A Hall sensor system and operation method for magnetic levitation platform motion positioning

Abstract

The present invention provides a Hall sensor system and operating method for positioning the motion of a magnetic levitation platform. The system includes a mover assembly and a stator assembly. The mover assembly includes a mover platform (1-2), a coil (1-1), and a linear Hall sensor (3-1); the stator assembly includes a Halbach permanent magnet array (1-3) and a base platform. The present invention uses a linear Hall sensor array to replace a commonly used laser rangefinder to measure the relative position of the mover, and the measurement range is not limited by travel. The Hall sensor matrix is used to measure not only displacement but also whether the mover has an angle of rotation relative to the stator. Five Hall sensors in the same group check each other, thereby increasing data reliability.

Description

Technical Field

[0001] The invention relates to a Hall sensor system and an operating method for movement positioning of a magnetic levitation platform, belonging to the technical field of magnetic levitation motion platforms. Background Art

[0002] Since the 1990s, the electronic information industry has rapidly developed into a strategic sector driving global economic growth. The manufacturing of various semiconductor devices, centered around integrated circuits, is the foundation and driving force of the electronic information industry. Precision instrument manufacturing places increasingly stringent demands on processing equipment, with positioning accuracy directly impacting the precision of the processed dimensions. Improving positioning accuracy can be achieved not only by increasing sensor accuracy and resolution but also through path prediction. Due to its non-contact nature, magnetic levitation systems are widely used in clean environment systems, high-precision positioning, and high-speed transportation systems. Given this background, research on the positioning accuracy of magnetic levitation motion platforms holds considerable promise.

[0003] Hall effect sensors are widely used for electromagnetic, pressure, acceleration, vibration, and other measurement applications. They are characterized by their compact size, low power consumption, long life, easy installation, and resistance to corrosion and contamination. They are suitable for both moving-iron and moving-coil magnetic levitation platforms with light loads and cable interference. Compared to laser sensors, which use distance or displacement for positioning, Hall effect sensors measure position based on the magnetic induction intensity generated by the permanent magnets inherent in the stator or mover of a magnetic levitation platform. Therefore, they offer a wider measurement range and a relatively simple structure and installation. Summary of the Invention

[0004] The present invention aims to solve the technical problem of low positioning accuracy of a magnetic levitation motion platform in the prior art, and further proposes a Hall sensor system and an operating method for the motion positioning of the magnetic levitation platform.

[0005] The technical solution adopted by the present invention to solve the above problems is: the present invention proposes a Hall sensor system for magnetic levitation platform motion positioning, comprising:

[0006] The mover assembly includes a mover platform (1-2), a coil (1-1) and a linear Hall sensor (3-1);

[0007] The stator assembly includes a Halbach permanent magnet array (1-3) and a base platform.

[0008] Optionally, the coil (1-1) is divided into three groups, and the linear Hall sensors (3-1) form a 5×5 Hall sensor matrix. The Hall sensor matrix is installed on the mover platform (1-2), and the distance between two adjacent linear Hall sensors (3-1) in the Hall sensor matrix is one quarter of the magnet array period.

[0009] Optionally, a mover platform (1-2) is provided on the Halbach permanent magnet array (1-3), and each set of coils (1-1) is vertically mounted on the mover platform (1-2).

[0010] A method for operating a Hall sensor system for positioning a magnetic levitation platform comprises:

[0011] S1: Combine two adjacent sensors in the Hall sensor matrix to form 40 measurement pairs and obtain the phase value of each pair of Hall sensors;

[0012] S2: Divide the Hall sensor matrix into five groups along the x-axis and y-axis, calculate the mutual differences of the four phase values in each row or column, and determine whether the mover has an angle deviation relative to the stator based on the mutual differences, completing the abnormality detection of the Hall sensor system;

[0013] S3: The predicted result of the magnetic levitation platform movement is obtained based on the phase value after the abnormality detection.

[0014] Optionally, obtaining the phase value of each pair of Hall sensors in S1 specifically includes:

[0015] After controlling the motion stage to rotate around the z-axis, the x-axis, and the y-axis, the return value of a Hall sensor measurement pair is taken as the arc tangent to obtain the phase value of the measurement point.

[0016] Optionally, the steps of detecting abnormality of the Hall sensor system in S2 include:

[0017] S201: Compare the differences between the four phase values and π / 2;

[0018] S202: If the difference between the four phase values is equal to π / 2, it is determined that the movable platform has no rotation angle, and errors are eliminated for each set of phase values. The linear change of the measuring point during the uniform motion is calculated based on the phase value after error elimination. During the motion of the measuring point, when the phase value jumps discontinuously, if the phase jumps from 2π to 0, the cycle number is increased by 1, and the moving distance is increased by one cycle length; if the phase jumps from 0 to 2π, the cycle number is reduced by 1, and the moving distance is reduced by one cycle length τ. Combined with the linear change during the uniform motion of the measuring point, the total displacement of the measuring point is calculated;

[0019] S203: If the difference between the four phase values is not equal to π / 2, it is determined that the sensor is damaged or the stator is rotating, and the abnormality detection of the Hall sensor system is completed;

[0020] The expression of the linear change of the measurement point during uniform motion is:

[0021] x=ατ / 2π(1);

[0022] In formula (1), x is the moving distance, α is the phase value of the Hall sensor measurement pair, and τ is the length of the magnet array in one cycle;

[0023] The total displacement of the measuring point is calculated as:

[0024] X=nτ+x(2);

[0025] In formula (2), X is the total displacement and n is the number of cycles.

[0026] Optionally, performing error elimination on each group of phase values in S202 specifically includes: performing fitting on each group of phase values so that adjacent phase values differ by π / 2.

[0027] Optionally, the prediction result of the magnetic levitation platform movement obtained in S3 specifically includes:

[0028] A displacement curve is drawn based on the total displacement of the measurement point, and the displacement curves of the measurement points in adjacent periods within the XY platform on the stator platform are connected to obtain the position of the measurement point relative to the stator platform. The relative motion speed and acceleration of the stator platform are calculated based on the phase value change rate of each measurement point to complete the motion positioning of the magnetic levitation platform.

[0029] The beneficial effects of the present invention are: the Hall sensor is easy to install and use, and the hardware cost is low. The present invention uses a linear Hall sensor array to replace the commonly used laser rangefinder to measure the relative position of the mover, and the measurement range is not limited by the stroke. In addition to measuring the displacement, the Hall sensor matrix can also be used to check whether the mover has an angle of rotation relative to the stator. The five Hall sensors in the same group check each other, and the data reliability is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A structural block diagram of a Hall sensor system for magnetic levitation platform motion positioning provided by the present invention;

[0031] Figure 1 In the figure, 1-1 is the coil, 1-2 is the mover platform, and 1-3 is the permanent magnet array / stator platform;

[0032] Figure 2 A schematic diagram of the magnetization direction of the permanent magnet array provided by the present invention;

[0033] Figure 3 A schematic diagram of the installation method of a single set of Hall sensors provided by the present invention;

[0034] Figure 3 In the figure, 3-1 is a linear Hall sensor and 3-2 is a mover platform;

[0035] Figure 4The present invention provides a flow chart of a method for operating a Hall sensor system for positioning the movement of a magnetic levitation platform. DETAILED DESCRIPTION

[0036] Specific implementation method 1: Combination Figure 1-3 This embodiment is described as follows. Figure 1-3 As shown, the structure of a Hall sensor system for movement and positioning of a magnetic levitation platform described in this embodiment includes a mover assembly and a stator assembly;

[0037] The mover assembly includes a mover platform (1-2), a coil (1-1) and a linear Hall sensor (3-1);

[0038] The stator assembly includes a Halbach permanent magnet array (1-3) and a base platform.

[0039] The coil (1-1) is divided into three groups, such as Figure 3 As shown, the linear Hall sensors (3-1) form a 5×5 Hall sensor matrix, which is installed on the mover platform (1-2). Four adjacent permanent magnets in the X or Y direction form a period in that direction, and the installation spacing between adjacent sensors is τ / 4, which corresponds to the phase difference π / 2 of the sinusoidal magnetic field generated by the Halbach magnet array.

[0040] A mover platform (1-2) is provided on a Halbach permanent magnet array (1-3), each set of coils (1-1) is vertically mounted on the mover platform (1-2), and the Halbach permanent magnet array (1-3) adopts neodymium iron boron NdFe35 material.

[0041] Specific implementation method 2: Combination Figure 4 This embodiment describes a method for operating a Hall sensor system for positioning a magnetic levitation platform, including the following steps:

[0042] S1: Combine two adjacent sensors in the Hall sensor matrix to form 40 measurement pairs and obtain the phase value of each pair of Hall sensors;

[0043] S101: Two adjacent sensors in the Hall sensor matrix form a measurement pair. The corresponding values of the return values of the two sensors in each pair of sensors, after controlling the motion platform to rotate around the z-axis, the x-axis, and the y-axis, are calculated by taking the arc tangent of the return value of a sensor measurement pair to obtain a certain phase value. A sensor matrix has a total of 40 measurement pairs, that is, 40 phase values.

[0044] S2: Divide the Hall sensor matrix into five groups along the x-axis and y-axis, calculate the mutual differences of the four phase values in each row or column, and determine whether the mover has an angle deviation relative to the stator based on the mutual differences, completing the abnormality detection of the Hall sensor system;

[0045] S201: Compare the differences between the four phase values and π / 2. In the absence of rotation, the four phase values in the same row or column should differ by π / 2. Fit the adjacent phase values of each group of phase values with a difference of π / 2 to reduce the error. In addition, during the axial translation of the mover within one cycle, the arc tangent phase value obtained based on the measured value returned by the same measurement pair changes linearly during the uniform motion. During the motion, when the phase value jumps discontinuously, if the phase jumps from 2π to 0, the cycle number is increased by 1, and the moving distance is increased by one cycle length; if the phase jumps from 0 to 2π, the cycle number is reduced by 1, and the moving distance is reduced by one cycle length τ. Combined with the linear change of the phase value during the uniform motion, the total displacement of the measuring point is obtained.

[0046] The expression of the linear change of the measurement point during uniform motion is:

[0047] x=ατ / 2π(1);

[0048] In formula (1), x is the moving distance, α is the phase value of the Hall sensor measurement pair, and τ is the length of the magnet array in one cycle;

[0049] The total displacement of the measuring point is calculated as:

[0050] X=nτ+x(2);

[0051] In formula (2), X is the total displacement and n is the number of cycles.

[0052] S202: If the difference between the four phase values is not equal to π / 2, it is determined that the sensor is damaged or the stator is rotating, and the abnormality detection of the Hall sensor system is completed;

[0053] S3: Starting from the initial position, the positioning method obtained by S2 has a displacement curve of adjacent periods connected end to end in the XY plane on the entire stator platform. The movement distance X along a certain direction is monotonically linearly related to α+2nπ, realizing a one-to-one correspondence to determine the movement distance. The position of the measurement point relative to the stator platform can be determined one by one by the phase value matrix, and the relative movement speed and acceleration of the stator platform are calculated according to the phase value change rate of each point, which is used as the prediction information of the motion control module.

[0054] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement of the above embodiments made according to the technical essence of the present invention, within the spirit and principles of the present invention, without departing from the content of the technical solution of the present invention, shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for operating a Hall sensor system for positioning a magnetic levitation platform, characterized in that: The system to which the Hall sensor system operation method is applied includes: mover assembly and stator assembly; The mover assembly comprises a mover platform (1-2), a coil (1-1) and a linear Hall sensor (3-1); The coil (1-1) is divided into three groups, and the linear Hall sensor (3-1) is composed of A Hall sensor matrix is mounted on the mover platform (1-2), and the spacing between two adjacent linear Hall sensors (3-1) in the Hall sensor matrix is one quarter of the magnet array period; The stator assembly includes a Halbach permanent magnet array (1-3) and a base platform; A mover platform (1-2) is provided on the Halbach permanent magnet array (1-3), and each set of coils (1-1) is vertically mounted on the mover platform (1-2); The Hall sensor system operation method specifically includes: S1: Combine two adjacent sensors in the Hall sensor matrix to form 40 measurement pairs and obtain the phase value of each pair of Hall sensors; The phase value of each pair of Hall sensors is obtained in S1 specifically including: After controlling the motion stage to rotate around the z-axis, the x-axis, and the y-axis, the return value of a Hall sensor measurement pair is taken as the arc tangent to obtain the phase value of the measurement point; S2: Divide the Hall sensor matrix into five groups along the x-axis and y-axis, calculate the mutual differences of the four phase values in each row or column, and determine whether the mover has an angle deviation relative to the stator based on the mutual differences, completing the abnormality detection of the Hall sensor system; The steps for abnormality detection of the Hall sensor system in S2 include: S201: sum the differences of the four phase values contrast; S202: If the difference between the four phase values is equal to , it is determined that the movable platform has no rotation angle, and the error of each phase value is eliminated. The linear change of the measuring point in the uniform motion process is calculated based on the phase value after the error is eliminated. During the motion of the measuring point, when the phase value jumps discontinuously, if the phase value jumps discontinuously, If it jumps to 0, the number of cycles will increase by 1, and the moving distance will be increased by the length of the magnet array in one cycle. ; If the phase jumps from 0 to Then the number of cycles is reduced by 1, and the moving distance is reduced by the length of the magnet array of one cycle. , combined with the linear change of the measuring point during uniform motion, the total displacement of the measuring point is calculated; S203: If the difference between the four phase values is not equal to , it is determined that the sensor is damaged or the stator is rotating, and the abnormality detection of the Hall sensor system is completed; The expression of the linear change of the measurement point during uniform motion is: （1）； In formula (1), is the moving distance, is the phase value of the Hall sensor measurement pair, is the length of the magnet array for one period; The total displacement of the measuring point is calculated as: （2）； In formula (2), is the total displacement, is the number of cycles; S3: Calculate the predicted result of the magnetic levitation platform movement based on the phase value after the anomaly detection; A displacement curve is drawn based on the total displacement of the measurement point, and the displacement curves of the measurement points in adjacent periods within the XY platform on the stator platform are connected to obtain the position of the measurement point relative to the stator platform. The relative motion speed and acceleration of the stator platform are calculated based on the phase value change rate of each measurement point to complete the motion positioning of the magnetic levitation platform.

2. The method for operating a Hall sensor system for magnetic levitation platform motion positioning according to claim 1, characterized in that: Eliminating the error of each phase value group in S202 specifically includes: performing phase difference calculation on adjacent phase values of each phase value group. The fitting of .

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