Hall point measurement method based on circular interpolation motion

Abstract

The invention provides a Hall point measurement method based on circular interpolation motion, and belongs to the technical field of magnetic field measurement. The method comprises the following steps: when a motion controller executes an arc interpolation algorithm to drive a Hall probe to perform arc interpolation motion, the motion controller outputs a synchronous trigger signal according to a preset spatial sampling interval; and in response to the synchronous trigger signal, acquiring and processing the Hall voltage output by the Hall probe through a Hall voltage acquirer to obtain magnetic field data corresponding to the preset spatial position of the magnet to be detected.

Description

Technical Field

[0001] This disclosure relates to the field of magnetic field measurement technology, and more specifically, to a method for Hall point measurement based on circular interpolation motion. Background Technology

[0002] In existing magnetic field measurement technologies, a static point measurement method is typically used to characterize magnets: first, the magnet is installed and spatially aligned; then, the Hall probe is moved to a preset position; and only after the movement has completely stopped is the Hall voltage acquisition system triggered to read the single-point magnetic field data. While this method can ensure local measurement accuracy, the overall measurement efficiency is low because each point needs to go through steps such as "positioning-stabilization-acquisition-reset," making it difficult to meet the needs of high-throughput or online detection scenarios.

[0003] To improve efficiency, some systems have attempted to introduce continuous motion scanning modes. However, current mainstream motion control systems are mostly designed for scenarios such as CNC machining, and their interpolation functions are mainly based on straight lines or simple curves, lacking the high-precision circular interpolation capability required for precise magnetic field measurement. Especially when scanning arc trajectories of devices with rotational symmetry structures such as toroidal magnets and dipole / quadrupole magnets, existing solutions struggle to generate smooth, high-resolution circular paths, limiting the spatial coverage and geometric fidelity of the measurement.

[0004] More importantly, during dynamic measurements, if the Hall probe's trajectory and voltage acquisition timing are not strictly synchronized, the acquired magnetic field data will be misaligned with its actual spatial location. For example, the probe may have already passed the theoretical sampling point before acquisition is triggered, or system delays may cause the position tag to become inaccurate, thus introducing significant spatial positioning errors. In regions with large magnetic field gradients, even micrometer-level positional deviations can lead to millitalas-level magnetic field misjudgments, severely weakening the reliability and repeatability of the measurement results. Summary of the Invention

[0005] In view of this, the present disclosure provides a method for Hall point measurement based on circular interpolation motion, which can at least partially solve the above-mentioned technical problems.

[0006] This disclosure provides a method for Hall point measurement based on circular interpolation motion, comprising: during the process of the motion controller executing the circular interpolation algorithm to drive the Hall probe to perform circular interpolation motion, the motion controller outputs a synchronous trigger signal according to a preset spatial sampling interval; in response to the synchronous trigger signal, the Hall voltage output by the Hall probe is collected and processed by the Hall voltage acquisition device to obtain the magnetic field data corresponding to the preset spatial position of the magnet under test.

[0007] According to an embodiment of this disclosure, during the process of the motion controller executing the circular interpolation algorithm to drive the Hall probe to perform circular interpolation motion, the motion controller outputs a synchronous trigger signal according to a preset spatial sampling interval, including: loading a control program containing circular trajectory parameters into the motion controller; and driving the Hall probe to perform circular interpolation motion along the circular trajectory based on the control program.

[0008] According to embodiments of this disclosure, the arc trajectory parameters include the starting point coordinates, the ending point coordinates, the center offset, and the radius.

[0009] According to an embodiment of this disclosure, in response to a synchronization trigger signal, the Hall voltage output by the Hall probe is acquired and processed by a Hall voltage acquisition device to obtain magnetic field data corresponding to a preset spatial position of the magnet under test. This includes: in response to the synchronization trigger signal, the Hall voltage acquisition device integrates the Hall voltage output by the Hall probe corresponding to the preset spatial position of the magnet under test; and performs analog-to-digital conversion on the integrated Hall voltage to obtain magnetic field spatial distribution data.

[0010] According to embodiments of this disclosure, the preset spatial sampling interval is a preset arc length interval or a preset angle interval.

[0011] According to an embodiment of this disclosure, before the motion controller executes the circular interpolation algorithm to drive the Hall probe to perform circular interpolation motion, the method further includes: fixing the Hall probe to the motion platform and fixing the magnet to be tested to the test bracket; and driving the Hall probe to move to the starting position of the circular trajectory of the magnet to be tested.

[0012] According to embodiments of this disclosure, after fixing the magnet to be tested to the test bracket, the method further includes: spatially calibrating and aligning the magnet to be tested so that the mechanical center coordinate system of the magnet to be tested is aligned with the measurement coordinate system.

[0013] According to an embodiment of this disclosure, the starting position of the circular arc trajectory is the mechanical center of the magnet to be tested.

[0014] According to embodiments of this disclosure, the method further includes: using a grating ruler to obtain the actual position of the Hall probe; and the motion controller adjusting the position deviation introduced by the mechanical transmission based on the deviation between the target position and the actual position of the Hall probe.

[0015] According to an embodiment of this disclosure, the Hall voltage acquisition device is an On-Fly Hall voltage acquisition device.

[0016] The Hall point measurement method based on circular interpolation motion according to the embodiments of this disclosure has at least the following beneficial effects:

[0017] By executing a high-precision circular interpolation algorithm during motion controller operation, a hardware-level synchronous trigger signal is output in real time according to a preset spatial sampling interval (such as a fixed arc length or angle). The Hall voltage acquisition unit responds to this signal to accurately acquire and process the voltage output by the Hall probe, achieving strict spatiotemporal synchronization between the motion trajectory and data acquisition during magnetic field measurement. This scheme eliminates the inefficient "walk-stop-acquire" mode of traditional static point measurement, enabling the Hall probe to acquire high-density magnetic field data during continuous, smooth circular motion, significantly improving measurement efficiency. Simultaneously, because the acquisition time is precisely bound to the theoretical spatial position, positional misalignment errors caused by asynchronous motion and acquisition are effectively avoided, significantly improving the geometric accuracy and repeatability of the magnetic field spatial distribution data. Attached Figure Description

[0018] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0019] Figure 1 A flowchart illustrating a Hall point measurement method based on circular interpolation motion according to an embodiment of the present disclosure is shown schematically.

[0020] Figure 2 A schematic diagram of a Hall point measuring device based on circular interpolation motion according to an embodiment of the present disclosure is provided. Detailed Implementation

[0021] The embodiments of the present disclosure will now 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 disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0023] Figure 1 A flowchart illustrating a Hall point measurement method based on circular interpolation motion according to an embodiment of the present disclosure is shown schematically.

[0024] like Figure 1 As shown, the Hall point measurement method based on circular interpolation motion in this embodiment includes: operation S110 to operation S120.

[0025] In operation S110, during the process of the motion controller executing the circular interpolation algorithm to drive the Hall probe to perform circular interpolation motion, the motion controller outputs a synchronous trigger signal according to the preset spatial sampling interval.

[0026] In operation S120, in response to the synchronous trigger signal, the Hall voltage output by the Hall probe is collected and processed by the Hall voltage acquisition device to obtain the magnetic field data corresponding to the preset spatial position of the magnet under test.

[0027] In the embodiments of this disclosure, the circular interpolation algorithm is a numerical control interpolation technique used to generate a smooth circular arc path between two coordinate points. Based on the input starting point coordinates, ending point coordinates, center offset, and rotation direction, it outputs a series of tiny displacement commands to make the motion approximate the ideal circular arc.

[0028] During the measurement phase, in operation S110, the motion controller initiates the circular interpolation algorithm to calculate the continuous position commands of the Hall probe along the theoretical circular arc trajectory in real time, and drives the multi-axis servo motors to coordinate their movements, enabling the motion platform carrying the Hall probe to move smoothly and without interruption along the circular arc path. During this process, the motion controller continuously monitors the accumulated interpolation displacement. Once the preset spatial sampling interval is reached, it immediately outputs a low-jitter, microsecond-level synchronization trigger signal (such as a TTL pulse) through the hardware I / O interface. This signal strictly corresponds to a specific theoretical spatial position on the circular arc trajectory.

[0029] Next, in operation S120, the Hall voltage acquisition unit monitors the synchronous trigger signal in real time. Once the trigger edge is detected, a complete acquisition and processing flow is immediately initiated: first, the weak analog voltage output by the Hall probe is amplified with low noise; then, it is integrated within a preset time window to suppress dynamic noise; then, it is converted into a digital value by a high-resolution analog-to-digital converter (ADC); and combined with pre-calibrated zero-point offset and sensitivity parameters, the magnetic field strength value at that location is calculated. Finally, this magnetic field data is automatically bound to the arc space coordinates (such as polar angle θ or Cartesian coordinates x, y) corresponding to the trigger moment, forming a structured "position-magnetic field" data pair.

[0030] The aforementioned S110 and S120 operations are executed cyclically throughout the entire circular arc scan until the Hall probe completes coverage of the entire trajectory. The entire process requires no interruption, achieving integrated high-efficiency measurement with continuous motion, precise positioning, synchronous acquisition, and real-time output. The measured scanning speed is increased by more than three times, significantly improving measurement efficiency. Furthermore, by deeply integrating high-precision circular arc interpolation motion with hardware-level synchronous integration technology, major error sources such as velocity effects, mechanical hysteresis, and vibration are effectively suppressed. Even under high-speed scanning conditions, near-static measurement accuracy can be achieved. Each magnetic field data point is strictly aligned with its theoretical spatial position, ultimately achieving an excellent performance with a spatial positioning error of less than 0.1 mm, realistically and meticulously reproducing the details of the magnetic field distribution. In addition, this method possesses excellent scalability; its modular architecture can be flexibly adapted to various demanding application scenarios such as superconducting magnets, particle therapy equipment, and MRI shimming loops, constructing a universal, high-performance magnetic field measurement platform. In summary, this embodiment successfully fills the technological gap between high-precision circular arc interpolation motion control and dynamic magnetic field synchronous measurement, possessing outstanding engineering practical value and broad application prospects.

[0031] Based on the above embodiments, during the process of the motion controller executing the circular interpolation algorithm to drive the Hall probe to perform circular interpolation motion, the motion controller outputs a synchronous trigger signal according to a preset spatial sampling interval, including: loading a control program containing circular trajectory parameters into the motion controller. Based on the control program, the Hall probe is driven to perform circular interpolation motion along the circular trajectory.

[0032] Furthermore, the parameters of the circular trajectory include the starting point coordinates, the ending point coordinates, the center offset, and the radius.

[0033] In the embodiments of this disclosure, to achieve high-precision scanning of the Hall probe along the arc-shaped region of the magnet under test, a control program containing complete circular arc trajectory parameters is first loaded into the motion controller. These parameters include the starting point coordinates, ending point coordinates, center offset, and radius. Based on this program, the motion controller performs real-time circular interpolation calculations, generating continuous position commands that drive a multi-axis servo platform to smoothly move the Hall probe along the theoretical circular arc trajectory. During this process, the controller outputs hardware synchronization trigger signals at precise trajectory positions according to a preset spatial sampling interval (e.g., every 0.1° angle), thereby providing a reliable reference for the spatiotemporal alignment of subsequent magnetic field data. This scheme achieves flexible configuration of the measurement path, high-fidelity reproduction of the motion process, and precise coupling of acquisition synchronization, significantly improving the efficiency and reliability of arc-shaped magnetic field characterization.

[0034] Based on the above embodiments, in response to a synchronization trigger signal, the Hall voltage output by the Hall probe is acquired and processed by the Hall voltage acquisition device to obtain magnetic field data corresponding to a preset spatial position of the magnet under test. This includes: in response to the synchronization trigger signal, the Hall voltage acquisition device integrates the Hall voltage output by the Hall probe corresponding to the preset spatial position of the magnet under test. The integrated Hall voltage is then converted from analog to digital to obtain magnetic field spatial distribution data.

[0035] Furthermore, the preset spatial sampling interval is either a preset arc length interval or a preset angle interval.

[0036] In the embodiments of this disclosure, the Hall voltage acquisition device accurately acquires the raw Hall voltage output by the Hall probe at the current spatial position. Since the Hall probe moves continuously with the motion platform, its output signal is susceptible to mechanical vibration, power supply noise, and electromagnetic interference. Therefore, the acquisition process is not a simple instantaneous sampling, but rather involves further integration processing: that is, time-domain integration of the Hall voltage is performed within a fixed time window (e.g., 100 microseconds) defined by the synchronous trigger signal. This integration operation effectively suppresses high-frequency noise, eliminates random disturbances, and improves the signal-to-noise ratio. Subsequently, the integrated analog voltage signal is sent to a high-resolution analog-to-digital converter to complete the analog-to-digital conversion, obtaining the corresponding digital quantity, and then calculating the true magnetic induction intensity of the magnet under test at the preset spatial position. Simultaneously, this magnetic field value is automatically associated with the theoretical spatial coordinates corresponding to the trigger moment, forming a structured "position-magnetic field" data pair, which is then compiled into magnetic field spatial distribution data for subsequent uniformity analysis, harmonic assessment, or magnet performance verification.

[0037] Furthermore, by using spatial intervals rather than time intervals as the sampling reference, it is ensured that even during variable-speed scanning or acceleration / deceleration phases, the data points remain uniformly distributed along the circular trajectory, avoiding uneven sampling density caused by speed fluctuations, thereby guaranteeing the geometric accuracy of the reconstructed magnetic field distribution.

[0038] Figure 2 A schematic diagram of a Hall point measuring device based on circular interpolation motion according to an embodiment of the present disclosure is provided.

[0039] like Figure 2 As shown, the device includes a three-axis motion platform, which serves as the geometric reference plane for the entire system.

[0040] The grating ruler is installed next to the X / Y / Z direction guide rails of the three-axis motion platform and is used to measure the actual position of the probe in real time.

[0041] An air-bearing slide, mounted on a three-axis motion platform, is used to achieve contactless, frictionless, and ultra-low friction torque motion.

[0042] Servo motors are used to receive commands from motion controllers to achieve precise speed and position control.

[0043] A Hall probe is used to measure the Hall voltage of a magnet under test.

[0044] See Figure 2 Before the motion controller executes the circular interpolation algorithm to drive the Hall probe to perform circular interpolation motion, the method further includes: fixing the Hall probe on the motion platform and fixing the magnet to be tested on the test bracket; driving the Hall probe to move to the starting position of the circular trajectory of the magnet to be tested.

[0045] Based on the above embodiments, after fixing the magnet to be tested to the test bracket, the method further includes: spatially calibrating and aligning the magnet to be tested so that the mechanical center coordinate system of the magnet to be tested is aligned with the measurement coordinate system.

[0046] Based on the above embodiments, the starting position of the arc trajectory is the mechanical center of the magnet to be tested.

[0047] Based on the above embodiments, the method further includes: using a grating ruler to obtain the actual position of the Hall probe; and the motion controller adjusting the position deviation introduced by the mechanical transmission based on the deviation between the target position and the actual position of the Hall probe.

[0048] Based on the above embodiments, the Hall voltage acquisition device is an On-Fly Hall voltage acquisition device, which supports microsecond-level synchronous sampling during high-speed probe movement, balancing measurement efficiency and accuracy.

[0049] In the embodiments of this disclosure, in order to achieve high-fidelity magnetic field characterization of the magnet under test along the arc trajectory, the system first performs physical installation and initial alignment: the Hall probe is firmly installed on the end effector of the multi-axis high-precision servo motion platform, and the magnet under test is firmly fixed on the special test bracket to ensure that it has no displacement or vibration during the measurement process.

[0050] Furthermore, after the magnets are installed, spatial calibration and magnetic axis alignment are performed: the spatial attitude of the magnet under test is precisely adjusted using a laser tracker to ensure that its magnetic axis (i.e., the direction of the main magnetic field) is strictly aligned with the global coordinate system of the measurement system. This step effectively eliminates systematic measurement errors caused by installation deviations and is a prerequisite for ensuring the geometric consistency of subsequent circular arc scanning.

[0051] Subsequently, the control system drives the motion platform to move the Hall probe to the preset starting position of the circular arc trajectory. This starting position is set as the mechanical center of the magnet under test (or a reference point on its axis of symmetry) to ensure that the scanning path is highly matched with the physical structure of the magnet, facilitating subsequent data analysis and performance evaluation. Before entering the dynamic measurement stage, the system activates a fully closed-loop position feedback mechanism: the actual physical position of the Hall probe is acquired in real time through a high-resolution grating ruler installed on the load end of the motion platform; the motion controller compares this actual position with the target position generated by the interpolation algorithm, calculates the mechanical transmission deviation caused by lead screw pitch error, backlash, guide rail deformation, etc., and dynamically corrects the control commands sent to the servo driver, thereby achieving sub-micron level position closed-loop control and significantly improving the execution accuracy of the circular arc trajectory. Based on this, the motion controller executes the circular arc interpolation algorithm, drives the Hall probe to move continuously along the theoretical circular arc, and outputs hardware-level synchronous trigger signals according to the preset spatial sampling interval (such as every 0.1° angle or every 0.05mm arc length). In response to the signal, the Hall voltage acquisition unit (i.e., a dedicated acquisition device that supports external triggering and has real-time integration and high-speed ADC capabilities) immediately amplifies the voltage output by the Hall probe with low noise, integrates it in the time domain to suppress dynamic interference, and completes high-resolution analog-to-digital conversion, finally outputting magnetic field data that strictly corresponds to the current spatial position.

[0052] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A method of Hall point measurement based on circular arc interpolation motion, characterized by, The method comprises the following steps: In the process of driving the Hall probe to perform circular interpolation motion by the motion controller executing a circular interpolation algorithm, the motion controller outputs a synchronous trigger signal according to a preset spatial sampling interval; In response to the synchronous trigger signal, the Hall voltage output by the Hall probe is collected and processed by a Hall voltage collector to obtain magnetic field data corresponding to a preset spatial position of the magnet to be measured.

2. The method of claim 1, wherein, In the process of driving the Hall probe to perform circular interpolation motion by the motion controller executing a circular interpolation algorithm, the motion controller outputs a synchronous trigger signal according to a preset spatial sampling interval, which comprises the following steps: Loading a control program containing circular trajectory parameters in the motion controller; Driving the Hall probe to perform circular interpolation motion along the circular trajectory based on the control program.

3. The method of claim 2, wherein, The circular trajectory parameters include start point coordinates, end point coordinates, center offset and radius.

4. The method of claim 1, wherein, In response to the synchronous trigger signal, the Hall voltage collector integrates the Hall voltage corresponding to the preset spatial position of the magnet to be measured obtained by the Hall probe; The Hall voltage after integration is subjected to analog-digital conversion to obtain magnetic field spatial distribution data. The preset spatial sampling interval is a preset arc length interval or a preset angle interval.

5. The method of claim 1, wherein, Before the process of driving the Hall probe to perform circular interpolation motion by the motion controller executing a circular interpolation algorithm, the method further comprises the following steps:

6. The method of claim 1, wherein, Fixing the Hall probe on a motion platform and fixing the magnet to be measured on a test support; Driving the Hall probe to move to the starting position of the circular trajectory of the magnet to be measured. After fixing the magnet to be measured on the test support, the method further comprises the following steps:

7. The method of claim 6, wherein, Calibrating and collimating the magnet to be measured in space to align the mechanical center coordinate system of the magnet to be measured with the measurement coordinate system. The starting position of the circular trajectory is the mechanical center of the magnet to be measured.

8. The method of claim 6, wherein, The method further comprises the following steps:

9. The method of claim 1, wherein, Using a grating ruler to obtain the actual position of the Hall probe; The motion controller adjusts the position deviation introduced by mechanical transmission based on the deviation between the target position of the Hall probe and the actual position. The Hall voltage collector is an On-Fly Hall voltage collector.

10. The method of claim 1, wherein, ​

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