Conveyance system, control method for conveyance system, processing system, article manufacturing method, and motor

Abstract

To provide a conveyance system which can more stably convey a needle in a non-contact state even in the case of a small needle or when arrangement of a stator is largely restricted.SOLUTION: A conveyance system comprises: a needle which has a magnetic substance; a stator which has a plurality of coils arranged along a first direction so that they can face the magnetic substance and applies force to the magnetic substance by the plurality of coils applied with current; and a control unit which controls the current to be applied to the plurality of coils to apply the force in the first direction, a second direction crossing the first direction and a third direction crossing the first direction and the second direction to the magnetic substance.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a conveyance system, a control method for a conveyance system, a processing system, a method for manufacturing an article, and a motor. [Background technology]

[0002] Conveyance systems are generally used in production lines for assembling industrial products, semiconductor exposure equipment, and the like. Conveyance systems in production lines, in particular, transport workpieces such as parts between multiple stations within factory-automated production lines or between production lines. They may also be used as conveyance devices within process equipment. Conveyance systems using moving magnet linear motors have already been proposed.

[0003] Conveyance systems using moving magnet linear motors are constructed using guide devices involving mechanical contact, such as linear guides. However, conveyance systems using guide devices such as linear guides have the problem of reduced productivity due to contaminants generated from the sliding parts of the linear guide, such as wear debris from rails and bearings, lubricating oil, and volatilized lubricating oil. Another problem is that high-speed conveyance increases friction in the sliding parts, shortening the lifespan of the linear guide.

[0004] Therefore, Patent Document 1 describes a magnetic levitation type transport system capable of transporting a mover without contact. In the transport system described in Patent Document 1, a plurality of permanent magnets are arranged on the mover in the transport direction so that the polarities of their magnetic poles alternate, and a plurality of magnets are arranged in a direction intersecting the transport direction so that the polarities of their magnetic poles alternate. The transport system described in Patent Document 1 transports the mover by applying independent forces on six axes to the mover using a plurality of coils to which currents are applied. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-28212 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the conveyance system described in Patent Document 1, the magnet areas are divided in a plane in the conveyance direction and in the direction perpendicular to that, which causes a bias in the force per unit current applied to the coil. As a result, the conveyance system described in Patent Document 1 may have difficulty in stably conveying the mover, especially in the case of a small mover or when there are significant constraints on the arrangement of the stators.

[0007] An object of the present invention is to provide a conveying system that can convey a mover more stably in a non-contact state even in the case of a small mover or when there are significant restrictions on the arrangement of the stators. [Means for solving the problem]

[0008] According to one aspect of the present invention, there is provided a conveying system comprising: a mover having a magnetic body; a stator having a plurality of coils arranged along a first direction so as to be able to face the magnetic body, and applying a force to the magnetic body by the plurality of coils to which a current is applied; and a control unit that controls the current applied to the plurality of coils to apply the force to the magnetic body in the first direction, a second direction intersecting the first direction, and a third direction intersecting the first direction and the second direction.

[0009] According to another aspect of the present invention, there is provided a control method for a conveying system having a mover having a magnetic body, and a stator having a plurality of coils arranged to face the magnetic body along a first direction, and applying a force to the magnetic body by the plurality of coils to which a current is applied, the control method being characterized in that the current applied to the plurality of coils is controlled to apply the force to the magnetic body in the first direction, a second direction intersecting the first direction, and a third direction intersecting the first direction and the second direction. [Effects of the Invention]

[0010] According to the present invention, even in the case of a small mover or when there are significant restrictions on the arrangement of the stators, the mover can be transported more stably in a non-contact state. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing a configuration of a transport system according to a first embodiment of the present invention. [Figure 2] 1 is a schematic diagram showing a configuration of a transport system according to a first embodiment of the present invention. [Figure 3] 1 is a schematic diagram showing a coil and a configuration related to the coil in a transport system according to a first embodiment of the present invention. FIG. [Figure 4] FIG. 1 is a schematic diagram showing a control system for controlling a transfer system according to a first embodiment of the present invention. [Figure 5] 3A and 3B are schematic diagrams illustrating a method for controlling the attitude of a mover in the transfer system according to the first embodiment of the present invention. [Figure 6] 3 is a schematic diagram showing an example of a control block for controlling the position and attitude of a mover in the transfer system according to the first embodiment of the present invention. FIG. [Figure 7A] 3 is a schematic view showing a magnetic body installed in a mover in the transport system according to the first embodiment of the present invention. FIG. [Figure 7B] 3 is a schematic view showing a magnetic body installed in a mover in the transport system according to the first embodiment of the present invention. FIG. [Figure 7C] 4 is a graph schematically showing thrust constant profiles in the q-axis direction, the d-axis direction, and the Y-axis direction in the transfer system according to the first embodiment of the present invention. [Figure 7D] 3 is a schematic view showing a magnetic body installed in a mover in the transport system according to the first embodiment of the present invention. FIG. [Figure 8] 1 is a plan view showing a configuration of a transport system according to a first embodiment of the present invention. [Figure 9A] FIG. 10 is a schematic view showing a magnetic body installed on a mover in a transport system according to a second embodiment of the present invention. [Figure 9B] 10 is a graph schematically showing thrust constant profiles in the q-axis direction, the d-axis direction, and the Y-axis direction in the transfer system according to the second embodiment of the present invention. [Figure 10A] FIG. 10 is a plan view showing the configuration of a transport system according to a second embodiment of the present invention. [Figure 10B] FIG. 10 is a plan view showing another configuration of the transport system according to the second embodiment of the present invention. [Figure 11] FIG. 10 is a schematic view showing a magnetic body provided on a mover in a transport system according to a third embodiment of the present invention. [Figure 12A] FIG. 10 is a schematic view showing a magnetic body installed in a mover in a transport system according to a fourth embodiment of the present invention. [Figure 12B] FIG. 10 is a schematic view showing a magnetic body installed in a mover in a transport system according to a fourth embodiment of the present invention. [Figure 12C] FIG. 10 is a schematic view showing a magnetic body installed in a mover in a transport system according to a fourth embodiment of the present invention. [Figure 12D] FIG. 10 is a schematic view showing a magnetic body installed in a mover in a transport system according to a fourth embodiment of the present invention. [Figure 13A] FIG. 10 is a schematic view showing a rotating device according to a fifth embodiment of the present invention. [Figure 13B] FIG. 10 is a schematic view showing a rotating device according to a fifth embodiment of the present invention. [Figure 13C]FIG. 10 is a schematic diagram showing coordinate axes and directions used to explain a rotating device according to a fifth embodiment of the present invention. [Figure 14] FIG. 10 is a schematic diagram illustrating a method for calculating the displacement of the rotor in the rotating device according to the fifth embodiment of the present invention. [Figure 15A] FIG. 10 is a schematic diagram illustrating a fifth embodiment of the present invention. [Figure 15B] FIG. 10 is a schematic diagram illustrating a fifth embodiment of the present invention. [Figure 15C] FIG. 10 is a schematic diagram illustrating a fifth embodiment of the present invention. [Figure 15D] FIG. 10 is a schematic diagram illustrating a fifth embodiment of the present invention. [Figure 16] FIG. 10 is a schematic diagram showing a control unit of a rotating device according to a fifth embodiment of the present invention. [Figure 17] FIG. 10 is a schematic diagram showing an example of a control block for controlling the position and attitude of a rotor in a rotating device according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] [First embodiment] A first embodiment of the present invention will be described below with reference to FIGS.

[0013] First, the configuration of a conveyance system 1 according to this embodiment will be described with reference to Figs. 1 to 3. Figs. 1 and 2 are schematic diagrams showing the configuration of a conveyance system 1 including a mover 101 and a stator 201 according to this embodiment. Note that Figs. 1 and 2 show only the main parts of the mover 101 and the stator 201, respectively. Fig. 1 is a view of the mover 101 seen from diagonally above, and Fig. 2 is a view of the mover 101 and the stator 201 seen from the X direction, which will be described later. Fig. 3 is a schematic diagram showing a coil 202 and a configuration related to the coil 202 in the conveyance system 1.

[0014] As shown in FIGS. 1 and 2 , a conveying system 1 according to this embodiment includes a mover 101 constituting a carrier, a carriage, or a slider, and a stator 201 constituting a conveying path. The conveying system 1 also includes an integrated controller 301, a coil controller 302, a coil unit controller 303, and a sensor controller 304. Note that FIG. 1 illustrates three movers 101a, 101b, and 101c as the mover 101, and two stators 201a and 201b as the stator 201. Hereinafter, when there is no need to distinguish between multiple possible components such as the mover 101 and the stator 201, a common numeral is used, and lowercase letters are added after the numerals to distinguish between them as needed. Furthermore, when distinguishing between the right-side and left-side components of the mover 101, a lowercase letter R indicating the right side or L indicating the left side is added after the lowercase letter.

[0015] The conveyance system 1 according to this embodiment is a conveyance system using an induction linear motor that conveys the mover 101 by generating an electromagnetic force between the coil 202 of the stator 201 and the magnetic body 103 of the mover 101. The conveyance system 1 according to this embodiment is also a magnetic levitation type conveyance system that levitates the mover 101 and conveys it in a non-contact manner. The conveyance system 1 according to this embodiment constitutes a part of a processing system that also has a process device that processes the workpiece 102 conveyed by the mover 101.

[0016] The transport system 1 transports the mover 101 by, for example, the stator 201, thereby transporting the workpiece 102 held by the mover 101 to a process device that performs a processing operation on the workpiece 102. The process device is not particularly limited, but is, for example, a film formation device such as a vapor deposition device or a sputtering device that forms a film on a glass substrate, which is the workpiece 102. Note that although FIG. 1 shows three movers 101 for two stators 201, the present invention is not limited to this. In the transport system 1, one or more movers 101 can be transported on one or more stators 201.

[0017] Here, we define the coordinate axes, directions, and the like used in the following description. First, the X-axis is taken along the horizontal direction, which is the transport direction of the mover 101, and the transport direction of the mover 101 is taken as the X-direction. The Z-axis is taken along the vertical direction, which is perpendicular to the X-direction, and the vertical direction is taken as the Z-direction. The vertical direction is the direction of gravity (mg direction). The Y-axis is taken along the direction perpendicular to the X- and Z-directions, and the direction perpendicular to the X- and Z-directions is taken as the Y-direction. Furthermore, the direction of rotation around the X-axis is taken as the Wx-direction, the direction of rotation around the Y-axis is taken as the Wy-direction, and the direction of rotation around the Z-axis is taken as the Wz-direction. Also, "*" is used as the multiplication symbol. The center of the mover 101 is taken as the origin Oc, and the Y+ side is taken as the R-side and the Y-side is taken as the L-side. The transport direction of the mover 101 does not necessarily have to be horizontal. In such a case, the transport direction can be taken as the X-direction, and the Y- and Z-directions can be similarly defined. The X direction, Y direction, and Z direction are not necessarily limited to directions perpendicular to each other, but may also be defined as directions intersecting each other.

[0018] Furthermore, displacement in the transport direction is defined as position, displacement in other directions as posture, and the combination of position and posture is defined as a state. The notations for the q-axis and d-axis used in the following description are the same as those for the q-axis and d-axis in vector control generally used in synchronous motor control. The direction along the q-axis is defined as the q-axis direction, and the direction along the d-axis is defined as the d-axis direction. In this embodiment, the q-axis corresponds to the X-axis, the d-axis corresponds to the Z-axis, the q-axis corresponds to the X-direction, and the d-axis corresponds to the Z-direction.

[0019] The symbols used in the following description are as follows: Oc: Origin (center) of the mover 101 j: an index for identifying the coil 202 (where j is an integer that satisfies 1≦j≦N, where N is an integer of 2 or greater.) N: Number of coils 202 installed Ij: Amount of current applied to the j-th coil 202

[0020] P: State including the position and orientation of the mover 101 (X, Y, Z, Wx, Wy, Wz) X(j, P): X coordinate from the center of the mover 101 in state P of the permanent magnet facing the j-th coil 202 Y(j, P): Y coordinate from the center of the mover 101 in state P of the permanent magnet facing the j-th coil 202 Z(j,P): Z coordinate from the center of the mover 101 in state P of the permanent magnet facing the j-th coil 202 The permanent magnet is included in the magnetic body 103 of the mover 101, as will be described later.

[0021] Eq(j,P): Force in the q-axis direction acting on the mover 101 in state P when a unit current is applied to the j-th coil 202 Ed(j,P): The force in the d-axis direction acting on the mover 101 in state P when a unit current is applied to the j-th coil 202 Ey(j,P): Y-direction force acting on the mover 101 in state P when a unit current is applied to the j-th coil 202

[0022] T: Force applied to the mover 101 Tx: Force component in the X direction of force T Ty: Y-direction force component of force T Tz: Z-direction force component of force T Twx: Torque component of force T in the Wx direction Twy: Torque component of force T in the Wy direction Twz: Torque component of force T in the Wz direction

[0023] Σ: Sum when index j is changed from 1 to N ΣL: The total when the index of the coil 202 on the L side is changed ΣR: The total when the index of the coil 202 on the R side is changed

[0024] *:Matrix, vector multiplication M: Torque contribution matrix K: pseudocurrent vector (column vector) Tq: Torque vector (column vector) Is: Coil current vector (column vector) Fs: Coil force vector (column vector) M(a,b): Element of row a and column b of torque contribution matrix M

[0025] Inv(): Inverse matrix Tr(): Transposed matrix Tr(element 1, element 2, ...): column vector with elements 1, 2, ...

[0026] 1, the mover 101 is configured to be movable along the X direction, which is the transport direction. The mover 101 has a magnetic body 103, a linear scale 104, a Y target 105, and a Z target 106.

[0027] The magnetic bodies 103 are attached to the R-side and L-side ends of the upper surface of the mover 101 along the X direction. Each magnetic body 103 has a permanent magnet group 1102, a permanent magnet group 1103, etc., as will be described later. Note that the installation locations and number of the magnetic bodies 103 are not limited to those shown in FIGS. 1 and 2, and can be changed as appropriate.

[0028] The linear scale 104, the Y target 105, and the Z target 106 are attached and installed in positions on the mover 101 that can be read by a linear encoder 204, a Y sensor 205, and a Z sensor 206, which are installed on the stator 201, respectively.

[0029] The stator 201 includes a coil 202 , a linear encoder 204 , a Y sensor 205 , and a Z sensor 206 .

[0030] A plurality of coils 202 are attached to the stator 201 along the X direction so as to face along the X direction magnetic bodies 103 placed on the top surface of the mover 101. Specifically, the plurality of coils 202 are arranged in two rows along the X direction so as to face from above along the Z direction two magnetic bodies 103 placed at the ends of the R side and L side on the top surface of the mover 101. Note that the installation locations and number of coils 202 are not limited to those shown in FIGS. 1 and 2 and can be changed as appropriate.

[0031] The stator 201 applies a force to the mover 101, which is movable along the conveyance direction, by each of the coils 202 to which a current is applied, so that the mover 101 is conveyed along the conveyance direction while its position and posture are controlled.

[0032] The linear encoder 204, the Y sensor 205, and the Z sensor 206 function as detection units that detect the position and posture of the mover 101 that moves along the transport direction.

[0033] The linear encoder 204 is attached to the stator 201 so as to be able to read the linear scale 104 attached to the mover 101. The linear encoder 204 detects the relative position of the mover 101 with respect to the linear encoder 204 by reading the linear scale 104.

[0034] The Y sensor 205 is attached to the stator 201 so as to be able to detect the distance in the Y direction from the Y target 105 attached to the mover 101 .

[0035] Z sensor 206 is attached to stator 201 so as to be able to detect the distance in the Z direction from Z target 106 attached to mover 101 .

[0036] The mover 101 is designed to be transported with the workpiece 102 attached or held above or below it. Note that Fig. 2 shows a state in which the workpiece 102 is attached below the mover 101. Note that the mechanism for attaching or holding the workpiece 102 to the mover 101 is not particularly limited, and general attachment mechanisms, holding mechanisms, etc., such as mechanical hooks and electrostatic chucks, can be used.

[0037] 2 also shows a case where the mover 101 and the stator 201 are incorporated in the chamber of a deposition apparatus 701, which is an example of a process apparatus that processes the workpiece 102. The deposition apparatus 701 has a deposition source 702 that deposits vapor on the workpiece 102 attached to the mover 101. The deposition source 702 is installed at the bottom of the chamber of the deposition apparatus 701 so as to be able to face the workpiece 102 attached to the bottom of the mover 101. A thin film of metal, oxide, or the like is formed on the substrate, i.e., the workpiece 102 attached to the bottom of the mover 101, by deposition using the deposition source 702. In this way, the workpiece 102 is transported together with the mover 101, and the transported workpiece 102 is processed by the process apparatus to manufacture an article.

[0038] 1 also shows an area including a location where a structure 100, such as a gate valve, exists between stators 201a and 201b. The location where structure 100 exists is a location where electromagnets and coils cannot be arranged continuously between multiple stations within a production line or between production lines.

[0039] The conveyance system 1 is provided with a control system 3 for controlling the conveyance system 1. The control system 3 may constitute a part of the conveyance system 1. The control system 3 includes an integrated controller 301, a coil controller 302, a coil unit controller 303, and a sensor controller 304. The integrated controller 301, the coil controller 302, the coil unit controller 303, and the sensor controller 304 execute control programs corresponding to the respective processes and perform various calculations to execute the respective processes. The coil controller 302 and the sensor controller 304 are communicatively connected to the integrated controller 301. The coil controller 302 is communicatively connected to a plurality of coil unit controllers 303. The sensor controller 304 is communicatively connected to a plurality of linear encoders 204, a plurality of Y sensors 205, and a plurality of Z sensors 206. Each coil unit controller 303 is connected to a coil 202.

[0040] The integrated controller 301 determines current command values ​​to be applied to the multiple coils 202 based on outputs from the linear encoder 204, the Y sensor 205, and the Z sensor 206 transmitted from the sensor controller 304. The integrated controller 301 transmits the determined current command values ​​to the coil controller 302. The coil controller 302 transmits the current command values ​​received from the integrated controller 301 to each coil unit controller 303. The coil unit controller 303 controls the amount of current in the connected coils 202 based on the current command values ​​received from the coil controller 302.

[0041] 3, one or more coils 202 are connected to each coil unit controller 303. A current sensor 312 and a current controller 313 are connected to the coils 202. The current sensor 312 detects the value of a current flowing through the connected coil 202. The current controller 313 controls the amount of current flowing through the connected coil 202.

[0042] The coil unit controller 303 commands the current controller 313 to control the desired amount of current based on the current command value received from the coil controller 302. The current controller 313 detects the current value detected by the current sensor 312 and controls the amount of current so that the desired amount of current flows through the coil 202.

[0043] Next, the control system 3 that controls the transfer system 1 according to this embodiment will be further described with reference to Fig. 4. Fig. 4 is a schematic diagram showing the control system 3 that controls the transfer system 1 according to this embodiment.

[0044] 4, the control system 3 includes an integrated controller 301, a coil controller 302, and a sensor controller 304. The control system 3 functions as a control device that controls the conveyance system 1 including the mover 101 and the stator 201. The coil controller 302 and the sensor controller 304 are communicatively connected to the integrated controller 301.

[0045] A plurality of coil unit controllers 303 are communicatively connected to the coil controller 302. The coil controller 302 and the plurality of coil unit controllers 303 connected thereto are provided corresponding to the respective columns of the coils 202. Each coil unit controller 303 is connected to a coil 202.

[0046] The coil controller 302 can issue a target current value to each of the connected coil unit controllers 303. The coil unit controller 303 can control the magnitude of the current in the connected coil 202.

[0047] A plurality of linear encoders 204, a plurality of Y sensors 205, and a plurality of Z sensors 206 are communicatively connected to the sensor controller 304.

[0048] The multiple linear encoders 204 are attached to the stator 201 at intervals such that one of them can always measure the position of one mover 101 even while the mover 101 is being transported. The multiple Y sensors 205 are attached to the stator 201 at intervals such that two of them can always measure the Y target 105 of one mover 101. The multiple Z sensors 206 are attached to the stator 201 at intervals and in a plane such that three of the two rows can always measure the Z target 106 of one mover 101.

[0049] Based on the outputs from the linear encoder 204, the Y sensor 205, and the Z sensor 206, the integrated controller 301 determines current command values ​​to be applied to the multiple coils 202 and transmits them to the coil controller 302. Based on the current command values ​​from the integrated controller 301, the coil controller 302 issues current value commands to the coil unit controller 303 as described above. In this way, the integrated controller 301 functions as a control unit, transports the mover 101 along the stator 201 in a non-contact manner, and controls the attitude of the transported mover 101 in six axes.

[0050] The integrated controller 301 controls the currents applied to the multiple coils 202 based on the position and attitude of the mover 101 acquired by the linear encoder 204, the Y sensor 205, and the Z sensor 206. Hereinafter, a method for controlling the attitude of the mover 101 executed by the integrated controller 301 will be described with reference to FIG. 5. FIG. 5 is a schematic diagram showing the method for controlling the attitude of the mover 101 in the transportation system 1 according to this embodiment. FIG. 5 outlines the method for controlling the attitude of the mover 101, focusing mainly on the data flow. As will be described below, the integrated controller 301 functions as a control unit that executes processing using a mover position calculation function 401, a mover attitude calculation function 402, a mover attitude control function 403, and a coil current calculation function 404. As a result, the integrated controller 301 controls the transportation of the mover 101 while controlling the attitude of the mover 101 in six axes. Note that instead of the integrated controller 301, the coil controller 302 may be configured to execute processing similar to that of the integrated controller 301.

[0051] First, mover position calculation function 401 calculates the number and positions of movers 101 on stators 201 that form the conveyance path from measurement values ​​from multiple linear encoders 204 and information on their mounting positions. As a result, mover position calculation function 401 updates mover position information (X) and number information of mover information 406, which is information on the movers 101. Mover position information (X) indicates the position of mover 101 on stator 201 in the X direction, which is the conveyance direction. Mover information 406 is prepared for each mover 101 on stator 201, as shown by POS-1, POS-2, ... in FIG. 5, for example.

[0052] Next, mover posture calculation function 402 identifies Y sensors 205 and Z sensors 206 capable of measuring each mover 101 from the mover position information (X) of mover information 406 updated by mover position calculation function 401. Next, mover posture calculation function 402 calculates posture information (Y, Z, Wx, Wy, Wz), which is information about the posture of each mover 101, based on the values ​​output from the identified Y sensors 205 and Z sensors 206, and updates mover information 406. Mover information 406 updated by mover posture calculation function 402 includes mover position information (X) and posture information (Y, Z, Wx, Wy, Wz).

[0053] Next, mover attitude control function 403 calculates applied force information 408 for each mover 101 from current mover information 406, including mover position information (X) and attitude information (Y, Z, Wx, Wy, Wz), and the target attitude value. Applied force information 408 is information regarding the magnitude of the force to be applied to each mover 101. Applied force information 408 includes information regarding the three-axis force components (Tx, Ty, Tz) and three-axis torque components (Twx, Twy, Twz) of the force T to be applied, which will be described later. Applied force information 408 is prepared for each mover 101 on the stator 201, as shown by TRQ-1, TRQ-2, ... in FIG. 5, for example.

[0054] Here, the three-axis components of the force, Tx, Ty, and Tz, are the X-direction component, Y-direction component, and Z-direction component of the force, respectively. Furthermore, the three-axis components of the torque, Twx, Twy, and Twz, are the X-axis component, Y-axis component, and Z-axis component of the torque, respectively. The conveyance system 1 according to this embodiment controls the six-axis components of the force T (Tx, Ty, Tz, Twx, Twy, Twz), thereby controlling the posture of the mover 101 in six axes and controlling the conveyance of the mover 101.

[0055] Next, the coil current calculation function 404 determines a current command value 409 to be applied to each coil 202 based on the applied force information 408 and the mover information 406 .

[0056] In this way, the integrated controller 301 executes processing using the mover position calculation function 401, the mover attitude calculation function 402, the mover attitude control function 403, and the coil current calculation function 404, thereby determining the current command value 409. The integrated controller 301 transmits the determined current command value 409 to the coil controller 302.

[0057] The control of the position and attitude of the mover 101 will be described in further detail with reference to Fig. 6. Fig. 6 is a schematic diagram showing an example of a control block diagram for controlling the position and attitude of the mover 101.

[0058] 6, P is the position and orientation (also referred to as position, orientation, or state) of the mover 101, and has components (X, Y, Z, Wx, Wy, Wz). ref is the target value of (X, Y, Z, Wx, Wy, Wz). err is the deviation between the target value ref and the position and orientation P.

[0059] The mover attitude control function 403 calculates the force T to be applied to the mover 101 to achieve the target value ref, based on the magnitude of the deviation err, the change in the deviation err, the integrated value of the deviation err, etc. The coil current calculation function 404 calculates the coil current I to be applied to the coil 202 to apply the force T to the mover 101, based on the force T to be applied and the position and attitude P. When the coil current I calculated in this way is applied to the coil 202, the force T acts on the mover 101, and the position and attitude P change to the target value ref.

[0060] By configuring the control block in this way, it becomes possible to control the position and attitude P of the mover 101 to a desired target value ref.

[0061] Next, magnetic body 103 installed in mover 101 and coil 202 installed in stator 201 will be described in detail with reference to FIGS. 7A to 7D.

[0062] 7A to 7C show an example of the magnetic body 103 installed in the mover 101. FIG. 7A is a plan view of permanent magnets 1108 and 1109 of a permanent magnet group 1102 included in the magnetic body 103, viewed from above along the Z direction. FIG. 7B is a plan view of permanent magnets 1106 and 1107 of a permanent magnet group 1103 included in the magnetic body 103, viewed from above along the Z direction. FIG. 7C is a cross-sectional view of the magnetic body 103 and the opposing coil 202, viewed from above along the X direction, showing the cross-sections of the magnetic body 103 and coil 202 taken along line AA′ in FIGS. 7A and 7B. The Y-direction positions of Y=0, R and Y=0, L shown in FIGS. 7A to 7C indicate the reference positions on the R side and L side, respectively. FIGS. 7A to 7C show the structures of the R-side magnetic body 103 and the L-side magnetic body 103, which have identical structures, in a common diagram. 7D is a graph schematically showing the magnitude of the force in the q-axis direction, the d-axis direction, and the Y-axis direction acting on the magnetic body 103 per unit current of the coil 202 facing the magnetic body 103, i.e., the thrust constant in each direction. Note that in FIGS. 7A, 7B, and 7D, the corresponding positions in the X-axis direction are indicated by dashed lines.

[0063] 7C, coil 202 has a winding 1104 and an iron core 1105. Winding 1104 is wound around iron core 1105 with an axis along the Z direction as its central axis. Coil 202 faces magnetic body 103 from above magnetic body 103 along the Z direction.

[0064] 7A to 7C, the magnetic body 103 has a yoke plate 1101, a permanent magnet group 1102, and a permanent magnet group 1103. The yoke plate 1101 is disposed on the upper surface of the mover 101. The permanent magnet group 1103 is disposed on top of the yoke plate 1101 in the Z direction. The permanent magnet group 1102 is disposed on top of the permanent magnet group 1103 in the Z direction. In this manner, the yoke plate 1101, the permanent magnet group 1103, and the permanent magnet group 1102 are stacked and fixed in the Z direction, which is the direction in which the magnetic body 103 and the coil 202 face each other. The permanent magnet groups 1102 and 1103 may have portions that repel each other depending on the direction of magnetic flux, but they are fixed to the mover 101 with an adhesive or the like.

[0065] Note that the permanent magnet group 1102 and the permanent magnet group 1103 stacked in the Z direction as described above may be stacked in the opposite order in the Z direction. That is, the permanent magnet group 1103 may be placed above the permanent magnet group 1102 in the Z direction.

[0066] 7A and 7B schematically show the direction of magnetic flux flowing from permanent magnet groups 1102 and 1103 due to Bvec. Bvec with a black circle inside a white circle indicates the direction of magnetic flux from the back of the paper to the front of the paper along the Z direction. Bvec with a cross inside a white circle indicates the direction of magnetic flux from the front of the paper to the back of the paper along the Z direction. Also, in FIG. 7C, the direction of magnetic flux from permanent magnet groups 1102 and 1103 is indicated by arrows.

[0067] 7A, the permanent magnet group 1102 includes a permanent magnet 1108 and a permanent magnet 1109. When viewed from the Z direction, the permanent magnets 1108 and 1109 each have a long rectangular planar shape with the X direction as the longitudinal direction. The permanent magnets 1108 and 1109 are installed adjacent to each other from the R side to the L side in the Y direction.

[0068] Permanent magnet 1108 is magnetized along the Z direction, with magnetic flux directed from the front to the back of the paper in Fig. 7A. Permanent magnet 1109 is magnetized along the Z direction, with magnetic flux directed from the back to the front of the paper in Fig. 7A. In this way, permanent magnets 1108 and 1109, which are adjacent to each other in the Y direction, are magnetized in opposite directions along the Z direction, with magnetic flux directed in opposite directions along the Z direction.

[0069] 7B, the permanent magnet group 1103 includes a plurality of permanent magnets 1106 and a plurality of permanent magnets 1107. In a plan view seen from the Z direction, the permanent magnets 1106 and 1107 have rectangular planar shapes that are shorter in the X direction and wider in the Y direction compared to the permanent magnets 1108 and 1109. The permanent magnets 1106 and 1107 are arranged alternately along the X direction.

[0070] Permanent magnet 1106 is magnetized in the Z direction so that the magnetic flux is directed from the back side to the front side of the paper in Fig. 7B. Permanent magnet 1107 is magnetized in the Z direction so that the magnetic flux is directed from the front side to the back side of the paper in Fig. 7B. In this way, permanent magnets 1106 and permanent magnets 1107, which are alternately arranged in the X direction, are magnetized in opposite directions to each other in the Z direction, and the directions of the magnetic flux along the Z direction are opposite to each other.

[0071] As described above, in this embodiment, the magnetic body 103 is configured by superimposing multiple types of permanent magnets 1106, 1107, 1108, and 1109, each having a different magnetic flux direction and shape. Because multiple types of permanent magnets 1106, 1107, 1108, and 1109 are superimposed, the magnetic body 103 has a magnetic flux density distribution that varies along the X direction, which is the conveyance direction, and also has a magnetic flux density distribution that varies along the Y direction, which intersects with the X direction.

[0072] That is, the magnetic body 103 has a magnetic flux density distribution that changes periodically along the X direction due to the permanent magnets 1106 and 1107, which are arranged alternately in the X direction and have magnetic flux directions opposite to each other, included in the permanent magnet group 1103. The permanent magnets 1106 and 1107 that form such a magnetic flux density distribution contribute to the application of forces in the q-axis and d-axis directions to the mover 101 including the magnetic body 103.

[0073] Furthermore, magnetic body 103 has a magnetic flux density distribution that changes so as to have a gradient along the Y direction due to permanent magnets 1108 and 1109, which are adjacent to each other in the Y direction and have magnetic flux directions opposite to each other and are included in permanent magnet group 1102 stacked on permanent magnet group 1103. Permanent magnets 1108 and 1109 that form such a magnetic flux density distribution contribute to applying a force in the Y direction to mover 101 including magnetic body 103.

[0074] Thus, on the side of the magnetic body 103 facing the coil 202, a magnetic flux density distribution is formed in which the magnitude of the magnetic flux linking the winding 1104 changes in either direction when the relative position of the magnetic body 103 with respect to the coil 202 changes in the X and Y directions.

[0075] 7D , the coil 202 has thrust constant profiles 1121, 1122, and 1123 in the q-axis, d-axis, and Y-axis directions, respectively. The thrust constant profile 1121 in the q-axis direction schematically shows the force in the q-axis direction acting on the magnetic body 103 when a unit current is applied to the coil 202. The thrust constant profile 1122 in the d-axis direction schematically shows the force in the d-axis direction acting on the magnetic body 103 when a unit current is applied to the coil 202. The thrust constant profile 1123 in the Y-axis direction schematically shows the force in the Y-axis direction acting on the magnetic body 103 when a unit current is applied to the coil 202.

[0076] 7D , a force in the Y direction can be applied to the mover 101 by causing the magnetic body 103 to act on the magnetic body 103. That is, the integrated controller 301 controls the currents applied to the multiple coils 202 to apply forces to the magnetic body 103 in the q-axis direction, the d-axis direction intersecting the q-axis direction, and the Y direction intersecting the q-axis direction and the d-axis direction.

[0077] In this manner, in this embodiment, a force can be applied to the mover 101 including the magnetic body 103 in the q-axis direction, the d-axis direction, and the Y-axis direction, and therefore the force applied to the mover 101 can be omnipresent in each of the q-axis direction, the d-axis direction, and the Y-axis direction. Therefore, even if the coil 202 does not cover the entire surface of the magnetic body 103, by applying a current to the coil 202, a force in the Y-axis direction sufficient to control the state of the mover 101 can be generated.

[0078] Therefore, according to this embodiment, by ubiquitously applying force to the mover 101, the mover 101 can be levitated and transported in a more stable non-contact state even in the case of a small mover 101 or when there are significant constraints on the arrangement of the stator 201.

[0079] Next, a method for calculating a coil current required to apply to the mover 101 a force T required to transport the mover 101 in the transport direction while controlling the attitude of the mover 101 will be further described with reference to Fig. 8. Fig. 8 is a plan view of the transport system 1 according to this embodiment as viewed from the Z direction. Note that although the coil 202 and the magnetic body 103 actually face each other in the Z direction as shown in Fig. 2, they are shown shifted in Fig. 8 for the sake of convenience.

[0080] As shown in FIG. 8, the j-th coil 202 and the magnetic body 103 exert a force on each other in an interaction region 207 of a predetermined range.

[0081] Components Tx, Ty, Tz, Twx, Twy, and Twz of force T acting on mover 101 by coil 202 to which current is applied are expressed by the following equations (1a) to (1f), respectively: Tx is the force component in the X direction, Ty is the force component in the Y direction, Tz is the force component in the Z direction, Twx is the torque component in the Wx direction, Twy is the torque component in the Wy direction, and Twz is the torque component in the Wz direction. Tx=Σ(Eq(j,P)*Ij) ...Equation (1a) Ty=Σ(Ey(j,P)*Ij) ...Equation (1b) Tz=Σ(Ed(j,P)*Ij) …Equation (1c) Twx=Σ{(Ey(j,P)*Z(j,P)-Ed(j,P)*Y(j,P))*Ij}...Formula (1d) Twy=Σ{(Ed(j,P)*X(j,P)-Eq(j,P)*Z(j,P))*Ij} …Equation (1e) Twz=Σ{(Eq(j,P)*Y(j,P)-Ey(j,P)*X(j,P))*Ij} …Equation (1f)

[0082] Here, the torque contribution matrix M is defined. Each element of the torque contribution matrix M is a coefficient multiplied by the current Ij in equations (1a) to (1f). The torque contribution matrix M is a matrix with 6 rows and N columns that indicates the magnitude of contribution to each force component and torque component (Tx, Ty, Tz, Twx, Twy, Twz) when a unit current is applied to each of the first to Nth coils 202 when the mover 101 is in state P. Each element M(1,j) to M(6,j) of the jth column from the 1st row and jth column to the 6th row and jth column of the torque contribution matrix M is expressed by the following equations (1a') to (1f'), respectively. M(1,j)=Eq(j,P) …Equation (1a′) M(2,j)=Ey(j,P) …Equation (1b′) M(3,j)=Ed(j,P) ...Equation (1c') M(4,j)=Ey(j,P)*Z(j,P)-Ed(j,P)*Y(j,P)…Formula (1d′) M(5,j)=Ed(j,P)*X(j,P)-Eq(j,P)*Z(j,P) …Equation (1e′) M(6,j)=Eq(j,P)*Y(j,P)-Ey(j,P)*X(j,P)...Formula (1f′)

[0083] Also, a coil current vector Is is defined. Each element of the coil current vector Is is the amount of current applied to the j-th coil 202. Then, the coil current vector Is is a column vector with N rows and 1 column expressed by the following equation (2). Is=Tr(I1,I2,…,Ij,…,IN)…Formula (2)

[0084] Furthermore, the torque vector Tq is defined by the following equation (3). Tq=Tr(Tx, Ty, Tz, Twx, Twy, Twz)...Equation (3)

[0085] Then, equations (1a) to (1f) can be expressed as the following equation (4) using the torque contribution matrix M, the coil current vector Is, and the torque vector Tq. Tq=M*Is…Equation (4)

[0086] Here, we introduce the pseudocurrent vector K. If the pseudocurrent vector K is a column vector with 6 rows and 1 column, and Tr(M) is the transposed matrix of the torque contribution matrix M, the pseudocurrent vector K is a vector that satisfies the following equation (5). Tr(M)*K=Is...Equation (5)

[0087] Equation (4) can be transformed into the following equation (6) using equation (5). Tq=M*Tr(M)*K…Equation (6)

[0088] Here, M*Tr(M) is the product of a 6-row, N-column matrix and its transpose, so it is a 6-row, 6-column square matrix and has an inverse matrix. Therefore, equation (6) can be transformed into the following equation (7). Inv(M*Tr(M))*Tq=K...Equation (7)

[0089] By substituting equation (7) into equation (5), the coil current vector Is expressed by the following equation (8) is obtained. Tr(M)*Inv(M*Tr(M))*Tq=Is...Equation (8)

[0090] By calculating the coil current vector Is in the above manner, it is possible to determine the current to be applied to each coil 202. As a result, it is possible to independently apply to the mover 101 a force component Tx in the X direction, a force component Ty in the Y direction, a force component Tz in the Z direction, a torque component Twx in the Wx direction, a torque component Twy in the Wy direction, and a torque component Twz in the Wz direction. Therefore, according to this embodiment, it is possible to more stably transport the mover 101.

[0091] [Second embodiment] A second embodiment of the present invention will be described with reference to Figures 9A to 10B. Note that the same components as those in the first embodiment are given the same reference numerals, and descriptions thereof will be omitted or simplified.

[0092] In the first embodiment, the magnetic body 103 is configured by stacking multiple types of permanent magnets in the Z direction, but the present invention is not limited to this. The magnetic body 103 can also be configured to have a magnetic flux density distribution similar to that of the first embodiment by configuring the permanent magnets that make up the magnetic body 103 so that their widths in a predetermined direction are partially different in the same plane. In this embodiment, a case will be described in which the magnetic body 103 is configured by multiple permanent magnets that have partially different widths in the Y direction in a plan view seen from the Z direction.

[0093] Fig. 9A is a plan view of a permanent magnet group 1130 included in a magnetic body 103 installed in a mover 101 according to this embodiment, viewed from above along the Z direction. Fig. 9B is a graph schematically showing the magnitude of the force in the q-axis direction, the d-axis direction, and the Y-axis direction acting on the magnetic body 103 per unit current of the coil 202 facing the magnetic body 103, i.e., the thrust constant in each direction. Note that in Figs. 9A and 9B, corresponding positions in the X direction are indicated by dashed dotted lines.

[0094] 9A, the magnetic body 103 according to this embodiment has a permanent magnet group 1130 including permanent magnets 1131a, 1131b, 1132a, and 1132b. The permanent magnets 1131a and 1131b are arranged alternately along the X direction. The permanent magnets 1132a and 1132b are arranged adjacent to the permanent magnets 1131a and 1131b in the Y direction and shifted in the X direction relative to the permanent magnets 1131a and 1131b, and are arranged alternately along the X direction.

[0095] The permanent magnets 1131a and 1131b are magnetized in the Z direction so that the magnetic flux is directed from the front to the back of the paper in Fig. 9A. The permanent magnets 1132a and 1132b are magnetized in the Z direction so that the magnetic flux is directed from the back to the front of the paper in Fig. 9A. In this way, the permanent magnets 1131a and 1131b and the permanent magnets 1132a and 1132b that are adjacent to each other in the Y direction are magnetized in opposite directions to each other in the Z direction, and the directions of the magnetic flux along the Z direction are opposite to each other.

[0096] Permanent magnets 1131a and 1131b have protrusions 1131p protruding in the Y direction toward permanent magnets 1132a and 1132b, respectively. Protrusions 1131p protrude in the Y direction so as to be positioned between permanent magnets 1132a and 1132b adjacent to permanent magnets 1131a and 1131b in the Y direction. Because permanent magnets 1131a and 1131b each have protrusions 1131p, their widths in the Y direction differ in parts, and they have a shape in which their width varies in the Y direction. Note that the shape of permanent magnets 1131a and 1131b is not limited to a shape having protrusions 1131p, and may be any shape in which the width varies in the Y direction.

[0097] Permanent magnets 1132a and 1132b have protrusions 1132p protruding in the Y direction toward permanent magnets 1131a and 1131b, respectively. Protrusions 1132p protrude in the Y direction so as to be positioned between permanent magnets 1131a and 1131b adjacent to permanent magnets 1132a and 1132b in the Y direction. Because permanent magnets 1132a and 1132b each have protrusions 1132p, their widths in the Y direction differ in parts, and they have a shape in which their width varies in the Y direction. Note that the shape of permanent magnets 1132a and 1132b is not limited to a shape having protrusions 1132p, and may be any shape in which the width varies in the Y direction.

[0098] Thus, magnetic body 103 is installed so that permanent magnets 1131 and 1132, which are magnetized in opposite directions along the Z direction, are alternately arranged along the X direction. Permanent magnets 1131 and 1132 each have protruding portions 1131p and 1132p that are wider in the Y direction than other portions. Permanent magnets 1131 and 1132 that are arranged adjacent to each other in the X direction are adjacent to each other in the Y direction except for protruding portions 1131p and 1132p, and are therefore partially adjacent to each other in the Y direction.

[0099] At the end of magnetic body 103 in the X direction, permanent magnets corresponding to any part of permanent magnets 1131a, 1131b, permanent magnets 1132a, and 1132b are appropriately arranged so that magnetic body 103 has a predetermined length in the X direction.

[0100] Thus, in this embodiment, the magnetic body 103 is configured such that the permanent magnets 1131a, 1131b and the permanent magnets 1132a, 1132b, whose magnetic flux directions are different from each other, are aligned in the X direction while being offset in the X direction and partially adjacent to each other in the Y direction. Furthermore, the permanent magnets 1131a, 1131b and the permanent magnets 1132a, 1132b have partially different widths in the Y direction due to the protrusions 1131p and 1132p, respectively. The magnetic body 103 configured in this manner has a magnetic flux density distribution that varies along the X direction, which is the transport direction, and also has a magnetic flux density distribution that varies along the Y direction that intersects the X direction.

[0101] That is, the magnetic body 103 has a magnetic flux density distribution that changes periodically along the X direction due to the protrusions 1131p of the permanent magnets 1131a and 1131b that protrude in the Y direction and the protrusions 1132p of the permanent magnets 1132a and 1132b that protrude in the Y direction. The protrusions 1131p of the permanent magnets 1131a and 1131b and the protrusions 1132p of the permanent magnets 1132a and 1132b that form this magnetic flux density distribution contribute to the application of forces in the q-axis and d-axis directions to the mover 101 including the magnetic body 103.

[0102] Furthermore, the magnetic body 103 has a magnetic flux density distribution that changes to have a gradient along the Y direction due to adjacent portions of the permanent magnets 1131a, 1131b and 1132a, 1132b, which are arranged with a shift in the X direction and have magnetic flux directions opposite to each other, in the Y direction. The adjacent portions of the permanent magnets 1131a, 1131b, 1132a, 1132b, which form such a magnetic flux density distribution, contribute to the application of a force in the Y direction to the mover 101 including the magnetic body 103.

[0103] FIG. 9B is a graph schematically showing the magnitude of the force in the q-axis direction, d-axis direction, and Y-axis direction acting on the magnetic body 103 per unit current of the coil 202 facing the magnetic body 103, that is, the thrust constant in each direction.

[0104] In this embodiment, the coil 202 has thrust constant profiles 1141, 1142, and 1143 in the q-axis, d-axis, and Y-axis directions, respectively, as shown in FIG. 9B. The thrust constant profile 1141 in the q-axis direction schematically shows the force in the q-axis direction acting on the magnetic body 103 when a unit current is applied to the coil 202. The thrust constant profile 1142 in the d-axis direction schematically shows the force in the d-axis direction acting on the magnetic body 103 when a unit current is applied to the coil 202. The thrust constant profile 1143 in the Y-direction schematically shows the force in the Y-direction acting on the magnetic body 103 when a unit current is applied to the coil 202.

[0105] 9A, for example, consider a case where coil 202 is located in region 1134 and faces magnetic body 103. In this case, a magnetic flux density gradient in the Y direction formed by permanent magnet 1132b and permanent magnet 1131a exists in the magnetic flux linking coil 202 located in region 1134. Therefore, as shown in FIG. 9B, in region 1134, the thrust constant (Ey) in the Y direction is not 0 but has a magnitude equal to or greater than a certain value.

[0106] 9A, for example, consider a case where coil 202 is located in region 1133 and faces magnetic body 103. In this case, the magnetic flux linking coil 202 located in region 1133 has a Y-direction magnetic flux density gradient formed by permanent magnet 1132a and permanent magnet 1131a, and a Y-direction magnetic flux density gradient formed by permanent magnet 1132b and permanent magnet 1131a. Therefore, even in region 1133, as shown in FIG. 9B, the Y-direction thrust constant Ey is not 0 but has a magnitude equal to or greater than a certain value.

[0107] As described above, in this embodiment as well, since the thrust constant in the Y direction is equal to or greater than a certain value, even if the force component Ty in the Y direction is equal to or greater than a certain value, a desired force in the Y direction can be obtained by applying a current equal to or less than a certain value to the coil 202. Therefore, by applying a current to the coil 202, a force in the Y direction sufficient to control the state of the mover 101 can be generated. That is, the integrated controller 301 controls the currents applied to the multiple coils 202 to apply forces to the magnetic body 103 in the q-axis direction, the d-axis direction intersecting the q-axis direction, and the Y direction intersecting the q-axis and d-axis directions.

[0108] In this way, in this embodiment too, forces can be applied to the movable element 101 including the magnetic material 103 in the q-axis direction, the d-axis direction, and the Y-axis direction, so that the forces applied to the movable element 101 can be distributed ubiquitously in each of the q-axis direction, the d-axis direction, and the Y-axis direction.

[0109] Therefore, according to this embodiment, by distributing the force applied to the mover 101 ubiquitously, the mover 101 can be more stably levitated and transported in a non-contact state even in the case of a small mover 101 or when there are significant constraints on the arrangement of the stator 201.

[0110] 10A is a plan view, seen from the Z direction, showing an example of a conveyance system 1 including a mover 101 having a magnetic body 103 configured as shown in FIG. 9. As shown in FIG. 10A, the magnetic body 103 installed in the mover 101 is composed of permanent magnets 1131 and 1132 whose magnetic flux directions are different from each other. The number and shape of the permanent magnets 1131 and 1132 can be changed as appropriate depending on the size of the mover 101, etc. For example, as shown in FIG. 10B, the magnetic body 103 installed in the mover 101 may be composed of permanent magnets 1131 and 1132 whose magnetic flux directions are different from each other and a permanent magnet 1135 magnetized along the Y direction. The permanent magnet 1135 is disposed between the permanent magnets 1131 and 1132.

[0111] [Third embodiment] A third embodiment of the present invention will be described with reference to Fig. 11. Note that the same components as those in the first and second embodiments are given the same reference numerals, and the description thereof will be omitted or simplified.

[0112] In the first and second embodiments, the magnetic body 103 is described as having a magnetic flux density distribution formed by a plurality of permanent magnets that are physically separate and independent from one another, but the present invention is not limited to this. The magnetic body 103 may be formed of a single permanent magnet that is magnetized in advance to have a desired magnetic flux density distribution. In this embodiment, the magnetic body 103 is described as having a single permanent magnet 1203 that is magnetized in advance to have a desired magnetic flux density distribution.

[0113] 11 is a plan view of a permanent magnet 1203 constituting the magnetic body 103 installed in the mover 101 according to this embodiment, viewed from above along the Z direction. As shown in Fig. 11, in this embodiment, the magnetic body 103 does not include a group of permanent magnets but includes a single permanent magnet 1203. In a plan view viewed from above along the Z direction, the permanent magnet 1203 has a rectangular plane with the longitudinal direction aligned with the X direction.

[0114] The permanent magnet 1203 is a single piece of permanent magnet that is not physically divided. When the permanent magnet 1203 is magnetized by a magnetizing device during its manufacture, it is pre-magnetized so that it has a magnetic flux density distribution that varies along the X direction, which is the conveyance direction, and also varies along the Y direction, which intersects with the X direction. Specifically, the permanent magnet 1203 has a magnetic flux density distribution that varies periodically along the X direction, and also has a magnetic flux density distribution whose gradient varies along the Y direction, which intersects with the X direction.

[0115] For example, the permanent magnet 1203 is magnetized to have a magnetic flux density distribution similar to that of the magnetic body 103 according to the first or second embodiment. Note that the permanent magnet 1203 may also be magnetized to have a magnetic flux density distribution similar to that of the magnetic body 103 according to a fourth embodiment, which will be described later.

[0116] As in this embodiment, the magnetic body 103 can be configured with a single permanent magnet 1203 magnetized to have a predetermined magnetic flux density distribution, instead of a plurality of physically separated permanent magnets.

[0117] [Fourth embodiment] A fourth embodiment of the present invention will be described with reference to Figures 12A to 12D. Note that the same components as those in the first to third embodiments are given the same reference numerals, and descriptions thereof will be omitted or simplified.

[0118] In the above first to third embodiments, the magnetization direction of the permanent magnets constituting the magnetic body 103 is the Z direction, but the present invention is not limited to this. In this embodiment, a case will be described in which the permanent magnet 1201 constituting the magnetic body 103 is magnetized in the Y direction, and the permanent magnets 1203 and 1204 of the permanent magnet group 1202 constituting the magnetic body 103 are magnetized in the X direction.

[0119] 12A is a plan view of the permanent magnet 1201 included in the magnetic body 103 as viewed from above along the Z direction. FIG. 12B is a plan view of the permanent magnets 1203 and 1204 of the permanent magnet group 1202 included in the magnetic body 103 as viewed from above along the Z direction. FIG. 12C is a cross-sectional view of the magnetic body 103 and the opposing coil 202 as viewed along the X direction, showing the cross-sections of the magnetic body 103 and the coil 202 along line AA′ in FIGS. 12A and 12B. FIG. 12D is a cross-sectional view of the magnetic body 103 and the opposing coil 202 as viewed along the X direction, showing the cross-sections of the magnetic body 103 and the coil 202 along line BB′ in FIGS. 12A and 12B.

[0120] 12A to 12D, the magnetic body 103 has a yoke plate 1101, a permanent magnet 1201, and a permanent magnet group 1202. The yoke plate 1101 is disposed on the upper surface of the mover 101. The permanent magnet group 1202 is disposed above the yoke plate 1101 in the Z direction. The permanent magnet 1201 is disposed above the permanent magnet group 1202 in the Z direction.

[0121] In this way, the yoke plate 1101, the permanent magnet group 1202, and the permanent magnet 1201 are stacked and fixed in the Z direction. Here, in Figures 12A to 12D, the directions of the magnetic flux of the permanent magnet 1201 and the permanent magnet group 1202 are indicated by arrows.

[0122] 12A, permanent magnet 1201 has a long rectangular planar shape with the longitudinal direction aligned with the X direction when viewed from the Z direction. As shown in Fig. 12A, 12C, and 12D, permanent magnet 1201 is magnetized so that magnetic flux is directed to one side along the Y direction.

[0123] 12B, permanent magnet group 1202 includes a plurality of permanent magnets 1203 and a plurality of permanent magnets 1204. In a plan view seen from the Z direction, permanent magnets 1203 and 1204 each have a rectangular planar shape that is shorter in the Z direction and wider in the Y direction compared to permanent magnet 1201. Permanent magnets 1203 and 1204 are arranged alternately along the X direction.

[0124] 12B to 12D, permanent magnet 1203 is magnetized so that the magnetic flux is directed to one side (X+ side) along the X direction. Permanent magnet 1204 is magnetized so that the magnetic flux is directed to the other side (X- side) along the X direction. In this way, the permanent magnets 1203 and 1204, which are alternately arranged in the X direction, have magnetic fluxes in opposite directions along the X direction.

[0125] As in this embodiment, the permanent magnet 1201 constituting the magnetic body 103 may be magnetized in the Y direction, and the permanent magnets 1203 and 1204 of the permanent magnet group 1202 constituting the magnetic body 103 may be magnetized in the X direction. According to this embodiment as well, the magnetic body 103 can be configured to have a magnetic flux density distribution that changes along a direction intersecting the X direction, which is the conveyance direction.

[0126] In the above description, the magnetic body 103 is configured by combining the permanent magnet 1201 magnetized along the Y direction and the permanent magnets 1203 and 1204 magnetized along the X direction. However, this is not limiting. The magnetic body 103 can be configured by appropriately combining permanent magnets magnetized in any direction along the X direction, permanent magnets magnetized in any direction along the Y direction, and permanent magnets magnetized in any direction along the Z direction. There may be one or more permanent magnets magnetized along each direction. The magnetic body 103 can be configured to have at least two of the permanent magnets magnetized along the X direction, the permanent magnets magnetized along the Y direction, and the permanent magnets magnetized along the Z direction. These multiple types of permanent magnets with different magnetization directions included in the magnetic body 103 can be stacked in the Z direction.

[0127] [Fifth embodiment] A fifth embodiment of the present invention will be described with reference to Figs. 13A to 17. In the first to fourth embodiments, a conveying system 1 using a linear motor was described, but in this embodiment, a rotating device that uses a rotary motor will be described. In the case of a rotating device that uses a rotary motor, it is also required to eliminate bias in the force applied to the rotor and rotate the rotor while levitating it more stably. In this embodiment, a case will be described in which more stable rotation of the rotor is achieved by unilaterally distributing the force applied to the rotor in the rotating device.

[0128] First, the overall configuration of the rotating device according to this embodiment will be described with reference to Figs. 13A to 14. Fig. 13A is a longitudinal cross-sectional view taken along the rotation axis of a rotating device B10 according to this embodiment. Fig. 13B is a cross-sectional view taken along line AA' in Fig. 13A. Fig. 13B is a cross-sectional view taken along the XY plane at line AA' in Fig. 13A. Fig. 13C is a schematic diagram showing coordinate axes and directions used in the following description of the rotating device B10. Fig. 14 is a schematic diagram illustrating a method for calculating the displacement of a rotor B101.

[0129] As shown in FIGS. 13A and 13B , a rotating device B10 according to this embodiment includes a rotary motor B20 having a rotor B101 as a first part and a stator B201 as a second part. The rotor B101 includes a magnetic body B111 having a permanent magnet group B112 and a permanent magnet group B113, which will be described later. The permanent magnet group B112 includes a plurality of permanent magnets B102. The permanent magnet group B113 includes a plurality of permanent magnets B103. The stator B201 includes a plurality of coils B204. The motor B20 is a radial-type magnetically levitated rotary motor that magnetically levitates the rotor B101 along its axial direction and rotates it while levitating it in a non-contact manner around its axis. In this embodiment, a pump in which fins B104 are attached to the rotor B101 will be described as an example of a rotating device B10 that uses the motor B20.

[0130] Here, the coordinate axes used in the following description are defined. First, the rotation axis around which the rotor B101 (described later) rotates is defined as the Z axis. The XY plane is defined as being perpendicular to the Z axis, and the X and Y axes are defined as being perpendicular to each other on the XY plane. The direction along the X axis is defined as the X direction, the direction along the Y axis as the Y direction, and the direction along the Z axis as the Z direction. The direction of rotation around the X axis is defined as the Wx direction, the direction of rotation around the Y axis as the Wy direction, and the direction of rotation around the Z axis as the Wz direction. The positive rotation directions of the Wx, Wy, and Wz directions correspond to right-handed screw directions relative to the directions in which the X, Y, and Z axes extend from the origin Os of the stator B201, which is the origin of the X, Y, and Z axes. Each axis and direction is shown in Figure 13C. The R axis is defined as the direction in which the radius increases with the Z axis as the central axis.

[0131] The symbols used in the following description are as follows: P: State including the position and orientation of the rotor B101 (X, Y, Z, Wx, Wy, Wz) T: Force T applied to the rotor B101 Tx: Force component in the X direction of force T Ty: Y-direction force component of force T Tz: Z-direction force component of force T Twx: Torque component of force T in the Wx direction Twy: Torque component of force T in the Wy direction Twz: Torque component of force T in the Wz direction Tq: A column vector with elements (Tx, Ty, Tz, Twx, Twy, Twz)

[0132] j: an index for identifying coil B204 (where j is an integer that satisfies 1≦j≦N, where N is an integer of 2 or greater.) N: Number of coils B204 installed Ij: current value applied to the jth coil B204 Is: A column vector with Ij as elements φj: Angle of the jth coil B204 in the Wz direction r: Radius from the center of rotation of the rotor B101 to the magnetic body B111

[0133] Eq(j,P): The force in the q-axis direction acting on the rotor B101 in state P when a unit current is applied to the j-th coil B204 Ed(j,P): The force in the d-axis direction acting on the rotor B101 in state P when a unit current is applied to the j-th coil B204 Ez(j,P): The force in the Z-axis direction acting on the rotor B101 in state P when a unit current is applied to the j-th coil B204 Σ: Sum when index j is changed from 1 to N

[0134] In this embodiment, for components such as permanent magnet B102, which may exist in multiple numbers, unless there is a particular need to distinguish them, a common symbol consisting of a B followed by a number is used, and if necessary, a number followed by a "-" such as "-1", "-2", etc. is added after the number to identify them individually. For example, unless there is a particular need to distinguish between them, multiple coils B204 will be referred to simply as "coil B204." When it is necessary to identify each coil B204 individually, each coil B204 will be individually identified by being referred to as "coil B204-1," "coil B204-2," etc.

[0135] Similarly, unless there is a particular need to distinguish between them, multiple permanent magnets B102 will be referred to simply as "permanent magnets B102." When it is necessary to identify each permanent magnet B102 individually, each permanent magnet B102 will be individually identified by being referred to as "permanent magnet B102-1," "permanent magnet B102-2," etc.

[0136] The stator B201 is configured as a housing having an inlet B202 and an outlet B203. The internal space of the stator B201 is formed into a cylindrical shape with the Z axis as its central axis. A rotor B101 having a disk-like outer shape is accommodated in the internal space of the stator B201 and is rotatable around the Z axis as its rotation axis. The inlet B202 is provided on one side of the stator B201 in the Z direction. The outlet B203 is provided on the other side of the stator B201 in the Z direction. When the rotor B101 rotates in a predetermined direction in a fluid such as gas or liquid as will be described later, the rotating device B10 operates as a pump because the fluid flows in through the inlet B202 and is discharged from the outlet B203.

[0137] The stator B201 also has a plurality of coils B204 installed to face the rotor B101 housed in its internal space. The plurality of coils B204 are arranged to face the outer periphery of the rotor B101 along the circumferential direction of the internal space of the stator B201. The coils B204 are configured by winding a conducting wire around an iron core or an air core.

[0138] On the other hand, the rotor B101 is configured as an impeller having a disk-like outer shape housed in the internal space of the stator B201. The rotor B101 has a magnetic body B111 and a plurality of fins B104. The magnetic body B111 has a permanent magnet group B112 and a permanent magnet group B113 (see FIGS. 15A and 15B). The permanent magnet group B112 includes a plurality of permanent magnets B102. The permanent magnet group B113 includes a plurality of permanent magnets B103. The magnetic body B111 including the permanent magnet groups B112 and B113 is attached and installed on the outer periphery of the rotor B101 in a circumferential direction centered on the rotation axis of the rotor B101 so as to be able to face the coil B204 of the stator B201. In the magnetic body B111, the permanent magnet B102 is installed on the outer periphery side of the permanent magnet B103. A yoke plate (not shown) can be attached to the outer periphery, i.e., the back side, of the permanent magnet B102 in order to increase the magnetic force of the magnetic body B111. The rotor B101 rotates around the Z-axis in the internal space of the stator B201.

[0139] In the rotating device B10, as described below, an electromagnetic force acting between the coil B204 and the magnetic body B111 to which a current is applied causes the rotor B101 housed in the internal space of the stator B201 to levitate in the Z direction and rotate in a predetermined direction around the Z axis as the rotation axis. The Z direction in which the rotor B101 levitates is, for example, the vertical direction, but may be a direction other than the vertical direction. When the fins B104 are attached and the rotor B101 rotates, fluid flows into the internal space of the stator B201 from the inlet B202 and is discharged from the outlet B203. In this way, the rotating device B10 operates to draw in fluid from the inlet B202 and discharge the drawn-in fluid from the outlet B203, thereby transferring the fluid. The rotating device B10 can be configured to transfer, for example, a liquid or a gas as the fluid.

[0140] The rotating device B10 has an X sensor B213 and a Y sensor B214. The X sensor B213 and the Y sensor B214 are each attached to the stator B201. The X sensor B213 can detect and output the distance in the X direction between the rotor B101 and the X sensor B213. The Y sensor B214 can detect and output the distance in the Y direction between the rotor B101 and the Y sensor B214.

[0141] The rotating device B10 also has a Wz sensor B211. The Wz sensor B211 is attached to the stator B201 and installed. The Wz sensor B211 can detect and output the rotation angle of the rotor B101 in the Wz direction. A scale B212 is attached to the outer circumferential surface of the rotor B101 facing the Wz sensor B211. The Wz sensor B211 can detect the rotation angle of the rotor B101 in the Wz direction by reading a pattern on the scale B212.

[0142] The rotating device B10 also has a Z sensor B210. The Z sensor B210 is attached to the stator B201 at three locations. The Z sensor B210 can detect and output the distance to the rotor B101 in the Z direction.

[0143] Here, a method for calculating the Z, Wx, and Wy displacements of the rotor B101 from the three Z sensors B210 will be described with reference to Fig. 14. Here, Z is the position of the rotor B101 in the Z direction, Wx is the rotation angle of the rotor B101 in the Wx direction, and Wy is the rotation angle of the rotor B101 in the Wy direction.

[0144] As shown in Fig. 14, the three Z sensors B210, namely, Z sensors B210a, B210b, and B210c, are installed at three locations dispersed on the XY plane. A plane ABC is formed based on the detection values ​​of the distance in the Z direction to the rotor B101 by each of the three Z sensors B210a, B210b, and B210c. The plane ABC can be regarded as the rotor B101. The displacement (Z, Wx, Wy) of the plane ABC, i.e., of the rotor B101, can be calculated from the gradient of the normal vector of the plane ABC and the distance from the origin Os to the plane ABC.

[0145] Next, the magnetic body B111 installed in the rotor B101 and the coil B204 installed in the stator B201 will be described in detail with reference to FIGS. 15A to 15D. FIGS. 15A and 15B show an example of the magnetic body B111 installed in the rotor B101. FIG. 15A is a development view of the permanent magnet B103 of the permanent magnet group B113 included in the magnetic body B111, expanded in the Wz direction and viewed in a direction along the R axis. FIG. 15B is a development view of the permanent magnet B102 of the permanent magnet group B112 included in the magnetic body B111, expanded in the Wz direction and viewed in a direction along the R axis. FIG. 15C is a development view of the coil B204 installed in the stator B201, expanded in the Wz direction and viewed in a direction along the R axis. The Wz direction is the circumferential direction around the rotation axis of the rotor B101. FIG. 15D is a graph schematically showing the magnitude of the force in the q-axis direction, d-axis direction, and Z-axis direction acting on the magnetic body B111 per unit current of the coil B204 facing the magnetic body B111, that is, the thrust constant in each direction.

[0146] Here, the rotation angle of the rotor B101 in the Wz direction is defined as θ. The reference Oc in the Wz direction on the stator B201 side is defined as the center of the coil B204-1. The reference Or in the Wz direction on the rotor B101 side is defined as the midpoint between the permanent magnets B102-1 and B102-4. The angle θ is defined as the angle from the reference Oc on the stator B201 side to the reference Or on the rotor B101 side.

[0147] 15A and 15B, the magnetic body B111 has a permanent magnet group B112 and a permanent magnet group B113. The permanent magnet group B112 is disposed on the outer periphery of the rotor B101 in a circumferential direction centered on the rotation axis of the rotor B101. The permanent magnet group B113 is disposed inside the permanent magnet group B112 in a circumferential direction centered on the rotation axis of the rotor B101. In this way, the permanent magnet group B112 and the permanent magnet group B113 are arranged and fixed adjacent to each other in a direction along the R axis. The permanent magnet group B112 and the permanent magnet group B113 may have portions that repel each other depending on the direction of magnetic flux, but they are fixed to the rotor B101 with an adhesive or the like.

[0148] 15A and 15B schematically show the direction of magnetic flux flowing from permanent magnet groups B112 and B113 due to Bvec. Bvec with a black circle inside a white circle indicates the direction of magnetic flux from the back side of the paper to the front side along the R axis. Bvec with a cross inside a white circle indicates the direction of magnetic flux from the front side of the paper to the back side along the R axis.

[0149] 15A, the permanent magnet group B113 includes two permanent magnets B103-1 and B103-2. The number of permanent magnets B103 is not limited to two and can be changed as appropriate. When viewed from the direction along the R axis, the permanent magnets B103-1 and B103-2 each have an elongated rectangular planar shape with the Wz direction as the longitudinal direction. The permanent magnets B103-1 and B103-2 are installed adjacent to each other from above to below in the Z direction.

[0150] Permanent magnet B103-1 is magnetized in a direction along the R axis, with magnetic flux directed from the rear side to the front side of the page in Fig. 15A. Permanent magnet B103-2 is magnetized in a direction along the R axis, with magnetic flux directed from the front side to the rear side of the page in Fig. 15A. In this way, permanent magnets B103-1 and B103-2, which are adjacent to each other in the Z direction, are magnetized in opposite directions along the R axis, with magnetic flux directed in opposite directions along the R axis.

[0151] 15B, the permanent magnet group B112 includes four permanent magnets B102-1, B102-2, B102-3, and B102-4. The number of permanent magnets B102 is not limited to four and can be changed as appropriate. In a plan view seen from the direction along the R axis, the permanent magnets B102-1, B102-2, B102-3, and B102-4 have planar shapes that are shorter in the Wz direction and wider in the Z direction compared to the permanent magnets B103-1 and B103-2, respectively. The permanent magnets B102-1, B102-2, B102-3, and B102-4 are arranged in order along the Wz direction.

[0152] Of the four permanent magnets B102, permanent magnets B102-1 and B102-3 are magnetized in a direction along the R axis, with magnetic flux directed from the rear side to the front side of the page in Fig. 15B. Permanent magnets B102-2 and B102-4 are magnetized in a direction along the R axis, with magnetic flux directed from the front side to the rear side of the page in Fig. 15B. In this way, permanent magnets B102-1, B102-2, B102-3, and B102-4, which are lined up in order along the Wz direction, are magnetized in alternate opposite directions along the Z direction, with the magnetic flux directed in alternate opposite directions along the Z direction.

[0153] 15C, six coils B204-1, B204-2, B204-3, B204-4, B204-5, and B204-6 are arranged in order along the Wz direction on the stator B201. The number of coils B204 is not limited to six and can be changed as appropriate. The coils B204-1, B204-2, B204-3, B204-4, B204-5, and B204-6 are arranged to face the magnetic material B111 of the rotor B101 in the direction along the R axis.

[0154] In this way, permanent magnets B102 and B103 are magnetized in a direction facing the coil installed on stator B201. For example, the surfaces of permanent magnets B102-1, B102-3, and B103-1 facing coil B204 are magnetized to the north pole, and permanent magnets B102-2, B102-4, and B103-2 are magnetized to the south pole. Note that the magnetization directions of permanent magnets B102 and B103 may be opposite to these.

[0155] In this manner, in this embodiment, the magnetic body B111 is configured by superimposing multiple types of permanent magnets B102 and B103 having different magnetic flux directions and shapes as described above. Because multiple types of permanent magnets B102 and B103 are superimposed, the magnetic body B111 has a magnetic flux density distribution that varies along the Wz direction (q-axis direction), which is the rotation direction, and also has a magnetic flux density distribution that varies along the Z direction that intersects with the Wz direction.

[0156] That is, the magnetic body B111 has a magnetic flux density distribution that changes periodically along the Wz direction due to the permanent magnets B102-1, B102-2, B102-3, and B102-4, which are included in the permanent magnet group B112 and are arranged alternately in the Wz direction and have magnetic flux directions opposite to each other. The permanent magnets B102-1, B102-2, B102-3, and B102-4 that form such a magnetic flux density distribution contribute to the application of forces in the Wz direction and the d-axis direction to the rotor B101 including the magnetic body B111.

[0157] Furthermore, the magnetic body B111 has a magnetic flux density distribution that changes along the Z direction due to permanent magnets B103-1 and B103-2, which are adjacent to each other in the Z direction and have magnetic flux directions opposite to each other and are included in permanent magnet group B113 arranged inside permanent magnet group B112. The permanent magnets B103-1 and B103-2 that form such a magnetic flux density distribution contribute to applying a force in the Z direction to the rotor B101 including the magnetic body B111.

[0158] Thus, on the side of magnetic body B111 facing coil B204, a magnetic flux density distribution is formed in which the magnitude of the magnetic flux linking the windings of coil B204 changes in either direction when the relative position of magnetic body B111 with respect to coil B204 in the Wz direction and Z direction changes.

[0159] 15D shows thrust constant profiles B1311, B1312, and B1313 in the q-axis, d-axis, and Z-axis directions when the rotor B101 angle θ is θ1. The q-axis thrust constant profile B1311 schematically shows the force in the q-axis direction acting on the magnetic body B111 when a unit current is applied to the coil B204, i.e., the thrust constant Eq in the q-axis direction. The d-axis thrust constant profile B1312 schematically shows the force in the d-axis direction acting on the magnetic body B111 when a unit current is applied to the coil B204, i.e., the thrust constant Ed in the d-axis direction. The Z-axis thrust constant profile B1313 schematically shows the force in the Z-axis direction acting on the magnetic body B111 when a unit current is applied to the coil B204, i.e., the thrust constant Ez in the Z-axis direction.

[0160] The q-axis and d-axis referred to here are the q-axis and d-axis in motor control theory. Fig. 13B shows the directions of the q-axis and d-axis for coil B204-3 as a representative. The q-axis direction corresponds to the circumferential Wz direction, and the d-axis direction corresponds to the direction along the radial R-axis.

[0161] The magnitude of each thrust constant Eq, Ed, Ez varies depending on the angle θ of the rotor B101 and the index j of the coil B204. Note that in Fig. 15D, the first argument of each thrust constant Eq, Ed, Ez represents the index j (1 to 4) of the coil B204, and the second argument represents the state P of the rotor B101. Each thrust constant Eq, Ed, Ez can be expressed as Eq(j,P), Ed(j,P), and Ez(j,P) using the index j and the state P, respectively.

[0162] In this way, in this embodiment, the magnetic flux density distribution formed by the magnetic body B111 also changes along the Z direction, so that a force in the Z direction can also be applied to the magnetic body B111, as shown in Fig. 15D, to apply a force in the Z direction to the rotor B101. That is, the motor controller B301 described below controls the currents applied to the multiple coils B204 to apply forces to the magnetic body B111 in the q-axis direction, the d-axis direction intersecting the q-axis direction, and the Z direction intersecting the q-axis and d-axis directions.

[0163] In this way, in this embodiment, forces can be applied to the rotor B101 including the magnetic body B111 in the q-axis direction, the d-axis direction, and the Z direction, so that the forces applied to the rotor B101 can be distributed ubiquitously in each of the q-axis direction, the d-axis direction, and the Z direction.

[0164] Therefore, according to this embodiment, the force applied to the rotor B101 is distributed ubiquitously, so that the rotor B101 can be more stably rotated while being levitated in a non-contact state.

[0165] As shown in Fig. 16, the rotating device B10 is provided with a motor controller B301, which is a control unit that controls the rotating device B10. The motor controller B301 is a control unit that executes a control program to control, for example, the attitude of the rotor B101, the rotation speed of the rotor B101, and the like, thereby controlling the rotor B101. The motor controller B301 will be further described with reference to Fig. 16. Fig. 16 is a schematic diagram showing the motor controller B301 that controls the rotating device B10. The motor controller B301 can constitute a part of the rotating device B10.

[0166] As shown in Fig. 16, a current controller B313 is connected to the motor controller B301, and the current controller B313 is provided for each coil B204. A coil B204 is connected to each current controller B313. A current sensor B312 is also connected to each current controller B313. A Z sensor B210, a Wz sensor B211, an X sensor B213, and a Y sensor B214 are also connected to the motor controller B301.

[0167] The motor controller B301 can detect the displacements (X, Y, Z, Wx, Wy, Wz) of the rotor B101 based on the detection values ​​from the Z sensor B210, Wz sensor B211, X sensor B213, and Y sensor B214.

[0168] In addition, the motor controller B301 has a control program and a clock built in, and can calculate a current value according to the detected displacement of the rotor B101 and calculate a current command value indicating the current to be applied to each coil B204.

[0169] Each current controller B313 can detect the current value of the coil B204 using the connected current sensor B312. Furthermore, each current controller B313 can detect the amount of current using the current sensor B312 in accordance with the current command value from the motor controller B301, and can apply a predetermined current to the coil B204 independently based on the detection result.

[0170] Next, a method for controlling the attitude of the rotor B101 by the motor controller B301 will be described with reference to Fig. 17. Fig. 17 is a schematic diagram showing a control loop for calculating the magnitude of the force to be applied to the rotor B101.

[0171] 17, ref is the target value of the displacement of the rotor B101, and pos is the displacement of the rotor B101 obtained from the sensor group, which is made up of a Z sensor B210, a Wz sensor B211, an X sensor B213, and a Y sensor B214.

[0172] 17, the motor controller B301 calculates the force T to be applied to the rotor B101 from the difference err between the target value ref and the displacement pos. The motor controller B301 may be, for example, a controller using PID control, or a controller using an appropriate filter depending on the characteristics of the rotor B101. Such a controller can stabilize the attitude of the rotor B101.

[0173] The motor controller B301 calculates the current I to be applied to each coil B204 from the force T and the displacement pos. Each current controller B313 applies a current to the coil B204 according to the current I calculated by the motor controller B301.

[0174] In this way, when a current is applied to each coil B204, a force T, which is an electromagnetic force, is generated between the coil B204 and the rotor B101, and the force T acts on the rotor B101, causing the rotor B101 to rotate. While the rotor B101 rotates, detection of the displacement pos and application of a current to each coil B204 are repeated.

[0175] The motor controller B301 controls a torque vector Tq, whose elements are force components Tx, Ty, Tz and torque components Twx, Twy, Twz of the force T applied to the rotor B101. In this way, the motor controller B301 rotates the rotor B101 while controlling the attitude (X, Y, Z, Wx, Wy) of the rotor B101. The torque vector Tq is a column vector expressed by the following equation (B1). Tq=(Tx,Ty,Tz,Twx,Twy,Twz) …Formula (B1)

[0176] Here, the coil current vector Is, which is a column vector indicating the current applied to the coil B204, is defined by the following equation (B2). Note that the following equation (B2) shows the coil current vector Is when the number N of installed coils B204 is 6. Is=(I1,I2,I3,I4,I5,I6) …Formula (B2)

[0177] Hereinafter, it will be explained that by moving the magnetic field generated in the coil B204 in accordance with the rotation of the rotor B101, it is possible to apply a torque vector Tq to the rotor B101 at any rotation angle in the Wz direction of the rotor B101.

[0178] The elements of the torque vector Tq are expressed by the following equations (B3-1) to (B3-6), respectively. Tx=Σ{(-Eq(j,P)*sin(φj)+Ed(j,P)*cos(φj))*Ij} …Formula (B3-1) Ty=Σ{(Eq(j,P)*cos(φj)+Ed(j,P)*sin(φj))*Ij} …Formula (B3-2) Tz=Σ(Ez(j,P)*Ij) …Formula (B3-3) Twx=Σ(Ed(j,P)*r*sin(φj)*Ij) …Formula (B3-4) Twy=Σ(-Eq(j,P)*r*cos(φj)*Ij) …Formula (B3-5) Twz=Σ(Eq(j,P)*r*Ij) …Equation (B3-6)

[0179] To apply the desired torque vector Tq, the current Ij that satisfies the above equations (B3-1) to (B3-6) is calculated as follows:

[0180] Here, we define the torque contribution matrix M. Each element of the torque contribution matrix M is a coefficient multiplied by the current Ij in equations (B3-1) to (B3-6). The torque contribution matrix M is a 6-row, N-column matrix that indicates the magnitude of the contribution to each force component and torque component (Tx, Ty, Tz, Twx, Twy, Twz) when a unit current is applied to each of the 1st to Nth coils B204 while the rotor B101 is in state P. Elements M(1,j) to M(6,j) of the 1st row, jth column to the 6th row, jth column of the torque contribution matrix M are expressed by the following equations (B3-1') to (B3-6'), respectively. M(1,j)=-Eq(j,P)*sin(φj)+Ed(j,P)*cos(φj) …Formula (B3-1′) M(2,j)=Eq(j,P)*cos(φj)+Ed(j,P)*sin(φj) …Formula (B3-2′) M(3,j)=Ez(j,P) …Formula (B3-3′) M(4,j)=Ed(j,P)*r*sin(φj) …Formula (B3-4′) M(5,j)=-Eq(j,P)*r*cos(φj) …Formula (B3-5′) M(6,j)=Eq(j,P)*r…Formula (B3-6′)

[0181] Then, equations (B3-1) to (B3-6) can be expressed as the following equation (B4-1) using the torque contribution matrix M, the coil current vector Is, and the torque vector Tq. Tq=M*Is ...Equation (B4-1)

[0182] Here, we introduce the pseudocurrent vector K. If the pseudocurrent vector K is a column vector with 6 rows and 1 column, and Tr(M) is the transpose matrix of the torque contribution matrix M, then the pseudocurrent vector is a vector that satisfies the following equation (B4-2). Tr(M)*K=Is...Formula (B4-2)

[0183] Equation (B4-1) can be transformed into the following equation (B4-3) using equation (B4-2). Tq=M*Tr(M)*K...Formula (B4-3)

[0184] Here, M*Tr(M) is the product of a 6-row, N-column matrix and its transpose, so it is a 6-row, 6-column square matrix and has an inverse matrix. Therefore, equation (B4-3) can be transformed into the following equation (B4-4): Inv(M*Tr(M))*Tq=K …Formula (B4-4)

[0185] By substituting equation (B4-4) into equation (B4-2), the coil current vector Is expressed by the following equation (B4-5) is obtained. Tr(M)*Inv(M*Tr(M))*Tq=Is...Formula (B4-5)

[0186] By calculating the coil current vector Is in the above manner, it is possible to determine the current to be applied to each coil B204. As a result, it is possible to independently apply to the rotor B101 a force component Tx in the X direction, a force component Ty in the Y direction, a force component Tz in the Z direction, a torque component Twx in the Wx direction, a torque component Twy in the Wy direction, and a torque component Twz in the Wz direction. Therefore, according to this embodiment, it is possible to more stably rotate the rotor B101 while levitating it in a non-contact state.

[0187] The positional relationship between the coil B204 and the magnetic body B111, the specific configuration of the magnetic body B111, and the like are not limited to the above. For example, in FIGS. 13A and 13B, the coil B204 can be disposed inside the permanent magnets B103, B103. In this case, the fins B104 can be disposed outside the rotor B101. Alternatively, for example, the magnetic body B111 can be disposed on the stator B201 side and the coil B204 on the rotor B101 side, and a battery for applying current to the coil B204 can be mounted on the rotor B101 to rotate the rotor B101. That is, instead of the above configuration in which the first portion including the magnetic body B111 is the rotor B101 and the second portion including the multiple coils B204 is the stator B201, the first portion including the magnetic body B111 may be the stator and the second portion including the multiple coils B204 may be the rotor.

[0188] Furthermore, the magnetic body B111 can be configured with the same arrangement and magnetization of permanent magnets as the magnetic body 103 according to the second to fourth embodiments. In this case as well, it is possible to distribute the force applied to the rotor B101 omnidirectionally in the q-axis direction, the d-axis direction, and the Z-axis direction.

[0189] [Modified embodiment] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, in the above embodiment, the position and posture of the mover 101 are controlled in the X direction, Y direction, Z direction, Wx direction, Wy direction, and Wz direction, but the present invention is not limited to this. The position and posture can be controlled by acquiring displacement in at least one of the X direction, Y direction, Z direction, Wx direction, Wy direction, and Wz direction.

[0190] In the above embodiment, the coils 202 are arranged in two rows, but the present invention is not limited to this. The coils 202 can be arranged in a predetermined number of rows depending on the magnetic bodies 103 arranged in the mover 101.

[0191] Furthermore, the conveying system according to the present invention can be used as a conveying system in a manufacturing system for manufacturing articles such as electronic devices, which conveys a workpiece together with a mover to the working area of ​​each process device, such as a machine tool, that performs each work process on the workpiece. The process device that performs the work process may be any device, such as a device that assembles parts on the workpiece or a device that paints it. Furthermore, the articles to be manufactured are not limited to specific ones, and may be any parts.

[0192] In this way, the conveyance system according to the present invention can be used to convey a workpiece to a working area, and a work process can be carried out on the workpiece conveyed to the working area to manufacture an article.

[0193] In the above embodiment, the magnetic body B111 is provided on the rotor B101 and the plurality of coils B204 is provided on the stator B201, but the present invention is not limited to this. The magnetic body B111 and the plurality of coils B204 may be interchanged in the rotor B101, which is the first part, and the stator B201, which is the second part. That is, the plurality of coils B204 may be provided on the rotor B101 and the magnetic body B111 may be provided on the stator B201.

[0194] In the above embodiment, a pump having fins B104 attached to a rotor B101 has been described as an example of the rotating device B10 using the motor B20, but the present invention is not limited to this. Rotating devices using the motor B20 may include, in addition to pumps, high-speed rotating machines, high-speed spindles for machine tools, artificial hearts, and the like. Depending on the rotating device, a rotating member that rotates together with the rotor B101 may be configured. [Explanation of symbols]

[0195] 1. Transport system 3. Control System 101 Mover 102 Work 103 Magnetic material 201 Stator 202 Coil 204 Linear Encoder 205 Y sensor 206 Z sensor 301 Integrated Controller 302 Coil Controller 303 Coil unit controller 304 Sensor Controller 312 Current Sensor 313 Current Controller 1101 York board 1102, 1103, 1130 permanent magnet group 1104 Winding 1105 Iron Core 1102, 1103, 1106, 1107, 1108, 1109, 1131, 1132 permanent magnets B10 Rotating Equipment B20 motor B101 Rotor B102, B103 permanent magnets B104 Fin B111 Magnetic material B112, B113 Permanent magnet group B201 stator B204 coil B210 Z Sensor B211 Wz sensor B212 scale B213 X sensor B214 Y sensor B301 Motor Controller B312 Current Sensor B313 Current Controller

Claims

1. a mover having a magnetic material; a stator having a plurality of coils arranged along a first direction so as to be able to face the magnetic body, and applying a force to the magnetic body by the plurality of coils to which a current is applied; a control unit that controls currents applied to the plurality of coils to apply the force to the magnetic body in the first direction, a second direction intersecting the first direction, and a third direction intersecting the first direction and the second direction, the magnetic body includes a first magnetic body and a second magnetic body stacked in the second direction, The first magnetic body is a first permanent magnet and a second permanent magnet magnetized in a direction different from that of the first permanent magnet; Including, the first permanent magnets and the second permanent magnets are arranged alternately along the first direction, The second magnetic body is a third permanent magnet; and a fourth permanent magnet magnetized in a direction different from that of the third permanent magnet. Including, The third permanent magnet and the fourth permanent magnet are provided adjacent to each other in the third direction. A transport system characterized by:

2. The magnetic body has a first magnetic flux density distribution that varies along the first direction and a second magnetic flux density distribution that varies along the third direction.

2. The transport system according to claim 1.

3. The first magnetic flux density distribution varies periodically along the first direction.

3. The transport system according to claim 2.

4. The plurality of coils are arranged to be able to face the magnetic body along the second direction.

4. The transport system according to claim 1, wherein the transport system is a transport system for transporting a plurality of objects.

5. The first magnetic body is the first permanent magnet magnetized along the second direction; the second permanent magnet being magnetized in the opposite direction to the first permanent magnet along the second direction; Including, The second magnetic body is the third permanent magnet magnetized along the second direction; the fourth permanent magnet that is magnetized in the opposite direction to the third permanent magnet along the second direction; Including, 2. The transport system according to claim 1.

6. a detection unit that acquires the position and attitude of the mover that moves along the first direction, The control unit controls currents to be applied to the plurality of coils based on the position and the attitude of the mover.

6. The transport system according to claim 1, wherein the transport system is a transport system for transporting a plurality of objects.

7. The second direction is the vertical direction.

7. The transport system according to claim 1, wherein the transport system is a transport system for transporting a plurality of objects.

8. A method for controlling a transport system, comprising: The transport system includes a mover having a magnetic body, and a stator having a plurality of coils arranged to be able to face the magnetic body along a first direction, the stator applying a force to the magnetic body by the plurality of coils to which a current is applied, the magnetic body having a first magnetic body and a second magnetic body stacked in a second direction intersecting the first direction, the first magnetic body including a first permanent magnet and a second permanent magnet magnetized in a direction different from that of the first permanent magnet, the first permanent magnet and the second permanent magnet being arranged alternately along the first direction, the second magnetic body including a third permanent magnet and a fourth permanent magnet magnetized in a direction different from that of the third permanent magnet, the third permanent magnet and the fourth permanent magnet being arranged adjacent to each other in the third direction, controlling currents applied to the plurality of coils to apply the force to the magnetic body in the first direction, the second direction, and the third direction intersecting the first direction and the second direction; A control method comprising:

9. A transport system according to any one of claims 1 to 7; a process device that processes the workpiece transported by the mover; A processing system comprising:

10. A method for manufacturing an article using the processing system according to claim 9, a step of transporting the workpiece by the mover; performing the processing on the workpiece transported by the mover by the processing device; A method for manufacturing an article, comprising:

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