Conveying system and control method for conveying system

Abstract

To provide a levitation-type transfer system and a control method for a mover capable of stabilizing a position of the mover regardless of magnitude of an external force applied to the mover during machining of a work.SOLUTION: A transport system has: a mover on which a work is mounted and which is movable along a first direction; a stator having a plurality of coils located along the first direction and giving a force of transporting the mover in the first direction, to the mover while floating in a second direction intersecting with the first direction by the plurality of coils, to which a current is applied; a control unit that acquires the position and orientation of the mover moving along the first direction while floating in the second direction and controls the operation of the mover by controlling the current value applied to the plurality of coils based on the acquired position and orientation; and a positioning unit for regulating the movement of the mover. The positioning unit includes a first positioning unit for regulating the movement of the mover in a direction of external force applied to the work.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a transport system and a method for controlling the transport system.

Background Art

[0002] Generally, in a production line for assembling industrial products, a semiconductor exposure apparatus, etc., a transport system is used. In particular, the transport system in a production line transports a plurality of movers for workpieces such as parts between a plurality of stations within a factory-automated production line or between production lines. It may also be used as a transport device in a process apparatus. As a transport system, a non-contact magnetic levitation type linear motor transport system has already been proposed.

[0003] In a transport system using a non-contact magnetic levitation type linear motor, a plurality of movers transport workpieces such as parts. In each process of the production line, a processing operation is performed on the workpiece. Patent Document 1 describes a method of arranging a permanent magnet on the side surface of the mover to achieve good access to the workpiece and performing a processing operation on the workpiece on the mover with a high degree of freedom by a process device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In order to achieve stable processing in each process of the production line, it is necessary for the mover that transports the workpiece to maintain a stable position and accurately position the workpiece against an external force during processing. In this regard, the method described in Patent Document 1 maintains the movable element in a stable position by receiving the external force applied to the movable element from the process using control stiffness. In other words, the method described in Patent Document 1 maintains the movable element in a stable position by controlling the current flowing through the coil that applies force to the movable element.

[0006] On the other hand, since there is an upper limit to the current that can be applied to the coil, there is an upper limit to the force required to maintain the movable element in a stable position. Therefore, the external force applied to the movable element from the process must be less than the upper limit of the force required to maintain the movable element in a stable position. Therefore, the movable element may not be able to maintain a stable position in the face of large external forces during machining. In order to position the workpiece accurately, the movable element must maintain a stable position regardless of the magnitude of the external force applied to it during workpiece machining.

[0007] The present invention aims to provide a levitation-type conveying system and a control method for the conveying system that can stabilize the position of a movable element regardless of the magnitude of the external force applied to the movable element during workpiece processing. [Means for solving the problem]

[0008] According to one aspect of the present invention, a transport system is provided comprising: a movable element that carries a workpiece and is movable along a first direction; a stator having a plurality of coils arranged along the first direction to which current is applied, which applies a force to the movable element that transports the movable element in the first direction while levitating it in a second direction intersecting the first direction; a control unit that acquires the position and orientation of the movable element as it levitates in the second direction and moves along the first direction, and controls the operation of the movable element by controlling the current values ​​applied to the plurality of coils based on the acquired position and orientation; and a positioning unit that restricts the movement of the movable element, wherein the positioning unit includes a first positioning unit that restricts the movement of the movable element in the direction of an external force applied to the workpiece.

[0009] According to another aspect of the present invention, a control method for a transport system is provided, comprising: a movable element that carries a workpiece and is movable along a first direction; a stator having a plurality of coils arranged along the first direction to which current is applied, which applies a force to the movable element to transport it in the first direction while causing it to levitate in a second direction intersecting the first direction; and a positioning unit that restricts the movement of the movable element, wherein the positioning unit includes a first positioning unit that restricts the movement of the movable element in the direction of an external force applied to the movable element during processing of the workpiece, the control method being characterized by acquiring the position and orientation of the movable element as it levitates in the second direction while moving along the first direction; controlling the operation of the movable element by controlling the current values ​​applied to the plurality of coils based on the acquired position and orientation; causing the movable element to land in the direction of the external force; and performing pressing control to press the movable element so that its movement is restricted by the first positioning unit. [Effects of the Invention]

[0010] According to the present invention, in a levitation-type transport system, the position of the movable element can be stabilized regardless of the magnitude of the external force applied to the movable element during workpiece processing. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing the configuration of a transport system according to the first embodiment of the present invention. [Figure 2A] This is a schematic diagram showing the configuration of a transport system according to the first embodiment of the present invention. [Figure 2B] This is a schematic diagram showing the configuration of a transport system according to the first embodiment of the present invention. [Figure 3] This is a schematic diagram showing a coil and related configuration in a conveying system according to a first embodiment of the present invention. [Figure 4] This is a schematic diagram showing a control system for controlling a transport system according to the first embodiment of the present invention. [Figure 5]It is a schematic diagram showing a method for controlling the attitude of a mover in a transport system according to the first embodiment of the present invention. [Figure 6] It is a schematic diagram showing an example of a control block for controlling the position and attitude of a mover in a transport system according to the first embodiment of the present invention. [Figure 7A] It is a schematic diagram for explaining the processing by the mover position calculation function in the transport system according to the first embodiment of the present invention. [Figure 7B] It is a schematic diagram for explaining the processing by the mover position calculation function in the transport system according to the first embodiment of the present invention. [Figure 8] It is a schematic diagram for explaining the processing by the mover attitude calculation function in the transport system according to the first embodiment of the present invention. [Figure 9A] It is a schematic diagram for explaining the processing by the mover attitude calculation function in the transport system according to the first embodiment of the present invention. [Figure 9B] It is a schematic diagram for explaining the processing by the mover attitude calculation function in the transport system according to the first embodiment of the present invention. [Figure 10] It is a schematic diagram showing the relationship between the force acting on the yoke plate attached to the mover in the transport system according to the first embodiment of the present invention, the force components acting on the mover, and the torque components. [Figure 11] It is a graph schematically showing the thrust constant profile in the Z direction in the transport system according to the first embodiment of the present invention. [Figure 12A] It is a schematic diagram showing the coil of the stator in the transport system according to the first embodiment of the present invention. [Figure 12B] It is a schematic diagram showing the coil of the stator in the transport system according to the first embodiment of the present invention. [Figure 13] It is a graph schematically showing the relationship between the amount of current applied to the coil and the magnitude of the attractive force acting between the coil and the yoke plate in the transport system according to the first embodiment of the present invention. [Figure 14] It is a schematic diagram of the mover in the transport system according to the first embodiment of the present invention as viewed from above along the Z direction. [Figure 15] It is a graph schematically showing the suction force profile in the Y direction in the transport system according to the first embodiment of the present invention. [Figure 16] It is a flowchart showing a control method of the transport system according to the first embodiment of the present invention. [Figure 17A] It is a schematic diagram showing the configuration of the transport system according to the second embodiment of the present invention. [Figure 17B] It is a schematic diagram showing the configuration of the transport system according to the second embodiment of the present invention. [Figure 18] It is a flowchart showing a control method of the transport system according to the second embodiment of the present invention. [Figure 19A] It is a schematic diagram showing the configuration of the transport system according to the third embodiment of the present invention. [Figure 19B] It is a schematic diagram showing the configuration of the transport system according to the third embodiment of the present invention. [Figure 20A] It is a schematic diagram showing another configuration of the transport system according to the third embodiment of the present invention. [Figure 20B] It is a schematic diagram showing another configuration of the transport system according to the third embodiment of the present invention. [Figure 21A] It is a schematic diagram showing another configuration of the transport system according to the third embodiment of the present invention. [Figure 21B] It is a schematic diagram showing another configuration of the transport system according to the third embodiment of the present invention. [Figure 22] It is a flowchart showing a control method of the transport system according to the third embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0012] [First Embodiment] Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 to 16. First, the configuration of the transport system 1 according to this embodiment will be explained using Figures 1 to 3. Figures 1 to 2B are schematic diagrams showing the configuration of the transport system 1 including the movable element 101 and the stator 201 according to this embodiment. Figures 1 and 2A show the main parts of the movable element 101 and the stator 201, respectively. Figure 2B shows the Z-axis positioning part 705 on the movable element 101 and the Z-axis positioning part 706 on the movable element 101 side. Also, Figures 1 and 2B are views of the movable element 101 from diagonally above, and Figure 2A is a view of the movable element 101 and the stator 201 from the X direction. Figure 3 is a schematic diagram showing the coils 202, 207, 208 and the configuration related to coils 202, 207, 208 in the transport system 1.

[0013] As shown in Figures 1 to 2B, the transport system 1 according to this embodiment has a movable element 101 that constitutes a carrier, trolley, or slider, and a stator 201 that constitutes a transport path. Furthermore, the transport system 1 includes an integrated controller 301, a coil controller 302, a coil unit controller 303, and a sensor controller 304. In Figure 1, three movable elements 101a, 101b, and 101c are shown as movable elements 101, and two stators 201a and 201b are shown as stators 201. Hereafter, when there is no need to distinguish between multiple components such as movable elements 101 and stators 201, a common numerical code will be used, and a lowercase letter of the alphabet will be added after the numerical code as needed to distinguish them individually. Also, when distinguishing between the R-side and L-side components of movable element 101, the letter R or L will be added after the lowercase letter of the alphabet to indicate the R side or L side.

[0014] The transport system 1 according to this embodiment is a transport system using an induction linear motor that generates an electromagnetic force between the coil 207 of the stator 201 and the conductive plate 107 of the movable element 101, thereby applying thrust in the X direction to the movable element 101. Furthermore, the transport system 1 according to this embodiment is a magnetic levitation type transport system that levitates the movable element 101 for contactless transport. The transport system 1 according to this embodiment also constitutes part of a processing system that includes a processing apparatus for processing the workpiece 102 transported by the movable element 101.

[0015] The transport system 1 transports the workpiece 102 held by the movable element 101 to a processing device that performs machining operations on the workpiece 102, for example, by transporting the movable element 101 using the stator 201. The processing device is not particularly limited, but for example, it could be an assembly device 701 that assembles parts or the like onto the workpiece 102. In Figure 1, three movable elements 101 are shown with two stator elements 201, but this is not limited to this configuration. In the transport system 1, one or more movable elements 101 may be transported on one or more stator elements 201.

[0016] Here, we define the coordinate axes, directions, etc., used in the following explanation. First, we take the X-axis along the horizontal direction, which is the transport direction of the movable element 101, and define the transport direction of the movable element 101 as the X-direction. Within the X-direction, the direction in which the movable element 101 moves is defined as the +X-direction, and the direction opposite to the +X-direction is defined as the -X-direction. We also take the Z-axis along the vertical direction, which is perpendicular to the X-direction, and define the vertical direction as the Z-direction. The vertical direction is the direction of gravity (mg-direction). Within the Z-direction, the direction in which gravity acts from top to bottom (mg-direction) is defined as the -Z-direction, and the direction opposite to the -Z-direction is defined as the +Z-direction. Furthermore, we take the Y-axis along the direction perpendicular to the X-direction and the Z-direction, and define the direction perpendicular to the X-direction and the Z-direction as the Y-direction. Within the Y-direction, the direction from left to right relative to the +X-direction is defined as the +Y-direction, and the direction opposite to the +Y-direction is defined as the -Y-direction. In addition, the rotation direction around the X-axis is defined as the Wx-direction, the rotation direction around the Y-axis is defined as the Wy-direction, and the rotation direction around the Z-axis is defined as the Wz-direction. The multiplication symbol "*" is used. Furthermore, the center of the movable element 101 is defined as the origin Oc, the Y+ side as the R side, and the Y- side as the L side. Note that the transport direction of the movable element 101 does not necessarily have to be horizontal, but in that case, the transport direction can be defined as the X direction, and the Y and Z directions can be defined similarly. Note that the X, Y, and X directions are not necessarily limited to mutually orthogonal directions, but can also be defined as mutually intersecting directions. In addition, the displacement in the transport direction is defined as position, the displacement in other directions is defined as attitude, and the position and attitude together are defined as state.

[0017] Furthermore, the symbols used in the following explanation are as follows. Note that the symbols are used redundantly for each case of coils 202, 207, and 208.

[0018] Oc: Origin of movable element 101 OS: Origin of Linear Scale 104 Oe: Origin of stator 201

[0019] j: An indicator for identifying the coil. (However, j is an integer such that 1 ≤ j ≤ N, where N is an integer greater than or equal to 2.) N: Number of coils installed Ij: Amount of current applied to the j-th coil

[0020] P: State including the position and orientation of the movable element 101 (X, Y, Z, Wx, Wy, Wz) X(j,P): X-coordinate of the j-th coil as seen from the center of the movable element 101 in state P. Y(j,P): The Y-coordinate of the j-th coil as seen from the center of the movable element 101 in state P. Z(j,P): Z-coordinate of the j-th coil as seen from the center of the movable element 101 in state P.

[0021] T: Force applied to the movable element 101 Tx: Force component of force T in the X direction Ty: Force component of force T in the Y direction Tz: Force component of force T in the Z direction 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

[0022] Ex(j,P): The force in the X direction acting on the movable element 101 in state P when a unit current is applied to the j-th coil. Ey(j,P): The force in the Y direction acting on the movable element 101 in state P when a unit current is applied to the j-th coil. Ez(j,P): The force in the Z direction acting on the movable element 101 in state P when a unit current is applied to the j-th coil.

[0023] Σ: Sum when index j is varied from 1 to N *: Matrix and vector product M: Torque contribution matrix K: Doubtful current 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 matrix M, row a, column b.

[0024] Inv(): Inverse matrix Tr(): Transposed matrix Tr(element1, element2, ...): a column vector whose elements are element1, element2, ...

[0025] As shown by the arrow in Figure 1, the movable element 101 is configured to move along the X direction, which is the transport direction. The movable element 101 has a yoke plate 103 and a conductive plate 107. The movable element 101 also has a linear scale 104, a Y target 105 and a Z target 106. The movable element 101 also has a Z-axis positioning unit 706. Furthermore, the movable element 101 has an RFID (Radio Frequency Identification) tag 512, which is an information medium on which identification information for identifying each movable element 101 is registered.

[0026] The yoke plates 103 are installed by being attached to multiple locations on the movable element 101. Specifically, the yoke plates 103 are installed on the upper surface of the movable element 101, attached along the X direction to the R side and L side ends. In addition, the yoke plates 103 are installed on the R side and L side sides of the movable element 101, attached along the X direction. Each yoke plate 103 is made of a material with high magnetic permeability, such as an iron plate.

[0027] The conductive plate 107 is mounted on the upper surface of the movable element 101, in the center, along the X direction. The conductive plate 107 is not particularly limited as long as it is made of a conductive material such as a conductive metal plate, but an aluminum plate or the like with low electrical resistance is preferred.

[0028] The installation locations and number of yoke plates 103 and conductive plates 107 are not limited to the above case and can be changed as appropriate.

[0029] The linear scale 104, Y target 105, and Z target 106 are mounted on the movable element 101 at positions where they can be read by the linear encoder 204, Y sensor 205, and Z sensor 206, respectively, which are installed on the stator 201.

[0030] The RFID tag 512 is attached to the movable element 101 at a position where it can be read by the RFID reader 513. The RFID reader 513 is installed at a specific position on the transport path of the movable element 101 in the transport system 1. The RFID tag 512 has an individual ID (Identification) registered on it, which is identification information, so that the movable element 101 to which the RFID tag 512 is attached can be identified. Alternatively, the movable element 101 may be provided with an information medium such as a QR code (registered trademark) that indicates the individual ID of the movable element 101 instead of the RFID tag 512. In this case, instead of the RFID reader 513, a reader such as a scanner that reads the individual ID from the information medium can be used depending on the information medium.

[0031] The movable element 101 is designed so that, for example, a workpiece 102 can be attached to or held above or below it for transport. Figure 2A shows the workpiece 102 mounted on the movable element 101. The mechanism for attaching or holding the workpiece 102 to the movable element 101 is not particularly limited, but general attachment and holding mechanisms such as mechanical hooks and electrostatic chucks can be used.

[0032] The stator 201 includes coils 202, 207, and 208, a linear encoder 204, a Y sensor 205, and a Z sensor 206. The stator 201 also includes a Z-axis positioning section 705.

[0033] In Figure 2A, the coils 202 are mounted on the stator 201 along the X direction in such a way that they can face the yoke plate 103 installed on the upper surface of the movable element 101 in the Z direction. Specifically, the multiple coils 202 are arranged in two rows along the X direction so that they can face the two yoke plates 103 installed at the R and L ends of the upper surface of the movable element 101 from above in the Z direction.

[0034] Multiple coils 208 are mounted on the stator 201 along the X direction so that they can face the yoke plates 103 installed on the side of the movable element 101 in the Y direction. Specifically, the multiple coils 208 are arranged in two rows along the X direction so that they can face the two yoke plates 103 installed on the R side and L side of the movable element 101 from the side in the Y direction.

[0035] Multiple coils 207 are mounted on the stator 201 along the X direction so that they can face the conductive plate 107 installed on the upper surface of the movable element 101 in the Z direction. Specifically, the multiple coils 207 are arranged in a single row along the X direction so that they can face the conductive plate 107 installed in the central part of the upper surface of the movable element 101 from above in the Z direction.

[0036] The stator 201 applies force to the movable element 101, which is movable along the transport direction, through the current applied to each coil 202, 207, and 208. As a result, the movable element 101 is transported along the transport direction while its position and orientation are controlled.

[0037] The installation locations of coils 202, 207, and 208 are not limited to the above-mentioned cases and can be changed as appropriate. Furthermore, the number of coils 202, 207, and 208 installed can be changed as appropriate.

[0038] The linear encoder 204, Y sensor 205, and Z sensor 206 function as detection units that detect the position and orientation of the movable element 101 as it moves along the transport direction.

[0039] The linear encoder 204 is mounted on the stator 201 so as to be able to read the linear scale 104 installed on the movable element 101. The linear encoder 204 detects the relative position of the movable element 101 with respect to the linear encoder 204 by reading the linear scale 104.

[0040] The Y sensor 205 is mounted on the stator 201 so as to be able to detect the distance in the Y direction between it and the Y target 105 installed on the movable element 101. The Z sensor 206 is mounted on the stator 201 so as to be able to detect the distance in the Z direction between it and the Z target 106 installed on the movable element 101.

[0041] Furthermore, Figure 1 shows a region between the stator 201a and the stator 201b that includes a structure 100 connecting processes, for example. The location where the structure 100 exists is a place where electromagnets or coils cannot be placed consecutively within a production line or between multiple stations in a production line.

[0042] Furthermore, the transport system 1 has a Z-axis positioning section 705 on the stator 201 side and a Z-axis positioning section 706 on the movable element 101 side as positioning sections for positioning the movable element 101 in the Z direction. The Z-axis positioning sections 705 and 706 are members that restrict the movement of the movable element 101 in the Z direction, which is the direction of the external force 704F that is applied to the workpiece 102 and the movable element 101 during processing of the workpiece 102.

[0043] In other words, the stator 201 has multiple Z-axis positioning sections 705. The Z-axis positioning sections 705 have surface accuracy on the surfaces facing the Z direction and can be used as a positioning reference in the Z direction. The movable section 101 has multiple Z-axis positioning sections 706 corresponding to the multiple Z-axis positioning sections 705. The Z-axis positioning sections 706 have surface accuracy on the surfaces facing the Z direction and can be used as a positioning reference in the Z direction.

[0044] In the stator 201, multiple Z-axis positioning units 705 are installed on the floor surface of the area where the movable element 101 lands. The area where the movable element 101 lands is a work area 707 in which the assembly device 701 assembles parts 704 onto the workpiece 102 on the movable element 101.

[0045] Each of the multiple Z-axis positioning sections 705 is a columnar member having an upper surface parallel to the XY plane and facing the +Z direction. The upper surfaces of the multiple Z-axis positioning sections 705 are all at the same position in the Z direction. The multiple Z-axis positioning sections 705 are provided on the floor surface, which is the bottom surface of the stator 201. The material of the multiple Z-axis positioning sections 705 may be the same as the material of the stator 201. In that case, the multiple Z-axis positioning sections 705 are formed integrally with the stator 201. Furthermore, an elastic material such as rubber (not shown) may be provided between the multiple Z-axis positioning sections 705 and the floor surface of the stator 201.

[0046] In the movable element 101, the multiple Z-axis positioning units 706 are installed on the lower surface facing the floor surface on which the Z-axis positioning unit 705 of the stator 201 is installed. Each of the multiple Z-axis positioning units 706 is a columnar member having a lower surface parallel to the XY plane and facing the -Z direction. The lower surfaces of the multiple Z-axis positioning units 706 are all at the same position in the Z direction. The multiple Z-axis positioning units 706 are positioned so as to be able to face their corresponding Z-axis positioning unit 705.

[0047] As described later, the movable element 101, which is levitated in the +Z direction and transported in the X direction, lands in the Z direction in the work area 707 such that the lower surface of each Z-axis positioning part 706 contacts the upper surface of the corresponding Z-axis positioning part 705. The landed movable element 101 can be levitated and transported again.

[0048] For the movable element 101 to levitate again after landing in the Z direction, it is necessary for the movable element 101 to be able to move in the +Z direction. Therefore, the Z-axis positioning unit 705 on the stator 201 side and the Z-axis positioning unit 706 on the movable element 101 side are installed within the range in which the movable element 101 can move in the +Z direction. In other words, the Z-axis positioning units 705 and 706 are installed within the movable range of the movable element 101 in the Z direction.

[0049] In other words, when the movable element 101 lands in the Z direction, the movable element 101 cannot move in the +Z direction unless the levitation force in the +Z direction that the coil 202 can generate is greater than the gravitational force in the -Z direction acting on the movable element 101. The maximum levitation force in the +Z direction that the coil 202 can generate is determined by the distance between the coil 202 and the yoke plate 103. If the distance between the coil 202 and the yoke plate 103 is large, the maximum levitation force will be small. Therefore, the Z-axis positioning section 705 on the stator 201 side and the Z-axis positioning section 706 on the movable element 101 side are installed such that the distance between the Z-axis positioning section 705 and the Z-axis positioning section 706 is within the range in which the movable element 101 can move in the +Z direction.

[0050] The movable element 101 and the stator 201 are equipped with processing equipment that performs machining operations on the workpiece 102 transported by the movable element 101. Figure 2A shows an example of a processing equipment that performs machining operations on the workpiece 102, in which the movable element 101 and the stator 201 are incorporated into an assembly device 701.

[0051] The assembly apparatus 701 has an assembly robot 703 that performs assembly work on a workpiece 102 attached to a movable element 101. The assembly work involves assembling parts 704 onto the workpiece 102. The assembly robot 703 is installed in the assembly apparatus 701 so that it can perform assembly work on the workpiece 102 attached to the upper part of the movable element 101. The assembly robot 703 assembles parts 704 onto the workpiece 102 attached to the upper part of the movable element 101, which has been transported to the work area 707 in front of the installation location of the assembly robot 703, from the Z direction.

[0052] A control system 3 is provided to control the transport system 1. The control system 3 may constitute a part of the transport 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 is communicatively connected to the coil controller 302 and the sensor controller 304. Multiple coil unit controllers 303 are communicatively connected to the coil controller 302. Multiple linear encoders 204, multiple Y sensors 205, and multiple Z sensors 206 are communicatively connected to the sensor controller 304. Coils 202, 207, and 208 are connected to each coil unit controller 303 (see Figure 3).

[0053] The integrated controller 301 determines the current command values ​​to be applied to the multiple coils 202, 207, and 208 based on the outputs from the linear encoder 204, Y sensor 205, and 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, 207, and 208 based on the current command values ​​received from the coil controller 302.

[0054] Furthermore, an RFID reader 513 is connected to the integrated controller 301 in a communication manner. The RFID reader 513 obtains the individual ID of the movable element 101 by reading the RFID tag 512 of the movable element 101. The RFID reader 513 transmits the obtained individual ID to the integrated controller 301. The integrated controller 301 receives and recognizes the individual ID of the movable element 101 transmitted from the RFID reader 513 and can identify the movable element 101. The RFID reader 513 is installed at one or more locations in the transport path formed by the stator 201.

[0055] As shown in Figure 3, one or more coils 202, 207, and 208 are connected to the coil unit controller 303. A current sensor 312 and a current controller 313 are connected to each of the coils 202, 207, and 208. The current sensor 312 detects the current value flowing through the connected coils 202, 207, and 208. The current controller 313 controls the amount of current flowing through the connected coils 202, 207, and 208.

[0056] The coil unit controller 303 commands the current controller 313 to provide a 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 each of the coils 202, 207, and 208.

[0057] Next, the control system 3 that controls the transport system 1 according to this embodiment will be further explained with reference to Figure 4. Figure 4 is a schematic diagram showing the control system 3 that controls the transport system 1 according to this embodiment.

[0058] As shown in Figure 4, the control system 3 includes an integrated controller 301, a coil controller 302, a coil unit controller 303, and a sensor controller 304. The control system 3 functions as a control unit that controls the transport system 1, which includes a movable element 101 and a stator 201. The integrated controller 301 is communicatively connected to the coil controller 302, the sensor controller 304, and the RFID reader 513.

[0059] Multiple coil unit controllers 303 are communicated to the coil controller 302. The coil controller 302 and the multiple coil unit controllers 303 connected to it are provided corresponding to each row of coils 202, 207, and 208. Coils 202, 207, and 208 are connected to each coil unit controller 303. The coil unit controller 303 can control the magnitude of the current in the connected coils 202, 207, and 208.

[0060] The coil controller 302 commands each connected coil unit controller 303 to set a target current value. The coil unit controller 303 controls the current flow of the connected coils 202, 207, and 208.

[0061] Multiple linear encoders 204, multiple Y sensors 205, and multiple Z sensors 206 are communicated to the sensor controller 304.

[0062] Multiple linear encoders 204 are mounted on the stator 201 at intervals such that at least one of them can always measure the position of one of the movable elements 101 while the movable elements 101 are being transported. Multiple Y sensors 205 are mounted on the stator 201 at intervals such that at least two of them can always measure the Y target 105 of one of the movable elements 101. Multiple Z sensors 206 are mounted on the stator 201 at intervals and in a plane such that three of the two rows of sensors can always measure the Z target 106 of one of the movable elements 101.

[0063] The integrated controller 301 determines current command values ​​to be applied to the multiple coils 202 based on the outputs from the linear encoder 204, Y sensor 205, and Z sensor 206, and transmits them to the coil controller 302. The coil controller 302 commands the coil unit controller 303 to apply current values ​​based on the current command values ​​from the integrated controller 301, as described above. As a result, the integrated controller 301 functions as a control unit, transporting the movable element 101 along the stator 201 without contact, and controlling the posture of the transported movable element 101 in six axes.

[0064] The integrated controller 301 can identify the movable element 101 by the individual ID of the movable element 101 received from the RFID reader 513, which reads the RFID tag 512 attached to the movable element 101. This allows the integrated controller 301 to control the operation of each movable element 101 by applying individual parameters to it.

[0065] Next, the method for controlling the attitude of the movable element 101, which is performed by the integrated controller 301, will be explained with reference to Figure 5. Figure 5 is a schematic diagram showing the method for controlling the attitude of the movable element 101 in the transport system 1 according to this embodiment. Figure 5 shows an overview of the method for controlling the attitude of the movable element 101, mainly focusing on the data flow. The integrated controller 301 performs processing using the movable element position calculation function 401, the movable element attitude calculation function 402, the movable element attitude control function 403, and the coil current calculation function 404, as described below. As a result, the integrated controller 301 controls the transport of the movable element 101 while controlling the attitude of the movable element 101 in 6 axes. Note that instead of the integrated controller 301, the coil controller 302 can be configured to perform the same processing as the integrated controller 301.

[0066] First, the movable element position calculation function 401 calculates the number and position of the movable elements 101 on the stator 201 that constitutes the transport path, based on measurements from multiple linear encoders 204 and information on their mounting positions.

[0067] Based on the above calculation, the movable element position calculation function 401 updates the movable element position information (X) and the number of movable elements in the movable element information 406, which is information about the movable elements 101. The movable element position information (X) indicates the position of the movable element 101 on the stator 201 in the X direction, which is the transport direction. The movable element information 406 is prepared for each movable element 101 on the stator 201, for example, as shown in Figure 5 as POS-1, POS-2, ...

[0068] Next, the movable element posture calculation function 402 identifies the Y sensor 205 and Z sensor 206 capable of measuring each movable element 101 from the movable element position information (X) of the movable element information 406 updated by the movable element position calculation function 401.

[0069] Next, the movable element attitude calculation function 402 calculates attitude information (Y, Z, Wx, Wy, Wz), which is information about the attitude of each movable element 101, and updates the movable element information 406. The movable element attitude calculation function 402 calculates attitude information (Y, Z, Wx, Wy, Wz) based on the values ​​output from the identified Y sensor 205 and Z sensor 206. The movable element information 406 updated by the movable element attitude calculation function 402 includes movable element position information (X) and attitude information (Y, Z, Wx, Wy, Wz).

[0070] Next, the movable element attitude control function 403 calculates applied force information 408 for each movable element 101 from the current movable element information 406, which includes movable element position information (X) and attitude information (Y, Z, Wx, Wy, Wz), and the attitude target value. The applied force information 408 is information regarding the magnitude of the force to be applied to each movable element 101. The applied force information 408 includes information regarding the three-axis components of the force T to be applied (Tx, Ty, Tz) and the three-axis components of the torque (Twx, Twy, Twz). The applied force information 408 is prepared for each movable element 101 on the stator 201, for example, as shown in Figure 5 as TRQ-1, TRQ-2, ...

[0071] Here, the three-axis components of force Tx, Ty, and Tz are the X-axis, Y-axis, and Z-axis components of the force, respectively. Similarly, the three-axis components of torque Twx, Twy, and Twz are the X-axis, Y-axis, and Z-axis components of the torque, respectively. The transport system 1 according to this embodiment controls the transport of the movable element 101 while controlling the posture of the movable element 101 in six axes by controlling these six-axis components of force T (Tx, Ty, Tz, Twx, Twy, Twz).

[0072] Next, the coil current calculation function 404 determines the current command value 409 to be applied to each coil 202 based on the applied force information 408 and the movable element information 406.

[0073] Thus, the integrated controller 301 determines the current command value 409 by executing processing using the movable element position calculation function 401, the movable element attitude calculation function 402, the movable element attitude control function 403, and the coil current calculation function 404. The integrated controller 301 transmits the determined current command value 409 to the coil controller 302.

[0074] The control of the position and orientation of the movable element 101 will be explained in more detail using Figure 6. Figure 6 is a schematic diagram showing an example of a control block for controlling the position and orientation of the movable element 101.

[0075] In Figure 6, P represents the position and orientation (also called position, orientation, or state) of the movable element 101, with 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.

[0076] The movable element attitude control function 403 calculates the force T that should be applied to the movable element 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.

[0077] The coil current calculation function 404 calculates the coil current I to be applied to coils 202, 207, and 208 in order to apply force T to the movable element 101, based on the force T to be applied and the position and orientation P. When the calculated coil current I is applied to coils 202, 207, and 208, force T acts on the movable element 101, causing its position and orientation P to change to the target value ref.

[0078] By configuring the control block in this way, it becomes possible to control the position and orientation P of the movable element 101 to a desired target value ref.

[0079] Here, the processing performed by the movable element position calculation function 401 will be explained using Figures 7A and 7B. Figures 7A and 7B are schematic diagrams illustrating the processing performed by the movable element position calculation function.

[0080] In Figure 7A, reference point Oe is the position reference of the stator 201 to which the linear encoder 204 is attached. Reference point Os is the position reference of the linear scale 104 attached to the movable element 101. Figure 7A shows a case where two movable elements 101a and 101b are transported as the movable element 101, and three linear encoders 204a, 204b, and 204c are arranged as the linear encoder 204. The linear scale 104 is attached to the same position along the X direction on each movable element 101a and 101b.

[0081] For example, a linear encoder 204c is positioned opposite the linear scale 104 of the movable element 101b shown in Figure 7A. The linear encoder 204c reads the linear scale 104 of the movable element 101b and outputs the distance Pc. The position of the linear encoder 204c on the X-axis, with the reference point Oe as the origin, is Sc. Therefore, the position Pos(101b) of the movable element 101b can be calculated by the following equation (1). Pos(101b)=Sc-Pc...Equation (1)

[0082] For example, the linear scale 104 of the movable element 101a shown in Figure 7A has two linear encoders 204a and 204b facing each other. Linear encoder 204a reads the linear scale 104 of the movable element 101a and outputs the distance Pa. The position on the X axis with the reference point Oe of the linear encoder 204a as the origin is Sa. Therefore, the position Pos(101a) of the movable element 101a on the X axis based on the output of the linear encoder 204a can be calculated by the following equation (2). Pos(101a)=Sa-Pa...Equation (2)

[0083] Furthermore, the linear encoder 204b reads the linear scale 104 of the movable element 101a and outputs the distance Pb. Also, the position on the X axis with the reference point Oe of the linear encoder 204b as the origin is Sb. Therefore, the position Pos(101a)' of the movable element 101a on the X axis based on the output of the linear encoder 204b can be calculated by the following equation (3). Pos(101a)′=Sb-Pb…Equation (3)

[0084] Here, since the positions of each linear encoder 204a and 204b have been accurately measured in advance, the difference between the two values ​​Pos(101a) and Pos(101a)' is sufficiently small. When the difference in the position of the movable element 101 on the X axis based on the outputs of the two linear encoders 204 is sufficiently small, it can be determined that the two linear encoders 204 are observing the same linear scale 104 of the movable element 101.

[0085] Furthermore, if multiple linear encoders 204 are facing the same movable element 101, the observed position of the movable element 101 can be uniquely determined by calculating the average position based on the outputs of the multiple linear encoders 204.

[0086] Furthermore, the movable element 101 can rotate around the Z-axis with a rotation amount Wz. Figure 7B illustrates the case where correction of the position of the movable element 101 due to this rotation amount Wz is necessary. Figure 7B illustrates the case where a linear scale 104 is attached to one side of the movable element 101b in the Y-direction. Os is the origin of the linear scale 104, and Oc is the origin of the movable element 101b. If D is the distance from the center Oc of the movable element 101b to the linear scale 104, the position Pos(101b) of the movable element 101b can be calculated using the following equation (1b) to obtain a more accurate position of the movable element 101b. Pos(101b)=Sc-Pc-Wz*D...Formula (1b)

[0087] The movable element position calculation function 401 calculates and determines the position X of the movable element 101 in the X direction as movable element position information based on the output of the linear encoder 204 as described above.

[0088] Next, the processing performed by the movable element posture calculation function 402 will be explained using Figures 8, 9A, and 9B.

[0089] Figure 8 shows a case where the movable element 101c is transported as the movable element 101, and Y sensors 205a and 205b are positioned as the Y sensors 205. In Figure 8, the Y target 105 of the movable element 101c has two Y sensors 205a and 205b facing each other. Let the relative distance values ​​output by the two Y sensors 205a and 205b be Ya and Yb, respectively, and when the distance between Y sensors 205a and 205b is Ly, the amount of rotation Wz of the movable element 101c around the Z axis is calculated by the following equation (4). Wz = (Ya - Yb) / Ly …Equation (4)

[0090] Depending on the position of the movable element 101, there may be three or more Y sensors 205 facing each other. In that case, the tilt of the Y target 105, i.e., the amount of rotation Wz around the Z axis, can be calculated using the least squares method or similar.

[0091] Furthermore, Figures 9A and 9B show the case where the movable element 101d is transported as the movable element 101, and Z sensors 206a, 206b, and 206c are arranged as the Z sensors 206. In Figures 9A and 9B, the Z target 106 of the movable element 101d is opposed by the three Z sensors 206a, 206b, and 206c. Here, the relative distance values ​​output by the three Z sensors 206a, 206b, and 206c are denoted as Za, Zb, and Zc, respectively. The distance between sensors in the X direction, i.e., the distance between Z sensors 206a and 206b, is denoted as Lz1. The distance between sensors in the Y direction, i.e., the distance between Z sensors 206a and 206c, is denoted as Lz2. Then, the amount of rotation Wy around the Y axis and the amount of rotation Wx around the X axis can be calculated by the following equations (5a) and (5b), respectively. Wy = (Zb - Za) / Lz1 …Equation (5a) Wx = (Zc - Za) / Lz² …Equation (5b)

[0092] As described above, the movable element attitude calculation function 402 can calculate the rotation amounts Wx, Wy, and Wz around each axis as attitude information for the movable element 101.

[0093] Furthermore, the movable element attitude calculation function 402 can calculate the position Y in the Y direction and the position Z in the Z direction of the movable element 101 as attitude information of the movable element 101 as follows.

[0094] First, the calculation of the Y-direction position Y of the movable element 101 will be explained using Figure 8. In Figure 8, the two Y sensors 205 on which the movable element 101c is located are denoted as Y sensors 205a and 205b, respectively. The measured values ​​of Y sensors 205a and 205b are denoted as Ya and Yb, respectively. The midpoint between the positions of Y sensor 205a and Y sensor 205b is denoted as Oe'. Furthermore, the position of the movable element 101c obtained from equations (1) to (3) is denoted as Os', and the distance from Oe' to Os' is denoted as dX'. At this time, the Y-direction position Y of the movable element 101c can be approximately calculated using the following equation. Y=(Ya+Yb) / 2-Wz*dX′ …Equation (6)

[0095] Next, the calculation of the Z-direction position Z of the movable element 101 will be explained using Figures 9A and 9B. The three Z sensors 206 on which the movable element 101d is attached are denoted as Z sensors 206a, 206b, and 206c, respectively. The measured values ​​of Z sensors 206a, 206b, and 206c are denoted as Za, Zb, and Zc, respectively. The X-coordinate of Z sensor 206a and the X-coordinate of Z sensor 206c are the same. The linear encoder 204 is assumed to be located midway between Z sensors 206a and 206c. The position X of Z sensors 206a and 206c is denoted as Oe''. Furthermore, the distance from Oe'' to the center Os'' of the movable element 101d is denoted as dX''. In this case, the Z-direction position Z of the movable element 101d can be approximately calculated using the following formula. Z=(Za+Zb) / 2+Wy*dX″…Equation (7)

[0096] Furthermore, if the rotation amounts of Wz and Wy are large for both position Y and position Z, the approximation accuracy can be further improved in the calculation.

[0097] Thus, the integrated controller 301 functions as an acquisition unit that acquires the position and orientation of the movable element 101 by executing processing using the movable element position calculation function 401 and the movable element orientation calculation function 402.

[0098] Next, a method for determining the current values ​​to be applied to coils 202, 207, and 208 for applying a desired force T to the movable element 101 will be described. As described above, the force T applied to the movable element 101 has three axial components of force: Tx, Ty, and Tz, and three axial components of torque: Twx, Twy, and Twz. The integrated controller 301, which performs processing using the coil current calculation function 404, can determine the current values ​​to be applied to coils 202, 207, and 208 according to the current value determination method described below.

[0099] In some cases, the influence of one force or torque on other forces or torques applied by coils 202, 207, and 208 can be sufficiently ignored. Specifically, the forces and torques applied by coils 202, 207, and 208 are the force in the X direction applied by coil 207, the force in the Y direction and torque in the Wz direction applied by coil 208, and the force in the Z direction, torque in the Wx direction, and torque in the Wy direction applied by coil 202. The force in the Y direction and torque in the Wz direction applied by coil 208 act in the horizontal direction. The force in the Z direction, torque in the Wx direction, and torque in the Wy direction applied by coil 202 act in the levitation direction. When the influence can be sufficiently ignored, the current value only needs to be calculated considering the force in the X direction for coil 207, the force in the Y direction and torque in the Wz direction for coil 208, and the force in the Z direction, torque in the Wx direction, and torque in the Wy direction for coil 202. The following describes cases where the impact can be sufficiently ignored.

[0100] First, the currents applied to each coil 202 in order to apply the force component Tz in the Z direction, the torque component Twx in the Wx direction, and the torque component Twy in the Wy direction to the movable element 101 will be explained using Figures 10 to 12B.

[0101] Figure 10 is a schematic diagram showing the relationship between the force acting on the yoke plate 103 mounted on the movable element 101 and the force component Tz and torque components Twx and Twy acting on the movable element 101.

[0102] In Figure 10, Fzj is the force applied by the j-th coil 202 to the yoke plate 103. Here, where N is an integer greater than or equal to 2, j is an integer satisfying 1 ≤ j ≤ N. The torque applied by each force Fzj contributes to the torque components Twx and Twy. The torque applied by each force Fzj is determined according to the force Fzj and the distance between its point of application and the center Oc of the movable element 101.

[0103] Figure 11 is a schematic graph showing the thrust constant profile 601 in the Z direction. The thrust constant profile 601 schematically shows the attractive force acting on the yoke plate 103 when a unit current is applied to the levitation coil 202 facing the yoke plate 103. The magnitude of this attractive force changes continuously with movement in the X direction.

[0104] Here, an example of the configuration of coil 202 will be explained using Figures 12A and 12B. Figures 12A and 12B are schematic diagrams showing coil 202. Figure 12A is a view of coil 202 from the Z direction, and Figure 12B is a view of coil 202 from the X direction.

[0105] As shown in Figures 12A and 12B, the coil 202 has a winding 210 and a core 211. Current is applied to the winding 210 by the current controller 313. When current is applied to the winding 210, a magnetic path 212, which is a path for magnetic flux, is formed. The magnetic flux in the magnetic path 212 thus formed creates an attractive force between the coil 202 and the yoke plate 103.

[0106] The relationship between the current applied to coil 202 and the magnitude of the force acting between coil 202 and yoke plate 103 will be explained in more detail using Figures 12A to 13. Figure 13 is a schematic graph showing the relationship between the current applied to coil 202 and the magnitude of the attractive force acting between coil 202 and yoke plate 103. In the graph shown in Figure 13, the horizontal axis represents the amount of current I applied to coil 202, and the vertical axis represents the magnitude of the attractive force Fz acting between coil 202 and yoke plate 103. The graph shown in Figure 13 shows an attractive force profile 604 that shows the magnitude of the attractive force Fz as a function of the amount of current I.

[0107] When the distance in the Z direction between the coil 202 and the yoke plate 103 is constant, the attractive force Fz is approximately proportional to the square of the current I. Here, in the graph shown in Figure 13, F0 is the magnitude of the average force acting on each coil necessary to compensate for the gravitational force mg acting on the movable element 101.

[0108] Here, we set the numerical values ​​and symbols as follows: Base area of ​​core 211 of one coil 202: S = 0.01 [m²] 2 ] A portion of the mass of the movable element 101 compensated by one coil 202: F0 = 100 [N] (approximately 10 [kg]) Permeability of vacuum: μ0 = 4π × 10⁻⁶ -7 Air gap: gap [m] Number of coil turns: n [turns] Coil current: I [A] Magnetic flux density between core 211 and yoke plate 103: B[T]

[0109] Assuming that the permeability of the core 211 and the yoke plate 103 is sufficiently large compared to the permeability of vacuum, Fz and B can be approximately calculated using the following equations (8a) and (8b), respectively. Fz = S * B 2 / (2*μ0) …Equation (8a) B = n * I * μ 0 / (2 * gap) ... Equation (8b)

[0110] Here, when the number of turns N is 500 and the coil current I0 is 1.0 A, the air gap can be calculated as 0.006266 m using equations (8a) and (8b).

[0111] Here, let Q be the point in the suction force profile 604 where I=I0 and Fz=F0. We will now explain the area around this point Q.

[0112] If the gap were to change from 0.006266[m] to 0.25mm larger, the coil 202 would need to generate a larger magnetomotive force to compensate for the expanding gap. If we calculate equations (8a) and (8b) using a gap of 0.006516[m] to generate the same Fz, the coil current I is calculated to be 1.0399[A]. Since this is a current value, the fluctuation in the coil current value during the transport of the movable element 101 is sufficiently small compared to the reference coil current I0.

[0113] Therefore, around point Q, the relationship between the additional current dI applied to the current I0 and the magnitude of the additional force dF generated in the Z direction by the application of current dI is given by equation (8c). Note that the relationship shown in equation (8c) does not hold around the origin O. dF ∝ dI …Equation (8c)

[0114] Here, the ratio of dF to dI is defined by the following equation (8d). dF / dI = Ez …Equation (8d)

[0115] In the thrust constant profile 601 shown in Figure 11, Ez(j,P) is shown. Ez(j,P) is the ratio shown in equation (8d). That is, Ez(j,P) is the ratio of the magnitude of the additional force dF generated in the Z direction to the current dI when an additional current dI is applied to the j-th coil 202 in addition to the current I0 that is applied on average when the movable element 101 is in position P.

[0116] The above notation method will be used to explain the case with reference to Figure 10, using j as an indicator to identify coil 202. Hereafter, for simplicity, the additional force dFzj in the Z direction will be simply denoted as Fzj, and the additional current dIj will be denoted as Ij.

[0117] The additional force Fzj in the Z direction generated by the j-th coil 202 is given by equation (9a), where Ij is the additional current applied to the j-th coil 202. Fzj=Ez(j,P)*Ij …Equation (9a)

[0118] Furthermore, let X(j,P) be the relative position in the X direction as seen from the center Oc of the movable element 101 of the j-th coil 202, and let Y(j,P) be the relative position in the Y direction as seen from the center Oc of the movable element 101 of the j-th coil 202. Then, the force component Tz in the Z direction, the torque component Twx in the Wx direction, and the torque component Twy in the Wy direction are expressed by the following equations (9b), (9c), and (9d), respectively. Tz = Σ(Ez(j,P)*Ij) …Equation (9b) Twx=Σ(-Ez(j,P)*Y(j,P)*Ij) …Equation (9c) Twy=Σ(Ez(j,P)*X(j,P)*Ij) …Formula (9d)

[0119] By applying a current Ij that satisfies equations (9b), (9c), and (9d) above to each coil 202, the desired force and torque components (Tz, Twx, Twy) can be obtained.

[0120] Here, we define the torque contribution matrix M. The torque contribution matrix M is a matrix that shows the magnitude of the contribution to each force component and torque component (Tz, Twx, Twy) when a unit current is applied to each of the 1st to jth coils 202 when the movable element 101 is in position P. In this way, the torque contribution matrix M is used to determine the current value applied to each coil 202 using information on the contribution of the unit current applied to each coil 202 to each component of the force component and torque component (Tz, Twx, Twy).

[0121] In the torque contribution matrix M, the first row corresponds to the Z direction, the second row to the Wx direction, and the third row to the Wy direction. Then, the elements M(1,j), M(2,j), and M(3,j) in the first row j, second row j, and third row j of the torque contribution matrix M are expressed by the following equations (10a), (10b), and (10c), respectively. The torque contribution matrix M is a 3xN matrix. Note that each row of the torque contribution matrix M is linearly independent of the others. M(1,j)=Ez(j,P)...Formula (10a) M(2,j)=-Ez(j,P)*Y(j,P)...Formula (10b) M(3,j)=Ez(j,P)*X(j,P)...Formula (10c)

[0122] On the other hand, a column vector is introduced as the coil current vector Is, whose elements are the currents I1 to IN applied to the 1st to Nth coils 202. The coil current vector Is is an N x 1 column vector represented by the following equation (10d). Is=Tr(I1,I2,…,Ij,…,IN)…Formula (10d)

[0123] Here, the torque vector Tq is defined by the following equation (11). Tq = Tr(Tz, Twx, Twy) …Equation (11)

[0124] Then, from equations (9b) to (9d), (10a) to (10d), and (11), we obtain equation (12). Tq=M*Is…Equation (12)

[0125] Here, we introduce the suspected current vector K. The suspected current vector K is a 3x1 column vector, and if Tr(M) is the transpose of the torque contribution matrix M, then it is a vector that satisfies equation (13). Tr(M)*K=Is...Equation (13)

[0126] By expressing the coil current vector Is by equation (13), a larger current value can be applied to coil 202, which has a large contribution to Tz, Twx, and Twy, thus enabling efficient current application.

[0127] Equation (12) can be transformed into equation (14) using equation (13). Tq=M*Tr(M)*K...Equation (14)

[0128] In equation (14), M*Tr(M) is a 3x3 square matrix, since it is the product of a 3xN matrix and an Nx3 matrix. Also, each row of the torque contribution matrix M is linearly independent of the others. Therefore, the inverse of M*Tr(M) can always be obtained. Thus, equation (14) can be transformed into equation (15). K=Inv(M*Tr(M))*Tq...Equation (15)

[0129] From equations (13) and (15), we ultimately obtain the coil current vector Is, which is represented by equation (16). In this way, the coil current vector Is can be uniquely determined. Tr(M)*Inv(M*Tr(M))*Tq=Is...Equation (16)

[0130] By calculating the coil current vector Is in the manner described above, the current to be applied to each coil 202 can be determined. This allows the force component Tz in the Z direction, the torque component Twx in the Wx direction, and the torque component Twy in the Wy direction to be applied independently to the movable element 101, thereby stabilizing the posture of the movable element 101 in the Z, Wx, and Wy directions.

[0131] Next, the current applied to the coil 208 to apply the force component Ty in the Y direction and the torque component Twz in the Wz direction to the movable element 101 will be explained using Figures 14 and 15. The force component Ty and the torque component Twz each act in the horizontal direction. Figure 14 is a schematic diagram of the movable element 101 viewed from top to bottom along the Z direction. Figure 15 is a graph schematically showing the attractive force profile 605 in the Y direction. In the graph shown in Figure 15, the horizontal axis represents the current applied to the coil 208, and the vertical axis represents the force acting on the movable element 101.

[0132] For simplicity, Figure 14 shows a case where four coils 208aR, 208bR, 208aL, and 208bL are installed on the stator 201 and face the movable element 101. Furthermore, coils 208aL and 208aR act as a single coil 208a. Similarly, coils 208bL and 208bR act as a single coil 208b. Thus, the j-th pair of coils 208jR and 208jL act as a single coil 208j.

[0133] In Figure 15, the attractive force profile 605 shows the relationship between the magnitudes IL and IR of the currents applied to the j-th pair of coils 208j and the magnitude of the force Fy acting on the movable element 101. There is no repulsive force between the coil 208 and the yoke plate 103; only an attractive force acts between them. Therefore, when applying a force to the movable element 101 in the Y+ direction, the current is applied to the R-side coil 208jR within the range 605a of the attractive force profile 605. When applying a force to the movable element 101 in the Y- direction, the current is applied to the L-side coil 208jL within the range 605b of the attractive force profile 605.

[0134] For example, when applying a force Fa in the Y+ direction, a current Ia can be applied to the R-side coil 208jR. Also, for example, when applying a force Fb in the Y- direction, a current Ib can be applied to the L-side coil 208jL.

[0135] Let j be an index that identifies a pair of coils 208. Let X(j,P) be the relative position in the X direction of the j-th pair of coils 208 as viewed from the center Oc of the movable element 101. Let Fyj be the force in the Y direction applied by the j-th pair of coils 208. Then, the horizontal force component Ty in the Y direction and the torque component Twz in the Wz direction are expressed by the following equations (17a) and (17b), respectively. Ty=ΣFyj …Equation (17a) Twz=Σ(-Fyj*X(j,P)) …Equation (17b)

[0136] Here, the Y-direction force vector Fys, whose elements are the Y-direction forces Fy1, Fy2, ..., FyN applied by the 1st to Nth coils 208, is defined by the following equation (17c). Fys=Tr(Fy1,Fy2,…,Fyj,…,FyN)…Formula (17c)

[0137] Furthermore, the torque vector Tq is defined by the following equation (17d). Tq=Tr(Ty,Twz) …Equation (17d)

[0138] In the torque contribution matrix M, the first row corresponds to the Y direction and the second row corresponds to the Wz direction. Then, the elements M(1,j) and M(2,j) in the first row and second row and j columns of the torque contribution matrix M are expressed by the following equations (17e) and (17f), respectively. M(1,j)=1 …Equation (17e) M(2,j)=X(j,P)...Formula (17f)

[0139] To calculate the current applied to coil 208, first determine the Y-direction force vector Fys that satisfies the following equation (17g). Tq=M*Fys…Formula (17g)

[0140] Since Tq is a 2x1 vector and M is a 2xN matrix, there are infinitely many combinations of elements for the Y-direction force vector Fys that satisfy equation (17g), but it can be uniquely calculated according to the following method.

[0141] Here, we introduce a 2x1 pseudocurrent vector K. The pseudocurrent vector K is a vector that satisfies equation (17h) if Tr(M) is the transpose of the torque contribution matrix M. Tr(M)*K=Fys...Formula (17h)

[0142] Equation (17g) can be transformed into equation (17i) using equation (17h). Tq=M*Tr(M)*K …Equation (17i)

[0143] Since M*Tr(M) is the product of a 2x2 matrix and an Nx2 matrix, it is a 2x2 square matrix. Also, each row of the torque contribution matrix M is linearly independent of the others. Therefore, the inverse matrix of M*Tr(M) can always be obtained. Thus, equation (17i) can be transformed into equation (17j). K=Inv(M*Tr(M))*Tq...Formula (17j)

[0144] From equations (17h) and (17j), we finally obtain the Y-direction force vector Fys, which is represented by the following equation (17k). This allows us to uniquely calculate the Y-direction force vector Fys. Tr(M)*Inv(M*Tr(M))*Tq=Fys...Formula (17k)

[0145] After obtaining the Y-direction force vector Fys, the current to be applied to each coil 208 can be calculated by working backward from the previously calculated or measured attractive force profile 605.

[0146] As described above, the current to be applied to each coil 208 can be determined. This allows the force component Ty in the Y direction and the torque component Twz in the Wz direction to be applied independently to the movable element 101, thereby stabilizing the posture of the movable element 101 in the Y and Wz directions. For example, a current can be applied to the coil 208 such that the torque in the Wz direction is always zero.

[0147] In this embodiment, the current values ​​applied to the multiple coils 202 and 208 are controlled. This controls the movement of the movable element 101 so that it achieves the target orientation (Y,Z,Wx, Wy,Wz).

[0148] Next, the control method for the coil 207 that applies thrust in the X direction, which is the transport direction, to the movable element 101 will be described. The transport system 1 according to this embodiment is a transport system using an induction linear motor. The coil 207 generates an electromagnetic force between itself and the conductive plate 107 of the movable element 101, thereby applying thrust in the X direction, i.e., the force component Tx in the X direction, to the movable element 101. The conductive plate 107 is not particularly limited, but a plate made of aluminum, for example, which has relatively low electrical resistance, is used.

[0149] Each coil 207 generates a moving magnetic field in the X direction, which is the transport direction, when current is applied, thereby generating an electromagnetic force between the coil 207 and the conductive plate 107. As a result, each coil 207 generates a force component Tx as thrust in the X direction, which is the transport direction, on the movable element 101. If the speed of the movable element 101 is insufficient, the current applied to each coil 207 can be increased, or the timing of the current applied to each coil 207 can be changed so that the speed at which the moving magnetic field moves increases.

[0150] As described above, the integrated controller 301 determines and controls the current command values ​​of the currents applied to each coil 202, 207, and 208. This allows the integrated controller 301 to control the orientation of the movable element 101, which is transported by the stator 201, in six axes, while simultaneously controlling the non-contact transport of the movable element 101 on the stator 201. Note that all or part of the functions of the integrated controller 301 as a control device may be replaced by the coil controller 302 or other control devices.

[0151] In this embodiment, we have described a case where the current of coil 207 is controlled in the same way as that of coils 202 and 208, but this is not the only case. For example, more simply, an induction motor controller can be connected to the integrated controller 301, and the induction motor controller can be configured to control the current of each coil 207 so that a constant moving magnetic field is generated.

[0152] As described above, according to this embodiment, force components and torque components (Tx, Ty, Tz, Twx, Twy, Twz) for six axes can be applied independently to the movable element 101. Therefore, according to this embodiment, the movable element 101 can be transported stably in a non-contact state in the X direction while stabilizing the posture of the movable element 101 in the Y, Z, Wx, Wy, and Wz directions.

[0153] The transport system 1 according to this embodiment can transport the movable element 101 to the work area 707 of the assembly device 701 while controlling the posture of the movable element 101 as described above, and can land and stop the movable element 101 in the Z direction in the work area 707. The transport system 1 can land and stop the movable element 101 in the work area 707 by adjusting the stopping position of the movable element 101 so that each of the Z-axis positioning parts 706 on the movable element 101 side contacts the corresponding Z-axis positioning part 705 on the stator 201 side.

[0154] The assembly robot 703 of the assembly device 701 performs processing operations such as assembling parts 704 onto a workpiece 102 that has been transported to the work area 707, attached to or held by the movable element 101, and mounted on the movable element 101. Specifically, the assembly robot 703 assembles parts 704 onto the workpiece 102 mounted on the movable element 101 in the Z direction. During the processing operation, as shown in Figures 2A and 2B, an external force 704F is applied in the -Z direction to the workpiece 102 and the movable element 101 by the assembly robot 703 as it assembles parts 704 in the Z direction.

[0155] On the other hand, when assembling the part 704 in the Z direction in this embodiment, the Z-axis positioning part 705 on the stator 201 side and the Z-axis positioning part 706 on the movable part 101 side are in contact. As a result, the external force 704F during machining can be received by the Z-axis positioning parts 705 and 706, which are in contact with each other. At this time, the Z-axis positioning parts 705 and 706 function as stoppers that limit the range of motion of the movable part 101 in the Z direction. Thus, in this embodiment, the movable part 101 can maintain a stable position against the external force 704F during machining, and the workpiece 102 can be positioned with high accuracy. Note that the Z-axis positioning parts 705 and 706 may be configured to move in the -Z direction from which the external force 704F is applied when the external force 704F is applied.

[0156] Furthermore, as shown in Figure 2B, the Z-axis positioning parts 705 and 706, which are in contact with each other, constitute a support structure 708 that supports the movable element 101 that has landed in the Z direction. The support structure 708 is configured such that the Z-axis positioning parts 705 and 706, which are in contact with each other, are arranged among all or some of the vertices of a polygon. The support structure 708 may also consist of one or two sets of Z-axis positioning parts 705 and 706 that are in contact with each other.

[0157] The Z-axis positioning sections 705 and 706 that constitute the support structure 708 are positioned such that the direction vector of the external force 704F during machining falls inside the support structure 708 composed of the Z-axis positioning sections 705 and 706. This reduces the rotational force acting on the workpiece 102 and the movable element 101 due to the external force 704F during machining, and furthermore, prevents the generation of such rotational force. Thus, in this embodiment, the position of the movable element 101 can be stabilized regardless of the magnitude of the external force 704F in the Z direction applied to the movable element 101 during machining of the workpiece 102, and especially even against large external forces 704F during machining. Furthermore, in this embodiment, by stabilizing the position of the movable element 101, the workpiece 102 can be positioned with high precision.

[0158] Next, a control method for the transport system 1 for positioning the movable element 101 using the Z-axis positioning unit 705 on the stator 201 side and the Z-axis positioning unit 706 on the movable element 101 side will be explained with reference to Figure 16. Figure 16 is a flowchart showing the control method for the transport system 1 for positioning the movable element 101 according to this embodiment. The computer, which functions as an integrated controller 301, can execute the control method shown in Figure 16 by reading a program for executing the control method shown in Figure 16 from a storage medium that the computer can read and executing the program.

[0159] First, the integrated controller 301 controls the levitation and transport of the movable element 101, including the workpiece 102, by controlling the current command values ​​of the currents applied to each coil 202, 207, and 208. As a result, the integrated controller 301 levitates the movable element 101 in the +Z direction and transports it in the X direction to above the Z-axis positioning unit 705 on the stator 201 side in the work area 707. Subsequently, the integrated controller 301 positions the movable element 101 during processing by the assembly robot 703 of the assembly device 701 according to the flowchart shown in Figure 16.

[0160] First, the integrated controller 301 executes step S100, which involves landing the movable element 101 in the Z direction, which is the machining axis direction. The machining axis direction is the direction in which machining is performed by the assembly robot 703. When the movable element 101 lands in the Z direction, the integrated controller 301 controls the current command values ​​of the current applied to each coil 202, 207, and 208 so that the Z-axis positioning unit 706 on the movable element 101 side contacts the corresponding Z-axis positioning unit 705 on the stator 201 side.

[0161] Next, the integrated controller 301 executes step S101, performing a pressing control that presses the movable element 101 in the Z direction. In the pressing control in the Z direction, the integrated controller 301 controls the current command value of the current applied to each coil 202 to control the force component Tz in the Z direction acting on the movable element 101, thereby pressing the movable element 101 in the -Z direction. As a result, the integrated controller 301 presses the Z-axis positioning part 706 on the movable element 101 side against the Z-axis positioning part 705 on the stator 201 side. When the Z-axis positioning part 706 is pressed against the Z-axis positioning part 705, the static friction force in the X direction and the static friction force in the Y direction increase between the Z-axis positioning part 705 and the Z-axis positioning part 706, which are in contact with each other. Therefore, when the workpiece 102 is processed from the Z direction by the assembly robot 703, the movement of the movable element 101 in the Z direction is restricted, and the position of the movable element 101 is less likely to shift in the X and Y directions. Thus, the integrated controller 301 lands the movable element 101 in the Z direction, which is the direction of the external force 704F, and performs pressing control by pressing the movable element 101 against the Z-axis positioning units 705 and 706 so that the movement of the movable element 101 in the Z direction is restricted.

[0162] As described above, the integrated controller 301 performs positioning control of the movable element 101 while the assembly robot 703 processes the workpiece 102. After processing is complete, the integrated controller 301 can terminate the positioning control and resume the levitation and transport of the movable element 101.

[0163] Thus, in this embodiment, after transporting the workpiece 102 together with the movable element 101, the movable element 101 is positioned using the Z-axis positioning units 705 and 706. This allows the movable element 101 to maintain a stable position against large external forces applied to the workpiece 102 during processing. As a result, the workpiece 102 is positioned with high precision, and the workpiece 102 is processed with high precision by the processing equipment to manufacture an article.

[0164] Based on the above, according to this embodiment, the position of the movable element 101 can be stabilized regardless of the magnitude of the external force applied to the movable element 101 during the machining of the workpiece 102.

[0165] [Second Embodiment] A second embodiment of the present invention will be described with reference to Figures 17A to 18. Components similar to those in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted or simplified.

[0166] First, the configuration of the transport system 1 according to this embodiment will be explained using Figures 17A and 17B. Figures 17A and 17B are schematic diagrams showing the configuration of the transport system 1 including the movable element 101 and the stator 201 according to this embodiment. Figure 17A shows the main parts of the movable element 101 and the stator 201. Figure 17B shows the Y-axis positioning part 1705 on the movable element 101 and the stator 201 side and the Y-axis positioning part 1706 on the movable element 101 side. Figure 17A is a view of the movable element 101 and the stator 201 from the X direction, and Figure 17B is a view of the movable element 101 from diagonally above.

[0167] The basic configuration of the transport system 1 according to this embodiment is the same as that of the first embodiment. In addition to the configuration of the first embodiment, the transport system 1 according to this embodiment has a Y-axis positioning section 1705 on the stator 201 side and a Y-axis positioning section 1706 on the movable element 101 side as positioning sections for positioning the movable element 101 in the Y direction. The Y-axis positioning sections 1705 and 1706 are members that restrict the movement of the movable element 101 in the Y direction, which is the direction of the external force 1704F, described later, applied to the workpiece 102 and the movable element 101 when the workpiece 102 is processed.

[0168] The movable element 101 is designed so that, for example, a workpiece 1102 can be attached to or held above or below it for transport. Figure 17A shows the workpiece 1102 mounted on the movable element 101. The mechanism for attaching or holding the workpiece 1102 to the movable element 101 is not particularly limited, but general attachment and holding mechanisms such as mechanical hooks and electrostatic chucks can be used.

[0169] The stator 201 has multiple Y-axis positioning sections 1705. The Y-axis positioning sections 1705 have surface accuracy on the surface facing the Y direction and can be used as a positioning reference in the Y direction. The movable section 101 has multiple Y-axis positioning sections 1706 corresponding to the multiple Y-axis positioning sections 1705. The Y-axis positioning sections 1706 have surface accuracy on the surface facing the Y direction and can be used as a positioning reference in the Y direction.

[0170] In the stator 201, the multiple Y-axis positioning sections 1705 are installed on the side surfaces of the area where the movable section 101 lands. The area where the movable section 101 lands is the work area 1707 where the assembly device 701 assembles the parts 1704 onto the workpiece 1102 on the movable section 101. Each of the multiple Y-axis positioning sections 1705 is a columnar member having a side surface parallel to the XZ plane facing the -Y direction. The side surfaces of the multiple Y-axis positioning sections 1705 are all at the same position in the Y direction. The multiple Y-axis positioning sections 1705 are provided on the side surface which is the inner wall surface of the stator 201. The material of the multiple Y-axis positioning sections 1705 may be the same as the material of the stator 201. In that case, the multiple Y-axis positioning sections 1705 are formed integrally with the stator 201. In addition, an elastic body such as rubber (not shown) may be provided between the multiple Y-axis positioning sections 1705 and the side surface of the stator 201. A Z-axis positioning unit 705 is installed on the floor of the work area 1707, similar to the first embodiment. However, the Z-axis positioning unit 705 is not necessarily required to be installed.

[0171] In the movable element 101, the multiple Y-axis positioning sections 1706 are installed on the side facing the side of the stator 201 where the Y-axis positioning section 1705 is installed. Each of the multiple Y-axis positioning sections 1706 is a columnar member having a side parallel to the XZ plane facing the +Y direction. The sides of the multiple Y-axis positioning sections 1706 are all at the same position in the Y direction. The multiple Y-axis positioning sections 1706 are positioned to face the corresponding Y-axis positioning section 1705. A Z-axis positioning section 706 is installed on the lower surface of the movable element 101, similar to the first embodiment. Note that the Z-axis positioning section 706 is not necessarily required to be installed.

[0172] As described later, the movable element 101, which is levitated in the +Z direction and transported in the X direction, lands in the Y direction in the work area 1707 such that the side surfaces of each Y-axis positioning part 1706 contact the side surfaces of the corresponding Y-axis positioning part 1705. The landed movable element 101 can be levitated again in the Y direction and transported. The Y-axis positioning parts 1705 and 1706 are installed within the movable range of the movable element 101 in the Y direction so that the movable element 101 can levitate again in the Y direction.

[0173] The movable element 101 and the stator 201 are equipped with processing equipment that performs machining operations on the workpiece 1102 transported by the movable element 101. Figure 17A shows an example of a processing equipment that performs machining operations on the workpiece 1102, in which the movable element 101 and the stator 201 are incorporated into an assembly device 701.

[0174] The assembly device 701 has an assembly robot 703 that performs assembly work on a workpiece 1102 attached to a movable element 101. The assembly work involves assembling a part 1704 onto the workpiece 1102. The assembly robot 703 is installed in the assembly device 701 so that it can perform assembly work on the workpiece 1102 attached to the upper part of the movable element 101. The assembly robot 703 assembles the part 1704 onto the workpiece 1102 attached to the upper part of the movable element 101, which has been transported to the work area 1707 in front of the installation location of the assembly robot 703, from the Y direction.

[0175] The transport system 1 according to this embodiment can transport the movable element 101 to the work area 1707 of the assembly device 701 while controlling the posture of the movable element 101 in the same manner as in the first embodiment, and can land and stop the movable element 101 in the work area 1707 in the Y direction. The transport system 1 can land and stop the movable element 101 in the work area 1707 by adjusting the stopping position of the movable element 101 so that each of the Y-axis positioning parts 1706 on the movable element 101 side contacts the corresponding Y-axis positioning part 1705 on the stator 201 side. In addition, the transport system 1 according to this embodiment can land the movable element 101 in the Z direction in the same manner as in the first embodiment.

[0176] The assembly robot 703 of the assembly device 701 performs processing operations such as assembling a part 1704 onto a workpiece 1102 that has been transported to the work area 1707 and is attached to or held by the movable element 101. Specifically, the assembly robot 703 assembles the part 1704 onto the workpiece 1102 in the Y direction. During processing operations by the assembly device 701, as shown in Figures 17A and 17B, an external force 1704F is applied in the +Y direction to the workpiece 1102 and the movable element 101 by the assembly robot 703 as it assembles the part 1704 in the Y direction.

[0177] On the other hand, when assembling the part 1704 in the Y direction in this embodiment, the Y-axis positioning part 1705 on the stator 201 side and the Y-axis positioning part 1706 on the movable part 101 side are in contact. As a result, the external force 1704F during machining can be received by the Y-axis positioning part 1705 and the Y-axis positioning part 1706. At this time, the Y-axis positioning parts 1705 and 1706 function as stoppers that limit the range of motion of the movable part 101 in the Y direction. Thus, in this embodiment, the movable part 101 can maintain a stable position against the external force 1704F during machining, and the workpiece 102 can be positioned with high accuracy. Note that the Y-axis positioning parts 1705 and 1706 may be configured to move in the Y direction to which the external force 1704F is applied when the external force 1704F is applied.

[0178] Furthermore, as shown in Figure 17B, the Y-axis positioning parts 1705 and 1706, which are in contact with each other, constitute a support structure 1708 that supports the movable element 101 when it lands in the Y direction. The support structure 1708 is constructed by arranging the Y-axis positioning parts 1705 and 1706, which are in contact with each other, among all or some of the vertices of a polygon. The support structure 1708 may also consist of one or two sets of Y-axis positioning parts 1705 and 1706 that are in contact with each other. Note that Figure 17B shows a support structure 1708 composed of two sets of Y-axis positioning parts 1705 and 1706 that are in contact with each other.

[0179] In Figure 17B, the direction vector of the external force 1704F during machining is not located inside the support structure 1708, which is composed of the Y-axis positioning section 1705 and the Y-axis positioning section 1706. As a result, the external force 1704F during machining generates a rotational force around the X-axis on the movable element 101. Therefore, from the viewpoint of stabilizing the position of the movable element 101, it is necessary to reduce the rotational force generated around the X-axis on the movable element 101 by the external force 1704F during machining, or to prevent the generation of such a rotational force.

[0180] First, the Y-axis positioning section 1705 and the Y-axis positioning section 1706 can be positioned such that the direction vector of the external force 1704F during machining falls inside the support structure 1708, which is composed of the Y-axis positioning section 1705 and the Y-axis positioning section 1706. In this case, the generation of rotational force around the X-axis due to the external force 1704F during machining can be prevented.

[0181] Furthermore, in order to reduce the rotational force generated around the X axis by the external force 1704F during machining, the distance between the point of application of the external force 1704F and the support structure 1708, which is composed of the Y-axis positioning section 1705 and the Y-axis positioning section 1706, should be reduced. In this case, the torque component Twx around the X axis acting on the movable element 101 is sufficiently large compared to the rotational force generated around the X axis on the movable element 101 by the external force 1704F during machining. Thus, in this embodiment, the position of the movable element 101 can be stabilized regardless of the magnitude of the external force 1704F in the Y direction applied to the movable element 101 during machining of the workpiece 1102, and especially even against large external forces 1704F during machining. In addition, in this embodiment, by stabilizing the position of the movable element 101, the workpiece 1102 can be positioned with high accuracy.

[0182] Furthermore, in this embodiment as well, when machining the workpiece 1102, the Z-axis positioning part 705 on the stator 201 side and the Z-axis positioning part 706 on the movable part 101 side can be kept in contact, similar to the first embodiment. This makes it possible to reduce or prevent misalignment of the movable part 101 in the Z direction during machining.

[0183] Next, a control method for the transport system 1 for positioning the movable element 101 using the Y-axis positioning unit 1705 on the stator 201 side and the Y-axis positioning unit 1706 on the movable element 101 side will be explained with reference to Figure 18. Figure 18 is a flowchart showing the control method for the transport system 1 for positioning the movable element 101 according to this embodiment. The computer, which functions as an integrated controller 301, can execute the control method shown in Figure 18 by reading a program for executing the control method shown in Figure 18 from a storage medium that the computer can read and executing the program.

[0184] First, the integrated controller 301 controls the levitation and transport of the movable element 101, including the workpiece 1102, in the same manner as in the first embodiment. As a result, the integrated controller 301 levitates the movable element 101 in the +Z direction and transports it in the X direction to the side of the Y-axis positioning unit 1705 on the stator 201 side in the work area 1707. Subsequently, the integrated controller 301 positions the movable element 101 during processing by the assembly robot 703 of the assembly device 701 according to the flowchart shown in Figure 18.

[0185] First, the integrated controller 301 performs step S200 to land the movable element 101 in the Y direction. When the movable element 101 lands in the Y direction, the integrated controller 301 controls the current command values ​​of the current applied to each coil 202, 207, and 208 so that the Y-axis positioning unit 1706 on the movable element 101 side contacts the corresponding Y-axis positioning unit 1705 on the stator 201 side.

[0186] Next, the integrated controller 301 executes step S201 to stop control of the movable element 101 in the Y direction. The integrated controller 301 can stop control in the Y direction by setting Ty=0 among the force and torque components (Tx, Ty, Tz, Twx, Twy, Twz) of the six axes. The integrated controller 301 can set Ty=0 by controlling the current command value of the current applied to each coil 208.

[0187] Next, the integrated controller 301 executes step S202 to land the movable element 101 in the Z direction. When the movable element 101 lands in the Z direction, the integrated controller 301 controls the current command values ​​of the current applied to each coil 202, 207, and 208 so that the Z-axis positioning unit 706 on the movable element 101 side contacts the corresponding Z-axis positioning unit 705 on the stator 201 side.

[0188] Next, the integrated controller 301 executes step S203 to stop control of the movable element 101 in the Z direction. The integrated controller 301 can stop control in the Z direction by setting Tz = 0 among the force and torque components (Tx, Ty, Tz, Twx, Twy, Twz) of the six axes. The integrated controller 301 can set Tz = 0 by controlling the current command value of the current applied to each coil 202. Alternatively, the integrated controller 301 can omit step S203 and execute the next step S204 immediately following step S202.

[0189] Next, the integrated controller 301 executes step S204 and performs pressing control to press the movable element 101 in the Z direction. In the pressing control in the Z direction, the integrated controller 301 presses the movable element 101 in the -Z direction in the same manner as in the first embodiment, pressing the Z-axis positioning part 706 on the movable element 101 side against the Z-axis positioning part 705 on the stator 201 side. This reduces or prevents misalignment of the movable element 101 in the Z direction when the workpiece 1102 is machined from the Y direction.

[0190] Next, the integrated controller 301 executes step S205, performing pressing control to press the movable element 101 in the Y direction. In pressing control in the Y direction, the integrated controller 301 controls the Y-direction force component Ty acting on the movable element 101 by controlling the current command value of the current applied to each coil 208, thereby pressing the movable element 101 in the +Y direction. As a result, the integrated controller 301 presses the Y-axis positioning part 1706 on the movable element 101 side against the Y-axis positioning part 1705 on the stator 201 side. When the Y-axis positioning part 1706 is pressed against the Y-axis positioning part 1705, the static friction force in the X direction increases between the Y-axis positioning part 1705 and the Y-axis positioning part 1706, which are in contact with each other. Therefore, when the workpiece 1102 is processed from the Y direction by the assembly robot 703, the movement of the movable element 101 in the Y direction is restricted, and the position of the movable element 101 is less likely to shift in the X direction.

[0191] Thus, the integrated controller 301 lands the movable element 101 in the Y direction, which is the direction of the external force 1704F, and performs pressing control by pressing the movable element 101 against it using the Y-axis positioning units 1705 and 1706 so that the movement of the movable element 101 in the Y direction is restricted. The integrated controller 301 also lands the movable element 101 in the Z direction and performs pressing control by pressing the movable element 101 against it using the Z-axis positioning units 705 and 706 so that the movement of the movable element 101 in the Z direction is restricted.

[0192] Next, the integrated controller 301 executes step S206, generating a torque component Twx in the Wx direction as a rotational force around the X axis to counteract the rotational force around the X axis generated in the movable element 101 by the pressing control in the Y and Z directions. The integrated controller 301 controls the torque component Twx in the Wx direction acting on the movable element 101 by controlling the current command value of the current applied to each coil 202. By counteracting the rotational force caused by the pressing control, the position of the movable element 101 can be further stabilized.

[0193] As described above, the integrated controller 301 performs positioning control of the movable element 101 while the assembly robot 703 processes the workpiece 1102. After processing is complete, the integrated controller 301 can terminate the positioning control and resume the levitation and transport of the movable element 101.

[0194] Thus, in this embodiment, after transporting the workpiece 1102 together with the movable element 101, the movable element 101 is positioned using the Y-axis positioning units 1705 and 1706 and the Z-axis positioning units 705 and 706. This allows the movable element 101 to maintain a stable position against large external forces applied to the workpiece 1102 during processing. As a result, the workpiece 1102 is positioned with high precision, and the workpiece 1102 is processed with high precision by the processing equipment to manufacture an article.

[0195] Based on the above, according to this embodiment, the position of the movable element 101 can be stabilized regardless of the magnitude of the external force applied to the movable element 101 during the machining of the workpiece 1102.

[0196] Although the above description includes a configuration in which Y-axis positioning units 1705 and 1706 and Z-axis positioning units 705 and 706 are installed, the system is not limited to this configuration. The Z-axis positioning units 705 and 706 do not necessarily have to be installed. In this case, the integrated controller 301 can position the movable element 101 in the Z direction by controlling the current command value of the current applied to each coil 207 and thereby controlling the force component Tz in the Z direction acting on the movable element 101.

[0197] Furthermore, the order of each step from step S200 to step S206 is not limited to the case shown in Figure 18, and can be changed as appropriate. For example, step S200 and the following step S201, and step S202 and the following step S202 may be executed in reverse order or in parallel. Also, for example, step S204 and step S205 may be executed in reverse order or in parallel.

[0198] [Third Embodiment] A third embodiment of the present invention will be described with reference to Figures 19A to 22. Components similar to those in the first and second embodiments will be denoted by the same reference numerals, and their descriptions will be omitted or simplified.

[0199] First, the configuration of the transport system 1 according to this embodiment will be explained using Figures 19A and 19B. Figures 19A and 19B are schematic diagrams showing the configuration of the transport system 1 including the movable element 101 and the stator 201 according to this embodiment. Figure 19A shows the main parts of the movable element 101 and the stator 201 extracted. Figure 19B shows the X-axis positioning part 2705 on the movable element 101 and the X-axis positioning part 2706 on the movable element 101 side extracted. Figure 19A is a view of the movable element 101 and the stator 201 from the X direction, and Figure 19B is a view of the movable element 101 from diagonally above.

[0200] The basic configuration of the transport system 1 according to this embodiment is the same as that of the second embodiment. In addition to the configuration of the second embodiment, the transport system 1 according to this embodiment has an X-axis positioning section 2705 on the stator 201 side and an X-axis positioning section 2706 on the movable element 101 side as positioning sections for positioning the movable element 101 in the X direction. The X-axis positioning sections 2705 and 2706 are members that restrict the movement of the movable element 101 in the X direction when processing the workpiece 102.

[0201] The movable element 101 is designed so that, for example, a workpiece 102 can be attached to or held above or below it for transport. Figure 19A shows the workpiece 102 mounted on the movable element 101. The mechanism for attaching or holding the workpiece 102 to the movable element 101 is not particularly limited, but general attachment and holding mechanisms such as mechanical hooks and electrostatic chucks can be used.

[0202] The stator 201 has an X-axis positioning section 2705. The X-axis positioning section 2705 has surface accuracy on the surface facing the X direction and can be used as a positioning reference in the X direction. When positioning the movable element 101, the X-axis positioning section 2705 is positioned so as to block the transport direction (X direction) of the movable element 101. Therefore, the X-axis positioning section 2705 is movable and is configured to advance into the transport path, i.e., the movable range of the movable element 101 in the X direction, when positioning the movable element 101.

[0203] Furthermore, the X-axis positioning unit 2705 does not necessarily have to be movable; it can also be a fixed unit fixed to a predetermined position on the transport path. In this case, the shape and transport position of the movable element 101 can be adjusted so that the movable element 101 is transported while avoiding the X-axis positioning unit 2705.

[0204] Furthermore, the movable element 101 has an X-axis positioning section 2706 that corresponds to the X-axis positioning section 2705. The X-axis positioning section 2706 has surface accuracy on the surface facing the X direction and can be used as a positioning reference in the X direction.

[0205] In the stator 201, the X-axis positioning unit 2705 is installed so as to be able to extend into the area where the movable element 101 lands. The area where the movable element 101 lands is the work area 2707 where the assembly device 701 assembles the parts 704 onto the workpiece 102 on the movable element 101. The X-axis positioning unit 2705 is a columnar member having a side surface parallel to the YZ plane facing the -X direction. The floor surface and side surface of the work area 2707 are installed, respectively, with a Z-axis positioning unit 705 and a Y-axis positioning unit 1705, similar to the second embodiment. Note that the Z-axis positioning unit 705 and the Y-axis positioning unit 1705 are not necessarily required to be installed.

[0206] In the movable element 101, the X-axis positioning section 2706 is installed on the side of the movable element 101 facing the direction of travel. The X-axis positioning section 2706 is a columnar member having a side surface parallel to the YZ plane facing the +X direction. The X-axis positioning section 2706 is positioned so as to be able to face the corresponding X-axis positioning section 2705. Similar to the second embodiment, the Z-axis positioning section 706 and the Y-axis positioning section 1706 are installed on the lower surface and side surface of the movable element 101. Note that the Z-axis positioning section 706 and the Y-axis positioning section 1706 are not necessarily required to be installed.

[0207] As described later, the movable element 101, which is levitated in the +Z direction and transported in the X direction, lands in the work area 2707 in the X direction such that the side surface of the X-axis positioning unit 2706 contacts the side surface of the corresponding X-axis positioning unit 2705. The landed movable element 101 can then be levitated and transported again.

[0208] The movable element 101 and the stator 201 are equipped with processing equipment that performs machining operations on the workpiece 102 transported by the movable element 101. Figure 19A shows an example of a processing equipment that performs machining operations on the workpiece 102, in which the movable element 101 and the stator 201 are incorporated into an assembly device 701.

[0209] The assembly apparatus 701 has the same configuration as the first embodiment, which includes an assembly robot 703. The assembly robot 703 assembles the part 704 from the Z direction onto the workpiece 102, which is attached to the upper part of the movable element 101 that has been transported to the work area 2707 in front of the installation location of the assembly robot 703.

[0210] The transport system 1 according to this embodiment can transport the movable element 101 to the work area 2707 of the assembly device 701 while controlling the posture of the movable element 101 in the same manner as in the first embodiment, and can land and stop the movable element 101 in the work area 2707 in the X direction. The transport system 1 can land and stop the movable element 101 in the work area 2707 by adjusting the stopping position of the movable element 101 so that the X-axis positioning part 2706 on the movable element 101 side contacts the corresponding X-axis positioning part 2705 on the stator 201 side. In addition, the transport system 1 according to this embodiment can land the movable element 101 in the Y direction and the Z direction in the same manner as in the second embodiment.

[0211] The assembly robot 703 of the assembly device 701 assembles the part 1704 in the Z direction to the workpiece 102, which is attached to or held by the movable element 101 that has been transported to the work area 2707, in the same manner as in the first embodiment. During the machining operation by the assembly device 701, as shown in Figures 19A and 19B, an external force 704F is applied to the workpiece 102 and the movable element 101 in the -Z direction, in the same manner as in the first embodiment.

[0212] On the other hand, when assembling the part 704 in the Z direction in this manner, the Z-axis positioning part 705 on the stator 201 side and the Z-axis positioning part 706 on the movable part 101 side are in contact, just as in the first embodiment. As a result, the external forces during machining can be received by the Z-axis positioning part 705 and the Z-axis positioning part 706. Thus, in this embodiment as well, the movable part 101 can maintain a stable position against large external forces 704F during machining, and the workpiece 102 can be positioned with high accuracy.

[0213] Furthermore, in this embodiment as well, when assembling the part 704, the Y-axis positioning portion 1705 on the stator 201 side and the Y-axis positioning portion 1706 on the movable element 101 side can be brought into contact, similar to the second embodiment. This makes it possible to reduce or prevent misalignment of the movable element 101 in the Y direction that occurs during machining.

[0214] Furthermore, in this embodiment, when assembling the part 704, the X-axis positioning part 2705 on the stator 201 side and the X-axis positioning part 2706 on the movable part 101 side are in contact. At this time, the X-axis positioning parts 2705 and 2706 function as stoppers that limit the range of motion of the movable part 101 in the X direction. This makes it possible to reduce or prevent misalignment of the movable part 101 in the X direction that occurs during machining. Note that the X-axis positioning parts 2705 and 2706 may be configured to be movable in the +X direction, which is the direction of advancement of the movable part 101, and in the -X direction, which is the direction of retraction, respectively.

[0215] Furthermore, the X-axis positioning unit 2706 on the movable element 101 side and the X-axis positioning unit 2705 on the stator 201 side can also have configurations different from those shown in Figures 19A and 19B, as shown in Figures 20A to 21B.

[0216] Figure 20A shows the X-axis positioning unit 3706 on the movable element 101 side as an alternative configuration of the X-axis positioning unit 2706 on the movable element 101 side, and the X-axis positioning unit 3705 on the stator 201 side as an alternative configuration of the X-axis positioning unit 2705 on the stator 201 side.

[0217] As shown in Figure 20A, the X-axis positioning unit 3705 on the stator 201 side is movable and moves in the +Z direction when positioning is required to position the movable element 101. During positioning, the movable element 101 moves in the +X direction. As a result, the X-axis positioning unit 3706 on the movable element 101 side and the X-axis positioning unit 3705 on the stator 201 side, which has moved in the +Z direction, come into contact, and positioning is achieved. In Figure 20A, when machining of the workpiece 102 is completed and the movable element 101 is to be levitated and transported again, the X-axis positioning unit 3705 on the stator 201 side moves in the -Z direction to secure a transport path for the movable element 101. In this way, the X-axis positioning unit 3705 is configured to be movable in order to secure a transport path for the movable element 101.

[0218] On the other hand, Figure 20B shows a case where the operation of the X-axis positioning unit 3705 on the stator 201 side and the X-axis positioning unit 3706 on the movable element 101 side is different from that shown in Figure 20A. That is, in Figure 20B, the X-axis positioning unit 3705 on the stator 201 side is fixed, while during positioning, the movable element 101 descends in the -Z direction and moves in the +X direction. As a result, the X-axis positioning unit 3706 on the movable element 101 side and the X-axis positioning unit 3705 on the stator 201 side come into contact, and positioning is achieved. In Figure 20B, when machining of the workpiece 102 is completed and the movable element 101 is to be levitated and transported again, the movable element 101 levitates in the +Z direction to a height that does not interfere with the X-axis positioning unit 3705 on the stator 201 side, thereby securing a transport path for the movable element 101.

[0219] Figure 21A shows the X-axis positioning unit 4706 on the movable element 101 side as an alternative configuration of the X-axis positioning unit 2706 on the movable element 101 side, and the X-axis positioning unit 4705 on the stator 201 side as an alternative configuration of the X-axis positioning unit 2705 on the stator 201 side.

[0220] As shown in Figure 21A, the X-axis positioning unit 4705 on the stator 201 side is movable and moves in the -Y direction when positioning is required to position the movable element 101. During positioning, the movable element 101 moves in the +X direction. As a result, the X-axis positioning unit 4706 on the movable element 101 side and the X-axis positioning unit 4705 on the stator 201 side, which has moved in the -Y direction, come into contact, and positioning is achieved. In Figure 21A, when machining of the workpiece 102 is completed and the movable element 101 is to be lifted and transported again, the X-axis positioning unit 4705 on the stator 201 side moves in the +Y direction to secure a transport path for the movable element 101. In this way, the X-axis positioning unit 4705 is configured to be movable in order to secure a transport path for the movable element 101.

[0221] On the other hand, Figure 21B shows a case where the operation of the X-axis positioning unit 4705 on the stator 201 side and the X-axis positioning unit 4706 on the movable element 101 side differs from that shown in Figure 21A. That is, in Figure 20B, the X-axis positioning unit 4705 on the stator 201 side is fixed, while during positioning, the movable element 101 moves in the +Y direction and then in the +X direction. As a result, the X-axis positioning unit 4706 on the movable element 101 side and the X-axis positioning unit 4705 on the stator 201 side come into contact, and positioning is achieved. In Figure 21B, when machining of the workpiece 102 is completed and the movable element 101 is lifted and transported again, the movable element 101 moves in the -Y direction to secure a transport path for the movable element 101 so as not to interfere with the X-axis positioning unit 4705 on the stator 201 side.

[0222] Next, a control method for the transport system 1 for positioning the movable element 101 using the X-axis positioning unit 2705 on the stator 201 side and the X-axis positioning unit 2706 on the movable element 101 side will be explained with reference to Figure 22. Figure 22 is a flowchart showing the control method for the transport system 1 for positioning the movable element 101 according to this embodiment. The computer, which functions as an integrated controller 301, can execute the control method shown in Figure 22 by reading a program for executing the control method shown in Figure 22 from a storage medium that the computer can read and executing the program.

[0223] First, the integrated controller 301 controls the levitation and transport of the movable element 101, including the workpiece 102, in the same manner as in the first embodiment. As a result, the integrated controller 301 levitates the movable element 101 in the +Z direction and transports it in the X direction to above the Z-axis positioning unit 705 on the stator 201 side in the work area 2707. Subsequently, the integrated controller 301 positions the movable element 101 during processing by the assembly robot 703 of the assembly device 701 according to the process shown in the flowchart in Figure 22.

[0224] First, the integrated controller 301 executes step S300, which involves the assembly robot 703 landing the movable element 101 in the Z-direction, which is the machining axis direction of the machining process. When the movable element 101 lands in the Z-direction, the integrated controller 301 controls the current command values ​​of the current applied to each coil 202, 207, and 208 so that the Z-axis positioning unit 706 on the movable element 101 side contacts the corresponding Z-axis positioning unit 705 on the stator 201 side.

[0225] Next, the integrated controller 301 executes step S301 and stops control of the movable element 101 in the Z direction. The integrated controller 301 can stop control in the Z direction by setting Tz = 0 among the force and torque components (Tx, Ty, Tz, Twx, Twy, Twz) of the six axes. The integrated controller 301 can set Tz = 0 by controlling the current command value of the current applied to each coil 202.

[0226] Next, the integrated controller 301 executes step S302, which involves landing the movable element 101 in the Y direction. When the movable element 101 lands in the Y direction, the integrated controller 301 controls the current command values ​​of the current applied to each coil 202, 207, and 208 so that the Y-axis positioning unit 1706 on the movable element 101 side contacts the corresponding Y-axis positioning unit 1705 on the stator 201 side.

[0227] Next, the integrated controller 301 executes step S303 to stop control of the movable element 101 in the Y direction. The integrated controller 301 can stop control in the Y direction by setting Ty=0 among the force and torque components (Tx, Ty, Tz, Twx, Twy, Twz) of the six axes. The integrated controller 301 can set Ty=0 by controlling the current command value of the current applied to each coil 208.

[0228] Next, the integrated controller 301 executes step S304 to land the movable element 101 in the X direction. When the movable element 101 lands in the X direction, the integrated controller 301 controls the current command values ​​of the current applied to each coil 202, 207, and 208 so that the X-axis positioning unit 2706 on the movable element 101 side contacts the corresponding X-axis positioning unit 2705 on the stator 201 side.

[0229] Next, the integrated controller 301 executes step S305 to stop control of the movable element 101 in the X direction. The integrated controller 301 can stop control in the X direction by setting Tx=0 among the force and torque components (Tx, Ty, Tz, Twx, Twy, Twz) of the six axes. The integrated controller 301 can set Tx=0 by controlling the current command value of the current applied to each coil 207. Alternatively, the integrated controller 301 can omit step S305 and execute the next step S306 following step S304.

[0230] Next, the integrated controller 301 executes step S306, performing pressing control to press the movable element 101 in the X direction. In pressing control in the X direction, the integrated controller 301 controls the force component Tx in the X direction acting on the movable element 101 by controlling the current command value of the current applied to each coil 207, thereby pressing the movable element 101 in the +X direction. As a result, the integrated controller 301 presses the X-axis positioning unit 2706 on the movable element 101 side against the X-axis positioning unit 2705 on the stator 201 side. This reduces or prevents misalignment of the movable element 101 in the X direction when the workpiece 102 is machined from the Z direction by the assembly robot 703.

[0231] Next, the integrated controller 301 executes step S307, performing pressing control to press the movable element 101 in the Y direction. In pressing control in the Y direction, the integrated controller 301 controls the Y-direction force component Ty acting on the movable element 101 by controlling the current command value of the current applied to each coil 208, thereby pressing the movable element 101 in the +Y direction. As a result, the integrated controller 301 presses the Y-axis positioning part 1706 on the movable element 101 side against the Y-axis positioning part 1705 on the stator 201 side. This reduces or prevents misalignment of the movable element 101 in the Y direction when the workpiece 102 is processed from the Z direction by the assembly robot 703.

[0232] Next, the integrated controller 301 executes step S308, performing a pressing control to press the movable element 101 in the Z direction. In the pressing control in the Z direction, the integrated controller 301 controls the force component Tz in the Z direction acting on the movable element 101 by controlling the current command value of the current applied to each coil 202, thereby pressing the movable element 101 in the -Z direction. As a result, the integrated controller 301 presses the Z-axis positioning part 706 on the movable element 101 side against the Z-axis positioning part 705 on the stator 201 side. This reduces or prevents misalignment of the movable element 101 in the Z direction when the workpiece 102 is machined from the Z direction by the assembly robot 703.

[0233] Next, the integrated controller 301 executes step S309 and generates rotational forces around the Y-axis and Z-axis to counteract the rotational forces around the Y-axis and Z-axis generated in the movable element 101 by the pressing control in the X-axis direction. That is, the integrated controller 301 generates a torque component Twy in the Wy direction and a torque component Twz in the Wz direction as rotational forces around the Y-axis and Z-axis. The integrated controller 301 controls the torque component Twy in the Wy direction acting on the movable element 101 by controlling the current command value of the current applied to each coil 202. The integrated controller 301 also controls the torque component Twz in the Wz direction acting on the movable element 101 by controlling the current command value of the current applied to each coil 208. By counteracting the rotational forces caused by the pressing control, the position of the movable element 101 can be further stabilized.

[0234] As described above, the integrated controller 301 performs positioning control of the movable element 101 while the assembly robot 703 processes the workpiece 102. After processing is complete, the integrated controller 301 can terminate the positioning control and resume the levitation and transport of the movable element 101.

[0235] Thus, in this embodiment, after transporting the workpiece 102 together with the movable element 101, the movable element 101 is positioned using the X-axis positioning units 2705, 2706, the Y-axis positioning units 1705, 1706, and the Z-axis positioning units 705, 706. This allows the movable element 101 to maintain a stable position against large external forces applied to the workpiece 102 during processing. As a result, the workpiece 102 is positioned with high precision, and the workpiece 102 is processed with high precision by the processing equipment to manufacture an article.

[0236] Based on the above, according to this embodiment, the position of the movable element 101 can be stabilized regardless of the magnitude of the external force applied to the movable element 101 during the machining of the workpiece 102.

[0237] The above description assumes a configuration in which X-axis positioning units 2705 and 2706, Y-axis positioning units 1705 and 1706, and Z-axis positioning units 705 and 706 are installed, but the system is not limited to this configuration. The Y-axis positioning units 1705 and 1706 do not necessarily have to be installed. In this case, the integrated controller 301 can position the movable element 101 in the Y direction by controlling the current command values ​​of the currents applied to each coil 208 to control the Y-direction force component Ty, etc. acting on the movable element 101. Similarly, the Z-axis positioning units 705 and 706 do not necessarily have to be installed. In this case, the integrated controller 301 can position the movable element 101 in the Z direction by controlling the current command values ​​of the currents applied to each coil 207 to control the Z-direction force component Tz, etc. acting on the movable element 101.

[0238] [Modified Embodiment] The present invention is not limited to the embodiments described above and can be modified in various ways. The example given uses the case where the X-axis positioning section 2705 of the stator 201 is movable, but it is not limited to this. At least one of the Z-axis positioning section 705 and the Y-axis positioning section 1705 of the stator 201 can be made movable. The example described uses a case where multiple coils 202, 207, and 208 are arranged in a predetermined number of rows, but it is not limited to this. Depending on the yoke plate 103 and conductive plate 107 arranged on the movable element 101, each coil can be arranged in a predetermined number of rows.

[0239] Furthermore, although the above embodiment was described using the case where the movable element 101 is provided with a yoke plate 103 and a conductive plate 107 as an example, it is not limited to this. The movable element 101 may have a magnet group including a plurality of permanent magnets instead of the yoke plate 103 and the conductive plate 107. The group of magnets may include, for example, a plurality of permanent magnets arranged along the X direction.

[0240] The present invention can also be realized by supplying a program that implements one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and causing one or more processors in a computer of the system or apparatus to read and execute the program. It can also be realized by a circuit (for example, ASIC) that implements one or more functions.

Explanation of Signs

[0241] 1 Carrier system 3 Control system 101 Mover 102 Workpiece 103 Yoke plate 104 Linear scale 105 Y target 106 Z target 107 Conductive plate 201 Stator 202 Coil 204 X sensor 206 Z sensor 207 Coil 208 Coil 210 Winding 211 Core 301 Integrated controller 302 Coil controller 303 Coil unit controller 304 Sensor controller 312 Current sensor 313 Current controller 512 RFID tag 513 RFID reader 701 Assembly device 703 Assembly robot 704 Parts 705 Z-axis positioning unit 706 Z-axis positioning unit 708 Support structure 1102 Workpiece 1704 Parts 1705 Y-axis positioning unit 1706 Y-axis positioning unit 1708 Support structure 2705 ​​X-axis positioning unit 2706 X-axis positioning unit 3705 X-axis positioning unit 3706 X-axis positioning unit 4705 X-axis positioning unit 4706 X-axis positioning unit

Claims

1. A movable element that mounts a workpiece and is movable along a first direction, A stator that applies force to the movable element to transport it in the first direction while causing it to float in a second direction intersecting the first direction, A control unit that acquires the position and orientation of the movable element as it floats in the second direction while moving along the first direction, and controls the operation of the movable element based on the acquired position and orientation, A positioning unit that restricts the movement of the movable element and It has, The positioning unit includes a first positioning unit that restricts the movement of the movable element in the direction of the external force applied to the workpiece. The control unit controls the movable element to contact the stator in the direction of the external force, such that the movement of the movable element is restricted by the first positioning unit. A transport system characterized by the following features.

2. The direction of the external force is the second direction, or a third direction that intersects the first and second directions. The transport system according to feature 1.

3. The positioning unit includes a second positioning unit that restricts the movement of the movable element in a direction intersecting the first direction and the direction of the external force. The transport system according to claim 1 or 2.

4. The control unit controls the movable element to contact the stator in a direction intersecting the direction of the external force and the first direction, such that the movement of the movable element is restricted by the second positioning unit. The transport system according to feature 3.

5. The positioning unit includes a third positioning unit that restricts the movement of the movable element in the first direction. The transport system according to any one of claims 1 to 4.

6. The control unit controls the movable element to contact the stator in the first direction such that the movement of the movable element is restricted by the third positioning unit. The transport system according to feature 5.

7. The positioning unit is movable so as to secure a transport path for the movable element in the first direction. The transport system according to any one of claims 1 to 6.

8. The control unit performs control to generate a rotational force that cancels out the rotational force generated in the movable element by controlling the movable element to bring it into contact with the stator. The transport system according to feature 4 or 6.

9. The positioning part is a stopper that limits the range of motion of the movable element. The transport system according to any one of claims 1 to 8.

10. The positioning unit is installed within the movable range. The transport system according to feature 9.

11. The position and orientation of a movable element that moves along the first direction while floating in a second direction intersecting the first direction relative to the stator, Based on the acquired position and orientation, the movement of the movable element is controlled. During machining of a workpiece mounted on the movable element, the first positioning part of the positioning unit that restricts the movement of the movable element brings the movable element into contact with the stator in the direction of the external force applied to the movable element, so as to restrict the movement of the movable element. A control method characterized by the following:

12. The movement of the movable element in the direction of the external force and in the direction intersecting the first direction is restricted by the second positioning part included in the positioning part. The movable element is brought into contact with the stator in a direction intersecting the direction of the external force and the first direction. The control method according to feature 11.

13. The movable element is brought into contact with the stator in the first direction such that the movement of the movable element in the first direction is restricted by the third positioning element included in the positioning element. The control method according to claim 11 or 12, characterized by the features described herein.

14. Control is performed to generate a rotational force that cancels out the rotational force generated in the movable part by bringing the movable part into contact with the stator. The control method according to any one of claims 11 to 13.

15. A transport system according to any one of claims 1 to 10, A processing apparatus for performing processing on the workpiece conveyed by the movable element A processing system characterized by having the following features.

16. A method for manufacturing an article using the processing system described in claim 15, The process of transporting the workpiece using the movable element, The process involves performing the processing on the workpiece conveyed by the movable element using the processing apparatus. A method for manufacturing an article, characterized by having the following:

17. A program characterized by causing a computer to execute the control method described in any one of claims 11 to 14.

18. A computer-readable storage medium storing the program described in claim 17.

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