of the second axis, and the magnetic field component in the Y-axis direction overlaps with the direction of the first axis. A method for calibrating a magnetic ball, comprising:

2. The magnetic ball rotates around the first axis by a first angle, and the detection data is obtained at the detection position during the rotation; Based on the detection data and the corresponding rotation angle during the process of the magnetic ball rotating around the first axis by the first angle, a first calibration position V ０ Get The magnetic ball is placed at the first calibration position V ０ and then rotating the magnetic ball a second angle about the first axis; the magnetic ball rotates around the second axis by a third angle, and the detection data is acquired at the detection position during the rotation; Based on the detection data and the corresponding rotation angle during the process of the magnetic ball rotating about the second axis by the third angle, a second calibration position H ０ Get 2. The method for calibrating a magnetic ball according to claim 1.

3. 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 45°; The third angle is greater than 360° or is 540°.

3. The method for calibrating a magnetic ball according to claim 2.

4. The first calibration position V when the magnetic ball rotates around the first axis ０ The acquisition is performed by calculating the position of the magnetic ball corresponding to the maximum or minimum value of the magnetic field component in the Z-axis direction as the first calibration position V based on the detection data and the corresponding rotation angle during the process in which the magnetic ball rotates around the first axis by the first angle. ０ determining that The second calibration position H when the magnetic ball rotates about the second axis ０ The acquisition of Based on the detection data and the corresponding rotation angle during the process in which the magnetic ball rotates around the second axis by the third angle, the rotation angle corresponding to the maximum value or minimum value of the magnetic field component in the Y-axis direction is determined as a second calibration position H ０ or Based on the detection data and the corresponding rotation angle during the process in which the magnetic ball rotates around the second axis by the third angle, the rotation angle corresponding to the maximum value or minimum value of the magnetic field component in the X-axis direction is set to the second calibration position H ０ including judging that 4. The method for calibrating a magnetic ball according to claim 2 or 3.

5. The first calibration position V when the magnetic ball rotates around the first axis ０ The acquisition of the first calibration position V is performed by obtaining a curve according to the rotation angle of the magnetic field component in the Z-axis direction from the detection data during the process in which the magnetic ball rotates around the first axis by the first angle, and calculating the rotation angle of the magnetic ball corresponding to the maximum or minimum value on the curve as the first calibration position V. ０ " The second calibration position H when the magnetic ball rotates about the second axis ０ The acquisition of A curve is obtained according to the rotation angle of the magnetic ball of the magnetic field component in the Y-axis direction from the detection data during the process in which the magnetic ball rotates around the second axis by the third angle, and the rotation angle corresponding to the maximum or minimum value on the curve is determined as the second calibration position H ０ or Based on the detection data and the corresponding rotation angle during the process of the magnetic ball rotating through the third angle, the rotation angle corresponding to the maximum value or minimum value of the magnetic field component in the X-axis direction is set to the second calibration position H ０ including judging that 4. The method for calibrating a magnetic ball according to claim 2 or 3.

6. A calibration device for a magnetic ball having magnetic poles aligned along a major axis, the calibration device for the magnetic ball comprising: a drive unit for driving the magnetic ball to rotate; a three-axis magnetic field sensor disposed adjacent to the magnetic ball for acquiring detection data of three-axis magnetic field components at a detection position during rotation of the magnetic ball; a data processing unit connected to the three-axis magnetic field sensor to receive the detection data and obtain a calibration position of the magnetic ball according to a change in the detection data with a rotation angle of the magnetic ball during the rotation; The driving unit includes a first driving unit and a second driving unit, the first driving unit drives the magnetic ball to rotate around a first axis, and the second driving unit drives the magnetic ball to rotate around a second axis and calibrates the magnetic ball based on the calibration position; When the magnetic ball is located at the calibration position, the primary axis overlaps 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 magnetic field component in the Z-axis direction overlaps with the direction of the second axis, and the magnetic field component in the Y-axis direction overlaps with the direction of the first axis. A magnetic ball calibration device comprising:

7. the first driving unit is for driving the magnetic ball to rotate about the first axis by a first angle; The data processing unit includes a third processing unit, and the third processing unit calculates a first calibration position V at which the magnetic ball rotates around the first axis based on the detection data and the corresponding rotation angle during the process of the magnetic ball rotating around the first axis by the first angle. ０ is used to obtain The first driving unit drives the magnetic ball to the first calibration position V ０ the first drive unit is also used to rotate the magnetic ball a second angle about the first axis; the second driving unit is for driving the magnetic ball to rotate about the second axis by a third angle; The data processing unit includes a fourth processing unit, and the fourth processing unit calculates a second calibration position H when the magnetic ball rotates around the second axis based on the detection data and a corresponding rotation angle during the process of the magnetic ball rotating around the second axis by the third angle. ０ used to obtain 7. The magnetic ball calibration device according to claim 6.

8. 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 45°; The third angle is greater than 360° or is 540°.

8. The magnetic ball calibration device according to claim 7.

9. The third processing unit further comprises: Based on the detection data and the corresponding rotation angle during the process in which the magnetic ball rotates around the first axis by the first angle, the position of the magnetic ball corresponding to the maximum or minimum value of the magnetic field component in the Z-axis direction is determined as the first calibration position V ０ It is used to judge The fourth processing unit further comprises: Based on the detection data and the corresponding rotation angle during the process in which the magnetic ball rotates around the second axis by the third angle, the rotation angle corresponding to the maximum value or minimum value of the magnetic field component in the Y-axis direction is set to the second calibration position H ０ or Based on the detection data and the corresponding rotation angle during the process in which the magnetic ball rotates around the second axis by the third angle, the rotation angle corresponding to the maximum value or minimum value of the magnetic field component in the X-axis direction is set to the second calibration position H ０ It is used to judge 9. A calibration device for magnetic balls according to claim 7 or 8.

10. The third processing unit is further used for obtaining a curve according to the rotation angle of the magnetic ball of the magnetic field component in the Z-axis direction from the detection data during the process in which the magnetic ball rotates around the first axis by the first angle, and the rotation angle of the magnetic ball corresponding to the maximum value or minimum value on the curve is the first calibration position V. ０ and The fourth processing unit further comprises: A curve according to the rotation angle of the magnetic ball of the magnetic field component in the Y-axis direction is obtained from the detection data in the process of the magnetic ball rotating about the second axis by the third angle, and the rotation angle corresponding to the maximum or minimum value on the curve is determined as the second calibration position H ０ or Based on the detection data and the corresponding rotation angle during the process of the magnetic ball rotating through the third angle, the rotation angle corresponding to the maximum value or minimum value of the magnetic field component in the X-axis direction is set to the second calibration position H ０ It is used to judge 9. A calibration device for magnetic balls according to claim 7 or 8.

11. the first axis or the second axis passes through the three-axis magnetic field sensor; The detection position includes a position where the three-axis magnetic field sensor is located.

7. The magnetic ball calibration device according to claim 6.

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