Magnetic field measurement method and device

Abstract

The invention provides a magnetic field measurement method which can be applied to the technical field of magnetic field measurement. The method comprises the following steps: respectively calibrating the rotating centers of a rotating single coil and a rotating double coil, and determining a rotating single coil coordinate system and a rotating double coil coordinate system; correcting and calibrating the mechanical center of the permanent magnet, and determining a mechanical center coordinate system of the permanent magnet; the position of the permanent magnet is adjusted, so that the mechanical center coordinate system, the rotary single-coil coordinate system and the rotary double-coil coordinate system of the permanent magnet coincide; and performing magnetic field measurement on the permanent magnet by using the calibrated single rotating coil and double rotating coils. The invention also provides a magnetic field measurement method.

Description

Technical Field

[0001] The present disclosure relates to the field of magnetic field measurement, and in particular to a magnetic field measurement method and device. Background Art

[0002] Conventional room temperature permanent magnets are mostly electromagnets, and the magnet aperture is relatively large, usually greater than 30mm. The magnetic field quality can be measured by the conventional measurement method of Hall point measurement. At the same time, performance indicators such as gradient integrated magnetic field, magnetic axis deviation, high-order field error, and integrated field uniformity can be directly obtained through a single measurement.

[0003] Since the aperture of micro permanent magnets is small, usually ranging from 10 to 16 mm, and the installation position is limited, the size of the Hall probe is large, and the conventional Hall point measurement method is difficult to meet the magnetic field quality measurement of micro permanent magnets, so it is necessary to use a high-precision rotating coil for magnetic field measurement. Based on the measurement principle of the rotating coil measurement method, in order to achieve high-precision magnetic field measurement, it is necessary not only to make a high-precision rotating coil, but also to improve the accuracy of magnet calibration and alignment, so as to achieve a more accurate magnetic field quality after correcting the magnetic axis deviation. Summary of the invention

[0004] In view of the above problems, the present disclosure provides a magnetic field measurement method and device.

[0005] According to the first aspect of the present disclosure, a magnetic field measurement method is provided, including: calibrating the rotation centers of a rotating single coil and a rotating double coil respectively to determine the rotating single coil coordinate system and the rotating double coil coordinate system; calibrating the mechanical center of a permanent magnet after correction to determine the permanent magnet mechanical center coordinate system; adjusting the position of the permanent magnet so that the permanent magnet mechanical center coordinate system, the rotating single coil coordinate system and the rotating double coil coordinate system coincide with each other; and measuring the magnetic field of the permanent magnet using the calibrated rotating single coil and the rotating double coil.

[0006] According to an embodiment of the present disclosure, the rotating single coil includes a driving shaft and a driven shaft, and calibrating the rotation center of the rotating single coil includes: measuring the outer diameters of the driving shaft and the driven shaft; based on the outer diameters of the driving shaft and the driven shaft, determining the rotation center axis of the rotating single coil and establishing a coordinate system of the rotating single coil; setting a plurality of target points around the rotation center axis of the rotating single coil; measuring the coordinates of the plurality of target points to obtain the coordinate values ​​of the target points relative to the origin of the rotating single coil coordinate system.

[0007] According to an embodiment of the present disclosure, the rotating double coil includes a driving shaft and a driven shaft, and calibrating the rotation center of the rotating double coil includes: measuring the outer diameters of the driving shaft and the driven shaft; based on the outer diameters of the driving shaft and the driven shaft, determining the rotation center axis of the rotating double coil and establishing a coordinate system of the rotating double coil; setting a plurality of target points around the rotation center axis of the rotating double coil; measuring the coordinates of the plurality of target points to obtain the coordinate values ​​of the target points relative to the origin of the rotating double coil coordinate system.

[0008] According to the embodiment of the present disclosure, the correction of the mechanical center of the permanent magnet includes: calibrating the mechanical center of the permanent magnet to obtain the mechanical center of the permanent magnet after initial calibration; obtaining the integral value of the induced voltage of the rotating single coil in the permanent magnet; determining the magnetic axis deviation of the permanent magnet according to the integral value of the induced voltage; and correcting the mechanical center of the permanent magnet after initial calibration according to the magnetic axis deviation to obtain a corrected permanent magnet.

[0009] According to an embodiment of the present disclosure, the calibration of the mechanical center of the permanent magnet includes: measuring the aperture of the permanent magnet; determining the aperture axis of the permanent magnet based on the aperture of the permanent magnet; establishing the mechanical center coordinate system of the permanent magnet based on the aperture axis of the permanent magnet; and measuring the coordinates of the target point on the permanent magnet based on the permanent magnet mechanical center coordinate system to obtain the coordinate value of the target point relative to the origin of the permanent magnet mechanical center coordinate system.

[0010] According to the embodiment of the present disclosure, the calibration after correction of the mechanical center of the permanent magnet includes: measuring the aperture of the corrected permanent magnet; determining the aperture axis of the corrected permanent magnet based on the aperture of the corrected permanent magnet; establishing the mechanical center coordinate system of the corrected permanent magnet based on the aperture axis of the corrected permanent magnet; based on the corrected permanent magnet mechanical center coordinate system, measuring the coordinates of the target point on the corrected permanent magnet, and obtaining the coordinate value of the target point relative to the origin of the corrected permanent magnet mechanical center coordinate system.

[0011] According to an embodiment of the present disclosure, the permanent magnet is a miniature permanent quadrupole magnet.

[0012] According to an embodiment of the present disclosure, the integral value of the induced voltage of the rotating double coil in the permanent magnet is obtained; and based on the integral value of the induced voltage of the rotating double coil in the permanent magnet, the magnetic field quality analysis of the permanent magnet is performed.

[0013] According to an embodiment of the present disclosure, adjusting the position of the permanent magnet so that the permanent magnet mechanical center coordinate system, the rotating single coil coordinate system and the rotating double coil coordinate system coincide with each other includes: aligning the permanent magnet using a three-coordinate measuring machine; adjusting the position of the permanent magnet through a three-coordinate best fitting method so that the permanent magnet mechanical center coordinate system, the rotating single coil coordinate system and the rotating double coil coordinate system coincide with each other.

[0014] The second aspect of the present disclosure provides a magnetic field measurement device, including: a coil calibration module, used to calibrate the rotation centers of a rotating single coil and a rotating double coil respectively, and determine the rotating single coil coordinate system and the rotating double coil coordinate system; a magnet calibration module, used to calibrate the mechanical center of a permanent magnet after correction, and determine the permanent magnet mechanical center coordinate system; a position adjustment module, used to adjust the position of the permanent magnet so that the permanent magnet mechanical center coordinate system, the rotating single coil coordinate system and the rotating double coil coordinate system coincide with each other; a magnetic field measurement module, used to measure the magnetic field of the permanent magnet using the calibrated rotating single coil and the rotating double coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above contents and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0016] Figure 1 The flowchart of the magnetic field measurement method according to the embodiment of the present disclosure is schematically shown.

[0017] Figure 2 The structure of a rotating coil measuring device according to an embodiment of the present disclosure is schematically shown.

[0018] Figure 3 A schematic diagram of a corrected magnet coordinate system and a hole expansion according to an embodiment of the present disclosure is schematically shown.

[0019] Figure 4 The structural block diagram of the magnetic field measuring device according to an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0020] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0021] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0022] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0023] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0024] Figure 1 The flowchart of the magnetic field measurement method according to the embodiment of the present disclosure is schematically shown.

[0025] like Figure 1 As shown, the magnetic field measurement method of this embodiment includes operations S110 to S140.

[0026] In operation S110, the rotation centers of the rotating single coil and the rotating double coil are calibrated respectively to determine the rotating single coil coordinate system and the rotating double coil coordinate system.

[0027] In some embodiments of the present disclosure, the rotating single coil includes a driving shaft and a driven shaft, and the above-mentioned calibration of the rotation center of the rotating single coil includes: measuring the outer diameters of the driving shaft and the driven shaft; based on the outer diameters of the driving shaft and the driven shaft, determining the rotation center axis of the rotating single coil and establishing a coordinate system of the rotating single coil; setting multiple target points around the rotation center axis of the rotating single coil; measuring the coordinates of the multiple target points to obtain the coordinate values ​​of the target points relative to the origin of the rotating single coil coordinate system.

[0028] In some embodiments of the present disclosure, the rotating double coil includes a driving shaft and a driven shaft, and the above-mentioned calibration of the rotation center of the rotating double coil includes: measuring the outer diameters of the driving shaft and the driven shaft; based on the outer diameters of the driving shaft and the driven shaft, determining the rotation center axis of the rotating double coil and establishing a coordinate system of the rotating double coil; setting multiple target points around the rotation center axis of the rotating double coil; measuring the coordinates of the multiple target points to obtain the coordinate values ​​of the target points relative to the origin of the rotating double coil coordinate system.

[0029] See also Figure 2 , a rotating coil measuring device is provided. A rotating coil can be placed on the rotating coil measuring device. Figure 2 The rotating coil may be the rotating single coil or the rotating double coil. The rotating coil measuring device comprises a base and two Y-shaped brackets, on which the driving shaft and the driven shaft of the rotating coil are respectively placed.

[0030] The rotation centers of the two rotating coils can be calibrated separately using a three-coordinate measuring machine. First, the active shaft end and the driven shaft end of the rotating coil are installed on the rotating coil measuring device respectively. After installation and tightening, the outer diameters of the active shaft and the driven shaft of the rotating coil are measured using a three-coordinate measuring machine. The measuring points are distributed according to 360° of the circumference to obtain the rotation center axis of the rotating coil and establish the lower rotating coil coordinate system. The target points are arranged on the rotating coil measuring device, and the target points on the three-coordinate measuring machine measuring device are used to obtain the coordinate value of the target point relative to the origin of the rotating coil coordinate system. That is, the calibration of the rotating coil is completed. Figure 1 The driving axis, driven axis measurement positions and targets are shown in the figure.

[0031] In operation S120, the mechanical center of the permanent magnet is corrected and then calibrated to determine the permanent magnet mechanical center coordinate system.

[0032] In some embodiments of the present disclosure, correction of the mechanical center of the permanent magnet includes: calibrating the mechanical center of the permanent magnet to obtain the mechanical center of the permanent magnet after initial calibration; obtaining the integral value of the induced voltage of the rotating single coil in the permanent magnet; determining the magnetic axis deviation of the permanent magnet based on the integral value of the induced voltage; and correcting the mechanical center of the permanent magnet after initial calibration based on the magnetic axis deviation to obtain a corrected permanent magnet.

[0033] In some embodiments of the present disclosure, calibrating the mechanical center of the permanent magnet includes: measuring the aperture of the permanent magnet; determining the aperture axis of the permanent magnet based on the aperture of the permanent magnet; establishing the mechanical center coordinate system of the permanent magnet based on the aperture axis of the permanent magnet; based on the mechanical center coordinate system of the permanent magnet, measuring the coordinates of the target point on the permanent magnet, and obtaining the coordinate value of the target point relative to the origin of the mechanical center coordinate system of the permanent magnet.

[0034] In some embodiments of the present disclosure, calibration of the corrected mechanical center of the permanent magnet includes: measuring the aperture of the corrected permanent magnet; determining the aperture axis of the corrected permanent magnet based on the aperture of the corrected permanent magnet; establishing the corrected permanent magnet mechanical center coordinate system based on the aperture axis of the corrected permanent magnet; and measuring the coordinates of the target point on the corrected permanent magnet based on the corrected permanent magnet mechanical center coordinate system to obtain the coordinate value of the target point relative to the origin of the corrected permanent magnet mechanical center coordinate system.

[0035] The coordinates of the target point relative to the origin of the mechanical center coordinate system of the magnet can be measured by a coordinate measuring machine (CMM). In one embodiment, the magnet can be placed on the workbench of the CMM, and then a specific target point on the magnet and a reference point (such as the aperture axis) used to establish the mechanical center coordinate system can be measured.

[0036] Specifically, the steps for calculating the coordinate value of the target point relative to the origin of the magnet mechanical center coordinate system are as follows 1) to 4).

[0037] 1) Establish the mechanical center coordinate system

[0038] First, determine one of the main directions of the magnet (for example, the Z axis) by measuring the aperture of the magnet and fitting the axis. Then, select a plane on the bottom or side of the magnet as a reference surface to determine the directions of the X and Y axes. Finally, define the midpoint of the aperture axis or the geometric center of the magnet as the origin of the coordinate system.

[0039] 2) Measuring target points

[0040] Use the probe of the coordinate measuring machine to touch the target points on the magnet and record the coordinate value of each target point in the coordinate system of the measuring machine.

[0041] 3) Coordinate transformation

[0042] Since the coordinates of the target points are initially measured in the CMM coordinate system, they need to be transformed into the magnet's mechanical center coordinate system. Translation and rotation matrices can be used to transform the coordinate values ​​in the CMM coordinate system into the magnet's mechanical center coordinate system.

[0043] 4) Calculate relative coordinates

[0044] The coordinate value of the target point relative to the origin of the magnet mechanical center coordinate system can be calculated based on the coordinate value of the target point in the magnet mechanical center coordinate system. The coordinate value of the target point relative to the origin of the magnet mechanical center coordinate system can be obtained by subtracting the coordinate value of the origin of the coordinate system from the coordinate value of the target point.

[0045] For example, the origin of the magnet mechanical center coordinate system is located at (0, 0, 0), and the measured coordinates of a target point are (x_m, y_m, z_m) (coordinates in the coordinate measuring machine coordinate system). If the transformation matrix from the coordinate measuring machine coordinate system to the magnet mechanical center coordinate system is known, the coordinates of the target point in the magnet mechanical center coordinate system (x_t, y_t, z_t) can be calculated. Then, the coordinate value of the target point relative to the origin of the magnet mechanical center coordinate system is (x_t - 0, y_t - 0, z_t - 0) = (x_t, y_t, z_t).

[0046] In operation S130, the position of the permanent magnet is adjusted so that the permanent magnet mechanical center coordinate system, the rotating single coil coordinate system, and the rotating double coil coordinate system coincide with each other.

[0047] In some embodiments of the present disclosure, a three-coordinate measuring machine can be used to align the permanent magnet, and the position of the permanent magnet can be adjusted through the three-coordinate best fitting method so that the permanent magnet mechanical center coordinate system, the rotating single coil coordinate system and the rotating double coil coordinate system coincide with each other.

[0048] In one example, see Figure 3 In order to ensure the final installation accuracy of the permanent magnet and reduce the error introduced by the magnetic axis deviation, the induced voltage integral value obtained by rotating a single coil (reference radius is (4.8mm)) is used for data analysis without correcting the permanent magnet reference D1 (10mm). After obtaining the magnetic axis deviation, the magnetic axis deviation (such as Figure 3 The X1, Y1) shown in the figure is used as the correction value, the reference D1 to D2 (16mm) is expanded, and the reference of the magnet mechanical coordinate system is changed to achieve the purpose of correcting the magnetic axis position. The induced voltage integral value obtained by using the rotating double coil (reference radius is 7.8mm) can be used for data analysis to obtain the magnetic field quality such as gradient integral field, high-order field error, and integral field uniformity.

[0049] In operation S140, the magnetic field of the permanent magnet is measured using the calibrated rotating single coil and rotating double coil.

[0050] The principle of permanent magnet based on rotating coil to measure magnetic field is to obtain induced voltage by having two rotating coils make uniform circular motion in the aperture of micro permanent magnet and cut the magnetic flux lines in the aperture of permanent magnet, and integrate the induced voltage value.

[0051] In some embodiments of the present disclosure, the permanent magnet may be a micro-quadrupole magnet. The micro-permanent quadrupole magnet is a permanent magnet with a relatively small size that can generate a quadrupole magnetic field distribution.

[0052] Based on the above magnetic field measurement method, the present disclosure also provides a magnetic field measurement device. Figure 4 The device is described in detail.

[0053] Figure 4 The structural block diagram of the magnetic field measuring device according to an embodiment of the present disclosure is schematically shown.

[0054] like Figure 4 As shown, the magnetic field measurement device 400 of this embodiment includes a coil calibration module 410 , a magnet calibration module 420 , a position adjustment module 430 and a magnetic field measurement module 440 .

[0055] The coil calibration module 410 is used to calibrate the rotation centers of the rotating single coil and the rotating double coils, respectively, and determine the rotating single coil coordinate system and the rotating double coil coordinate system. In one embodiment, the coil calibration module 410 can be used to perform the operation S110 described above, which will not be repeated here.

[0056] The magnet calibration module 420 is used to calibrate the mechanical center of the permanent magnet after correction, and determine the permanent magnet mechanical center coordinate system. In one embodiment, the magnet calibration module 420 can be used to perform the operation S120 described above, which will not be repeated here.

[0057] The position adjustment module 430 is used to adjust the position of the permanent magnet so that the permanent magnet mechanical center coordinate system, the rotating single coil coordinate system and the rotating double coil coordinate system coincide. In one embodiment, the position adjustment module 430 can be used to perform the operation S130 described above, which will not be repeated here.

[0058] The magnetic field measurement module 440 is used to measure the magnetic field of the permanent magnet using the calibrated rotating single coil and rotating double coil. In one embodiment, the magnetic field measurement module 440 can be used to perform the operation S140 described above, which will not be described in detail here.

[0059] It is understandable that the magnetic field measuring device 400 may also include a rotating single coil, a rotating double coil, a rotating coil measuring device, a three-coordinate measuring machine, etc. The present disclosure does not limit this.

[0060] In some embodiments of the present disclosure, the rotating single coil includes a driving shaft and a driven shaft, and calibrating the rotation center of the rotating single coil includes: measuring the outer diameters of the driving shaft and the driven shaft; based on the outer diameters of the driving shaft and the driven shaft, determining the rotation center axis of the rotating single coil and establishing a coordinate system of the rotating single coil; setting a plurality of target points around the rotation center axis of the rotating single coil; measuring the coordinates of the plurality of target points to obtain the coordinate values ​​of the target points relative to the origin of the rotating single coil coordinate system.

[0061] In some embodiments of the present disclosure, the rotating double coil includes a driving shaft and a driven shaft, and calibrating the rotation center of the rotating double coil includes: measuring the outer diameters of the driving shaft and the driven shaft; based on the outer diameters of the driving shaft and the driven shaft, determining the rotation center axis of the rotating double coil and establishing a coordinate system of the rotating double coil; setting a plurality of target points around the rotation center axis of the rotating double coil; measuring the coordinates of the plurality of target points to obtain the coordinate values ​​of the target points relative to the origin of the rotating double coil coordinate system.

[0062] In some embodiments of the present disclosure, the correction of the mechanical center of the permanent magnet includes: calibrating the mechanical center of the permanent magnet to obtain the mechanical center of the permanent magnet after initial calibration; obtaining the integral value of the induced voltage of the rotating single coil in the permanent magnet; determining the magnetic axis deviation of the permanent magnet based on the integral value of the induced voltage; and correcting the mechanical center of the permanent magnet after initial calibration based on the magnetic axis deviation to obtain a corrected permanent magnet.

[0063] In some embodiments of the present disclosure, the calibration of the mechanical center of the permanent magnet includes: measuring the aperture of the permanent magnet; determining the aperture axis of the permanent magnet based on the aperture of the permanent magnet; establishing the mechanical center coordinate system of the permanent magnet based on the aperture axis of the permanent magnet; and measuring the coordinates of the target point on the permanent magnet based on the permanent magnet mechanical center coordinate system to obtain the coordinate value of the target point relative to the origin of the permanent magnet mechanical center coordinate system.

[0064] In some embodiments of the present disclosure, the calibration of the mechanical center of the permanent magnet after correction includes: measuring the aperture of the corrected permanent magnet; determining the aperture axis of the corrected permanent magnet based on the aperture of the corrected permanent magnet; establishing the mechanical center coordinate system of the corrected permanent magnet based on the aperture axis of the corrected permanent magnet; and measuring the coordinates of the target point on the corrected permanent magnet based on the corrected mechanical center coordinate system to obtain the coordinate value of the target point relative to the origin of the corrected permanent magnet mechanical center coordinate system.

[0065] In some embodiments of the present disclosure, the permanent magnet is a miniature permanent quadrupole magnet.

[0066] In some embodiments of the present disclosure, the device 400 further includes: an integral acquisition module for acquiring the integral value of the induced voltage of the rotating double coil in the permanent magnet; and a quality analysis module for performing magnetic field quality analysis on the permanent magnet based on the integral value of the induced voltage of the rotating double coil in the permanent magnet.

[0067] In some embodiments of the present disclosure, adjusting the position of the permanent magnet so that the permanent magnet mechanical center coordinate system, the rotating single coil coordinate system and the rotating double coil coordinate system coincide with each other includes: aligning the permanent magnet using a three-coordinate measuring machine; adjusting the position of the permanent magnet through a three-coordinate best fitting method so that the permanent magnet mechanical center coordinate system, the rotating single coil coordinate system and the rotating double coil coordinate system coincide with each other.

[0068] According to an embodiment of the present disclosure, any multiple modules of the coil calibration module 410, the magnet calibration module 420, the position adjustment module 430 and the magnetic field measurement module 440 can be combined in one module, or any one of them can be split into multiple modules. Alternatively, at least part of the functions of one or more of these modules can be combined with at least part of the functions of other modules and implemented in one module. According to an embodiment of the present disclosure, at least one of the coil calibration module 410, the magnet calibration module 420, the position adjustment module 430 and the magnetic field measurement module 440 can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application specific integrated circuit (ASIC), or can be implemented by hardware or firmware such as any other reasonable way of integrating or packaging the circuit, or implemented in any one of the three implementation methods of software, hardware and firmware or in any appropriate combination of any of them. Alternatively, at least one of the coil calibration module 410 , the magnet calibration module 420 , the position adjustment module 430 , and the magnetic field measurement module 440 may be at least partially implemented as a computer program module, and when the computer program module is executed, a corresponding function may be performed.

[0069] The flow charts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flow chart or block diagram can represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flow chart, and the combination of the boxes in the block diagram or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0070] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations and / or combinations are not explicitly described in the present disclosure. In particular, the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways without departing from the spirit and teachings of the present disclosure. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0071] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. The scope of the present disclosure is defined by the attached claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A magnetic field measurement method, characterized in that: include: The rotation centers of the rotating single coil and the rotating double coil are calibrated respectively to determine the rotating single coil coordinate system and the rotating double coil coordinate system; Calibrate the mechanical center of the permanent magnet after correction to determine the mechanical center coordinate system of the permanent magnet; Adjusting the position of the permanent magnet so that the permanent magnet mechanical center coordinate system, the rotating single coil coordinate system and the rotating double coil coordinate system coincide with each other; The magnetic field of the permanent magnet is measured using the calibrated rotating single coil and the rotating double coil.

2. The method according to claim 1, characterized in that The rotating single coil includes a driving shaft and a driven shaft, and the calibrating the rotation center of the rotating single coil includes: Measuring the outer diameters of the driving shaft and the driven shaft; Based on the outer diameters of the driving shaft and the driven shaft, determining the rotation center axis of the rotating single coil and establishing a coordinate system of the rotating single coil; Setting a plurality of target points around the rotation center axis of the rotating single coil; The coordinates of the multiple target points are measured to obtain the coordinate values ​​of the target points relative to the origin of the rotating single coil coordinate system.

3. The method according to claim 1, characterized in that The rotating double coil includes a driving shaft and a driven shaft, and the calibrating the rotation center of the rotating double coil includes: Measuring the outer diameters of the driving shaft and the driven shaft; Based on the outer diameters of the driving shaft and the driven shaft, determining the rotation center axis of the rotating double coil and establishing a coordinate system of the rotating double coil; Arranging a plurality of target points around the rotation center axis of the rotating double coil; The coordinates of the multiple target points are measured to obtain the coordinate values ​​of the target points relative to the origin of the rotating double-coil coordinate system.

4. The method according to claim 1, characterized in that: The mechanical center correction of the permanent magnet includes: Calibrate the mechanical center of the permanent magnet to obtain an initially calibrated mechanical center of the permanent magnet; Obtaining an integral value of the induced voltage of the rotating single coil in the permanent magnet; Determining the magnetic axis deviation of the permanent magnet according to the integral value of the induced voltage; According to the magnetic axis deviation, the mechanical center of the initial calibrated permanent magnet is corrected to obtain a corrected permanent magnet.

5. The method according to claim 4, characterized in that The calibrating the mechanical center of the permanent magnet includes: Measuring the aperture of the permanent magnet; Based on the aperture of the permanent magnet, determining the aperture axis of the permanent magnet; Based on the aperture axis of the permanent magnet, establishing the permanent magnet mechanical center coordinate system; Based on the permanent magnet mechanical center coordinate system, the coordinates of the target point on the permanent magnet are measured to obtain the coordinate value of the target point relative to the origin of the permanent magnet mechanical center coordinate system.

6. The method according to claim 4, characterized in that The calibration after correcting the mechanical center of the permanent magnet comprises: Measuring the aperture of the corrected permanent magnet; Based on the aperture of the corrected permanent magnet, determining the aperture axis of the corrected permanent magnet; Based on the aperture axis of the corrected permanent magnet, establishing the corrected permanent magnet mechanical center coordinate system; Based on the corrected permanent magnet mechanical center coordinate system, the coordinates of the target point on the corrected permanent magnet are measured to obtain the coordinate value of the target point relative to the origin of the corrected permanent magnet mechanical center coordinate system.

7. The method according to claim 1, characterized in that The permanent magnet is a miniature permanent quadrupole magnet.

8. The method according to claim 1, characterized in that The method further comprises: Obtaining an integral value of the induced voltage of the rotating double coil in the permanent magnet; Based on the integral value of the induced voltage of the rotating double coil in the permanent magnet, the magnetic field quality analysis of the permanent magnet is performed.

9. The method according to claim 1, characterized in that: The step of adjusting the position of the permanent magnet so that the permanent magnet mechanical center coordinate system, the rotating single coil coordinate system and the rotating double coil coordinate system coincide with each other comprises: Using a three-dimensional coordinate measuring machine to align the permanent magnet; The position of the permanent magnet is adjusted by a three-coordinate best fitting method so that the permanent magnet mechanical center coordinate system, the rotating single coil coordinate system and the rotating double coil coordinate system coincide with each other.

10. A magnetic field measuring device, characterized in that: include: A coil calibration module, used to calibrate the rotation centers of the rotating single coil and the rotating double coil respectively, and determine the rotating single coil coordinate system and the rotating double coil coordinate system; A magnet calibration module, used to calibrate the mechanical center of the permanent magnet after correction, and determine the mechanical center coordinate system of the permanent magnet; A position adjustment module, used for adjusting the position of the permanent magnet so that the permanent magnet mechanical center coordinate system, the rotating single coil coordinate system and the rotating double coil coordinate system coincide with each other; The magnetic field measurement module is used to measure the magnetic field of the permanent magnet using the calibrated rotating single coil and the rotating double coil.

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