Control device, transport system, and control method

Abstract

The control device (3) includes a memory unit (14) that stores a table in which first position information representing a set position on the conveying path (20) and second position information representing the position of the second movable element (22) when the distance between the first jig (24) and the second jig (25) is a preset distance when the first movable element (21) is at the set position are associated with each other; a first position command generation unit (11) that generates a first position command for moving the first movable element (21); and a second position command generation unit (12) that generates a second position command for moving the second movable element (22) to a position determined based on the position of the first movable element (21) and the table.

Description

[Technical Field]

[0001] The present disclosure relates to a control device, a conveyance system, and a control method for controlling a linear motor conveyance device. [Background technology]

[0002] A linear motor conveyance device equipped with a stator provided on a conveyance path and a mover that moves along the conveyance path is known to convey an object held by two movers. For example, a linear motor conveyance device that conveys an object placed on a fixture attached to each of the two movers moves the two movers while maintaining a constant distance between the two fixtures. In this case, a control device that controls the linear motor conveyance device controls the two movers to coordinate with each other so that the distance between the two fixtures is maintained constant.

[0003] Patent Document 1 discloses a linear motor conveyance device that includes a guide section having a stator and multiple shuttles that move along the guide section. In the linear motor conveyance device disclosed in Patent Document 1, each shuttle houses a mover. The linear motor conveyance device disclosed in Patent Document 1 moves each shuttle along a guide section that has straight and curved sections.

[0004] The linear motor conveyance device disclosed in Patent Document 1 moves a master shuttle, whose absolute position is controlled, and a slave shuttle, whose relative position with respect to the master shuttle is controlled. The object to be conveyed is held by the master shuttle and the slave shuttle. The object is conveyed as the master shuttle and the slave shuttle move along a guide section. In straight sections, the distance between the master shuttle and the slave shuttle is adjusted to L1, a distance that can hold the object. In curved sections, the distance between the master shuttle and the slave shuttle in the curved direction is adjusted to L11, a distance shorter than L1. In this way, the linear motor conveyance device disclosed in Patent Document 1 controls the master shuttle and the slave shuttle so that the distance between them is maintained constant in the guide section. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2022 / 209837 Summary of the Invention [Problem to be solved by the invention]

[0006] The technology of Patent Document 1 can be applied to a linear motor conveying device that conveys an object using two movers to which jigs are attached. When the curved portion is a simple arc shape, the technology of Patent Document 1 can maintain a constant distance between the two jigs.

[0007] The conveyance path of a linear motor conveyance device may include curved sections with non-constant curvature, such as transition curves. When the conveyance path includes a curved section with non-constant curvature, it is necessary to adjust the distance between the two movers in the direction of the curve in order to keep the distance between the two jigs constant as the two movers move along the curved section.

[0008] In the technology of Patent Document 1, when each mover moves along a curved section, the distance between the two movers in the curved direction is kept constant. Therefore, with the technology of Patent Document 1, for example, in a curved section with an inconstant curvature, it becomes impossible to maintain a constant distance between the two jigs, making it difficult to stably transport the transported object. As such, the technology of Patent Document 1 has the problem that it may not be possible to stably transport the transported object using a linear motor transport device.

[0009] The present disclosure has been made in view of the above, and has an object to provide a control device that enables a linear motor conveyance device to stably convey an object to be conveyed. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems and achieve the object, a control device according to the present disclosure is a control device that controls a linear motor conveyance device that includes a stator provided on a conveyance path and first and second movers that move on the conveyance path, and that conveys an object held by a first jig attached to the first mover and a second jig attached to the second mover. The control device according to the present disclosure includes: a storage unit that stores a table in which first position information representing a set position on the conveyance path and second position information representing a position of the second mover when the distance between the first jig and the second jig is a preset distance when the first mover is at the set position are associated with each other; a first position command generation unit that generates a first position command to move the first mover; and a second position command generation unit that generates a second position command to move the second mover to a position determined based on the position of the first mover and the table. [Effects of the Invention]

[0011] The control device according to the present disclosure has the effect of enabling the linear motor conveyance device to stably convey an object. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing a configuration example of a transport system according to a first embodiment; [Figure 2] FIG. 10 is a diagram showing an example of a table stored in a storage unit of the control device according to the first embodiment; [Figure 3] FIG. 10 is a diagram showing an example of a plurality of positions preset on a conveying path in the first embodiment. [Figure 4] FIG. 1 is a diagram for explaining an example of a method for calculating second position information by the table generating device according to the first embodiment; [Figure 5] 1 is a flowchart showing an example of a processing procedure performed by a table generating device according to a first embodiment. [Figure 6] 10 is a flowchart showing an example of a processing procedure performed by a second position command generating unit of the control device according to the first embodiment. [Figure 7] FIG. 10 is a diagram showing a configuration example of a control device according to a modification of the first embodiment; [Figure 8] FIG. 10 shows an example of a plurality of positions preset on a transport path in the second embodiment. [Figure 9] FIG. 10 is a diagram showing an example of a plurality of positions preset on a conveying path in a modification of the second embodiment. [Figure 10] FIG. 11 is a diagram showing an example of a table stored in a storage unit of a control device according to a third embodiment. [Figure 11] FIG. 13 is a diagram showing an example of a plurality of positions preset on a conveying path in the third embodiment. [Figure 12] FIG. 1 shows an example of the configuration of a control circuit according to first to third embodiments. [Figure 13] FIG. 1 shows an example of the configuration of a dedicated hardware circuit according to first to third embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0013] A control device, a transport system, and a control method according to an embodiment will be described in detail below with reference to the drawings.

[0014] Embodiment 1 1 is a diagram showing an example of the configuration of a conveyance system 1 according to embodiment 1. The conveyance system 1 includes a linear motor conveyance device 2 that conveys an object, a control device 3 that controls the linear motor conveyance device 2, and a table generation device 4. Hereinafter, the object conveyed by the linear motor conveyance device 2 will be referred to as a workpiece.

[0015] The linear motor conveyance device 2 includes a first mover 21, a second mover 22, and a plurality of rail modules 23. The plurality of rail modules 23 are connected to each other and form a conveyance path 20. Each rail module 23 is a stator that forms a linear motor. The first mover 21 and the second mover 22 move on the conveyance path 20.

[0016] The straight portion 23a is a straight rail module 23 that forms a straight path. The curved portion 23b is a curved rail module 23 that forms a curved path. The conveying path 20 shown in FIG. 1 is composed of four straight portions 23a and four curved portions 23b. Note that the number of straight portions 23a and curved portions 23b that form the conveying path 20 is arbitrary. The conveying path 20 shown in FIG. 1 is a closed path in a track shape. The conveying path 20 of the conveying system 1 may be an open path. In other words, the conveying path 20 of the conveying system 1 may be a path having a start point and an end point that are located apart from each other. The conveying path 20 may not have the straight portion 23a and may consist only of the curved portion 23b. The overall shape of the conveying path 20 is arbitrary.

[0017] Each of the first mover 21 and the second mover 22 has a permanent magnet. Each rail module 23 has a coil and an inverter that adjusts the current flowing through the coil. The coil of each rail module 23 generates a magnetic field when a current flows through the coil. A thrust force that moves the first mover 21 and the second mover 22 is generated by the interaction between this magnetic field and the magnetic field generated by the permanent magnet of each of the first mover 21 and the second mover 22. The first mover 21 and the second mover 22 move due to this thrust force.

[0018] A jig is attached to each of the first mover 21 and the second mover 22. Hereinafter, the jig attached to the first mover 21 will be referred to as the first jig 24. The jig attached to the second mover 22 will be referred to as the second jig 25. The linear motor conveyance device 2 conveys the workpiece held by the first jig 24 and the second jig 25.

[0019] For example, the workpiece is placed on the first jig 24 and the second jig 25. Alternatively, the workpiece may be sandwiched between the first jig 24 and the second jig 25. The linear motor conveyance device 2 can stably convey objects that are difficult to convey with a single mover, such as long or heavy objects. FIG. 1 shows the first jig 24 and the second jig 25 in a schematic manner. The configuration of each of the first jig 24 and the second jig 25 is arbitrary. The workpiece is not shown in FIG. 1.

[0020] In the following description, a plane refers to a plane that includes a single line representing the transport path 20. The transport path 20 shown in Fig. 1 is represented by a single line that forms a loop.

[0021] The control point of the first jig 24 is located at a position shifted from the control point of the first mover 21 in the plane. The control point of the first mover 21 is a point that serves as a reference for the position of the first mover 21 when the control device 3 controls the first mover 21. The control point of the first jig 24 is a point that serves as a reference for the position of the first jig 24. For example, the control point of the first mover 21 is set at a position on the first mover 21 where the first jig 24 is attached. For example, the control point of the first jig 24 is set at the tip of the first jig 24. The position of the control point on the first mover 21 is arbitrary. The position of the control point on the first jig 24 is arbitrary. The first jig 24 is fixed to the first mover 21. The positional relationship between the control point of the first mover 21 and the control point of the first jig 24 is fixed.

[0022] The control point of the second jig 25 is located at a position shifted from the control point of the second mover 22 in the plane. The control point of the second mover 22 is a point that serves as a reference for the position of the second mover 22 when the control device 3 controls the second mover 22. The control point of the second jig 25 is a point that serves as a reference for the position of the second jig 25. For example, the control point of the second mover 22 is set at a position on the second mover 22 where the second jig 25 is attached. For example, the control point of the second jig 25 is set at the tip of the second jig 25. The position of the control point on the second mover 22 is assumed to be arbitrary. The position of the control point on the second jig 25 is assumed to be arbitrary. The second jig 25 is fixed to the second mover 22. The positional relationship between the control point of the second mover 22 and the control point of the second jig 25 is assumed to be fixed.

[0023] When holding a workpiece, the distance between the control point of the first jig 24 and the control point of the second jig 25 is adjusted to a preset distance D. Here, the distance between the control point of the first jig 24 and the control point of the second jig 25 is referred to as the jig distance. The linear motor conveyance device 2 moves the first mover 21 and the second mover 22 while maintaining the jig distance at a constant distance D. The control device 3 controls the first mover 21 and the second mover 22 to coordinate with each other so that the jig distance remains at the constant distance D.

[0024] The first movable element 21 and the second movable element 22 can move in a forward direction on the conveying path 20 and in a reverse direction on the conveying path 20. For example, in the conveying path 20 shown in Fig. 1, the direction reverse to the clockwise direction in Fig. 1 is the forward direction, and the clockwise direction in Fig. 1 is the reverse direction.

[0025] 1 shows one set of the first mover 21 and the second mover 22, but the set of the first mover 21 and the second mover 22 that moves along the conveyance path 20 is not limited to one. The linear motor conveyance device 2 may also move multiple sets of the first mover 21 and the second mover 22.

[0026] A linear scale is attached to the transport path 20 to detect the positions of the first movable element 21 and the second movable element 22 or the speed of the first movable element 21 and the second movable element 22. The linear scale is not shown in FIG.

[0027] The control device 3 includes a first position command generator 11, a second position command generator 12, a drive controller 13, and a storage unit 14. The first position command generator 11 generates a first position command, which is a position command for moving the first mover 21. The first position command includes information indicating a target position on the conveying path 20 to which the first mover 21 is to be moved. The first position command generator 11 outputs the first position command to each of the second position command generator 12 and the drive controller 13. The first position command generator 11 outputs the first position command at a preset time period.

[0028] The command speed is expressed by the time derivative of a waveform that represents the time change of the signal that is the first position command, or the difference between signals that are the first position command. Examples of command speed patterns include trapezoidal acceleration / deceleration and triangular acceleration / deceleration. Trapezoidal acceleration / deceleration is acceleration / deceleration such that the graph representing the relationship between time and speed becomes a trapezoid. Triangular acceleration / deceleration is acceleration / deceleration such that the graph representing the relationship between time and speed becomes a triangle.

[0029] The second position command generation unit 12 generates a second position command, which is a position command for moving the second mover 22. The second position command includes information indicating a target position on the conveying path 20 to which the second mover 22 is to be moved. The second position command generation unit 12 outputs the second position command at a preset time period. The second position command generation unit 12 outputs the second position command to the drive control unit 13.

[0030] The storage unit 14 stores a table. In the table stored in the storage unit 14, first position information indicating a set position on the conveying path 20 and second position information indicating the position of the second mover 22 when the distance between the first jig 24 and the second jig 25 is a preset distance D when the first mover 21 is at the set position are associated with each other.

[0031] The second position command generating unit 12 generates a second position command for moving the second mover 22 to a position determined based on the first position command and a table stored in the storage unit 14. Details of the method for generating the second position command by the second position command generating unit 12 and details of the table stored in the storage unit 14 will be described later.

[0032] The drive control unit 13 receives a first position command and a second position command from the control device 3 and drives the linear motor conveyance device 2. The drive control unit 13 is, for example, a power amplifier. The drive control unit 13 controls the first mover 21 and the second mover 22 by controlling the current flowing through the linear motor conveyance device 2. The drive control unit 13 supplies current to the rail module 23, which generates thrust for moving the first mover 21, in response to the first position command. The drive control unit 13 supplies current to the rail module 23, which generates thrust for moving the second mover 22, in response to the second position command.

[0033] 1, the first position command generator 11, the second position command generator 12, the drive control unit 13, and the storage unit 14 are provided in a single device, the control device 3. The first position command generator 11, the second position command generator 12, the drive control unit 13, and the storage unit 14 may be distributed across two or more devices. For example, the drive control unit 13 may be provided in a device separate from the device in which the first position command generator 11, the second position command generator 12, and the storage unit 14 are provided. The drive control unit 13 may be integrated with the conveying path 20.

[0034] Drive control unit 13 has established therein a control loop that controls the current based on the difference between the position of first mover 21 detected by the linear scale and the position indicated by the first position command, and a control loop that controls the current based on the difference between the position of second mover 22 detected by the linear scale and the position indicated by the second position command. Drive control unit 13 performs feedback control of first mover 21 and second mover 22 using these control loops.

[0035] The table generating device 4 is realized by a computer system. The table generating device 4 generates a table. Information indicating the set distance D, information indicating the specifications of the first jig 24 and the second jig 25, and information indicating the configuration of the conveying path 20 are input to the table generating device 4. The table generating device 4 generates a table based on the input information. The table generated by the table generating device 4 is stored in the memory unit 14.

[0036] Next, a description will be given of tables stored in the storage unit 14. Fig. 2 is a diagram showing an example of a table stored in the storage unit 14 of the control device 3 according to the first embodiment.

[0037] The position numbers shown in the first column of the table are numbers assigned to each of the multiple positions preset on the conveying path 20. Each of the multiple positions set on the conveying path 20 can be identified by its position number. The position number also serves as an index assigned to each row of the table. In the following description, "i" represents the position number. "i" is an integer from 1 to N. N represents the number of positions set on the conveying path 20. N is also the number of rows in the table. The multiple positions set on the conveying path 20 are represented as P1, P2, P3, . . . , PN. P1 represents the position where i=1. Similarly, P2 to PN represent the positions where i=2, . . . , i=N. P1 is the reference position on the conveying path 20. The multiple positions are arranged, for example, in the forward direction of the conveying path 20, in the order of P1, P2, P3, . . . , PN. L represents the length of one circumference of the conveying path 20.

[0038] FIG. 3 is a diagram showing an example of a plurality of positions preset on the conveying path 20 in the first embodiment. In FIG. 3, the conveying path 20 is represented by a single looping line. The black circles shown in FIG. 3 are points representing the preset positions. In FIG. 3, the points representing the preset positions are arranged at equal intervals. Here, it is assumed that N positions are set on the conveying path 20 at intervals of 100 μm (micrometers). Note that the intervals between the positions are not limited to 100 μm and may be any interval.

[0039] In FIG. 2, the first position information shown in the second column of the table indicates the location of the set position. The first position information can also be said to be information for identifying the set position within the conveying path 20. The second column of the table stores first position information representing each of multiple positions set on the conveying path 20. Here, the first position information is information representing the distance from P1, which is the reference position. In FIG. 2, the first position information is expressed only by numerical values, and the distance unit "μm" is omitted. "X(i)" represents the first position information. In the example shown in FIG. 2, it is expressed as X(1) = 0, X(2) = 100, ..., X(N) = L.

[0040] The second position information shown in the third column of the table represents the position of the second mover 22 when the distance between the first jig 24 and the second jig 25 is distance D when the first mover 21 is located at the position indicated by the first position information. The second position information is information representing the distance from P1, which is the reference position. "Y(i)" represents the second position information. In FIG. 2, the second position information is shown as Y(1), Y(2), ..., Y(N), but the table stores specific numerical values ​​as the second position information.

[0041] In this way, pairs of numerical values ​​that are the first position information and numerical values ​​that are the second position information are written in N rows of the table. The first position information and second position information for each of a plurality of positions that are preset on the conveying path 20 are associated with each other in the table.

[0042] Next, a description will be given of an example of a method for calculating the second position information by the table generating device 4. Fig. 4 is a diagram for explaining an example of a method for calculating the second position information by the table generating device 4 according to the first embodiment.

[0043] In FIG. 4, a portion of the conveying path 20 where the straight portion 23a and the curved portion 23b are connected to each other is represented by a single line. Control point 31 is a control point for the first mover 21. Control point 32 is a control point for the second mover 22. In FIG. 4, the position of the first mover 21 is represented by control point 31, and the first mover 21 is not shown. In FIG. 4, the position of the second mover 22 is represented by control point 32, and the second mover 22 is not shown. Control point 33 is a control point for the first jig 24. Control point 34 is a control point for the second jig 25.

[0044] FIG. 4 shows a schematic representation of the linear motor conveyance device 2 when the control point 31 reaches Pk, the kth position from P1, with P1 being the first position. Pk is a position on the curved section 23b. X(k), which is the first position information for Pk, represents the travel distance from P1 to Pk. The tangent line TL is a tangent to the line representing the conveyance path 20. FIG. 4 shows the tangent line TL at Pk.

[0045] w1 and w2 are parameters that represent the length of the first jig 24, and represent the offset of control point 33 from control point 31. w1 represents the length of the first jig 24 in the normal direction of the conveying path 20. w2 represents the length of the first jig 24 in the tangential direction of the conveying path 20. The normal direction is the direction perpendicular to the tangent line TL. The tangential direction is the direction of the tangent line TL. w1 and w2 are included in the specifications of the first jig 24. Note that, as with the first jig 24, the specifications of the second jig 25 also include a parameter that represents the offset of the control point 34 from the control point 32. The offset described here is an offset in a plane. The normal direction and the tangential direction are both directions that are included in a plane.

[0046] θ represents the tangent angle, which is the angle between the reference line and the tangent line TL. Here, the straight line representing the straight line portion 23a of the conveying path 20 including P1 is taken as the reference line. Note that the method for determining the reference line is arbitrary. The distance d is the distance between the first jig 24 and the second jig 25. Specifically, the distance d is the jig distance, i.e., the distance between the control point 33 and the control point 34.

[0047] The table generating device 4 receives input of information indicating the set distance D, information indicating the specifications of the first jig 24, information indicating the specifications of the second jig 25, and information indicating the configuration of the conveying path 20. The distance D is set appropriately depending on the size of the workpiece to be conveyed. The information indicating the specifications of the first jig 24 includes a value indicating the offset of the control point 33 from the control point 31. That is, the information indicating the specifications of the first jig 24 includes a value indicating the length of the first jig 24 in the normal direction and a value indicating the length of the first jig 24 in the tangential direction. The information indicating the specifications of the second jig 25 includes a value indicating the offset of the control point 34 from the control point 32. That is, the information indicating the specifications of the second jig 25 includes a value indicating the length of the second jig 25 in the normal direction and a value indicating the length of the second jig 25 in the tangential direction.

[0048] The table generating device 4 receives input of first position information for each of P1 to PN set for the conveying path 20. The table generating device 4 stores the input first position information in a table. The table generating device 4 determines the coordinates on a plane for each of P1 to PN based on information indicating the configuration of the conveying path 20 and the first position information for each of P1 to PN. The origin (0,0) of the coordinates is set to P1. The information indicating the configuration of the conveying path 20 includes information about the shape of the conveying path 20, such as the length of the straight portions of the conveying path 20 and the length and curvature of the curved portions of the conveying path 20. From the information indicating the configuration of the conveying path 20, the tangent angle θ is determined for each of P1 to PN.

[0049] Here, a method for calculating Y(k), which is the second position information corresponding to X(k), which is the first position information for Pk, will be described. The table generating device 4 calculates the coordinates of control point 32 when the interval d matches the distance D, based on the coordinates of Pk, a value indicating the offset of control point 33 from control point 31, and a value indicating the offset of control point 34 from control point 32. Next, the table generating device 4 calculates the distance from P1 of control point 32 when the interval d matches the distance D, based on the coordinates of control point 32 and information indicating the configuration of the conveying path 20. In this way, the table generating device 4 calculates Y(k), which is the second position information.

[0050] As in the case of Pk, the table generating device 4 calculates second position information corresponding to the first position information for each position other than Pk. The table generating device 4 generates a table in which the first position information and the second position information for each of P1 to PN are stored. Note that the method for calculating the second position information by the table generating device 4 is not limited to the above method. The table generating device 4 may calculate the second position information by a method other than the above.

[0051] When the control device 3 controls the linear motor conveyance device 2, the table in the storage unit 14 stores the second position information calculated in advance by the table generation device 4 as described above. The table stores the second position information calculated in advance based on a value indicating a preset distance D, a value indicating the offset of the control point of the first jig 24 from the control point of the first mover 21, a value indicating the offset of the control point of the second jig 25 from the control point of the second mover 22, coordinates indicating a set position on the conveyance path 20, and the angle of the tangent to the line representing the conveyance path 20 at the position indicated by the coordinates.

[0052] 5 is a flowchart showing an example of a processing procedure by the table generating device 4 according to Embodiment 1. Here, the processing procedure when calculating the second position information will be described.

[0053] In step S1, the table generating device 4 sets "i" to 1. In step S2, the table generating device 4 acquires X(i) stored in the second column of the table. In the first step S2 after the process shown in FIG. 5 starts, the table generating device 4 acquires X(1).

[0054] In step S3, the table generating device 4 calculates the coordinates of the control point 31, which is the control point of the first movable element 21, from X(i) acquired in step S2. The table generating device 4 calculates the coordinates of the control point 31 based on the information indicating the configuration of the transport path 20 and X(i).

[0055] In step S4, the table generating device 4 calculates the coordinates of the control point 33, which is the control point of the first jig 24, from the coordinates of the control point of the first mover 21, which are the coordinates calculated in step S3. The table generating device 4 calculates the coordinates of the control point 33 based on a value indicating the offset of the control point 33 from the control point 31 and θ in the coordinates calculated in step S3.

[0056] In step S5, the table generation device 4 calculates Y(i). The table generation device 4 sets temporary coordinates of the control point 32, which is the control point of the second mover 22. The table generation device 4 calculates the temporary coordinates of the control point 34 based on the set temporary coordinates, a value indicating the offset of the control point 34 from the control point 32, and θ at the set temporary coordinates. The table generation device 4 calculates the distance d between the control point 33 and the control point 34 based on the coordinates of the control point 33 calculated in step S4 and the temporary coordinates of the control point 34. If the distance d does not match the distance D, the table generation device 4 changes the temporary coordinates of the control point 32 and repeats the same calculation as above. The table generation device 4 calculates the coordinates of the control point 32 when the distance d matches the distance D as Y(i). In this way, the table generation device 4 calculates Y(i) by numerical calculation. Alternatively, if all of the geometric shapes of the transport path 20 can be expressed by mathematical expressions, the table generating device 4 may calculate Y(i) by an analytical method.

[0057] In step S6, the table generation device 4 determines whether the currently set value of "i" is equal to N. If the value of "i" is not equal to N (step S6, No), in step S7, the table generation device 4 adds 1 to the currently set value of "i". Then, the table generation device 4 repeats the procedure from step S2 to step S6.

[0058] On the other hand, if the value of "i" is equal to N (step S6, Yes), the table generation device 4 ends the processing according to the procedure shown in FIG. 5. Thereby, the table generation device 4 calculates the second position information for each of P1 to PN.

[0059] Next, generation of the second position command by the second position command generation unit 12 will be described. FIG. 6 is a flowchart showing an example of the procedure of the processing by the second position command generation unit 12 of the control device 3 according to the first embodiment.

[0060] In step S11, the second position command generation unit 12 acquires the first position command from the first position command generation unit 11. That is, the second position command generation unit 12 acquires the first position command generated by the first position command generation unit 11.

[0061] The first position command indicates the position for the purpose of moving the first mover 21. Here, let the value representing the position indicated by the first position command be x. x is a numerical value representing the distance from the reference P1. The second position command generation unit 12 acquires the value of x by acquiring the first position command in step S11.

[0062] In step S12, the second position command generation unit 12 searches the table stored in the storage unit 14 for the value of "i" that satisfies X(i) ≤ x < X(i + 1). By comparing each value stored in the second column of the table with the value of x, the value of "i" that satisfies X(i) ≤ x < X(i + 1) is obtained.

[0063] In step S13, the second position command generation unit 12 calculates y by interpolation processing of the second position information. Here, let y be the value representing the position targeted for moving the second mover 22. The second position command generation unit 12 reads out the values of X(i) and Y(i) stored in the row of the value of "i" obtained in step S12 in the table. Also, the second position command generation unit 12 reads out the values of X(i + 1) and Y(i + 1) stored in the row next to the row of the value of "i" obtained in step S12 in the table, that is, the row of the value of "i + 1". The second position command generation unit 12 calculates the value of y by, for example, linear interpolation.

[0064] When the second position command generation unit 12 executes linear interpolation, for example, it calculates the value of y by the following formula (1). y = [{x - X(i)} × {Y(i + 1) - Y(i)} / {X(i + 1) - X(i)}] + Y(i) ···(1)

[0065] Through the interpolation processing, the second position command generation unit 12 can calculate the value of y that corresponds to the value of x and satisfies Y(i) ≤ y < Y(i + 1). Note that the interpolation processing executed by the second position command generation unit 12 is not limited to linear interpolation. The second position command generation unit 12 may calculate the value of y by interpolation processing other than linear interpolation. The second position command generation unit 12 may calculate the value of y by, for example, spline interpolation, nearest neighbor interpolation, or Newton interpolation.

[0066] In this way, the second position command generation unit 12 generates a second position command including the value of y, which is information indicating the position targeted for moving the second mover 22. In step S14, the second position command generation unit 12 outputs the generated second position command. As described above, the second position command generation unit 12 ends the processing according to the procedure shown in FIG. 6.

[0067] The second position command generator 12 executes the process from step S11 to step S14 at a preset time period. The linear motor conveyance device 2 moves the first mover 21 according to the first position command and moves the second mover 22 according to the second position command, thereby maintaining a constant distance between the first jig 24 and the second jig 25. This allows the linear motor conveyance device 2 to transport workpieces stably.

[0068] The linear motor conveyance device 2 can maintain a constant distance between the first jig 24 and the second jig 25 regardless of the shape of the conveyance path 20. For example, when the conveyance path 20 includes a portion with a shape that is not constant in curvature, the linear motor conveyance device 2 can maintain a constant distance between the first jig 24 and the second jig 25. Furthermore, when one of the first mover 21 and the second mover 22 is on the straight portion 23a and the other is on the curved portion 23b, the linear motor conveyance device 2 can maintain a constant distance between the first jig 24 and the second jig 25.

[0069] In the above description, second position command generator 12 generates the second position command based on the first position command and the table. In this case, second position command generator 12 acquires the first position command, which is information indicating the position of first mover 21, and obtains the position of second mover 22 based on the position indicated in the first position command and the table.

[0070] The information indicating the position of the first mover 21, which is acquired by the second position command generation unit 12, is not limited to the first position command. The second position command generation unit 12 may acquire information other than the first position command as information indicating the position of the first mover 21.

[0071] For example, the information indicating the position of first mover 21 may be the result of detecting the position of first mover 21 using a linear scale. In this case, second position command generator 12 acquires the result of detecting the position of first mover 21, and calculates the position of second mover 22 based on the detected position of first mover 21 and the table. In this way, second position command generator 12 may generate the second position command based on the result of detecting the position of first mover 21 and the table.

[0072] The second position command generation unit 12 may use information obtained by filtering the first position command as information indicating the position of the first mover 21. A filter having a low-pass characteristic is used for the filtering. Alternatively, the second position command generation unit 12 may use information obtained by filtering a result of detecting the position of the first mover 21 using a linear scale as information indicating the position of the first mover 21. In this case, a filter having a low-pass characteristic is also used for the filtering. In this way, the second position command generation unit 12 may generate the second position command based on the result of filtering the first position command using a filter having a low-pass characteristic or the result of filtering the result of detecting the position of the first mover 21 using a filter having a low-pass characteristic, and the table.

[0073] According to embodiment 1, the control device 3 includes a memory unit 14 that stores a table in which first position information representing a set position on the conveying path 20 and second position information indicating the position of the second movable element 22 when the distance between the first jig 24 and the second jig 25 becomes a predetermined distance when the first movable element 21 is at the set position are correlated with each other, a first position command generation unit 11 that generates a first position command for moving the first movable element 21, and a second position command generation unit 12 that generates a second position command for moving the second movable element 22 to a position determined based on the position of the first movable element 21 and the table.

[0074] When the conveying path 20 includes a curved portion with an inconstant curvature, the control device 3 can control the first mover 21 and the second mover 22 so that the distance between the first jig 24 and the second jig 25 is constant. When one of the first mover 21 and the second mover 22 is in a straight portion and the other is in a curved portion, the control device 3 can control the first mover 21 and the second mover 22 so that the distance between the first jig 24 and the second jig 25 is constant. As described above, an effect is achieved in which the linear motor conveying device 2 can stably convey the conveyed object. Furthermore, by referring to a table in which the first position information and the second position information when the distance between the first jig 24 and the second jig 25 is a predetermined distance are associated with each other, the control device 3 can determine the position of the second mover 22 through calculation processing with a small load. This allows the control device 3 to reduce the load of calculation processing that is executed simultaneously with the control of the linear motor conveyance device 2.

[0075] Alternatively, second position command generator 12 may obtain a position to which second mover 22 is to be moved by interpolating the second position information read from the table, and generate a second position command for moving second mover 22 to the obtained position. This allows control device 3 to control first mover 21 and second mover 22 with high precision so that the distance between first jig 24 and second jig 25 is constant.

[0076] The table also stores second position information that is calculated in advance based on a value indicating a preset distance, a value indicating the offset of the control point of the first jig 24 from the control point of the first mover 21, a value indicating the offset of the control point of the second jig 25 from the control point of the second mover 22, coordinates indicating a set position on the conveying path 20, and the angle of the tangent to the line representing the conveying path 20 at the position indicated by the coordinates. This allows the control device 3 to generate a second position command that can keep the distance between the first jig 24 and the second jig 25 constant, based on the position of the first mover 21 and the table.

[0077] According to the first embodiment, the conveying system 1 includes a table generating device 4 that generates a table, and the storage unit 14 stores the table generated by the table generating device 4. The control device 3 can control the first mover 21 and the second mover 22 so that the distance between the first jig 24 and the second jig 25 is a preset distance. This allows the conveying system 1 to stably convey the object using the linear motor conveying device 2.

[0078] Next, a description will be given of a modified example of the control device 3. In the above, the table is generated by the table generating device 4 outside the control device 3. However, the transport system 1 may generate the table inside the control device 3.

[0079] Fig. 7 is a diagram showing an example of the configuration of a control device 3A according to a modification of the first embodiment. The control device 3A is provided in the transport system 1 in place of the control device 3 and the table generating device 4 shown in Fig. 1. The control device 3A has the same configuration as the control device 3 shown in Fig. 1. The control device 3A also includes a table generating unit 15 that generates a table.

[0080] Information indicating the set distance D, information indicating the specifications of the first jig 24 and the second jig 25, and information indicating the configuration of the conveying path 20 are input to the table generating unit 15. The table generating unit 15 calculates the second position information according to the procedure shown in FIG. 5, similar to the table generating device 4. The table generated by the table generating unit 15 is stored in the storage unit 14. Even when the control device 3A is provided in the conveying system 1, the conveying system 1 can control the first mover 21 and the second mover 22 so that the distance between the first jig 24 and the second jig 25 is a preset distance.

[0081] Embodiment 2 In the first embodiment, a plurality of preset positions are arranged at equal intervals on the conveying path 20. In the second embodiment, an example will be described in which the intervals between adjacent positions among the plurality of positions are made different. The conveying system 1 according to the second embodiment has the same configuration as the conveying system 1 shown in FIG. In the second embodiment, differences from the first embodiment will be mainly described.

[0082] Fig. 8 is a diagram showing an example of a plurality of positions preset on the conveying path 20 in the second embodiment. In Fig. 8, the conveying path 20 is represented by a single looping line. The black circles shown in Fig. 8 represent the set positions.

[0083] In the example shown in Fig. 8, the points representing set positions are arranged at equal intervals in the straight portions of the conveying path 20. The points representing set positions are arranged at equal intervals in the curved portions of the conveying path 20. The distance between points in the straight portions is greater than the distance between points in the curved portions. In this way, the points are arranged so that the points are more densely spaced in the curved portions than in the straight portions. In other words, the positions set in the conveying path 20 are arranged so that the points are more densely spaced in the curved portions than in the straight portions.

[0084] Because the multiple positions set in the conveying path 20 are closer together in the curved portion, the position of the second mover 22 is adjusted at more positions when the first mover 21 and the second mover 22 pass through the curved portion. Therefore, the control device 3 can control the first mover 21 and the second mover 22 with high precision so that the distance between the first jig 24 and the second jig 25 is constant in the curved portion. For example, when the curvature of the curved portion is not constant, the control device 3 can adjust the position of the second mover 22 with high precision in accordance with changes in the curvature.

[0085] When the first mover 21 and the second mover 22 pass through the linear portion, the distance between the first mover 21 and the second mover 22 is kept constant, and therefore the distance between the first jig 24 and the second jig 25 is kept constant. Even if the distance between the set positions is large in the linear portion, the distance between the first jig 24 and the second jig 25 can be kept constant by the interpolation process in the procedure shown in Fig. 6. Therefore, even if there are few set positions in the linear portion, the control device 3 can control the first mover 21 and the second mover 22 with high precision so that the distance between the first jig 24 and the second jig 25 is constant.

[0086] In this case, the number of preset positions for the linear portion can be reduced, thereby reducing the number of rows in the table. Reducing the number of rows in the table can also reduce the data size of the table. This allows the control device 3 to store the table in the storage unit 14, which has a small data capacity.

[0087] According to the second embodiment, the conveying path 20 includes straight and curved portions, and the table stores first position information representing a plurality of positions set on the conveying path 20, with the plurality of positions being set closer together in the curved portions than in the straight portions. The control device 3 can control the first mover 21 and the second mover 22 with high precision so that the distance between the first jig 24 and the second jig 25 is constant. This enables the linear motor conveying device 2 to stably convey the conveyed object. Furthermore, by reducing the data size of the table, the storage capacity of the control device 3 can be reduced.

[0088] Next, a description will be given of a modified example of embodiment 2. The modified example of embodiment 2 is an example in which the intervals between adjacent positions among a plurality of positions are made different, and is an example different from the example shown in FIG.

[0089] Fig. 9 is a diagram showing an example of a plurality of positions preset on the conveying path 20 in a modification of the second embodiment. In Fig. 9, the conveying path 20 is represented by a single looping line. The black circles shown in Fig. 9 represent the set positions.

[0090] In the example shown in Figure 9, multiple positions are set so that the density is higher in the portion of the conveying path 20 when at least one of the positions indicated in the first position information and the positions indicated in the second position information is included in a curved portion than in the portion of the conveying path 20 when both the position indicated in the first position information and the position indicated in the second position information are included in a straight portion.

[0091] Fig. 9 shows an example in which the position indicated by the first position information is included in a linear portion, and the position indicated by the second position information is included in a curved portion. In Fig. 9, the position of control point 31 represents the position indicated by the first position information, and the position of control point 32 represents the position indicated by the second position information. Fig. 9 also shows first jig 24 and second jig 25. In the example shown in Fig. 9, first mover 21 and second mover 22 move in the forward direction, which is counterclockwise in Fig. 9.

[0092] A portion of the conveying path 20 where both the position indicated by the first position information and the position indicated by the second position information are included in a linear portion is referred to as a first section. A portion of the conveying path 20 where at least one of the position indicated by the first position information and the position indicated by the second position information is included in a curved portion is referred to as a second section.

[0093] Here, up, down, right, and left represent the directions in Figure 9. Of the conveying path 20, the upper straight portion is referred to as section 20a, and the lower straight portion is referred to as section 20b. Of the conveying path 20, the curved portion on the left is referred to as section 20c, and the straight portion on the right is referred to as section 20d.

[0094] When control point 32 reaches the right end of portion 20a, both control point 31 and control point 32 enter portion 20a. The starting point of the first section of portion 20a is a position shifted a preset length to the left from the right end of portion 20a. The preset length is the length between control point 31 and control point 32 when control point 31 and control point 32 are aligned in a straight line and the distance between control point 33 and control point 34 is distance D. After control point 31 reaches the left end of portion 20a, control point 31 enters portion 20c. The end point of the first section of portion 20a is the left end of portion 20a.

[0095] When control point 32 reaches the left end of portion 20b, both control point 31 and control point 32 enter portion 20b. The start point of the first section of portion 20b is a position shifted to the right from the left end of portion 20b by the above-mentioned preset length. After control point 31 reaches the right end of portion 20b, control point 31 enters portion 20d. The end point of the first section of portion 20b is the right end of portion 20b. The second section is a portion of conveying path 20 other than the first section. The multiple positions set on conveying path 20 are set so that they are closer together in the second section than in the first section.

[0096] Because the multiple positions set in the conveying path 20 are denser in the second section, the position of the second mover 22 is adjusted at more positions when the first mover 21 and the second mover 22 pass through the second section. Therefore, the control device 3 can control the first mover 21 and the second mover 22 with high precision so that the distance between the first jig 24 and the second jig 25 is constant in the second section. The control device 3 can control the first mover 21 and the second mover 22 with high precision so that the distance between the first jig 24 and the second jig 25 is constant near the boundary between the straight portion and the curved portion of the conveying path 20.

[0097] When the first mover 21 and the second mover 22 pass through the first section, the distance between the first mover 21 and the second mover 22 is kept constant, and thus the distance between the first jig 24 and the second jig 25 is kept constant. In the first section, even if the distance between the set positions is large, the distance between the first jig 24 and the second jig 25 can be kept constant by the interpolation process in the procedure shown in Fig. 6. Therefore, even if the number of set positions in the first section is small, the control device 3 can control the first mover 21 and the second mover 22 with high precision so that the distance between the first jig 24 and the second jig 25 is constant.

[0098] In this case, the number of preset positions for the first section can be reduced to reduce the number of rows in the table. Reducing the number of rows in the table can reduce the data size of the table. This allows the control device 3 to store the table in the storage unit 14 with a small data capacity.

[0099] According to a modification of the second embodiment, the multiple positions are set closer together in a second section of the conveying path 20, where at least one of the positions indicated by the first position information and the positions indicated by the second position information is included in a curved portion, than in a first section of the conveying path 20, where both the positions indicated by the first position information and the positions indicated by the second position information are included in a straight portion. The control device 3 can control the first mover 21 and the second mover 22 with high precision so that the distance between the first jig 24 and the second jig 25 is constant. This enables the linear motor conveying device 2 to stably convey the conveyed object. Furthermore, by reducing the data size of the table, the storage capacity of the control device 3 can be reduced.

[0100] In the above, the transport system 1 according to the second embodiment has the same configuration as the transport system 1 shown in Fig. 1. The transport system 1 according to the second embodiment may be provided with a control device 3A shown in Fig. 7 instead of the control device 3 and the table generating device 4 shown in Fig. 1.

[0101] Embodiment 3 In the first and second embodiments, the distance between the first jig 24 and the second jig 25 is constant. In the third embodiment, an example will be described in which the distance between the first jig 24 and the second jig 25 is varied for each region of the conveying path 20. The conveying system 1 according to the third embodiment has the same configuration as the conveying system 1 shown in FIG. In the third embodiment, differences from the first or second embodiment will be mainly described.

[0102] In embodiment 3, for a certain area of ​​the conveying path 20, first position information and second position information are set so that the distance between the first jig 24 and the second jig 25 is a first distance, and for a different area of ​​the conveying path 20 from the said area, first position information and second position information are set so that the distance between the first jig 24 and the second jig 25 is a second distance different from the first distance.

[0103] Fig. 10 is a diagram showing an example of a table stored in the storage unit 14 of the control device 3 according to the embodiment 3. Fig. 11 is a diagram showing an example of a plurality of positions set in advance on the conveying path 20 according to the embodiment 3.

[0104] In the third embodiment, M represents the length of half the circumference of the conveying path 20. The multiple positions set on the conveying path 20 are represented as P1, P2, P3, . . ., PM, P(M+1), P(M+2), . . ., PN. In the example shown in FIGS. 10 and 11, the conveying path 20 is divided into two regions. The region including P1 to PM is the first region, and the region including P(M+1) to PN is the second region.

[0105] 10, for i=1 to M, the second position information shown in the third column of the table represents the position of the second mover 22 when the distance between the first jig 24 and the second jig 25 is the first distance D1 when the first mover 21 is located at the position represented by the first position information. For i=(M+1) to N, the second position information shown in the third column of the table represents the position of the second mover 22 when the distance between the first jig 24 and the second jig 25 is the second distance D2 when the first mover 21 is located at the position represented by the first position information. In this way, the first position information and the second position information are set so that the distance between the first jig 24 and the second jig 25 is the first distance D1 in the first region. The first position information and the second position information are set so that the distance between the first jig 24 and the second jig 25 is the second distance D2 in the second region.

[0106] The table generating device 4 receives input of information indicating the set first distance D1, information indicating the set second distance D2, information indicating the specifications of the first jig 24, information indicating the specifications of the second jig 25, and information indicating the configuration of the transport path 20. The first distance D1 is set appropriately depending on the size of the workpiece to be transported in the first area. The second distance D2 is set appropriately depending on the size of the workpiece to be transported in the second area.

[0107] For i=1 to M, the table generating device 4 calculates second position information when the distance d between the control point 33 and the control point 34 is the first distance D1. For i=(M+1) to N, the table generating device 4 calculates second position information when the distance d between the control point 33 and the control point 34 is the second distance D2.

[0108] The second position command generator 12 of the control device 3 generates a second position command for moving the second mover 22 to a position determined based on the position of the first mover 21 and the table shown in Fig. 10. The control device 3 can control the first mover 21 and the second mover 22 so that the distance d is set to a first distance D1 in the first region and to a second distance D2 in the second region.

[0109] In the above description, the conveying path 20 is divided into two regions. In the third embodiment, the conveying path 20 may be divided into three or more regions. The first position information and the second position information may be set so that the distance d is different for each of the three or more regions.

[0110] According to the third embodiment, for a certain region of the conveying path 20, the first position information and the second position information are set so that the distance between the first jig 24 and the second jig 25 is a first distance, and for another region of the conveying path 20 other than the said region, the first position information and the second position information are set so that the distance between the first jig 24 and the second jig 25 is a second distance different from the first distance. As a result, when conveying workpieces of different sizes in each region of the conveying path 20, the linear motor conveying device 2 can stably convey the conveyed object in each region.

[0111] In the above, the transport system 1 according to the third embodiment has the same configuration as the transport system 1 shown in Fig. 1. The transport system 1 according to the third embodiment may be provided with a control device 3A shown in Fig. 7 instead of the control device 3 and the table generating device 4 shown in Fig. 1.

[0112] Next, a hardware configuration for realizing the processing units of the control devices 3 and 3A according to the first to third embodiments will be described. The processing units of the control device 3 are the first position command generating unit 11, the second position command generating unit 12, and the storage unit 14 shown in FIG. 1. The processing units of the control device 3A are the first position command generating unit 11, the second position command generating unit 12, the storage unit 14, and the table generating unit 15 shown in FIG. 7. The processing units of the control devices 3 and 3A are realized by processing circuits. The processing circuits may be circuits in which a processor executes software, or may be dedicated circuits.

[0113] When the processing circuit is realized by software, the processing circuit is, for example, a control circuit 50 shown in FIG. 12. FIG. 12 is a diagram showing an example configuration of the control circuit 50 according to the first to third embodiments. The control circuit 50 includes an input unit 51, a processor 52, a memory 53, and an output unit 54. The input unit 51 is an interface circuit that receives data input from outside the control circuit 50 and provides the data to the processor 52. The output unit 54 is an interface circuit that sends data from the processor 52 or the memory 53 to outside the control circuit 50.

[0114] The processing units of the control devices 3 and 3A are realized by software, firmware, or a combination of software and firmware. The software or firmware is written as a program and stored in memory 53. In the control circuit 50, the processor 52 reads and executes the program stored in memory 53, thereby realizing each function of the processing units of the control devices 3 and 3A. That is, the control circuit 50 includes memory 53 for storing a program that results in the processing of the processing units of the control devices 3 and 3A. Furthermore, this program can also be said to cause a computer system to execute the processing procedures and methods executed by the processing units of the control devices 3 and 3A. The memory 53 is also used as a temporary memory when the processor 52 executes various processes.

[0115] The first position command generating unit 11, the second position command generating unit 12, and the table generating unit 15 are realized by using a processor 52 and a memory 53. The storage unit 14 is realized by using the memory 53.

[0116] The processor 52 is a CPU (Central Processing Unit). The processor 52 may be a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, a processor, or a DSP (Digital Signal Processor). The memory 53 may be, for example, a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable Read Only Memory), or an EEPROM (registered trademark) (Electrically Erasable Programmable Read Only Memory), a magnetic disk, a flexible disk, an optical disk, a compact disk, a minidisk, or a DVD (Digital Versatile Disc).

[0117] Fig. 12 shows an example of hardware in which the functions of the processing units of the control devices 3 and 3A are realized using a general-purpose processor 52 and memory 53. The functions of the processing units of the control devices 3 and 3A may also be realized by dedicated hardware circuits. Fig. 13 shows an example of the configuration of a dedicated hardware circuit 55 according to the first to third embodiments.

[0118] The dedicated hardware circuit 55 includes an input unit 51, an output unit 54, and a processing circuit 56. The processing unit of the control device 3, 3A is realized by the processing circuit 56. The processing circuit 56 is a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a circuit combining these. Each function of the processing unit of the control device 3, 3A may be realized by the processing circuit 56 separately, or all functions may be realized collectively by the processing circuit 56. The processing unit of the control device 3, 3A may be realized by combining the control circuit 50 and the hardware circuit 55.

[0119] The table generating device 4 shown in Fig. 1 is realized by a hardware configuration similar to that shown in Fig. 12. Alternatively, the table generating device 4 is realized by a hardware configuration similar to that shown in Fig. 13. The table generating device 4 may be provided with an input device for inputting information and a monitor for displaying information. The input device includes, for example, a keyboard, a mouse, a keypad, or a touch panel. The monitor is, for example, an LCD (Liquid Crystal Display) or an organic EL (Electro-Luminescence) display.

[0120] The configurations shown in the above embodiments are examples of the contents of the present disclosure. The configurations of each embodiment can be combined with other known technologies. The configurations of each embodiment can also be combined as appropriate. Part of the configuration of each embodiment can be omitted or modified without departing from the gist of the present disclosure. [Explanation of symbols]

[0121] 1 conveying system, 2 linear motor conveying device, 3, 3A control device, 4 table generating device, 11 first position command generating unit, 12 second position command generating unit, 13 drive control unit, 14 memory unit, 15 table generating unit, 20 conveying path, 20a, 20b, 20c, 20d portion, 21 first movable element, 22 second movable element, 23 rail module, 23a straight portion, 23b curved portion, 24 first jig, 25 second jig, 31, 32, 33, 34 control point, 50 control circuit, 51 input unit, 52 processor, 53 memory, 54 output unit, 55 hardware circuit, 56 processing circuit.

Claims

1. A control device for controlling a linear motor conveyance device that includes a stator provided on a conveyance path, and a first movable element and a second movable element that move on the conveyance path, and that conveys an object held by a first jig attached to the first movable element and a second jig attached to the second movable element, a storage unit that stores a table in which first position information indicating a set position on the transport path and second position information indicating a position of the second mover when the first jig and the second jig are spaced a predetermined distance apart when the first mover is at the set position are associated with each other; a first position command generator that generates a first position command for moving the first mover; a second position command generating unit that generates a second position command for moving the second mover to a position determined based on the position of the first mover and the table. A control device characterized by:

2. The second position command generating unit obtains a position to which the second mover is to be moved by interpolating the second position information read from the table, and generates the second position command for moving the second mover to the obtained position.

2. The control device according to claim 1.

3. The table stores the second position information calculated in advance based on a value indicating the distance set in advance, a value indicating the offset of the control point of the first jig from the control point of the first mover, a value indicating the offset of the control point of the second jig from the control point of the second mover, coordinates indicating a position set on the transport path, and an angle of a tangent to a line representing the transport path at the position indicated by the coordinates.

3. The control device according to claim 1 or 2.

4. the conveying path includes a straight portion and a curved portion, the table stores the first position information representing each of a plurality of positions set on the transport path; The plurality of positions are set so as to be denser in the curved portion than in the straight portion.

3. The control device according to claim 1 or 2.

5. the conveying path includes a straight portion and a curved portion, the table stores the first position information representing each of a plurality of positions set on the transport path; The plurality of positions are set to be denser in a second section of the conveying path, in which at least one of the positions indicated in the first position information and the positions indicated in the second position information is included in the curved portion, than in a first section of the conveying path, in which both the positions indicated in the first position information and the positions indicated in the second position information are included in the straight portion.

3. The control device according to claim 1 or 2.

6. For a certain region of the transport path, the first position information and the second position information are set so that the distance between the first jig and the second jig is a first distance, and for a region of the transport path other than the certain region, the first position information and the second position information are set so that the distance between the first jig and the second jig is a second distance different from the first distance.

3. The control device according to claim 1 or 2.

7. The second position command generating unit generates the second position command based on the first position command and the table.

3. The control device according to claim 1 or 2.

8. The second position command generating unit generates the second position command based on the result of detecting the position of the first mover and the table.

3. The control device according to claim 1 or 2.

9. The second position command generating unit generates the second position command based on a result of processing the first position command by a filter having a low-pass characteristic or a result of processing the result of detecting the position of the first mover by a filter having a low-pass characteristic and the table.

3. The control device according to claim 1 or 2.

10. a table generation unit that generates the table, The storage unit stores the table generated by the table generation unit.

3. The control device according to claim 1 or 2.

11. a linear motor conveyance device including a stator provided on a conveyance path and a first movable element and a second movable element that move on the conveyance path, and that conveys an object held by a first jig attached to the first movable element and a second jig attached to the second movable element; a control device that controls the linear motor conveyance device, The control device a storage unit that stores a table in which first position information indicating a set position on the transport path and second position information indicating a position of the second mover when the first jig and the second jig are spaced a predetermined distance apart when the first mover is at the set position are associated with each other; a first position command generator that generates a first position command for moving the first mover; a second position command generating unit that generates a second position command for moving the second mover to a position determined based on the position of the first mover and the table. A transport system characterized by:

12. a table generating device for generating the table; The storage unit stores the table generated by the table generating device.

12. The transport system according to claim 11.

13. A control method for controlling, by a computer system, a linear motor conveyance device that includes a stator provided on a conveyance path and first and second movable elements that move on the conveyance path, and that conveys an object held by a first jig attached to the first movable element and a second jig attached to the second movable element, comprising: generating a first position command for moving the first mover; and generating a second position command for moving the second mover to a position determined based on a table in which first position information representing a set position on the transport path and second position information representing a position of the second mover when the distance between the first jig and the second jig is a preset distance when the first mover is at the set position are associated with each other, and the position of the first mover. A control method comprising:

Images