Displacement device of magnetic suspension planar motor

Abstract

The utility model discloses a displacement device of a magnetic suspension planar motor, which comprises a stator and a rotor, the stator is provided with a magnet array, reading heads and a spectrum confocal displacement sensor, the magnet array extends along a horizontal plane, the reading heads comprise at least one first reading head and at least one second reading head, and the spectrum confocal displacement sensor is arranged on the stator. The at least three spectrum confocal displacement sensors are arranged in a non-collinear manner; the rotor is provided with a first array three-phase coil, a second array three-phase coil and a plane grating; wherein in the moving process of the rotor, the plane grating is always located in the reading range of the at least one first reading head and the at least one second reading head and above the at least three non-collinear spectrum confocal displacement sensors. According to the displacement device of the magnetic suspension planar motor, the planar grating can be used as a unified measurement reference, so that the motion control precision of a system can be effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of magnetic levitation planar motors, and in particular to a displacement device of a magnetic levitation planar motor. Background Art

[0002] In the related technology, the magnetic levitation planar motor motion platform is mainly used in semiconductor equipment, such as photolithography machines, wafer cutting machines, etc. Its characteristic is that it can ensure the precision movement of micro-nano precision to achieve accurate processing of wafers. The displacement measurement system of the traditional planar motor motion platform, whether it uses a laser interferometer or a scale, an eddy current displacement sensor or a Hall sensor, etc., the measured objects are not uniform, and different measurement bases themselves have certain errors, which affects the motion control accuracy of the system. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a displacement device of a magnetically suspended planar motor, which can use a planar grating as a unified measurement reference, thereby effectively improving the motion control accuracy of the system.

[0004] According to the displacement device of the magnetic levitation planar motor of the embodiment of the utility model, it includes: a stator and a mover, the stator is provided with a magnet array, a reading head and a spectral confocal displacement sensor, the magnet array extends along the horizontal plane, the reading head includes at least one first reading head and at least one second reading head, and the spectral confocal displacement sensor is provided with at least three and non-collinear arrangements; the mover is provided with a first array of three-phase coils, a second array of three-phase coils and a plane grating; wherein the first reading head is used to read the coordinates of the plane grating along the first direction, and the second reading head is used to read the coordinates of the plane grating along the second direction, and during the movement of the mover, the plane grating is always located within the reading range of at least one first reading head, at least one second reading head and above the at least three non-collinear spectral confocal displacement sensors, and the first direction and the second direction are orthogonal and are both along the horizontal direction.

[0005] The displacement device of the magnetically levitated planar motor according to the embodiment of the utility model has at least the following beneficial effects: the displacement device of the magnetically levitated planar motor comprises a stator and a mover, the mover is provided with a first array of three-phase coils, a second array of three-phase coils and a plane grating, and the stator is provided with a magnet array, a reading head and a spectral confocal displacement sensor; the first array of three-phase coils is used to interact with the magnet array and generate thrust along the first direction and the vertical direction, and the second array of three-phase coils is used to interact with the magnet array and generate thrust along the second direction and the vertical direction, so that the mover can be suspended above the stator; the first reading head is used to read the coordinates of the plane grating along the first direction, and the second reading head is used to read the coordinates of the plane grating along the second direction, so as long as there is always a first reading head and a second reading head located below the plane grating, the translation of the mover in the first direction and the second direction can be calculated and controlled according to the coordinates of the read plane grating in the first direction and the second direction; the stator is provided with at least Three non-collinear spectral confocal displacement sensors, as long as there are always three non-collinear spectral confocal displacement sensors located below the plane grating, the three spectral confocal displacement sensors can respectively read the coordinates of the three positions on the plane grating surface corresponding to them, determine a plane according to the three non-collinear points, and feed back at least three vertical displacement signals to the control system. The control system can control the vertical translation of the mover, as well as the rotation around the first direction and the second direction. That is to say, no matter whether the coordinates of the mover in the first direction, the second direction or the vertical direction are read, the plane grating is used as a unified object to be measured, thereby achieving a unified measurement reference; therefore, the displacement device of the magnetic levitation planar motor of the present application can use the plane grating as a unified measurement reference, thereby effectively improving the motion control accuracy of the system. In addition, by using spectral confocal displacement sensors instead of Hall sensors, eddy current displacement sensors, etc., the measurement accuracy in the vertical direction can be greatly improved.

[0006] According to some embodiments of the utility model, the reading head includes at least one first reading head and at least two second reading heads, and the plane grating is always located above the at least one first reading head and the at least two second reading heads; or, the reading head includes at least two first reading heads and at least one second reading head, and the plane grating is always located above the at least two first reading heads and at least one second reading head.

[0007] According to some embodiments of the present invention, the magnet array is a two-dimensional Halbach array.

[0008] According to some embodiments of the utility model, the first array of three-phase coils includes a first three-phase coil group and a second three-phase coil group, the second array of three-phase coils includes a third three-phase coil group and a fourth three-phase coil group, and the first three-phase coil group, the third three-phase coil group, the second three-phase coil group and the fourth three-phase coil group are arranged in a quadrilateral shape outside the plane grating.

[0009] According to some embodiments of the present invention, the plane grating is in the shape of a right-angled quadrilateral, and the plane grating includes horizontal stripes and vertical stripes that are arranged perpendicularly and crosswise to each other.

[0010] According to some embodiments of the present invention, the plane grating is an incremental plane grating.

[0011] According to some embodiments of the utility model, the plane grating is provided with at least two positioning marks, and the stator is correspondingly provided with at least two positioning cameras, and the positioning cameras are used to calibrate the zero position of the first reading head and the second reading head.

[0012] According to some embodiments of the present invention, the two positioning marks are respectively located near two vertices of the diagonal plane grating.

[0013] According to some embodiments of the present invention, the pattern of the positioning mark is a concentric circle with a crosshair inside.

[0014] According to some embodiments of the present invention, four positioning marks are provided and are respectively located near four vertices of the plane grating.

[0015] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0017] Figure 1 It is a top view of one embodiment of the displacement device of the magnetic levitation planar motor of the utility model;

[0018] Figure 2 for Figure 1 A top view of the displacement device of the magnetically suspended planar motor shown in , with the mover removed;

[0019] Figure 3 for Figure 1 A top view of the planar grating in the displacement device of the magnetically levitated planar motor shown in FIG.

[0020] Reference numerals:

[0021] Stator 100; magnet array 110; mover 200; first three-phase coil group 210; second three-phase coil group 220; third three-phase coil group 230; fourth three-phase coil group 240; first reading head 310; second reading head 320; first spectral confocal displacement sensor 410; second spectral confocal displacement sensor 420; third spectral confocal displacement sensor 430; fourth spectral confocal displacement sensor 440; plane grating 500; first positioning mark 510; second positioning mark 520; third positioning mark 530; fourth positioning mark 540; first positioning camera 610; second positioning camera 620. DETAILED DESCRIPTION

[0022] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0023] In the description of the present application, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0024] In the description of this application, "several" means more than one, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0025] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0026] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0027] Reference below Figures 1 to 3 The present invention describes a displacement device of a magnetically suspended planar motor according to an embodiment of the present invention.

[0028] like Figures 1 to 3 As shown, the displacement device of the magnetic levitation planar motor according to the embodiment of the utility model includes: a stator 100 and a mover 200, the stator 100 is provided with a magnet array 110, a reading head and a spectral confocal displacement sensor, the magnet array 110 extends along the horizontal plane, the reading head includes at least one first reading head 310 and at least one second reading head 320, and the spectral confocal displacement sensor is provided with at least three and non-collinear arrangements; the mover 200 is provided with a first array three-phase coil, a second array three-phase coil and a plane grating 500; wherein the first reading head 310 is used to read the coordinates of the plane grating 500 along the first direction, and the second reading head 320 is used to read the coordinates of the plane grating 500 along the second direction, and during the movement of the mover 200, the plane grating 500 is always located within the reading range of at least one first reading head 310, at least one second reading head 320 and above at least three non-collinear spectral confocal displacement sensors, and the first direction and the second direction are orthogonal and are both along the horizontal direction.

[0029] It can be understood that the displacement device of the magnetically suspended planar motor includes a stator 100 and a mover 200, the mover 200 is provided with a first array of three-phase coils, a second array of three-phase coils and a plane grating 500, and the stator 100 is provided with a magnet array, a reading head and a spectral confocal displacement sensor; the first array of three-phase coils is used to interact with the magnet array and generate thrust along the first direction and the vertical direction, and the second array of three-phase coils is used to interact with the magnet array 110 and generate thrust along the second direction and the vertical direction, so that the mover 200 can be suspended above the stator 100; the first reading head 310 is used to read the coordinates of the plane grating 500 along the first direction, and the second reading head 320 is used to read the coordinates of the plane grating 500 along the second direction, so as long as there is always a first reading head 310 and a second reading head 320 located below the plane grating 500, according to the read coordinates of the plane grating 500 in the first direction and the second direction, the translation of the mover 200 in the first direction and the second direction can be calculated and controlled; the stator 100 At least three non-collinear spectral confocal displacement sensors are provided. As long as there are always three non-collinear spectral confocal displacement sensors located below the plane grating 500, the three spectral confocal displacement sensors can respectively read the coordinates of the three positions on the surface of the plane grating 500 corresponding to them in the vertical direction, determine a plane according to the three non-collinear points, and feed back at least three vertical displacement signals to the control system. The control system can control the vertical translation of the mover 200, as well as the rotation around the first direction and the second direction. That is to say, no matter whether the coordinates of the mover 200 in the first direction, the second direction or the vertical direction are read, the plane grating 500 is used as a unified measured object, thereby achieving a unified measurement reference; therefore, the displacement device of the magnetic levitation planar motor of the present application can use the plane grating 500 as a unified measurement reference, thereby effectively improving the motion control accuracy of the system. In addition, by using spectral confocal displacement sensors instead of Hall sensors, eddy current displacement sensors, etc., the measurement accuracy in the vertical direction can be greatly improved.

[0030] When the combined force of the first thrust and the second thrust is balanced with the gravity of the mover 200 , the mover 200 can be suspended.

[0031] Specifically, in this embodiment, the stator 100 is provided with four spectral confocal displacement sensors and is always located below the plane grating 500. The four spectral confocal displacement sensors are respectively a first spectral confocal displacement sensor 410, a second spectral confocal displacement sensor 420, a third spectral confocal displacement sensor 430 and a fourth spectral confocal displacement sensor 440, and the positions of the four spectral confocal displacement sensors are quadrilateral. During the movement of the mover 200, the four spectral confocal displacement sensors respectively read the displacement signals of the plane grating 500 surface in the vertical direction corresponding to their positions.

[0032] It can be understood that the reading head includes at least one first reading head 310 and at least two second reading heads 320, and the plane grating 500 is always located above the at least one first reading head 310 and the at least two second reading heads 320; or, the reading head includes at least two first reading heads 310 and at least one second reading head 320, and the plane grating 500 is always located above the at least two first reading heads 310 and the at least one second reading head 320. For example, Figure 2 As shown, in the present embodiment, that is, at least three reading heads in different directions are located below the plane grating 500, when a first reading head 310 and a second reading head 320 are added, the translational motion of the mover 200 in the first direction and the second direction can be calculated and controlled according to the read coordinate values ​​of the first direction and the second direction. By adding a first direction reading head or a second direction reading head, the translational motion of the mover 200 in the first direction and the second direction and the rotation around the vertical direction can be controlled through the displacement signals read by the three reading heads.

[0033] It is understood that the magnet array 110 is a two-dimensional Halbach array. Figure 1 to Figure 2 As shown, in this embodiment, a plurality of N magnets, S magnets and H magnets are arranged in a two-dimensional Halbach manner along a horizontal plane in a periodic arrangement. That is, an H magnet is provided between adjacent N magnets and S magnets, and the magnetization direction of the H magnet points to the N magnet. The angle between the arrangement direction of the magnets NHSHNHSH and the first direction is α=π / 4.

[0034] It can be understood that the first array of three-phase coils includes a first three-phase coil group 210 and a second three-phase coil group 220, and the second array of three-phase coils includes a third three-phase coil group 230 and a fourth three-phase coil group 240. The first three-phase coil group 210, the third three-phase coil group 230, the second three-phase coil group 220 and the fourth three-phase coil group 240 are arranged in a quadrilateral shape outside the plane grating 500. For example, Figure 1 As shown, in this embodiment, the first three-phase coil group 210, the third three-phase coil group 230, the second three-phase coil group 220 and the fourth three-phase coil group 240 are sequentially arranged outside the plane grating 500, so that the first three-phase coil group 210, the second three-phase coil group 220, the third three-phase coil group 230, the fourth three-phase coil group 240 and the plane grating 500 are basically located in the same plane, thereby ensuring the interaction effect between the coil group and the magnet array 110 at a smaller height, and realizing the mutual cooperation between the reading head, the spectral confocal displacement sensor and the plane grating 500.

[0035] Specifically, the mover 200 is roughly in a right-angled quadrilateral structure, and the first three-phase coil group 210, the second three-phase coil group 220, the third three-phase coil group 230 and the fourth three-phase coil group 240 are respectively arranged on the four sides of the right-angled quadrilateral to form a square shape, and the plane grating 500 is arranged in the center area of ​​the square shape. The first three-phase coil group 210 and the second three-phase coil group 220 are respectively arranged on a set of opposite sides of the quadrilateral of the mover 200, and the third three-phase coil group 230 and the fourth three-phase coil group 240 are respectively arranged on the other set of opposite sides of the quadrilateral of the mover 200. The three-phase coil groups are preferably arranged on the same plane. The first three-phase coil group 210 and the second three-phase coil group 220 interact with the magnet array 110 to generate thrust in the first direction and thrust in the vertical direction. The third three-phase coil group 230 and the fourth three-phase coil group 240 interact with the magnet array 110 to generate thrust in the second direction and thrust in the vertical direction, thereby driving the mover 200 to move in six degrees of freedom in the working area, namely, translation in the first direction, the second direction, and the vertical direction, and rotation around the first direction, the second direction, and the vertical direction.

[0036] It can be understood that the plane grating 500 is in the shape of a rectangular quadrilateral, and the plane grating 500 includes horizontal stripes and vertical stripes that are arranged perpendicularly and crosswise to each other. Figure 3 As shown, in this embodiment, specifically, the width of the horizontal stripes and the vertical stripes are both b, and the center distance between two adjacent horizontal and vertical stripes is 2b.

[0037] It can be understood that the plane grating 500 is an incremental plane grating 500. For example, Figures 1 to 3 As shown, in this embodiment, the plane grating 500 is an incremental plane grating 500. In some other embodiments, the plane grating 500 may also be an absolute value grating.

[0038] It can be understood that the plane grating 500 is provided with at least two positioning marks, and the stator 100 is correspondingly provided with at least two positioning cameras, and the positioning cameras are used to calibrate the zero position of the first reading head 310 and the second reading head 320. Figures 1 to 3 As shown, in this embodiment, in the incremental plane grating 500 system, it is necessary to first set two positioning marks in the plane grating 500. The function of the two positioning cameras on the stator 100 is to calibrate the zero position of the first direction and the second direction reading head of the plane grating 500. When the centers of the two positioning marks are respectively in specific areas of the field of view of the two positioning cameras, the corresponding zero positions of the first direction and the second direction reading heads are determined.

[0039] It can be understood that the two positioning marks are respectively located near two vertices of the planar grating 500. Figures 2 to 3As shown, in this embodiment, two diagonal positions are preferably used as two positioning marks: the positions of the first positioning mark 510 and the second positioning mark 520. The positions of the two positioning cameras correspond to the positions of the two positioning marks, respectively, so that more accurate positioning can be obtained through a longer distance.

[0040] It is understandable that the pattern of the positioning mark is a concentric circle with a crosshair inside. Figure 3 As shown, in this embodiment, when two positioning marks are set, the pattern of the positioning marks is a circle with an inscribed crosshair, which can facilitate the two positioning cameras to confirm the zero position.

[0041] It can be understood that there are four positioning marks, and they are respectively located near the four vertices of the plane grating 500. Figure 3 As shown, in this embodiment, a first positioning mark 510 , a second positioning mark 520 , a third positioning mark 530 and a fourth positioning mark 540 are respectively arranged near the four vertices of the plane grating 500 .

[0042] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present application. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. A displacement device for a magnetically suspended planar motor, characterized in that: include: A stator, wherein the stator is provided with a magnet array, a reading head and a spectral confocal displacement sensor, the magnet array extends along a horizontal plane, the reading head includes at least one first reading head and at least one second reading head, and the spectral confocal displacement sensor is provided with at least three and is not arranged in a colinear manner; A mover, wherein the mover is provided with a first array of three-phase coils, a second array of three-phase coils and a plane grating; wherein, The first reading head is used to read the coordinates of the plane grating along the first direction, and the second reading head is used to read the coordinates of the plane grating along the second direction. During the movement of the mover, the plane grating is always located above at least one of the first reading head, at least one of the second reading head and at least three non-collinear spectral confocal displacement sensors, and the first direction and the second direction are orthogonal and are both along the horizontal direction.

2. The displacement device of the magnetically suspended planar motor according to claim 1, characterized in that: The reading head includes at least one first reading head and at least two second reading heads, and the plane grating is always located above the at least one first reading head and the at least two second reading heads; or, the reading head includes at least two first reading heads and at least one second reading head, and the plane grating is always located above the at least two first reading heads and at least one second reading head.

3. The displacement device of the magnetically suspended planar motor according to claim 2, characterized in that: The magnet array is a two-dimensional Halbach array.

4. The displacement device of the magnetically suspended planar motor according to claim 3, characterized in that: The first array of three-phase coils includes a first three-phase coil group and a second three-phase coil group, the second array of three-phase coils includes a third three-phase coil group and a fourth three-phase coil group, and the first three-phase coil group, the third three-phase coil group, the second three-phase coil group and the fourth three-phase coil group are arranged in a quadrilateral shape outside the plane grating.

5. The displacement device of the magnetically suspended planar motor according to claim 3, characterized in that: The plane grating is in the shape of a right-angled quadrilateral and includes horizontal stripes and vertical stripes that are arranged perpendicularly and crosswise to each other.

6. The displacement device of the magnetically suspended planar motor according to claim 5, characterized in that: The plane grating is an incremental plane grating.

7. The displacement device of the magnetically suspended planar motor according to claim 6, characterized in that: The plane grating is provided with at least two positioning marks, and the stator is correspondingly provided with at least two positioning cameras, and the positioning cameras are used to calibrate the zero position of the first reading head and the second reading head.

8. The displacement device of the magnetically suspended planar motor according to claim 7, characterized in that: The two positioning marks are respectively located near two vertices of the diagonal corners of the plane grating.

9. The displacement device of the magnetically suspended planar motor according to claim 8, characterized in that: The pattern of the positioning mark is a concentric circle with a crosshair inside.

10. The displacement device of the magnetically suspended planar motor according to claim 7, characterized in that: There are four positioning marks, which are respectively located near the four vertices of the plane grating.

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