TRANSPORTATION APPARATUS, PRODUCTION SYSTEM, AND PRODUCTION METHOD OF ARTICLE

Abstract

To provide a transport device that can transport a movable element in a stable and smooth manner.SOLUTION: A transport device includes a movable element that moves along a first direction, a stator disposed along the first direction and having a plurality of first sensors that detect position information of the movable element, and a control unit that corrects the position information of the movable element and controls the position and / or posture of the movable element on the basis of at least one of a relative position between at least one of the plurality of first sensors and the movable element, which is obtained from detected values of the plurality of first sensors, and a detection time at which the plurality of first sensors detect the movable element.SELECTED DRAWING: Figure 14

Description

[Technical field]

[0001] The present invention relates to a transport system and a control method thereof. [Background technology]

[0002] Generally, conveyance systems are used in production lines for assembling industrial products, semiconductor exposure devices, and the like. In particular, conveyance systems in production lines convey workpieces such as parts between multiple stations within an automated production line or between production lines. They may also be used as conveyance devices in production equipment (process equipment). As a conveyance system, a conveyance system using a moving magnet type linear motor has already been proposed.

[0003] In a conveyance system using a moving magnet type linear motor, a permanent magnet is placed on the mover, and a linear motor stator is installed on a frame so as to face the permanent magnet. Furthermore, a sensor that detects the mover is provided on the frame on which the stator is installed. The position and attitude of the mover are calculated based on the detection data from this sensor, and the linear motor is driven and controlled based on the position and attitude.

[0004] For example, Patent Document 1 discloses a method for controlling a moving magnet type magnetic levitation transport device. The magnetic levitation transport device described in Document 1 is configured such that the mover is always facing three displacement sensors and six magnetic poles, and the displacement sensors measure the vertical distance to the mover to identify and control the three-dimensional coordinates of the mover. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 5-64315 Summary of the Invention [Problem to be solved by the invention]

[0006] In the above-mentioned conventional conveying system, in a conveying system in which a sensor installed on the stator side detects and controls the mover, in order to continuously calculate and control the position of the mover, it is necessary to convey the mover while switching sensors as it moves in the conveying direction.

[0007] When the sensors are switched, it is ideal that the sensor (eject sensor) that no longer detects the mover and the sensor (entrance sensor) that starts to detect the mover should provide outputs indicating the same detection surface. However, differences occur in the outputs of the sensors due to the installation accuracy of the sensors, differences between sensors, or differences in the surface condition of the mover to be detected, and the position and orientation calculated using these detection data vary greatly. This causes a problem of undesirable behavior such as vibration of the mover, which could not be sufficiently eliminated by the above-mentioned conventional technology. Furthermore, the vibration can cause serious problems such as the inability to maintain stable transportation of the mover or damage to the workpiece.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a transport device and a control method thereof that can transport a mover stably and smoothly. [Means for solving the problem]

[0009] A transport device according to a first aspect for solving the above problems includes a mover that moves along a first direction, a stator that is arranged along the first direction and has a plurality of first sensors that detect position information of the mover, and a control unit that corrects position information of the mover and controls a position and / or attitude of the mover based on at least one of a relative position between at least one of the plurality of first sensors and the mover that is obtained from detection values ​​of the plurality of first sensors and a detection time at which the plurality of first sensors detect the mover. The control unit corrects the position information of the mover by weighting a detection value of a sensor that detects a position near the center of the mover more heavily than a detection value of a sensor that detects a position outside the center. The present invention is characterized by the above.

[0010] A transport device of a second aspect for solving the above problem includes a stator having a mover that moves along a first direction, a plurality of first sensors that are arranged along the first direction and detect position information of the mover in the first direction, and a plurality of second sensors that detect position information of the mover in a second direction intersecting the first direction, and a control unit that selects at least one of the plurality of second sensors using detection values ​​of the plurality of first sensors, corrects position information of the mover in the second direction based on a relative position between the selected second sensor and the mover, and controls a position and / or attitude of the mover. The control unit corrects the position information of the mover by weighting a detection value of a sensor that detects a position near the center of the mover more heavily than a detection value of a sensor that detects a position outside the center. The present invention is characterized by the above. Effect of the Invention

[0011] According to the present invention, it is possible to suppress the fluctuation in the calculation result of the position of the mover caused by switching of the sensors during transportation to a small value, and the mover can be transported stably and smoothly. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing a conveying device according to a first embodiment of the present invention. [Diagram 2] 1 is a schematic diagram showing a conveying device according to a first embodiment of the present invention. [Diagram 3] 1 is a configuration diagram of a transport system showing a first embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram illustrating a data flow according to the first embodiment of the present invention. [Diagram 5] FIG. 2 is a schematic diagram illustrating conveyance direction position detection according to the first embodiment of the present invention. [Figure 6] 5A to 5C are schematic diagrams illustrating a mover attitude calculation information process in a direction perpendicular to the transport direction according to the first embodiment of the present invention. [Figure 7] 4 is a schematic diagram illustrating a function for calculating a coefficient based on installation position information of a sensor according to the first embodiment of the present invention. FIG. [Figure 8] 8 is a schematic diagram illustrating a mover attitude calculation information process in a direction different from that in FIG. 7 that is orthogonal to the transport direction in the first embodiment of the present invention. [Figure 9] 5A to 5C are schematic diagrams illustrating a mover attitude calculation process in a direction perpendicular to the transport direction according to the first embodiment of the present invention. [Figure 10] 10 is a schematic diagram illustrating the mover attitude calculation process in a direction different from that in FIG. 9 that is orthogonal to the transport direction in the first embodiment of the present invention. [Figure 11] FIG. 2 is a schematic diagram illustrating the effect of the first embodiment of the present invention. [Figure 12] 5 is a schematic diagram illustrating a different configuration of a mover attitude calculation information processing function in the first embodiment of the present invention. FIG. [Figure 13] 4 is a schematic diagram showing a method of applying forces independently in the X direction and the Z direction to a permanent magnet in the first embodiment of the present invention. FIG. [Figure 14] FIG. 11 is a schematic diagram showing the entire conveyance system according to a second embodiment of the present invention. [Figure 15] FIG. 11 is a configuration diagram of a transport system showing a second embodiment of the present invention. [Figure 16] FIG. 11 is a schematic diagram illustrating a data flow according to a second embodiment of the present invention. [Figure 17] 10A and 10B are schematic diagrams illustrating conveying direction position detection according to a second embodiment of the present invention. [Figure 18] FIG. 11 is a schematic diagram illustrating the effect of the second embodiment of the present invention. [Figure 19] FIG. 11 is a schematic diagram illustrating the effect of the second embodiment of the present invention. [Figure 20] FIG. 4 is a schematic diagram illustrating a second embodiment of the present invention. [Figure 21] FIG. 11 is a schematic diagram showing a transport system according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The conveying device according to the present embodiment will be described with reference to the drawings.

[0014] 1, 2(A) and 2(B) are schematic diagrams showing the conveying device according to this embodiment.

[0015] In Fig. 1, Fig. 2(A) and Fig. 2(B), 201 denotes a stator constituting a conveying path, and 301 denotes a mover constituting a dolly, slider or carriage. Fig. 1 is a schematic diagram of the stator 201 and mover 301 of this embodiment as viewed from the Y direction. Fig. 2(A) is a schematic diagram of the stator 201 and mover 301 of this embodiment as viewed from the -X direction. Fig. 2(B) shows the arrangement of permanent magnets 303 on the upper surface of the mover 301. The left half of Fig. 2(A) shows a cross section (A) taken along the line (A)-(A) in Fig. 2B. The right half of Fig. 2(A) shows a cross section (B) taken along the line (B)-(B) in Fig. 2B.

[0016] 1, 2(A) and 2(B), one mover 301 is shown for the stator 201, but the present invention is not limited to this. In the conveying device 1, a plurality of movers 301 can be conveyed on the stator 201.

[0017] The conveying device 1 according to this embodiment is preferably used to convey the mover 301 by the stator 201, thereby conveying the workpiece 302 held by the mover 301 to a production device. Alternatively, it may be used as a conveying device in a production device (process device). By performing an operation (process operation) such as a machining operation or an inspection operation on the workpiece held by the mover conveyed by the conveying device according to this embodiment, an article can be manufactured with high precision.

[0018] In addition, a system including a conveying device and a production device according to the embodiment may be referred to as a production system in this specification. In this specification, the production device refers to a device for performing an operation such as a processing operation or an inspection operation on a workpiece, and examples of the production device include an inspection device, an assembly device, a semiconductor exposure device, and a deposition device. The production system according to the present embodiment may have multiple production devices, and the multiple production devices may be production devices for performing the same operation on a workpiece, or may be production devices for performing different operations.

[0019] Here, the coordinate axes, directions, etc. used in the following description are defined. First, the X-axis is taken along the horizontal direction, which is the transport direction of the mover 301, and the transport direction of the mover 301 is taken as the X-direction. The Z-axis is taken along the vertical direction, which is a direction perpendicular to the X-direction, and the vertical direction is taken as the Z-direction. The Y-axis is taken along a direction perpendicular to the X-direction and the Z-direction, and the direction perpendicular to the X-direction and the Z-direction is taken as the Y-direction. Rotation around the X-axis is taken as Wx, and rotation around the Y-axis and Z-axis is taken as Wy and Wz, respectively. Also, "*" is used as a multiplication symbol, and "^" is used as an exponentiation symbol. Also, a natural exponential function is expressed as exp(). Also, the Y+ side of the mover 301 is described as the R side, and the Y-side is described as the L side. Note that the transport direction of the mover 301 does not necessarily have to be horizontal, but in that case, the transport direction can be similarly defined as the X-direction, and the Y-direction and Z-direction can be similarly defined.

[0020] The conveying device 1 does not have a guiding device such as a linear guide, and is configured as a magnetic levitation type conveying device that conveys the mover 301 on the stator 201 in a non-contact manner.

[0021] As shown in FIG. 2B, the mover 301 has, as the permanent magnet 303, permanent magnets 303aR, 303bR, 303cR, 303dR, 303aL, 303bL, 303cL, and 303dL.

[0022] Permanent magnets 303aR, 303bR, 303cR, and 303dR are attached to the top surface of the R side of the mover 301. Permanent magnets 303aL, 303bL, 303cL, and 303dL are attached to the top surface of the L side of the mover 301. In the following, unless there is a need to distinguish between them, the permanent magnets of the mover 301 will be simply referred to as "permanent magnets 303". In addition, although there is no need to distinguish between the R side and the L side, if it is necessary to individually identify each permanent magnet 303, each permanent magnet 303 will be individually identified using a code consisting of lowercase alphabets as an identifier excluding R or L from the end of the code for each permanent magnet 303. In this case, each permanent magnet 303 will be individually identified by being written as "permanent magnet 303a", "permanent magnet 303b", "permanent magnet 303c", or "permanent magnet 303d".

[0023] The permanent magnets 303aR, 303dR are attached to one end and the other end in the X direction on the top surface of the R side along the X direction of the mover 301. The permanent magnets 303bR, 303cR are attached between the permanent magnets 303aR, 303dR on the top surface of the R side of the mover 301. The permanent magnets 303aR, 303bR, 303cR, 303dR are arranged, for example, at equal pitches in the X direction. Furthermore, the permanent magnets 303aR, 303bR, 303cR, 303dR are arranged such that their centers are aligned, for example, on a straight line along the X direction that passes through the center of the top surface of the R side of the mover 301.

[0024] The permanent magnets 303aL and 303dL are attached to one end and the other end in the X direction on the upper surface of the L side along the X direction of the mover 301. The permanent magnets 303bL and 303cL are attached between the permanent magnets 303aL and 303dL on the upper surface of the L side of the mover 301. The permanent magnets 303aL, 303bL, 303cL, and 303dL are arranged, for example, at equal pitches in the X direction. Furthermore, the permanent magnets 303aL, 303bL, 303cL, and 303dL are arranged so that their centers are aligned, for example, on a straight line along the X direction passing through the center of the upper surface of the L side of the mover 301. Furthermore, the permanent magnets 303aL, 303bL, 303cL, and 303dL are arranged at the same positions in the X direction as the permanent magnets 303aR, 303bR, 303cR, and 303dR, respectively.

[0025] In this embodiment, an example is shown in which the magnet group is provided on the upper surface of the mover, but the magnet group may be provided on the side surface of the mover.

[0026] Permanent magnets 303aR, 303bR, 303cR, and 303dR arranged on the R side of the upper surface of mover 301 are each arranged at a distance rx3 from origin O, which is the center of mover 301, on the R side in the Y direction.

[0027] Moreover, permanent magnets 303aL, 303bL, 303cL, and 303dL arranged on the L-side portion of the upper surface of the mover 301 are arranged at positions spaced a distance rx3 from the origin O on the L side in the Y direction.

[0028] The permanent magnets 303a and 303d are attached at positions spaced a distance rz3 from the origin O on one side and the other side in the X direction. The permanent magnets 303c and 303b are attached at positions spaced a distance ry3 from the origin O on one side and the other side in the X direction.

[0029] On the upper surface of the mover 301, the central portion between the R-side portion and the L-side portion where the permanent magnets 303 are arranged as described above is a portion on which the workpiece 302 to be transported is placed.

[0030] Each of the permanent magnets 303aR, 303dR, 303aL, and 303dL is a set of two permanent magnets arranged along the Y direction. Each of the permanent magnets 303a and 303d is configured by arranging two permanent magnets along the Y direction so that the polarities of the outer magnetic poles facing the stator 201 side are alternated. The number of permanent magnets arranged along the Y direction constituting the permanent magnets 303a and 303d is not limited to two, but may be more than one. The direction in which the permanent magnets constituting the permanent magnets 303a and 303d are arranged does not necessarily have to be the Y direction perpendicular to the X direction, which is the conveying direction, but may be a direction (second direction) intersecting the X direction (first direction). In other words, each of the permanent magnets 303a and 303d may be a magnet group consisting of a plurality of permanent magnets arranged along a direction (second direction) intersecting the X direction so that the polarities of the magnetic poles are alternated.

[0031] On the other hand, the permanent magnets 303bR, 303cR, 303bL, and 303cL are each a set of three permanent magnets arranged along the X direction. The permanent magnets 303b and 303c are each configured by arranging three permanent magnets along the X direction so that the polarities of the outer magnetic poles facing the stator 201 side are alternately different. The number of permanent magnets arranged along the X direction constituting the permanent magnets 303b and 303c is not limited to three, but may be any number. In other words, the permanent magnets 303b and 303c may be a magnet group consisting of a plurality of permanent magnets arranged along the X direction so that the polarities of the magnetic poles are alternated.

[0032] Each permanent magnet 303 is attached to a yoke 307 provided on the upper surface of the R side and the L side of the mover 301. The yoke 307 is made of a material with high magnetic permeability, such as iron. In this specification, a material with high magnetic permeability refers to a material with a magnetic permeability of 5000 or more.

[0033] In this manner, the movable element 301 on which the permanent magnet 303 is arranged has its posture controlled in six axes by electromagnetic forces acting on the permanent magnet 303 by the multiple coils 202 of the stator 201 as described below, and is controlled to be movable in the X direction.

[0034] On the other hand, as shown in Fig. 2(A), a plurality of coils 202 are attached to the stator 201 so as to be located above the upper surface of the mover 301. The plurality of coils 202 are attached to the stator 201 and arranged in two rows along the X direction so as to be able to face from above the permanent magnets 303 in the R-side and L-side portions of the upper surface of the mover 301. The plurality of coils 202 on the R side are arranged in one row along the X direction so as to be able to face from above the permanent magnets 303aR, 303bR, 303cR, and 303dR on the R side of the mover 301. The plurality of coils 202 on the L side are arranged in one row along the X direction so as to be able to face from above the permanent magnets 303aL, 303bL, 303cL, and 303dL on the L side of the mover 301.

[0035] The mover 301 is movable in the X direction along a plurality of coils 202 arranged in two rows along the X direction. The mover 301 is transported with the workpiece 102 to be transported placed on its upper surface. The mover 301 may have a holding mechanism, such as a work holder, for holding the workpiece 102 on the mover 301.

[0036] The stator 201 has a plurality of coils 202 arranged in two rows along the X direction which is the transport direction of the mover 301. The stator 201 extends in the X direction which is the transport direction to form a transport path for the mover 301.

[0037] The multiple coils 202 are attached to the stator 201 and arranged in two rows along the X direction so as to be able to face the permanent magnets 303 on the R and L sides of the mover 301. The multiple coils 202 arranged in one row on the R side are arranged along the X direction so as to be able to face the permanent magnets 303aR, 303bR, 303cR, and 303dR on the R side of the mover 301. The multiple coils 202 arranged in one row on the L side are arranged along the X direction so as to be able to face the permanent magnets 303aL, 303bL, 303cL, and 303dL on the L side of the mover 301.

[0038] In this embodiment, the rows of coils 202 on the R side and the L side of the mover 301 are arranged to face permanent magnets 303a, 303d and permanent magnets 303b, 303c, which are different in arrangement direction of the multiple permanent magnets constituting the mover 301. Therefore, with a small number of rows of coils 202, it is possible to apply a force in the transport direction and a force different from the transport direction to the mover 301, as described later, and therefore it is possible to realize transport control and posture control of the mover 301.

[0039] The multiple coils 202 are arranged at predetermined intervals in the X direction. Each coil 202 is attached so that its central axis faces the Z direction. The coils 202 may be either a coil with a core or a coreless type coil.

[0040] The coils 202 are configured to be current-controlled in units of, for example, three coils. The unit of coils 202 for which current is controlled is referred to as a "coil unit 203." When current is applied to the coils 202, electromagnetic force is generated between the coils 202 and the permanent magnets 303 of the mover 301, and the force can be applied to the mover 301.

[0041] 2B, permanent magnets 303a and 303d are each configured as a magnet group in which two permanent magnets are arranged in the Y direction. Meanwhile, each coil 202 is arranged such that the Y direction centers of the two permanent magnets 303a and 303d coincide with the Y direction center of coil 202. By passing current through coil 202 facing permanent magnets 303a and 303d, a force is generated in the Y direction on permanent magnets 303a and 303d.

[0042] Moreover, the permanent magnets 303b and 303c are configured as a magnet group in which three permanent magnets are arranged in the X direction. By applying current to the coil 202 facing the permanent magnets 303b and 303c, forces are generated in the X direction and the Z direction on the permanent magnets 303b and 303c. In this embodiment, permanent magnets are used as the magnets that configure the magnet group, but electromagnets may also be used.

[0043] Reference numeral 101 shown in Fig. 2(A) is an X sensor (first sensor), which is, for example, a linear encoder that detects a linear scale 304 attached to the mover 301 and identifies the position of the mover 301 in the transport direction. Reference numeral 102 shown in Fig. 2(A) is a Y sensor (second sensor) that detects the distance from the mover 301 in the Y direction. A Z sensor 103 (third sensor) detects the distance from the mover 301 in the Z direction. For example, an eddy current sensor or the like may be disposed as the Y sensor or Z sensor. Note that the X sensor may also be configured to be something other than a linear encoder, such as a laser interferometer.

[0044] A plurality of X sensors 101 (first sensors) are attached to the stator 201 along the X direction (first direction) so as to be able to face each linear scale 304 of the mover 301. Each X sensor 101 can detect the relative position of the mover 301 with respect to the X sensor 101 by reading the linear scale 304 attached to the mover 301, and output the detection value.

[0045] A plurality of Y sensors 102 (second sensors) are attached to the stator 201 along the X direction (first direction) so as to be able to face the Y target 305 of the mover 301. Each Y sensor 102 can detect the relative distance in the Y direction between the Y target 305 attached to the mover 301 and output the detection value. Here, the Y target 305 is a convex part attached to the mover 301 and having a surface parallel to the target transport direction of the mover, and the surface parallel to the target transport direction of the mover is measured by the Y sensor 102 fixed to the stator. This makes it possible to detect the position and / or attitude of the mover in the Y direction. The Y sensor 102 (second sensor) does not necessarily need to detect the relative distance in the Y direction perpendicular to the X direction, which is the transport direction, but only needs to be in a direction (second direction) intersecting the X direction (first direction). It is also possible to directly detect the relative distance between the mover and the Y target 305, but it may be difficult to process the mover itself with high precision. In such a case, the Y target 305 can be used.

[0046] A plurality of Z sensors 103 (third sensors) are attached to the stator 201 in two rows along the X direction so that each sensor can face the Z target 306 of the mover 301. Each Z sensor 103 can detect and output the relative distance in the Z direction between the Z target 306 attached to the mover 301. Here, the Z target 306 is a convex part attached to the mover 301 and has a surface perpendicular to the vertical direction, and the surface perpendicular to the vertical direction is measured by the Z sensor 103 fixed to the stator. This makes it possible to detect the vertical position and / or attitude of the mover. The Z sensor 103 (third sensor) does not necessarily need to detect the relative distance in the Z direction perpendicular to the X direction, which is the conveying direction, but only needs to detect the direction (third direction) intersecting the X direction (first direction). It is also possible to directly detect the relative distance between the mover and the Z target 306, but it may be difficult to process the mover itself with high precision. In such a case, the Z target 306 can be used.

[0047] In this embodiment, an example is shown in which the X sensor 101, the Y sensor 102, and the Z sensor 103 are provided on the bottom of the stator, and the linear scale 304, the Y target 305, and the Z target 306 are provided on the bottom surface of the mover. However, the present invention is not limited to this. The linear scale 304, the Y target 305, and the Z target 306 may be provided at any position on the mover, and the X sensor 101, the Y sensor 102, and the Z sensor 103 may be provided at any position on the stator as long as they are positioned to face each other. In addition, it is not necessary to provide both the Y sensor 102 and the Z sensor 103, and the effect of the present invention can be achieved even if only one of them is provided. For example, even if the Y sensor 102 is not provided, the present invention can be applied to a conveying device or the like that does not control the Y direction only by the attractive force of a magnet. In addition, even if the Z sensor 103 is not provided, the present invention can be configured to control the Z direction only by the attractive force of a magnet. Alternatively, the present invention can be configured to levitate by another method such as air. In addition, the present invention can be applied to an XY stage that does not perform levitation control in the Z direction.

[0048] Next, the control unit for controlling the transport device 1 according to this embodiment will be further described with reference to Fig. 3. Fig. 3 is a schematic diagram showing the control unit 3 for controlling the transport device 1 according to this embodiment.

[0049] 3, the control unit 3 has an integrated controller 401, a coil controller 402, and a sensor controller 404, and functions as a control unit that controls the conveying device 1 including the mover 301 and the stator 201. The coil controller 402 is communicatively connected to the integrated controller 401. The sensor controller 404 is communicatively connected to the integrated controller 401.

[0050] A plurality of current controllers 403 are communicatively connected to the coil controller 402. The coil controller 402 and the plurality of current controllers 403 connected thereto are provided corresponding to the two rows of coils 202, respectively. A coil unit 203 is connected to each current controller 403. The current controller 403 can control the magnitude of the current of each coil 202 of the connected coil unit 203.

[0051] The coil controller 402 issues a target current value to each of the connected current controllers 403. The current controllers 403 control the amount of current in the coils 202 connected thereto.

[0052] A plurality of X sensors 101, a plurality of Y sensors 102, and a plurality of Z sensors 103 are communicatively connected to the sensor controller 404.

[0053] The multiple X sensors 101 are attached to the stator 201 at intervals such that one of them can always measure the position of one of the movers 301 even while the mover 301 is being transported. The multiple Y sensors 102 are attached to the stator 201 at intervals such that two of them can always measure the Y target 305 of one of the movers 301. The multiple Z sensors 103 are attached to the stator 201 at intervals such that three of the two rows can always measure the Z target 306 of one of the movers 301.

[0054] The integrated controller 401 determines current command values ​​to be applied to the multiple coils 202 based on the outputs from the X sensor 101, the Y sensor 102, and the Z sensor 103, and transmits the current command values ​​to the coil controller 402. The coil controller 402 issues a current value command to the current controller 403 as described above based on the current command value from the integrated controller 401. In this way, the integrated controller 401 functions as a control device, and transports the mover 301 along the stator 201 in a non-contact manner, and controls the attitude of the transported mover 301 in six axes.

[0055] Hereinafter, the attitude control method of the mover 301 executed by the integrated controller 401 will be described with reference to FIG. 4. FIG. 4 is a schematic diagram showing the attitude control method of the mover 301 in the transport device 1 according to this embodiment. FIG. 4 shows an outline of the attitude control method of the mover 301, focusing mainly on the data flow. As described below, the integrated controller 401 executes processing using a mover position calculation function 501, a mover attitude calculation information processing function 502, a mover attitude calculation function 503, a mover attitude control function 504, and a coil current calculation function 505. In this way, the integrated controller 401 controls the transport of the mover 301 while controlling the attitude of the mover 301 in six axes. Note that instead of the integrated controller 401, the coil controller 402 can be configured to execute the same processing as the integrated controller 401.

[0056] First, mover position calculation function 501 calculates the number and positions of movers 301 on stator 201 constituting the conveying path from measurement values ​​from multiple X sensors 101 and information on their mounting positions. As a result, mover position calculation function 501 updates mover position information (X) and number information of mover information 506, which is information on movers 301. Mover position information (X) indicates the position of mover 301 on stator 201 in the X direction, which is the conveying direction. Mover information 506 is prepared for each mover 301 on stator 201, for example, as shown by POS-1, POS-2, ... in FIG. 4.

[0057] Next, mover posture calculation information processing function 502 identifies Y sensors 102 and Z sensors 103 capable of measuring each mover 301 from mover position information (X) of mover information 506 updated by mover position calculation function 501. At this time, mover posture calculation information processing function 502 calculates a coefficient (W) based on sensor installation position information 507 on stator 201 of the identified Y sensors 102 and Z sensors 103 and the mover position information (X).

[0058] The mover posture calculation function 503 calculates posture information (Y, Z, Wx, Wy, Wz) based on the detection values ​​output from the specified Y sensor 102 and Z sensor 103 and the coefficient (W) calculated by the mover posture calculation information processing function 502, and updates the mover information 506. The mover information 506 updated by the mover posture calculation function 503 includes mover position information (X) and posture information (Y, Z, Wx, Wy, Wz).

[0059] Next, mover attitude control function 504 calculates applied force information 509 for each mover 301 from current mover information 506 including mover position information (X) and attitude information (Y, Z, Wx, Wy, Wz) and the attitude target value. Applied force information 509 is information on the magnitude of the force to be applied to each mover 301. Applied force information 509 includes information on three-axis components (Tx, Ty, Tz) of force T to be applied and three-axis components (Twx, Twy, Twz) of torque. Applied force information 509 is prepared for each mover 301 on stator 201, for example, as shown by TRQ-1, TRQ-2, ... in FIG. 4.

[0060] Next, a coil current calculation function 505 determines a current command value 510 to be applied to each coil 202 based on the applied force information 509 and the mover information 506 .

[0061] In this way, the integrated controller 401 executes processing using the mover position calculation function 501, the mover attitude calculation information processing function 502, the mover attitude calculation function 503, the mover attitude control function 504, and the coil current calculation function 505, thereby determining a current command value 510. The integrated controller 401 transmits the determined current command value 510 to the coil controller 402.

[0062] Here, the process by the mover position calculation function 501 will be described with reference to Fig. 5. Fig. 5 is a schematic diagram for explaining the process by the mover position calculation function. Fig. 5 is also a diagram showing the positional relationship of the linear scales 304a, 304b and the X-sensors 101a to 101f on the bottom surfaces of the movers 301a, 301b shown in Fig. 1 and Fig. 3 when the movers are viewed from the -Z direction shown in Fig. 1.

[0063] In Fig. 5, reference point Oe is the position reference of stator 201 to which X sensor 101 is attached. Also, reference point Os is the position reference of linear scales 304a, 304b attached to mover 301. Fig. 5 shows a case in which two movers 301a, 301b are transported as mover 301, and three X sensors 101a, 101b, 101f are arranged as X sensor 101. Note that linear scales 304a, 304b are attached along the X direction at the same positions of each mover 301a, 301b.

[0064] For example, one X-sensor 101f faces linear scale 304b of mover 301b shown in Fig. 5. X-sensor 101f reads linear scale 304b of mover 301b and outputs distance Pf. The position on the X-axis of X-sensor 101f with reference point Oe as the origin is Sf. Therefore, position Pos(301b) of mover 301b can be calculated by the following equation (1). Pos(301b)=Sf-Pf...Equation (1)

[0065] For example, two X-sensors 101a and 101b face linear scale 304a of mover 301a shown in Fig. 5. X-sensor 101a reads linear scale 304a of mover 301a and outputs distance Pa. The position on the X-axis of X-sensor 101a with reference point Oe as the origin is Sa. Therefore, the position Pos(301a) of mover 301a on the X-axis based on the output of the detection value of X-sensor 101a can be calculated by the following equation (2). Pos(301a) = Sa - Pa ... Equation (2)

[0066] Furthermore, the X-sensor 101b reads the linear scale 304a of the mover 301a and outputs the distance Pb. Furthermore, the position on the X-axis of the X-sensor 101b with the reference point Oe as the origin is Sb. Therefore, the position Pos(301a)' of the mover 301a on the X-axis based on the output of the detection value of the X-sensor 101b can be calculated by the following equation (3). Pos(301a)′=Sb-Pb…Equation (3)

[0067] Here, the installation positions of the X sensors 101a, 101b are accurately measured in advance, so the difference between the two values ​​Pos(301a) and Pos(301a)' is sufficiently small. When the difference in the position of the mover 301 on the X axis based on the outputs of the two X sensors 101 is sufficiently small, it can be determined that the two X sensors 101 are observing the linear scale 304 of the same mover 301.

[0068] When multiple X-sensors 101 face the same mover 301, the observed position of the mover 301 can be uniquely determined, for example, by calculating an average value of positions based on the outputs of the multiple X-sensors 101. Alternatively, the position based on the output of the detection value of any one of the X-sensors 101 may be determined as the position of the mover 301.

[0069] As described above, based on the output of the X sensor 101, the mover position calculation function 501 calculates and determines the position X of the mover 301 in the X direction as mover position information. From the mover position information (X) of the mover information 506 updated by the mover position calculation function 501, the Y sensor 102 and the Z sensor 103 capable of measuring each mover 301 are identified.

[0070] Next, the processing by mover attitude calculation information processing function 502 will be explained with reference to Fig. 6. The upper drawings in Fig. 6(A) and Fig. 6(B) are diagrams showing the positional relationship of Y target 305 (305a) and Y sensor 102 (102a to 102c) on the bottom surface of mover 301 (301a) shown in Fig. 1 when the mover is viewed from the -Z direction shown in Fig. 1. Fig. 6(B) shows a state in which the mover has advanced a little further along the +X direction compared to Fig. 6(A).

[0071] A first area is set in the center of the mover or the Y target of the mover as a detection target area, a second area is set at the end, and a third area is set between the first and second areas. Hereinafter, the first area may be referred to as sensor information valid area 510A, the second area as sensor information invalid areas 512a, 512b, and the third area as sensor information load areas 511a, 511b.

[0072] As shown in the lower drawings in FIGS. 6(A) and 6(B), a sensor information valid area 510A is an area where the sensor information is determined to be valid (a coefficient W is assigned as 1).

[0073] The sensor information invalid areas 512a, 512b are areas where the Y sensor 102 detects the edge of the Y target 305 and the output of the detection value is unstable, i.e., the detection error is above a certain level, and are provided to ignore the output of the detection value of the Y sensor (coefficient W is assigned as 0).

[0074] Sensor information weighting regions 511a, 511b are regions between sensor information valid region 510A and sensor information invalid regions 512a, 512b, and are regions for weighting the detection values ​​of the sensors depending on their positions within the regions (coefficient W is given a value between 0 and 1). In this way, the position information of the mover using the detection values ​​of the Y sensor can be adjusted by the coefficient.

[0075] 6A, the mover position information (X) of the mover 301a is calculated as PosXa. Then, from the relationship between PosXa and each of the sensor installation position information 507, Sa, Sb, and Sc, three Y sensors 102a, 102b, and 102c are identified as Y sensors capable of measuring the mover 301a.

[0076] Since the Y sensors 102a and 102b in FIG. 6A are determined to be present in the sensor information effective area 510A, the calculation is performed as in the following expressions (4) and (5). W(102a)=1...Equation (4) W(102b)=1...Equation (5)

[0077] Since the Y sensor 102c in FIG. 6A is determined to be present in the sensor information invalid area 512b, the calculation is performed as in the following formula (6). W(102c)=0…Equation (6)

[0078] Similarly, mover 301a shown in FIG. 6B has mover position information (X) calculated as PosXa, and a plurality of Y sensors 102a, 102b, and 102c are identified as measurable Y sensors.

[0079] Since the Y sensors 102b and 102c in FIG. 6B are determined to be present in the sensor information effective area 510A, the calculation is performed as in the following expressions (7) and (8). W(102b)=1...Equation (7) W(102c)=1...Equation (8)

[0080] Also, the Y sensor 102a in FIG. 6B is determined to be present in the sensor information load area 511a. When it is determined to be present in such a sensor information load area 511a, a coefficient (W) of 0 or more and 1 or less is calculated. For example, the coefficient (W) is calculated as a value of 0 or more and 1 or less using a continuous function that monotonically increases and decreases from 0 to 1 or from 1 to 0, such as a sigmoid function as shown in the following equation (9). In equation (9), a is the gain of the sigmoid function. FIG. 7A shows the function of the coefficient W. The dotted line in FIG. 7A is the function of the coefficient (W) in the sensor information load area 511a. Incidentally, the solid line is the function of the coefficient (W) in the sensor information load area 511b. In equation (9), Pa is the relative distance between the Y sensor 102a and the mover 301a calculated from PosXa, which is the mover position information (X), and Sa, which is the sensor installation position information 507 of the Y sensor 102a. W(102a)=1 / (1+exp(-a*Pa))…Equation (9)

[0081] The same process is carried out for the Z sensor 103.

[0082] The upper drawings in Figures 8(A) and 8(B) are diagrams showing the positional relationship between Z target 306 (306Ra) on the bottom surface of mover 301 (301a) shown in Figure 1 and Z sensors 103 (103Ra to 103Rc) when the mover is viewed from the -Z direction shown in Figure 1. Figure 8(B) shows a state in which the mover has advanced a little further along the +X direction compared to Figure 8(A).

[0083] 8A, mover position information (X) is calculated as PosXa. Then, from the relationship between PosXa and each of sensor installation position information 507, SRa and SRb, three Z sensors 103Ra, 103Rb, and 103Rc are identified as Z sensors capable of measuring mover 301a.

[0084] Since Z sensors 103Ra and 103Rb in FIG. 8A are determined to be present in sensor information valid area 510B, calculation is performed as in the following equations (10) and (11). W(103Ra)=1...Equation (10) W(103Rb)=1...Equation (11)

[0085] Since 103Rc in FIG. 8A is determined to be present in the sensor information invalid area 512d, it is calculated as in the following formula (12). W(103Rc)=0…Equation (12)

[0086] Similarly, mover 301a shown in FIG. 8B has mover position information (X) calculated as PosXa, and multiple Z sensors 103Ra, 103Rb, and 103Rc are identified as measurable Z sensors.

[0087] Since Z sensors 103Rb and 103Rc in FIG. 8B are determined to be present in sensor information valid area 510B, calculation is performed as in the following equations (13) and (14). W(103Rb)=1…Equation (13) W(103Rc)=1...Equation (14)

[0088] Also, Z sensor 103Ra in FIG. 8B is determined to be present in sensor information load area 511c. When it is determined to be present in such sensor information load area 511c, a coefficient (W) of 0 or more and 1 or less is calculated. For example, coefficient (W) is calculated as a value of 0 or more and 1 or less using a continuous function that monotonically increases and decreases from 0 to 1 or from 1 to 0, such as a sigmoid function as shown in the following equation (15). In equation (15), a is the gain of the sigmoid function. FIG. 7A shows the function of coefficient W. The dotted line in FIG. 7A is the function of coefficient (W) in sensor information load area 511c. Incidentally, the solid line is the function of coefficient (W) in sensor information load area 511d. In equation (15), PRa is the relative distance between Z sensor 103Ra and mover 301a calculated from PosXa, which is mover position information (X), and SRa, which is sensor installation position information 507 of Z sensor 103Ra. W(103Ra)=1 / (1+exp(-a*PRa))…Equation (15)

[0089] Using the coefficient (W) calculated in the above-mentioned mover attitude calculation information processing function 502, attitude information of the mover 301 is obtained by mover attitude calculation function 503. This makes it possible to calculate the attitude of the mover 301 while continuously changing the valid and invalid states of the sensor information. This makes it possible to suppress discontinuous fluctuations in the detected position and attitude when the sensor used to calculate mover information 506 is switched due to the transportation of the mover 301.

[0090] As a function for calculating the coefficient (W), in addition to the above-mentioned sigmoid function, it is possible to replace it with a linear function as shown in FIG. 7(B) or a discontinuous function that changes the coefficient (W) stepwise as shown in FIG. 7(C). It is also possible to replace it with a hyperbolic function as shown in FIG. 7(D) and FIG. 7(E). The sigmoid function in FIG. 7(A) can smoothly change from 0 to 1, and the rate of change can be changed by adjusting the gain. In contrast, the linear function in FIG. 7(B) is uniquely determined by the sensor information load area 511 and can be processed at high speed because it is composed of only four arithmetic operations. In addition, the discontinuous function in FIG. 7(C) can be realized without a coefficient calculation process by storing it in the memory of the integrated controller 401 as a coefficient profile, and a complex coefficient profile other than the above functions can also be set. In addition, PosSensor shown in FIG. 7 is the relative distance between the sensor and the mover 301 calculated from the mover position information (X) and the sensor installation position information 507.

[0091] 7(C), the coefficient (W) calculated based on the positional relationship between the mover 301 and each of the sensors 102 and 103 is stored as a coefficient profile in the memory of the integrated controller 401. This makes it possible to configure the function to execute processing similar to that of the mover attitude calculation information processing function 502.

[0092] As described above, mover attitude calculation information processing function 502 calculates the coefficient (W) from mover position information (X) of mover information 506 and sensor installation position information 507. Mover attitude calculation information 508 to which the calculated coefficient (W) is added is output, and this is used as an input to mover attitude calculation function 503 together with mover information 506.

[0093] Next, the process by the mover attitude calculation function 503 will be described with reference to FIG. 9 and FIG.

[0094] 9 shows a case where mover 301c is transported as mover 301, and Y sensors 102s, 102t, and 102u are arranged as Y sensor 102. Three Y sensors 102s, 102t, and 102u face Y target 305c of mover 301c shown in FIG. 9. The relative distance values ​​output by the three Y sensors 102s, 102t, and 102u are Ys, Yt, and Yu, respectively, and the measured values ​​(detected values) are indicated by black circles in the figure. Then, the position of mover 301c, Y, and the amount of rotation Wz around the Z axis can be considered as the slope and intercept of the regression line.

[0095] Each parameter of the regression line Y=a*X+b, which is the mover position information (Y, Wz), can be found by, for example, using the least squares method to calculate a and b that minimize the weighted square error shown in the following equation (16). In this case, the slope a of the regression line is tan(Wz), and the intercept b is the position Y. In addition, in equation (16), Ws, Wt, and Wu are coefficients of each of the Y sensors 102s, 102t, and 102u included in the mover calculation information 508. Ws*(Ys-(a*Ps+b))^2+Wt*(Yt-(a*Pt+b))^2+Wu*(Yu-(a*Pu+b))^2...Equation (16)

[0096] Furthermore, if at least two Y sensors 102 face each other, the mover position information (Y, Wz) of mover 301 can be calculated, but as described above, three or more Y sensors 102 may face each other depending on the position of mover 301. In that case, too, the tilt of Y target 305, i.e., the amount of rotation Wz around the Z axis and the position Y of mover 301 can be calculated similarly using the least squares method or the like.

[0097] From the viewpoint of the accuracy of detecting the attitude of the mover 301, it is desirable that the Y sensors 102 are installed on the stator 201 along the transport direction (X) so that at least two sensors are present in the sensor information effective area 510 where the coefficient (W) is 1. In other words, it is desirable that the distance between adjacent Y sensors is equal to or less than half the length K (see FIGS. 6(A) and (B)) of the sensor information effective area 510A in the X direction.

[0098] 10 shows a case where mover 301d is transported as mover 301, and Z sensors 103d, 103e, and 103f are arranged as Z sensor 103. Three Z sensors 103d, 103e, and 103f face Z target 306 of mover 301d shown in FIGS. 10(A) and 10(B). Here, the relative distance values ​​output by the three Z sensors 103d, 103e, and 103f are Zd, Ze, and Zf, respectively, and the measured values ​​are indicated by black circles in the figure. Then, the position Z of mover 301d, the amount of rotation Wy around the Y axis, and the amount of rotation Wx around the X axis can be obtained as parameters of the regression plane.

[0099] Each parameter of the regression plane Z=d*X+e*Y+f, which is the mover position information (Z, Wx, Wy), is found by, for example, using the least squares method to calculate d, e, and f that minimize the weighted square error shown in the following equation (17). In this case, d is tan(Wy), e is tan(Wx), and f is position Z. In addition, in equation (17), Wd, We, and Wf are coefficients of each of Z sensors 103d, 103e, and 103f included in mover posture calculation information 508. Wd*(Zd-(d*PdX+e*PdY+f))^2+We*(Ze-(d*PeX+e*PeY+f))^2+Wf*(Zf-(d*PfX+e*PfY+f))^2...Equation (17)

[0100] Also, four or more Z sensors 103 may face each other depending on the position of the mover 301. In that case, the tilt of the Z target 306, that is, the amount of rotation Wx around the X axis and the amount of rotation Wy around the Y axis, and the position Z of the mover 301 can be calculated similarly using the least squares method or the like.

[0101] From the viewpoint of the posture detection accuracy of the movable element 301, it is desirable that the Z sensors 103 are installed along the transport direction (X) in the sensor information effective area 510B where the coefficient (W) is 1, at least one on either the R side or the L side, and two on the other side. In the present embodiment, an example of at least two on the R side and at least one on the L side is shown, but at least two on the L side and at least one on the R side may be used. That is, in order to install at least two sensors in the sensor information effective area 510B, it is preferable that the distance between adjacent Z sensors 103 is half or less of the length L in the X direction of the sensor information effective area 510B (see FIGS. 8A and 8B). In order to install at least one sensor in the sensor information effective area 510B, it is preferable that the distance between adjacent Y sensors is equal to or less than the length L in the X direction of the sensor information effective area 510B (see FIGS. 8A and 8B).

[0102] As described above, the mover attitude calculation function 503 can calculate the position Y and position Z, and the rotation amounts Wx, Wy, and Wz around each axis as the attitude information of the mover 301.

[0103] Using the mover information 506 calculated above, the mover attitude control function 504 calculates the force T to be applied to the mover 301, and the coil current calculation function 505 determines the amount of current to be applied to each coil 202 from the force acting on each permanent magnet 303.

[0104] Next, the process by the coil current calculation function 505 will be described with reference to Fig. 2(B). In the notation of forces used below, the directions in which the forces act in the X, Y, and Z directions are indicated by x, y, and z, respectively, the R side which is the Y+ side in Fig. 2(B) is indicated by R, the L side which is the Y- side is indicated by L, the X+ side is indicated by f, and the X- side is indicated by b.

[0105] 2(B), the forces acting on each permanent magnet 303 on the R side and L side are expressed as follows. The forces acting on each permanent magnet 303 are electromagnetic forces that the permanent magnet 303 receives from the multiple coils 202 to which current is applied. The permanent magnet 303 receives electromagnetic forces in the X direction, which is the transport direction of the mover 101, as well as in the Y direction and Z direction, which are directions different from the X direction, from the multiple coils 202 to which current is applied.

[0106] The forces acting on the R-side permanent magnet 303 are expressed as follows: FzfR: Force acting in the Z direction on the R-side permanent magnet 303bR FxfR: Force acting in the X direction of the permanent magnet 303bR on the R side FyfR: Force acting in the Y direction on the R-side permanent magnet 303aR FxbR: Force acting in the X direction of the R-side permanent magnet 303cR FybR: Force acting in the Y direction on the R-side permanent magnet 303dR FzbR: Force acting in the Z direction on the R-side permanent magnet 303cR

[0107] The forces acting on the L-side permanent magnet 303 are expressed as follows: FzfL: Force acting in the Z direction on the L-side permanent magnet 303bL FxfL: Force acting in the X direction of the L-side permanent magnet 303bL FyfL: Force acting in the Y direction of the L-side permanent magnet 303aL FxbL: Force acting in the X direction of the L-side permanent magnet 303cL FybL: Force acting in the Y direction on the L-side permanent magnet 303dL FzbL: Force acting in the Z direction on the L-side permanent magnet 303cL

[0108] Moreover, the force T applied to the mover 301 is expressed by the following formula (18). Note that Tx, Ty, and Tz are three-axis components of the force, which are the X-direction component, the Y-direction component, and the Z-direction component of the force, respectively. Furthermore, Twx, Twy, and Twz are three-axis components of the moment, which are the X-axis component, the Y-axis component, and the Z-axis component of the moment, respectively. The transport device 1 according to this embodiment controls the transport of the mover 301 while controlling the posture of the mover 301 in six axes by controlling these six-axis components (Tx, Ty, Tz, Twx, Twy, Twz) of the force T. T=(Tx,Ty,Tz,Twx,Twy,Twz)…Equation (18)

[0109] Then, Tx, Ty, Tz, Twx, Twy, and Twz are calculated by the following equations (19a), (19b), (19c), (19d), (19e), and (19f), respectively. Tx=FxfR+FxbR+FxfL+FxbL…Equation (19a) Ty=FyfL+FyfR+FybL+FybR…Equation (19b) Tz=FzbR+FzbL+FzfR+FzfL…Equation (19c) Twx={(FzfL+FzbL)-(FzfR+FzbR)}*rx3…Formula (19d) Twy={(FzfL+FzfR)-(FzbL+FzbR)}*ry3…Formula (19e) Twz={(FyfL+FyfR)-(FybL+FybR)}*rz3…Formula (19f)

[0110] In this case, the limitations expressed by the following equations (19g), (19h), (19i), and (19j) can be introduced into the forces acting on the permanent magnets 303. By introducing these limitations, it is possible to uniquely determine the combination of forces acting on each permanent magnet 303 to obtain a force T having predetermined six-axis components. FxfR=FxbR=FxfL=FxbL…Formula (19g) FyfL = FyfR ... formula (19h) FybL=FybR…Equation (19i) FzbR = FzbL ... Equation (19j)

[0111] Next, a method for determining the amount of current to be applied to each coil 202 from the force acting on each permanent magnet 303 by the coil current calculation function 505 will be described.

[0112] First, a case will be described in which a force in the Z direction is applied to permanent magnets 303a and 303d, whose N and S poles are arranged alternately in the Y direction. The coil 202 is arranged so that its center in the Z direction is located at the center of the permanent magnets 303a and 303d in the Y direction. This ensures that almost no force acts on the permanent magnets 303a and 303d in the X and Z directions.

[0113] Let X be the position of the mover 301, j be the number of the coil 202 in the row, Fy(j,X) be the magnitude of the force acting in the Y direction of the coil 202(j) per unit current, and i(j) be the current applied to the coil 202(j). Note that the coil 202(j) is the j-th coil 202. In this case, the current i(j) can be determined so as to satisfy the following equation (8). Note that the following equation (20) is an equation for the permanent magnet 303dR. The currents applied to the coils 202 of the other permanent magnets 303aR, 303aL, and 303dL can be determined in a similar manner. ΣFy(j, X)*i(j)=FybR…Equation (20)

[0114] In addition, when multiple coils 202 exert a force on the permanent magnet 303, the force acting on the permanent magnet 303 can be uniquely determined by apportioning the current based on the magnitude of force per unit current according to the force exerted by each coil 202.

[0115] 2(B), the permanent magnets 303 are arranged symmetrically on the L side and the R side of the mover 301. Such a symmetric arrangement of the permanent magnets 303 makes it possible to cancel out a multi-component force acting on the permanent magnets 303, for example, the force Wx acting on the permanent magnets 303a and 303d, i.e., the moment component around the X-axis, with the forces on the L side and the R side. As a result, it becomes possible to control the attitude of the mover 301 with higher precision.

[0116] Next, a method of applying forces in the X and Z directions independently to the permanent magnet 303b, in which the polarities of N, S and N poles are alternately arranged in the X direction, will be described. Fig. 13 is a schematic diagram illustrating a method of applying forces in the X and Z directions independently to the permanent magnet 303b. The coil current calculation function 505 determines a current command value to be applied to the coil 202 in order to apply forces in the X and Z directions independently to the permanent magnet 303b according to the following. Note that forces can also be applied independently to the permanent magnet 303c in the X and Z directions, similar to the permanent magnet 303b.

[0117] Let X be the position of the mover 301, j be the number of the coils 202 in the row, and let Fx(j,X) and Fz(j,X) be the magnitudes of the forces acting in the X and Z directions of the coil 202(j) per unit current, respectively. Also, let i(j) be the magnitude of the current in the coil 202(j). Note that the coil 202(j) is the j-th coil 202.

[0118] The upper diagram in Fig. 13 is a diagram showing six coils 202 facing permanent magnet 303bR, with the X axis running horizontally and the Y axis running vertically. The middle diagram in Fig. 13 is a diagram seen from the Y direction of the upper diagram in Fig. 13. The coils 202 are given numbers j from 1 to 6 in the order they are lined up in the X direction, and below each coil 202 will be identified by a notation such as coil 202(1).

[0119] 13, the coils 202 are arranged at a pitch of a distance L. On the other hand, the permanent magnets 303 of the mover 301 are arranged at a pitch of a distance 3 / 2*L.

[0120] The lower graph in FIG. 13 is a graph that illustrates the magnitude of the X-direction force Fx and the Z-direction force Fz that are generated when a unit current is applied to each of the coils 202 shown in the upper and middle diagrams in FIG. 13.

[0121] For simplicity, in Fig. 13, the origin Oc of the X-direction position of coil 202 is set to the midpoint between coil 202(3) and coil 202(4), and the center Om of permanent magnet 303bR in the X-direction is set to the origin. For this reason, Fig. 13 shows the case where Oc and Om coincide with each other, that is, the case where X=0.

[0122] In this case, for example, the force per unit current acting on coil 202(4) is Fx(4,0) in the X direction and Fz(4,0) in the Z direction. Also, the force per unit current acting on coil 202(5) is Fx(5,0) in the X direction and Fz(5,0) in the Z direction.

[0123] Here, the current values ​​applied to coils 202(1) to 202(6) are i(1) to i(6), respectively. Then, the magnitude of force FxfR acting in the X direction and the magnitude of force FzfR acting in the Z direction on permanent magnet 303bR are generally expressed by the following equations (21) and (22), respectively. FxfR=Fx(1,X)*i(1)+Fx(2,X)*i(2)+Fx(3,X)*i(3)+Fx(4,X)*i(4)+Fx(5,X)*i(5)+Fx(6,X)*i(6)...Equation (21) FzfR=Fz(1,X)*i(1)+Fz(2,X)*i(2)+Fz(3,X)*i(3)+Fz(4,X)*i(4)+Fz(5,X)*i(5)+Fz(6,X)*i(6)...Equation (22)

[0124] By determining the current command value so that current values ​​i(1) to i(6) that satisfy the above expressions (21) and (22) are applied to coils 202(1) to 202(6), respectively, it is possible to apply forces independently in the X and Z directions to permanent magnet 303bR. Coil current calculation function 505 can determine the current command value to be applied to coil 202(j) as described above in order to apply forces independently in the X and Z directions to permanent magnet b303.

[0125] For simplicity's sake, consider an example in which, in the case shown in Fig. 13, only coils 202(3), 202(4), and 202(5) of coils 202(1) to 202(6) are used for permanent magnet 303bR, and furthermore, the sum of the current values ​​of these three is controlled to be 0. In this example, force FxfR acting in the X direction and force FzfR acting in the Z direction on permanent magnet 303bR are expressed by the following equations (23) and (24), respectively. FxfR=Fx(3,X)*i(3)+Fx(4,X)*i(4)+Fx(5,X)*i(5)...Equation (23) FzfR=Fz(3,X)*i(3)+Fz(4,X)*i(4)+Fz(5,X)*i(5)...Equation (24)

[0126] Moreover, the current values ​​of the coils 202(1) to 202(6) can be set so as to satisfy the following expressions (25) and (26). i(3)+i(4)+i(5)=0…Eq. (25) i(1)=i(2)=i(6)=0…Eq.(26)

[0127] Therefore, when the magnitude of the force (FxfR, FzfR) required for the permanent magnet 303bR is determined, the current values ​​i(1), i(2), i(3), i(4), i(5), and i(6) can be uniquely determined. Forces are applied to the mover 301 in the X and Z directions by the current command value determined in this way. The force in the X direction applied to the mover 301 causes the mover 301 to obtain a propulsive force for moving in the X direction, and moves in the X direction. In addition, the posture of the mover 301 is controlled by the forces in the X and Z directions applied to the mover 301 by the current command value determined in this way.

[0128] In this way, the integrated controller 401 controls the currents applied to the multiple coils 202, thereby controlling each of the six axis components of the force applied to the mover 301.

[0129] When the center Oc of the coil 202 moves relative to the center Om of the permanent magnet 303bR due to the movement of the mover 301, that is, when X≠0, the coil 202 according to the moved position can be selected. Furthermore, the same calculation as above can be performed based on the force per unit current generated in the coil 202.

[0130] As described above, the integrated controller 401 determines and controls the current command values ​​of the currents applied to the multiple coils 202, thereby controlling the attitude of the mover 301 on the stator 201 in six axes, while controlling the non-contact transportation of the mover 301 on the stator 201. That is, the integrated controller 401 functions as a transportation control means for controlling the transportation of the mover 301, and controls the non-contact transportation of the mover 301 on the stator 201 by controlling the electromagnetic force that the permanent magnet 303 receives from the multiple coils 202. The integrated controller 401 also functions as a posture control means for controlling the attitude of the mover 301, and controls the attitude of the mover 301 on the stator 201 in six axes. Note that all or part of the functions of the integrated controller 401 as a control device can be substituted by the coil controller 402 or other control devices.

[0131] In this way, according to this embodiment, six-axis forces, i.e., three-axis force components (Tx, Ty, Tz) and three-axis moment components (Twx, Twy, Twz), can be applied to the mover 301 by the multiple coils 202 arranged in two rows. This makes it possible to control the transport of the mover 301 while controlling the attitude of the mover 301 in six axes. According to this embodiment, two rows of coils 202, which is fewer rows than the number of six-axis components of the force, which is the variable to be controlled, make it possible to control the transport of the mover 301 while controlling the attitude of the mover 301 in six axes.

[0132] Therefore, according to this embodiment, the number of rows of coils 202 can be reduced, and therefore the mover 301 can be transported in a non-contact manner while controlling the attitude of the mover 301, without enlarging or complicating the system. Furthermore, according to this embodiment, the number of rows of coils 202 can be reduced, and therefore a small-sized magnetic levitation type transport system can be configured at low cost.

[0133] Furthermore, according to this embodiment, since the permanent magnet 303 is disposed on the upper surface of the mover 301, it is possible to realize good access to the workpiece 302. As a result, it is possible to perform a machining operation on the workpiece 302 on the mover 301 with a high degree of freedom by a process device.

[0134] Next, the effect of the present invention will be described using an example of detection by a Y sensor shown in FIG.

[0135] FIG. 11(A) shows how a Y target 305 attached to a mover 301 (not shown) moves as the mover 301 is transported, and the sensor installation positions of the multiple Y sensors 102a, 102b, and 102c differ due to variations in sensor installation accuracy.

[0136] As shown in FIGS. 11B to 11E, with the transport of mover 301, Y sensor 102c starts to newly detect Y target 305 at the position indicated by PosXa in the figure.

[0137] 11B shows the calculation result of the mover position information (Y, Wz) by the conventional technique that does not have the sensor information load region 511. Due to the switching of the Y sensor 102, the calculation result of the mover position information (Y, Wz) fluctuates greatly and discontinuously.

[0138] In contrast, Fig. 11(C) shows the calculation results of mover position information (Y, Wz) using a coefficient (W) calculated by a sigmoid function. Fig. 11(D) shows the results using a coefficient (W) calculated by a linear function, and Fig. 11(E) shows the results using a coefficient (W) calculated by a discontinuous function as shown in Fig. 7(C). In the area shown as sensor information load area 511 in Fig. 11, the coefficient (W) of Y sensor 102c is calculated by each function and used to calculate mover position information (Y, Wz).

[0139] It is desirable that the detection position and attitude when the detection sensor is switched should change smoothly as shown in Fig. 11(C) from the viewpoint of suppressing vibration of the mover 301. However, even if they are configured with a linear function or a discontinuous function for implementation reasons such as speeding up the calculation process of the mover position information, it is possible to suppress the above-mentioned fluctuations to a small value as shown in Figs. 11(D) and (E).

[0140] In addition, the sensors used to calculate the mover information 506 are successively switched by the transport of the mover 301. At that time, the installation positions of the sensors change continuously with the coefficient (W) from the sensor information invalid area 512b to the sensor information load area 511b to the sensor information valid area 510A to the sensor information load area 511a to the sensor information invalid area 512a. Therefore, according to this embodiment, it is possible to suppress the fluctuation of the detection position and the attitude when the detection sensor is switched. Therefore, it is possible to eliminate the vibration of the mover caused by the switching of the detection sensor, and stable transport is possible.

[0141] In this embodiment, the sensor information load area 511 and the sensor information invalid area 512 are provided only in front of and behind the movable element 301. However, depending on the configuration of the movable element 301, the targets 305 and 306 may be divided and arranged in the conveying direction, or the targets 305 and 306 may be floating or deformed due to variations in the installation accuracy. In this case, the detection of the sensors 102 and 103 may become unstable, and there may be multiple locations where the detection error is equal to or greater than a certain level. In such a case, as shown in FIG. 12, it is also possible to divide the Y target 305 into Y targets 3051 and 3052. Alternatively, it is also possible to divide the Z target 306R into 306R1 and 306R2, and the Z target 306L into 306L1 and 306L2. The sensor information valid area 510 is divided accordingly, and the sensor information load area 511 and the sensor information invalid area 512 are set.

[0142] This makes it possible to suppress fluctuations in the detected position and orientation caused by division of the Y target 305 and the Z target 306, etc.

[0143] In this embodiment, the conveying device 1 is an example of a moving magnet type linear motor (moving permanent magnet type linear motor, moving field type linear motor), but is not limited to this. The conveying device 1 may be a moving coil type linear motor (moving coil type linear motor, fixed field type linear motor).

[0144] [Second embodiment] Hereinafter, a second embodiment of the present invention will be described with reference to the drawings, using FIGS.

[0145] 14 is a schematic diagram showing the entire conveying system according to the second embodiment. In the conveying system of the second embodiment, the mover 301 is restricted by the guide rail 204 so as not to move in the Y and Z directions. In addition, the only sensor attached to the stator 201 is the X sensor 101. Hereinafter, the same reference numerals are used for configurations having the same functions as those in the first embodiment, and the description thereof will be omitted.

[0146] A conveying system 1001 according to the second embodiment has a mover 301 constituting a dolly, slider or carriage, a stator 201 constituting a conveying path, and a plurality of X-sensors 101 fixed to the stator 201. The conveying system 1001 is a conveying system using a moving magnet type linear motor (a moving permanent magnet type linear motor, a moving field type linear motor).

[0147] Furthermore, the movable element 301 is restricted so as not to move in the Y and Z directions by the guide rails 204. In this embodiment, an example in which the movable element 301 is restricted by the guide rails 204 has been shown, but the movable element 301 may be restricted in the Y and Z directions by guide rollers.

[0148] The X-sensor 101 is, for example, a linear encoder that detects a linear scale 304 attached to the mover 301 and specifies the position of the mover 301 in the transport direction.

[0149] The multiple X sensors 101 are attached to the stator 201 along the X direction so as to face the linear scale 304 of the mover 301. Each X sensor 101 can detect and output the position of the mover 301 relative to the X sensor 101 by reading the linear scale 304 attached to the mover 301.

[0150] Next, the control system for controlling the transport system 1001 according to the present embodiment will be further described with reference to Fig. 15. Fig. 15 is a schematic diagram showing a control system for controlling the transport system 1001 according to the second embodiment.

[0151] As shown in Fig. 15, the control system has a host controller 1400, an integrated controller 1401 (1401a and 1401b), a coil controller 1402, and a sensor controller 1404, and functions as a control device that controls a conveyance system 1001 including a mover 301 and a stator 201. The integrated controller 1401 is communicatively connected to the host controller 1400. The coil controller 1402 is communicatively connected to the integrated controller 1401. In addition, the sensor controller 1404 is communicatively connected to the integrated controller 1401.

[0152] The host controller 1400 controls the entire production equipment including the transport system 1001 and the process equipment that performs processing work on the workpiece 302 on the movable element 301. The host controller 1400 transmits movement commands (movement destination, movement speed, movement acceleration / deceleration, etc.) for each movable element 301 to the integrated controller 1401.

[0153] A plurality of current controllers 1403 (not shown) are communicatively connected to the coil controller 1402. The coil controller 1402 and the plurality of current controllers 1403 connected thereto are provided corresponding to the plurality of coils 202. Each current controller 1403 is connected to a coil unit 203. The current controller 1403 can control the magnitude of the current of each coil 202 of the connected coil unit 203.

[0154] The coil controller 1402 issues a target current value to each of the connected current controllers 1403. The current controllers 1403 control the amount of current in the connected coils 202.

[0155] A plurality of X sensors 101 are communicatively connected to the sensor controller 1404 .

[0156] The multiple X-sensors 101 are attached to the stator 201 at intervals such that one of them can always measure the position of one of the movers 301 even while the movers 301 are being transported.

[0157] The integrated controller 1401 determines a current command value to be applied to the multiple coils 202 based on the output from the X sensor 101, and transmits it to the coil controller 1402. The coil controller 1402 issues a current value command to the current controller 1403 based on the current command value from the integrated controller 1401, and executes current control. In this way, the integrated controller 1401 functions as a control device, and controls the transport of the mover 301 along the stator 201.

[0158] Hereinafter, the position control method of the mover 301 executed by the integrated controller 1401 will be described with reference to FIG. 16. FIG. 16 is a schematic diagram showing the control method of the mover 301 in the transport system 1001 according to this embodiment. FIG. 16 shows the outline of the control method of the mover 301, focusing mainly on the data flow. The integrated controller 1401 executes processing using a mover position calculation information processing function 1512, a mover position calculation function 1513, a mover position control function 1514, and a coil current calculation function 1515, as described below. In this way, the integrated controller 1401 controls the transport of the mover 301 while controlling the position of the mover 301. Note that instead of the integrated controller 1401, the coil controller 1402 may be configured to execute the same processing as the integrated controller 1401.

[0159] First, mover position calculation information processing function 1512 calculates mover position calculation information 1508 from measurement values ​​from multiple X sensors 101 and information 1507 on their mounting positions. Next, mover position calculation function 1513 calculates the number and positions of movers 301 on stator 201 that constitutes the transport path from mover position calculation information 1508. As a result, mover position calculation function 1513 updates mover position information and number information of mover information 1506, which is information on movers 301. The mover position information indicates the position of mover 301 on stator 201 in the X direction, which is the transport direction. Mover information 1506 is prepared for each mover 301 on stator 201.

[0160] Movable element position calculation information processing function 1512 identifies the X sensor 101 that detects the linear scale 304 attached to each movable element 301 from the measurement values ​​of the multiple X sensors 101. At this time, a coefficient (W) is calculated based on the sensor installation position information 1507 on the stator 201 of the identified X sensor 101 and the measurement value.

[0161] Next, the mover position calculation function 1513 calculates the position information of each mover 301 based on the mover position calculation information 1508 including the specified measurement value of the X sensor 101 and the calculated coefficient (W), and the sensor position information 1507, and updates the mover information 1506.

[0162] Next, mover position control function 1514 calculates applied force information 1509 for each mover 301 from current mover information 1506 including mover position information and the target position value. The applied force information 1509 is information on the magnitude of the force to be applied to each mover 301. The applied force information 1509 is prepared for each mover 301 on the stator 201, for example, as shown by Trq-1, Trq-2, ... in FIG.

[0163] Next, a coil current calculation function 1515 determines a current command value 15101 to be applied to each coil 202 based on the applied force information 1509 and the mover information 1506 .

[0164] In this way, the integrated controller 1401 executes processing using the mover position calculation information processing function 1512, the mover position calculation function 1513, the mover position control function 1514, and the coil current calculation function 1515, to determine the current command value 15101. The integrated controller 1401 transmits the determined current command value 15101 to the coil controller 1402.

[0165] Here, the process by the mover position calculation information processing function 1512 will be described with reference to Fig. 17. Fig. 17 is a schematic diagram for explaining the process by the mover position calculation information processing function 1512.

[0166] In Fig. 17, reference point Oe is the position reference of stator 201 to which X sensor 101 is attached. Also, reference point Os is the position reference of linear scale 304 attached to mover 301. Fig. 17 shows a case in which two movers 301a and 301b are transported as movers 301, and four X sensors 101a, 101b, 101c, and 101d are arranged as X sensor 101. Note that linear scale 304 is attached along the X direction at the same position of each of movers 301a and 301b.

[0167] Each of the X sensors 101a to 101d observing the mover 301 calculates a coefficient (W) between 0 and 1 based on each of the output distances Pa, Pb, Pc, and Pd.

[0168] For example, since the X sensors 101a and 101c in FIG. 17 are determined to be present in the sensor information effective area 1510, the following equations (27) and (28) are used for the calculation. W(101a)=1...Equation (27) W(101c)=1...Equation (28)

[0169] 17 is determined to be in sensor information invalid area 1512a, so is calculated as in the following equation (29). Sensor information invalid area 1512 is provided to ignore the output in an area where the detection error of X sensor 101 is equal to or greater than a certain value, since X sensor 101 detects the end of linear scale 304. W(101b)=0…Equation (29)

[0170] 17 is determined to be present in the sensor information weight region 1511b, a value between 0 and 1 is calculated using a continuous function that monotonically increases and decreases from 0 to 1 or from 1 to 0, such as a sigmoid function as shown in the following equation (30). In equation (30), a is the gain of the sigmoid function. W(101d)=1 / (1+exp(-a*Pd))…Formula (30)

[0171] As described above, mover position calculation information processing function 1512 calculates the coefficient (W) based on the output of X sensor 101 and sensor installation position information 1507. Mover position calculation information 1508 to which the calculated coefficient (W) is added is output, and is used as an input to mover position calculation function 1513.

[0172] It is possible to perform processing similar to the above-mentioned mover position calculation information processing function 1512 by using another function exemplified in the first embodiment as a function for calculating the coefficient (W) or by storing the coefficient profile in the memory of the integrated controller 1401.

[0173] Next, the process by the mover position calculation function 1513 will be described with reference to FIG.

[0174] For example, one X-sensor 101a faces linear scale 304 of mover 301a shown in Fig. 17. X-sensor 101a reads linear scale 304 of mover 301a and outputs distance Pa. The position on the X-axis of X-sensor 101a with reference point Oe as the origin is Sa. Therefore, using the output of X-sensor 101a, position Pos(301a, 101a) of mover 301a can be calculated by the following equation (31). Pos(301a, 101a)=Sa-Pa…Equation (31)

[0175] For example, three X-sensors 101b, 101c, and 101d face linear scale 304 of mover 301b shown in Fig. 17. X-sensor 101b reads linear scale 304 of mover 301b and outputs distance Pb. Furthermore, the position on the X-axis of X-sensor 101b with reference point Oe as the origin is Sb. Therefore, position Pos(301b, 101b) of mover 301b on the X-axis based on the output of X-sensor 101b can be calculated by the following equation (32). Pos(301b, 101b)=Sb-Pb…Equation (32)

[0176] Similarly, X-sensors 101c and 101d read linear scale 304 of mover 301b and output distances Pc and Pd, respectively. Furthermore, the positions on the X-axis of X-sensors 101c and 101d with reference point Oe as the origin are Sc and Sd, respectively. Therefore, positions Pos(301b, 101c) and Pos(301b, 101d) of mover 301b on the X-axis based on the outputs of X-sensors 101c and 101d can be calculated by the following equations (33) and (34). Pos(301b, 101c)=Sc-Pc…Equation (33) Pos(301b, 101d)=Sd-Pd…Equation (34)

[0177] Here, since the installation positions of the X sensors 101b, 101c, and 101d are accurately measured in advance, the difference between the three values ​​Pos(301b, 101b), Pos(301b, 101c), and Pos(301b, 101d) is sufficiently small relative to the length of the mover 301. When the difference between the positions of the mover 301 on the X axis based on the outputs of the multiple X sensors 101 is sufficiently small in this way, it can be determined that the multiple X sensors 101 are observing the linear scale 304 of the same mover 301.

[0178] Next, the position Pos(301, 101) of the mover 301 on the X-axis calculated based on the output of the X-sensor 101 determined to be observing the same mover 301, and based on the mover position calculation information 1508, a weighted average is calculated to uniquely determine the position of the observed mover 301.

[0179] For example, the position Pos(301a) of the mover 301a shown in FIG. 17 is calculated using the following equation (35). Pos(301a)=W(101a)*Pos(301a, 101a) / W(101a)...Equation (35)

[0180] Alternatively, in terms of calculation errors, when there is only one X sensor 101 detecting the same mover 301, it is also possible to use the following equation (36). Pos(301a)=Pos(301a, 101a)...Equation (36)

[0181] Next, for example, the position Pos(301b) of the mover 301b shown in FIG. 17 is calculated using the following equation (37). Pos(301b)={W(101b)*Pos(301b, 101b)+W(101c)*Pos(301b, 101c)+W(101d)*Pos(301b, 101d)} / {W(101b)+W(101c)+W(101d)}...Equation (37)

[0182] Next, mover position control function 1514 calculates applied force information 1509 for each mover 301 from current mover information 1506 and the target value (command position). Applied force information 1509 is information regarding the magnitude of the force to be applied to each mover 301.

[0183] Next, a coil current calculation function 1515 determines a current command value 15101 to be applied to each coil 202 based on the applied force information 1509 and the mover information 1506 .

[0184] Next, the process performed by the coil current calculation function 1515 will be described with reference to Fig. 20. In the notation of forces used below, the directions in which forces act in the X direction and the Y direction are indicated by x and y, respectively.

[0185] 21(a), the force acting on the permanent magnet 303 is expressed as follows. The force acting on each permanent magnet 303 is an electromagnetic force that the permanent magnet 303 receives from the multiple coils 202 to which a current is applied. The permanent magnet 303 receives an electromagnetic force Fy in the Y direction, in addition to an electromagnetic force Fx in the X direction, which is the transport direction of the mover 301, from the multiple coils 202 to which a current is applied.

[0186] A method of applying a force in the X direction to the permanent magnet 303 in which S poles and N poles are alternately arranged in the X direction will be described. Fig. 20 is a schematic diagram illustrating a method of applying a force in the X direction to the permanent magnet 303. The coil current calculation function 1515 determines a current command value to be applied to the coil 202 in order to apply a force in the X direction to the permanent magnet 303 according to the following.

[0187] Let X be the position of the mover 301, j be the number of the coils 202 in the row, and let Fx(j,X) and Fy(j,X) be the magnitudes of the forces acting in the X and Y directions of the coil 202(j) per unit current. Also, let i(j) be the magnitude of the current in the coil 202(j). Note that the coil 202(j) is the j-th coil 202.

[0188] The top diagram in Fig. 20 is a diagram showing nine coils 202 facing permanent magnet 303, with the X axis running horizontally and the Z axis running vertically. The middle diagram in Fig. 20 is a diagram seen from the Z direction of the top diagram in Fig. 20. Numbers j from 1 to 6 are given to the coils 202 in the order they are lined up in the X direction, and below each coil 202 will be identified by a notation such as coil 202(1).

[0189] 20, the coils 202 are arranged at a pitch of a distance L. On the other hand, the permanent magnets 303 of the mover 301 are arranged at a pitch of a distance 3 / 2*L.

[0190] The lower graph in FIG. 20 is a graph that shows a schematic representation of the magnitude of the X-direction force Fx and the Y-direction force Fy that are generated when a unit current is applied to each of the coils 202 shown in the upper and middle diagrams in FIG. 20.

[0191] For simplicity, in Fig. 20, the origin Oc of the X-direction position of coil 202 is set as the center of coil 202(5), and the center Om of permanent magnet 303 in the X-direction is set as the origin. For this reason, Fig. 20 shows the case where Oc and Om coincide, that is, the case where X=0.

[0192] In this case, for example, the force per unit current acting on coil 202(4) has a magnitude of Fx(4,0) in the X direction and Fy(4,0) in the Y direction. Also, the force per unit current acting on coil 202(5) has a magnitude of Fx(5,0) in the X direction and Fy(5,0) in the Y direction.

[0193] Here, the current values ​​applied to coils 202(1) to 202(9) are i(1) to i(9), respectively. Then, the magnitude of force Fx acting in the X direction and the magnitude of force Fy acting in the Y direction on permanent magnet 303 are generally expressed by the following equations (38) and (39), respectively. Fx=Σ{Fx(j,X)*i(j)}, (j=1,...,9)...Equation (38) Fy=Σ{Fy(j,X)*i(j)}, (j=1,...,9)...Equation (39)

[0194] By determining the current command value so that current values ​​i(1) to i(9) satisfying the above expressions (38) and (39) are applied to coils 202(1) to 202(9), respectively, it is possible to apply forces in the X and Y directions to permanent magnet 303. Coil current calculation function 1515 can determine the current command value to be applied to coil 202(j) as described above in order to apply forces in the X and Y directions to permanent magnet 303.

[0195] For simplicity's sake, consider an example in which, in the case shown in Fig. 20, only coils 202(3), 202(4), and 202(5) of coils 202(1) to 202(9) are used for permanent magnet 303, and furthermore, the sum of the current values ​​of these three is controlled to be 0. In this example, force Fx acting in the X direction and force Fy acting in the Y direction on permanent magnet 303 are expressed by the following equations (40) and (41), respectively. Fx=Fx(3,X)*i(3)+Fx(4,X)*i(4)+Fx(5,X)*i(5)...Equation (40) Fy=Fy(3,X)*i(3)+Fy(4,X)*i(4)+Fy(5,X)*i(5)…Equation (41)

[0196] Moreover, the current values ​​of the coils 202(1) to 202(9) can be set so as to satisfy the following expressions (42) and (43). i(3)+i(4)+i(5)=0…Eq.(42) i(1)=i(2)=i(6)=i(7)=i(8)=i(9)=0...Equation (43)

[0197] 21(b), the mover 301 is constrained in the Y direction by the guide rail 204, but it is desirable to transport it without applying unnecessary load. Therefore, it is desirable to set the force Fy acting on the permanent magnet 303 in the Y direction so as to satisfy the following formula (44). Fy=0…Equation (44)

[0198] Therefore, when the magnitude of force Fx required for the permanent magnet 303 is determined, the current values ​​i(1) to i(9) can be uniquely determined. A force in the X direction is applied to the mover 301 by the current command value determined in this manner. Due to the force in the X direction applied to the mover 301, the mover 301 obtains a propulsive force for moving in the X direction, and is transport-controlled in the X direction.

[0199] In this way, the integrated controller 1401 controls the current applied to the multiple coils 202 , thereby controlling the force applied to the mover 301 in the X direction.

[0200] When the center Oc of the coil 202 moves relative to the center Om of the permanent magnet 303bR due to the movement of the mover 301, that is, when X≠0, the coil 202 according to the moved position can be selected. Furthermore, the same calculation as above can be performed based on the force per unit current generated in the coil 202.

[0201] As described above, the integrated controller 1401 controls the position of the mover 301 on the stator 201 by determining and controlling the current command values ​​of the currents applied to the multiple coils 202. That is, the integrated controller 1401 functions as a transport control means for controlling the transport of the mover 301, and controls the transport of the mover 301 on the stator 201 by controlling the electromagnetic force that the permanent magnet 303 receives from the multiple coils 202. Note that all or part of the functions of the integrated controller 1401 as a control device can be substituted by the coil controller 1402 or other control devices.

[0202] Next, the effect of the present invention will be described using an example of detection by an X sensor shown in FIGS.

[0203] Fig. 18 shows how linear scale 304 attached to mover 301 (not shown) moves as mover 301 (not shown) is transported, and multiple X-sensors 101a, 101b have different sensor installation positions due to variations in sensor installation accuracy. In Fig. 18, X-sensors 101a', 101b' indicated by dashed lines are the installation positions of the X-sensors in the design, and X-sensors 101a, 101b are schematic representations of the installation positions of the X-sensors actually attached.

[0204] 18, as the mover 301 is transported, the X-sensor 101b newly starts detecting the linear scale 304. From the viewpoint of suppressing vibration of the mover 301, it is desirable that the detection position and orientation when the detection sensor is switched be detected without error, regardless of the switching of the X-sensor 101. However, as described above, detection errors occur due to the installation accuracy of the sensor, machine differences, etc.

[0205] In the conventional technology, the calculation result of the mover position information would vary discontinuously and significantly due to switching of the X sensor 101. In contrast, the calculation result of the mover position information using the coefficient (W) varies continuously, and it is possible to minimize the variation in the detection position due to switching of the X sensor.

[0206] In addition, the sensors used to calculate the mover information 1506 are successively switched by the transport of the mover 301. At that time, the installation positions of the sensors change continuously with the coefficient (W) from the sensor information invalid area 1512b to the sensor information load area 1511b to the sensor information valid area 1510A to the sensor information load area 1511a to the sensor information invalid area 1512a. Therefore, according to this embodiment, the fluctuation of the detection position when the detection sensor is switched can be suppressed to a small value. Therefore, the vibration of the mover caused by the switching of the detection sensor can be eliminated, and stable transport is possible.

[0207] Also, in the first embodiment, the calculation process of the mover position information indicated by the mover position calculation function 501 in FIG. 4 can be replaced with the mover position calculation information processing function 1512 and the mover position calculation function 1513 of the second embodiment. Thereby, also in the calculation process of the mover position information of the first embodiment, vibrations of the mover caused by the switching of the detection sensors in the first direction can be removed in the same manner as in the second embodiment.

[0208] Also, in this embodiment, the coefficient (W) calculated by the mover position calculation information processing function 1512 is calculated based on the relative position (calculated from the output and the installation position) between the mover 301 and the X sensor 101, but a method of calculating the coefficient (W) according to the detection time of the X sensor 101 can also be used. With this method shown below, vibrations of the mover caused by the switching of the detection sensors can be removed regardless of the moving speed of the mover 301, enabling stable conveyance. Note that, for this example in which the position information of the mover corresponding to the detection time when the X sensor 101 detects the mover 301 is corrected, information on the relative position between the mover 301 and the X sensor 101 may also be taken into account.

[0209] For example, the X sensor 101e in FIG. 19 starts detecting the mover 301c at time Ts and stops detecting the mover 301c at time Te as the mover 301c is conveyed.

[0210] For example, the X sensor 101e in FIG. 19 is determined to be in the sensor information invalid time 1522 from time Ts to T1 and from time T4 to Te, and thus is calculated as shown in the following formula (45). W(101e, t) = 0, (Ts < t < T1, T4 < t < Te) … Formula (45)

[0211] Also, the X sensor 101e in FIG. 19 is determined to be in the sensor information valid time 1520 from time T2 to T3, and thus is calculated as shown in the following formula (46). W(101e, t) = 1, (T2 ≤ t ≤ T3) … Formula (46)

[0212] Also, the X sensor 101e in FIG. 19 is determined as the sensor information load time 1521 from time T1 to T2 and from time T3 to T4. Therefore, for example, it is calculated with a value between 0 and 1 using a continuous function that monotonically increases or decreases from 0 to 1 or from 1 to 0, such as the sigmoid functions in the following equations (47) and (48). In equations (47) and (48), a is the gain of the sigmoid function. W(101e, t) = 1 / {1 + exp(−a*(t − t1´))}, (T1 ≤ t < T2, t1´ = (T2 − T1) / 2) … Equation (47) W(101e, t) = 1 − 1 / {1 + exp(−a*(t − t2´))}, (T3 < t ≤ T4, t2´ = (T4 − T3) / 2) … Equation (48)

[0213] The mover position calculation information processing function 1512 may calculate the coefficient (W) based on the detection time of the X sensor 101 as described above. Output the mover position calculation information 1508 with the calculated coefficient (W) added, and use it as the input to the mover position calculation function 1513.

[0214] Note that the time Te when the mover 301c can no longer be detected can be determined according to the movement state of the mover 301c.

[0215] For example, when the mover 301c in FIG. 19 is being conveyed at a constant speed Vc, the detection end time Te is determined as in the following equation (49). In equation (49), Lc is the length of the linear scale 304 installed on the mover 301c. Te = Ts + Lc / Vc … Equation (49)

[0216] Also, when the mover 301 stops while the X sensor 101 is detecting the mover 301, the detection end time Te can be correctly determined by adding the stop time and the acceleration / deceleration time.

[0217] By performing position control of the mover using the mover position calculation information 1508 with the coefficient (W) added calculated in this way, it is possible to similarly suppress fluctuations in the detection position when the detection sensor is switched. [Explanation of symbols]

[0218] 101 X Sensor 102 Y sensor 103 Z sensor 201 Stator 202 Coil 203 Coil unit 301 Mover 302 Work 303 Permanent Magnets 304 Linear Scale 305 Y Target 306 Z Target

Claims

1. A mover that moves along a first direction; a stator having a plurality of first sensors arranged along the first direction and configured to detect position information of the mover; a control unit that corrects position information of the mover based on a relative position between at least one of the first sensors and the mover obtained from a detection value of the first sensor and / or a detection time at which the first sensor detects the mover, and controls a position and / or an attitude of the mover, The control unit corrects the position information of the mover by weighting a detection value of a sensor that detects a position near the center of the mover more heavily than a detection value of a sensor that detects a position outside the center. A conveying device characterized by the above.

2. 2 . The transport device according to claim 1 , wherein the control unit adjusts at least one of the detection values ​​of the first sensors by using a coefficient to correct the position information of the mover.

3. When a detection target area of ​​the mover is set to a first area set in a central portion, a second area set at an end portion in the first direction, and a third area between the first area and the second area, 3. The transport device according to claim 2, wherein the coefficient for the second region and / or the coefficient for the third region is smaller than the coefficient for the first region.

4. The coefficient for the third region is 4. The transport device according to claim 3, wherein the weighting is set to vary between 0 and 1 depending on a relative position between at least one of the plurality of first sensors and the mover.

5. A mover that moves along a first direction; a stator including a plurality of first sensors arranged along the first direction to detect position information of the mover in the first direction, and a plurality of second sensors to detect position information of the mover in a second direction intersecting the first direction; a control unit that selects at least one of the plurality of second sensors using detection values ​​of the plurality of first sensors, corrects position information of the mover in a second direction based on a relative position between the selected second sensor and the mover, and controls a position and / or an attitude of the mover, The control unit corrects the position information of the mover by weighting a detection value of a sensor that detects a position near the center of the mover more heavily than a detection value of a sensor that detects a position outside the center. A conveying device characterized by the above.

6. The conveying device according to claim 5 , wherein the control unit adjusts at least one of the detection values ​​of the second sensors using a coefficient to correct position information of the mover in the second direction.

7. When a detection target area of ​​the mover is set to a first area set in a central portion, a second area set at an end portion in the first direction, and a third area between the first area and the second area, 7. The transport device according to claim 6, wherein the coefficient for the second region and / or the coefficient for the third region is smaller than the coefficient for the first region.

8. The coefficient for the third region is 8. The transport device according to claim 7, wherein the weighting is set to vary between 0 and 1 depending on the relative position between the selected second sensor and the mover.

9. 9. The transport device according to claim 7, wherein the distance between two adjacent ones of the plurality of second sensors is equal to or less than half the length of the mover in the first direction in the first region.

10. the stator has a plurality of third sensors that detect position information of the mover in a third direction that intersects with the first direction and the second direction; The conveying device according to any one of claims 5 to 9, characterized in that the control unit selects at least one of the multiple third sensors using detection values ​​of the multiple first sensors, corrects position information of the mover in a third direction based on a relative position between the selected third sensor and the mover, and controls the position and / or attitude of the mover.

11. 11. The transport device according to claim 10, wherein the control unit adjusts at least one of the detection values ​​of the third sensors by using a coefficient to correct position information of the mover in the third direction.

12. the mover has a first magnet group consisting of a plurality of magnets arranged along the first direction, and a second magnet group consisting of a plurality of magnets arranged along a second direction intersecting the first direction, 12. The transport device according to claim 5, wherein the stator has a plurality of coils arranged along the first direction so as to be opposed to the first magnet group and the second magnet group.

13. The conveying device according to claim 12, characterized in that the movement of the mover in the first direction is controlled by the first group of magnets and the plurality of coils, and the position of the mover in a second direction intersecting the first direction is controlled by the second group of magnets and the coils.

14. 14. A production system comprising: the transport device according to claim 1; and a production device that processes a workpiece moved by the transport device.

15. A method for manufacturing an article, the article being manufactured by the production system according to claim 14.

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