Hall sensor system for movement positioning of magnetic levitation platform and operation method

Abstract

The invention provides a Hall sensor system for magnetic levitation platform motion positioning and an operation method, the system comprises a rotor assembly and a stator assembly, the rotor assembly comprises a rotor platform (1-2), a coil (1-1) and a linear Hall sensor (3-1); the stator assembly comprises a Halbach permanent magnet array (1-3) and a basic platform. The linear Hall sensor array is adopted to replace a common laser range finder to measure the relative position of the rotor, and the measurement range is not limited by the stroke; the Hall sensor matrix is adopted to measure displacement and detect whether the rotor has a rotation angle relative to the stator, five Hall sensors in the same group detect each other, and the data reliability is higher.

Description

Technical Field

[0001] The invention relates to a Hall sensor system and an operating method for positioning the movement 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 developed rapidly and become a strategic industry that drives the growth of the world economy. The manufacture of various semiconductor devices with integrated circuits as the core is the foundation and leader of the electronic information industry. The requirements for processing equipment in precision instrument manufacturing are getting higher and higher. The positioning accuracy directly affects the accuracy of the size to be processed. Improving positioning accuracy can not only be achieved by improving the accuracy and resolution of sensors, but also by path prediction. Due to the non-contact characteristics of the magnetic levitation system, it is widely used in clean environment systems, high-precision positioning and high-speed transportation systems. Based on the above background, the research on the positioning accuracy of the magnetic levitation motion platform has certain development prospects.

[0003] The Hall sensor is a sensor based on the Hall effect, which is widely used in the measurement of electromagnetic, pressure, acceleration, vibration, etc. It is characterized by small size, low power consumption, long life, easy installation, corrosion and pollution resistance. It is not only suitable for moving iron magnetic levitation motion platform but also for moving coil magnetic levitation platform with small load weight and cable interference. Compared with laser sensors that locate by distance or displacement, the Hall sensor measures the position based on the magnetic induction intensity generated by the permanent magnet structure inherent in the stator or mover of the magnetic levitation motion platform, so it has a wider measurement range, and the structure and installation method are relatively simple. 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 motion positioning of a 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 positioning the motion of a magnetic levitation platform, comprising:

[0006] The mover assembly comprises 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 spacing 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 group 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 5 groups according to the x-axis and y-axis respectively, calculate the mutual difference of the four phase values ​​in each row or column, and judge whether the mover has an angle deviation relative to the stator according to the mutual difference, so as to complete the abnormal detection of the Hall sensor system;

[0013] S3: The predicted result of the movement of the magnetic levitation platform is obtained according to 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 the motion stage is controlled 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 of the four phase values ​​with 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 the error of each group of phase values ​​is eliminated. The linear change of the measuring point in the uniform motion process is calculated according to the phase value after the error of the measuring point is eliminated. 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 of the measuring point in the uniform motion process, 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, the 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 movement of the magnetic levitation platform obtained in S3 specifically includes:

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

[0029] The beneficial effects of the present invention are as follows: the Hall sensor is easy to install and use, and the hardware cost is low. The present invention adopts a linear Hall sensor array to replace the commonly used laser rangefinder to measure the relative position of the mover, and the measuring 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 relative to the stator. 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 positioning the motion of a magnetic levitation platform provided by the present invention;

[0031] Figure 1 In the figure, 1-1 is a coil, 1-2 is a mover platform, and 1-3 is a 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 motion of a magnetic levitation platform. DETAILED DESCRIPTION

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

[0037] The mover assembly comprises 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, and the Hall sensor matrix is ​​installed on the mover platform (1-2). Four adjacent permanent magnets in the X or Y direction are a period in this direction, and the installation spacing of 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 the Halbach permanent magnet array (1-3), each group of coils (1-1) is vertically mounted on the mover platform (1-2), and the Halbach permanent magnet array (1-3) is made of neodymium iron boron NdFe35 material.

[0041] Specific implementation method 2: Combination Figure 4 The present embodiment is described. The steps of a Hall sensor system operation method for positioning the motion of a magnetic levitation platform described in the present embodiment include:

[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, take 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 5 groups according to the x-axis and y-axis respectively, calculate the mutual difference of the four phase values ​​in each row or column, and judge whether the mover has an angle deviation relative to the stator according to the mutual difference, so as to complete the abnormal detection of the Hall sensor system;

[0045] S201: Compare the mutual differences of the four phase values ​​with 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 the process of axial translation of the mover within one cycle, the inverse tangent phase value obtained according to 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 displacement curves of adjacent periods connected end to end in the XY plane on the entire stator platform, and 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 measuring 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 is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. A Hall sensor system for positioning the motion of a magnetic levitation platform, characterized in that: The structure of the Hall sensor system for the motion positioning of the Halbach magnetic levitation platform includes a mover assembly and a stator assembly; The mover assembly comprises a mover platform (1-2), a coil (1-1) and a linear Hall sensor (3-1); The stator assembly comprises a Halbach permanent magnet array (1-3) and a base platform.

2. The Hall sensor system for motion positioning of Halbach magnetic levitation platform according to claim 1, characterized in that: The coils (1-1) are 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.

3. The Hall sensor system for motion positioning of Halbach magnetic levitation platform according to claim 1, characterized in that: A mover platform (1-2) is provided on the Halbach permanent magnet array (1-3), and each group of coils (1-1) is vertically mounted on the mover platform (1-2).

4. A method for operating a Hall sensor system for positioning a magnetic levitation platform, applied to a Hall sensor system for positioning a magnetic levitation platform according to any one of claims 1 to 3, characterized in that: include: 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; S2: Divide the Hall sensor matrix into 5 groups according to the x-axis and y-axis respectively, calculate the mutual difference of the four phase values ​​in each row or column, and judge whether the mover has an angle deviation relative to the stator according to the mutual difference, so as to complete the abnormal detection of the Hall sensor system; S3: The predicted result of the movement of the magnetic levitation platform is obtained according to the phase value after the abnormality detection.

5. The method for operating a Hall sensor system for positioning a magnetic levitation platform according to claim 4, characterized in that: The phase value of each pair of Hall sensors is obtained in S1 specifically including: After the motion stage is controlled 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.

6. The method for operating a Hall sensor system for positioning a magnetic levitation platform according to claim 4, characterized in that: The steps of abnormality detection of the Hall sensor system in S2 include: S201: Compare the differences of the four phase values ​​with π / 2; 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 the error of each group of phase values ​​is eliminated. The linear change of the measuring point in the uniform motion process is calculated according to the phase value after the error of the measuring point is eliminated. 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 of the measuring point in the uniform motion process, the total displacement of the measuring point is calculated; 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; The expression of the linear change of the measurement point during uniform motion is: x = ατ / 2π(1); 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; The total displacement of the measuring point is calculated as: X = nτ + x(2); In formula (2), X is the total displacement and n is the number of cycles.

7. The method for operating a Hall sensor system for positioning a magnetic levitation platform according to claim 6, characterized in that: Eliminating errors for each group of phase values ​​in S202 specifically includes: fitting adjacent phase values ​​of each group of phase values ​​so that they differ by π / 2.

8. The method for operating a Hall sensor system for positioning a magnetic levitation platform according to claim 4, characterized in that: The prediction results of the maglev platform motion obtained in S3 specifically include: The displacement curve is drawn according to the total displacement of the measuring point, and the displacement curves of the measuring points of adjacent periods in the XY platform on the stator platform are connected to obtain the position of the measuring point relative to the stator platform. The relative motion speed and acceleration of the stator platform are calculated according to the phase value change rate of each measuring point to complete the motion positioning of the magnetic levitation platform.

Images