Conveyor system and control device

Abstract

A conveying system (10) comprises a drive unit (20A) that supplies drive currents to several coils (9A1 to 9A5) arranged along a conveying path (8), a thrust command generation unit (15) that generates a thrust command, which is a command value of a thrust to be applied by a runner (4A) based on a motion target value, which is a time series motion target value, and a current command generation unit (13') that provides current target values, which are the target values ​​of the drive currents to be supplied to the several coils (9A1 to 9A5), as current commands, so that the thrust applied by the runner (4) follows the thrust command.The current command generation unit (13') generates the current target values ​​to be provided to the multiple coils (9A1 to 9A5) using a portion of actual thrust characteristics determined by characteristics of the multiple coils (9A1 to 9A5) and the rotor (4A), thus reducing the number of coils through which the drive currents flow.

Description

Area

[0001] The present disclosure relates to a conveying system for transporting objects and a control device included in the conveying system. background

[0002] Conveyor systems for transporting workpieces are generally used in production lines with factory automation, such as assembly lines for commercial products, food packaging lines, and so on. In recent years, a conveyor system has become widely used in which a conveyor path for transporting workpieces is divided into several zones, and carriers on which the workpieces are placed are moved by control devices located in the respective zones. This type of conveyor system is highly effective in terms of production efficiency.

[0003] One type of conveyor system uses a so-called linear motor with a movable magnet, in which magnets are arranged on a carrier acting as a rotor, and coils are arranged on a stator that forms a conveying path. Compared to a linear motor with a movable coil, which uses coils as a rotor, the linear motor with a movable magnet is suitable for long-distance conveying. However, if long-distance conveying is required with the linear motor with a movable magnet relative to the rotor size, multiple coils are needed, corresponding to the conveying distance. Furthermore, the conveyor system using the linear motor with a movable magnet should be able to control multiple carriers individually and control the movements of the multiple carriers with high accuracy, even when the carriers are positioned side by side.

[0004] Patent Reference 1 below discloses a conveying system using a linear motor. The conveying system disclosed in Patent Reference 1 comprises carriers with magnets and multiple coil units arranged in a conveying path. Each coil unit comprises multiple coils. The conveying system disclosed in Patent Reference 1 generates thrusts to move the carriers through the interactions between the currents flowing through the coils and the magnetic fields generated by the magnets. The conveying system includes a control unit. The control unit determines the ratios of the currents to be supplied to the respective coil units based on the positions of the multiple carriers, as well as the respective impedances and thrust characteristics of the multiple coil units. Patent Reference 1 describes that even in a case where the carriers are controlled by the multiple coil units, the carriers can be controlled with high accuracy. List of patent literature

[0005] Patent literature 1: Publication of Japanese patent application number 2017 - 79 569 (JP 2017 - 79 569 A) Overview of the invention; Problem to be solved by the invention

[0006] The conveyor system disclosed in patent literature 1 is equipped with switches in addition to the current control units that regulate the currents flowing through the coils. The conveyor system disclosed in patent literature 1 must generate and output open and close commands to control the switches. Consequently, the conveyor system according to patent literature 1 has a problem in that the circuit configuration is complicated due to the need for the switches. Furthermore, the conveyor system according to patent literature 1 must generate and output the open and close commands in addition to the current commands, and therefore has a problem in that the processing of the conveyor system's control is complicated.

[0007] The present disclosure was made in consideration of the above. An objective of the present disclosure is to provide a conveying system that simplifies circuit configuration and enables control through simple processing. Means to solve the problem

[0008] To solve the problems described above and achieve the objective, a conveying system according to the present disclosure is a conveying system with a runner and a conveying path along which the runner moves, and comprises a drive unit, a thrust command generation unit, and a current command generation unit. The drive unit supplies drive currents to the multiple coils arranged along the conveying path. The thrust command generation unit generates a thrust command, which is a command value for a thrust to be applied by the runner, based on a motion target value, which is a time-series motion target value that is externally input or internally generated. The current command generation unit generates current target values, which are target values ​​of the drive currents to be supplied to the multiple coils, as current commands, such that the thrust applied by the runner follows the thrust command.The current command generation unit generates the current target values ​​to be provided to the multiple coils using a portion of actual thrust characteristics determined by characteristics of the multiple coils and the rotor, such that the number of coils through which the drive currents flow is reduced. Effects of the invention

[0009] The conveying system of the present disclosure has the advantages that a circuit configuration can be simplified and control is made possible by simple processing. Brief description of the drawings Fig. Figure 1 is a diagram showing an exemplary configuration of a conveying system according to a first embodiment. Fig. Figure 2 is a diagram showing an exemplary configuration of a control device and a drive device according to the first embodiment. Fig. Figure 3 is a diagram to illustrate a problem in the first embodiment. Fig. Figure 4 is a diagram to illustrate a modified thrust coefficient distribution used in a current command generation unit of the first embodiment. Fig. Figure 5 is a diagram illustrating an effect that occurs when current commands are issued using the parameters shown in the Fig. The modified shear coefficient distribution shown in section 4 can be generated. Fig. Figure 6 is a diagram showing an exemplary configuration of a control device according to a first modification of the first embodiment. Fig. Figure 7 is a diagram showing an exemplary configuration of a control device according to a second modification of the first embodiment. Fig. Figure 8 is a diagram to illustrate a problem in a second embodiment. Fig. Figure 9 is a diagram to explain the operation of a control device according to the second embodiment. Fig. Figure 10 is a diagram to illustrate a problem in a third embodiment. Fig. Figure 11 is a diagram to illustrate a modified thrust coefficient distribution used in a current command generation unit of the third embodiment. Fig. Figure 12 is a diagram to explain the operation of a control device according to a fourth embodiment. Fig. Figure 13 is a block diagram showing an example of a hardware configuration, illustrating the functions of the control device and the drive device in the first to fourth embodiments. Fig. Figure 14 is a block diagram showing another example of a hardware configuration, illustrating the functions of the control device and the drive device in the first to fourth embodiments. Description of embodiments

[0010] A conveying system and a control device according to embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. In the following description, several similar components are designated by a reference numeral with letters or symbols appended to it. However, when the individual components are described without distinction, the notation of the letters or symbols is omitted appropriately. First embodiment

[0011] A conveying system according to a first embodiment is a system used for transporting objects. The conveying system transports objects by moving runners on which the objects are placed. The runners are, for example, carriers.

[0012] Fig. Figure 1 is a diagram showing an exemplary configuration of a conveying system 10 according to the first embodiment. As shown in the Fig. As shown in Figure 1, the conveyor system 10 of the first embodiment comprises a control device 1, drive devices 2A, 2B, 2C, 2D, 2E, 2F, 2G and 2H (hereinafter appropriately referred to as "2A to 2H". Other reference numerals are designated similarly), coil units 3A to 3H, rotors 4A to 4C and measuring rail heads 5A to 5C. As shown in the Fig. As shown in Figure 2, the conveyor system 10 of the first embodiment also includes straight measuring rails 6A and 6B. Although not shown in the Fig. The drive devices 2C to 2H also include straight measuring rails.

[0013] The drive devices 2 are interconnected. In the conveyor system 10, the drive devices 2 are interconnected in such a way as to form a conveyor path 8 along which the runner 4 moves. The drive devices 2 provide currents to the coil units 3 to generate thrusts on the runners 4 in order to move the runners 4.

[0014] Fig. Figure 1 shows a ring-shaped closed path, but the present invention is not limited to this example. The conveying path 8 of the conveying system 10 can be an open path. That is, the conveying path 8 of the conveying system 10 can be a path with a starting point and an end point.

[0015] The drive devices 2A, 2B, 2E, and 2F are linear drive devices 2 that form straight paths. The drive devices 2C, 2D, 2G, and 2H are curved drive devices 2 that form curved paths and change the direction of movement of the runners 4. The conveyor path 8 can also consist exclusively of the curved drive devices 2 without the straight drive devices 2. This means that the conveyor path 8 can have any overall shape.

[0016] The conveyor system 10 according to the first embodiment is a linear motor with a movable magnet. The runners 4 move along a guide rail (not shown) provided at the side of the conveyor path 8. The runners 4 include permanent magnets (not shown) and are mounted at the side of the conveyor path 8. The runners 4 include guide rollers (not shown) which move along the guide rail by rotating on them. The runners 4 move along the side of the conveyor path 8 and stop at the side of the conveyor path 8. It should be noted that the guide rollers can be provided on top of the conveyor path 8.

[0017] The direction of movement of each runner (4) is clockwise. Fig. 1 or a counterclockwise direction in the Fig. 1. Of the directions of movement, the clockwise direction is used in the Fig. 1 is designated as a forward direction. Of the directions of movement, the counterclockwise direction is designated in the Fig. Arrow 1 is designated as a reverse direction. Arrow 17A represents the forward direction and arrow 17B represents the reverse direction.

[0018] In the Fig. In the example shown, the conveyor system 10 comprises the eight drive devices 2 and the three runners 4. The number of drive devices 2 in the conveyor system 10 is arbitrary. This means that the number of drive devices 2 forming the conveyor path 8 is arbitrary, as is the number of runners 4 moving along the conveyor path 8. The number of runners 4 moving along the conveyor path 8 can be one.

[0019] The control device 1 is connected to the drive devices 2 via data communication lines 7. The control device 1 controls each of the drive devices 2. The data communication lines 7 comprise a communication line connecting the control device 1 to one of the drive devices 2, and communication lines connecting the adjacent drive devices 2 to each other. This means that the conveyor system 10 has a configuration in which the control device 1 is connected to the drive devices 2 in a daisy-chain connection. It should be noted that the connection topology between the control device 1 and the drive devices 2 is not limited to the daisy-chain connection.The connection topology between the control device 1 and the drive devices 2 can be a star connection, in which each of the drive devices 2 is connected to the control device 1 via a communication hub. Alternatively, the conveyor system 10 can include multiple data communication lines 7, and the control device 1 can be directly connected to each drive device 2 via the corresponding data communication line 7. The data communication line 7 can be provided by communication channels that enable wireless communication instead of physical communication lines.

[0020] Next, a configuration and functions of the control device 1 and the drive devices 2 will be described with reference to the Fig. 2 described. Fig. Figure 2 is a diagram showing an exemplary configuration of the control device 1 and the drive devices 2 according to the first embodiment.

[0021] Top left in the Fig. Figure 2 shows the drive device 2A, the coil unit 3A, the rotor 4A, the measuring rail head 5A, and the straight measuring rail 6A. On the right in the Fig. Figure 2 shows the drive device 2B, the coil unit 3B, the rotor 4B, the measuring rail head 5B, and the straight measuring rail 6B. (Lower left in the) Fig. Figure 2 shows the control device 1.

[0022] The drive device 2A comprises a drive unit 20A, a data communication unit 21A, a detector communication unit 24A, and current detectors 23A. The drive unit 20A comprises several current control units 22A. The coil unit 3A comprises several coils 9A, which are connected one-to-one to the current control units 22A of the drive unit 20A. As in the Fig. As shown in Figure 1, the multiple coils 9A are arranged along the conveyor path 8. As shown in the Fig. As shown in Figure 2, the multiple coils 9A are single-phase coils. Like the drive device 2A, the drive device 2B also comprises a drive unit 20B, a data communication unit 21B, and a detector communication unit 24B.

[0023] The runner 4A includes permanent magnets 40. The permanent magnets 40 included in the runner 4A are permanent magnets that contribute to the drive of the runner 4A.

[0024] As with regard to the Fig. As described in Section 1, drive devices 2A, 2B, 2E, and 2F are all linear drive devices 2. Drive devices 2C, 2D, 2G, and 2H, on the other hand, are curved drive devices 2. The configuration of the curved drive devices 2 is the same as that of the linear drive devices 2, except that the coils 9 are arranged differently compared to the linear drive devices 2. Accordingly, the following description focuses on drive device 2A, which is the linear drive device 2. It should be noted that the content described below is not limited to the linear drive devices 2.

[0025] In the Fig. In Figure 2, five of the coils 9A in the coil unit 3A are designated by reference numerals 9A1 to 9A5, and five of the current control units 22A in the drive unit 20A are designated by reference numerals 22A1 to 22A5. Here, the five coils 9A designated by reference numerals 9A1 to 9A5 are the coils located in the area influenced by the magnetic field emanating from the permanent magnet 40 enclosed in the rotor 4A, and are the coils that contribute to driving the rotor 4A. The five current control units 22A designated by reference numerals 22A1 to 22A5 are the current control units connected to the coils 9A designated by reference numerals 9A1 to 9A5. If the positional relationship between the rotor 4A and the coil unit 3A is that described in the Fig. As shown in Figure 2, the coils 9A, which are located far from the rotor 4A, do not contribute much to driving the rotor 4A. In the first embodiment, coils 9A1 to 9A5 are described as the coils that contribute to driving the rotor 4A. Driving currents are then supplied to coils 9A1 to 9A5 by the current control units 22A1 to 22A5, which are connected one-to-one to coils 9A1 to 9A5. The number of coils 9 that contribute to driving a rotor 4 is determined by the number of coils 9 that are arranged in the area influenced by the size, magnetic field strength, etc., of the permanent magnets 40 of the rotor 4. The number of coils 9A that drive the rotor 4A described here is an example, and the present invention is not limited to this example. This means that the number of coils 9A contributing to the drive of the rotor 4A can be different than five.

[0026] The measuring rail head 5A is attached to the runner 4A. The measuring rail head 5A moves along the linear measuring rail 6A together with the runner 4A. The linear measuring rail 6A detects position information of the runner 4A and transmits this position information to the detector communication unit 24A of the drive device 2. In particular, the linear measuring rail 6 detects a motion detection value yA, such as the position or speed of the runner 4A, based on the position of the measuring rail head 5, which is connected to the runner 4A, and transmits the detected motion detection value yA to the detector communication unit 24A. The measuring rail head 5A can, for example, be formed from a permanent magnet for position detection. The linear measuring rail 6A can be formed from a sensor element that detects the magnetic field of the position detection magnet.

[0027] The control device 1 comprises a motion target value generation unit 11, a position and velocity control unit 12, a current command generation unit 13, and a data communication unit 14. The motion target value generation unit 11 and the position and velocity control unit 12 form a thrust command generation unit 15.

[0028] Data communication unit 14 and data communication unit 21A are connected via a communication line 7A. Data communication unit 21A and data communication unit 21B are connected via a communication line 7B. This connection topology is the daisy-chain connection described above. Communication data TxRx sent and received by data communication unit 14 and data communication unit 21A includes not only information about drive unit 2A, but also information about drive units 2B to 2H. Data communication unit 21A of drive unit 2A sends the communication data TxRx received from data communication unit 14 to data communication unit 21B of drive unit 2B. Similarly, data communication unit 21B sends the received communication data TxRx to the next drive unit 2C (not shown in the diagram). Fig. 2 shown).

[0029] The data communication unit 14 receives information about motion detection values ​​y via the data communication unit 21A of the drive device 2A. The motion detection values ​​y received by the data communication unit 14 include not only the motion detection value yA of runner 4A, but also the motion detection values ​​of runners 4B and 4C.

[0030] The thrust command generation unit 15 generates thrust commands τref, which are the thrust commands for the thrusts to be applied by the runners 4, based on motion target values ​​yref, which are time-series motion target values ​​generated by the motion target value generation unit 11, and the motion detection values ​​y, which represent the motion positions or motion velocities of the runners 4. Specifically, the position and velocity control unit 12 generates the thrust commands τref such that the motion detection values ​​y follow the motion target values ​​yref. Similarly to the motion detection values ​​y, the motion target values ​​yref include motion target values ​​for all of the runners 4A to 4C present in the conveyor system 10. The thrust commands τref are generated for the respective runners 4 and include thrust commands for all of the runners 4A to 4C. In the Fig. 2. The motion target values ​​yref are generated within the control device 1, but the present disclosure is not limited to this configuration. The motion target values ​​yref can be entered into the control device 1 from outside.

[0031] The current command generation unit 13 generates target current values, which are the target values ​​of the drive currents to be supplied to the multiple coils 9, as current commands Iref based on the thrust commands τref and the motion detection values ​​y, which represent the motion positions or motion speeds of the runner 4. A specific procedure for generating the current commands Iref is described later. Information about the generated current commands Iref is sent from the data communication unit 14 to the data communication unit 21A.

[0032] The data communication unit 21A of the drive device 2A extracts current commands IrefA1 to IrefA5, which are current commands for the drive device 2A, from the communication data TxRx sent by the data communication unit 14, and outputs the extracted current commands IrefA1 to IrefA5 to the current control units 22A1 to 22A5. Naturally, the communication data TxRx sent by the data communication unit 14 includes the current commands Iref for the drive devices 2B to 2H.

[0033] Current detectors 23A1 to 23A5 detect currents IA1 to IA5 flowing through coils 9A1 to 9A5. Current control units 22A1 to 22A5 receive the current commands IrefA1 to IrefA5 from data communication unit 21A, the motion detection value yA from detector communication unit 24A, and the current detection values ​​IA1 to IA5 from current detectors 23A1 to 23A5. Current control units 22A1 to 22A5 control the currents IA1 to IA5, which are the drive currents to be supplied to coils 9A1 to 9A5, such that the current detection values ​​IA1 to IA5 follow the current commands IrefA1 to IrefA5. It should be noted that the currents IA1 to IA5 can be controlled by any method.

[0034] Next, a detailed operation of the current command generation unit 13, which is included in the control device 1 according to the first embodiment, will be described with reference to the drawings of the Fig. 3 to 5 are described in detail. Fig. Figure 3 is a diagram to illustrate a problem in the first embodiment. Fig. Figure 4 is a diagram to illustrate a modified thrust coefficient distribution used in the current command generation unit 13 of the first embodiment. Fig. 5 is a diagram to illustrate an effect in a case where the current commands Iref are used with the information in the Fig. The modified shear coefficient distribution shown in section 4 is generated. Fig. 3 and Fig. Figure 5 are diagrams derived from the control device 1, the drive device 2A, the coil unit 3A, the rotor 4A, the measuring rail head 5A, and the straight measuring rail 6A. Fig. 2 are obtained, and components that belong to those in the Fig. Two items that are identical or equivalent are designated with the same reference symbols. In the following description, sections that overlap with the content described above are omitted as appropriate.

[0035] As described above, the current command generation unit 13 generates the current commands IrefA based on the thrust commands τref and the motion detection values ​​y of the runners 4. Specifically, the current command generation unit 13 calculates the current commands IrefA1 to IrefA5, which are the target values ​​of the drive currents to be supplied to the coils 9A1 to 9A5, using formula (1) below. The current command generation unit 13 calculates the current commands Iref for the respective coils 9 of each coil unit 3 included in the conveyor system 10. For simplicity, the calculation of the five current commands IrefA1 to IrefA5 is described here. IrefA1=KA1 / (KA12+KA22+KA32+KA42+KA52)×τref IrefA2=KA2 / (KA12+KA22+KA32+KA42+KA52)×τref IrefA3=KA3 / (KA12+KA22+KA32+KA42+KA52)×τref IrefA4=KA4 / (KA12+KA22+KA32+KA42+KA52)×τref IrefA5=KA5 / (KA12+KA22+KA32+KA42+KA52)×τref

[0036] In formula (1), KA1 to KA5 are coefficients representing the magnitudes of the thrusts generated with respect to the currents IA1 to IA5 flowing through the coils 9A1 to 9A5. In this description, the coefficients are referred to as "thrust coefficients".

[0037] Here the Fig. 3 The waveform of an actual shear coefficient distribution KA(x). The actual shear coefficient distribution KA(x) is a waveform that represents the relationship between the runner position, which represents the distance from the center position of runner 4, and the shear coefficients. The horizontal axis of the graph showing the waveform of the actual shear coefficient distribution KA(x) represents the position of the runner and is an axis that coincides with the shear coefficient “0 (zero)”. The same applies to the following drawings. The shear coefficients KA1 to KA5 in the above formula (1) can be derived from the one in the Fig. The actual thrust coefficient distribution KA(x) shown in Figure 3 can be determined. The actual thrust coefficient distribution KA(x) represents actual thrust characteristics determined by the characteristics of the coils 9 and the rotor 4. Here, the characteristics of the coils 9 for determining the actual thrust characteristics include the number of windings of the coils 9, the radius of the coil turns, etc., and the characteristics of the rotor 4 include the magnetic flux density, the magnetic pole intervals, etc., of the permanent magnets 40 contained within the rotor 4.

[0038] The thrust coefficients KA1 to KA5 in the actual thrust coefficient distribution KA(x) have the same values ​​as induced voltage coefficients, which represent the relationships between the rotor position and the induced voltages generated in coils 9A1 to 9A5 when rotor 4 moves. Accordingly, this description uses the actual thrust coefficient distribution KA(x), which is generated using the induced voltages generated in coils 9A1 to 9A5 when rotor 4 moves.

[0039] According to the equations in formula (1), the current commands IrefA, which are 0 [A], are generated when the thrust coefficients KA1 to KA5 are zero. The current commands IrefA, which are 0 [A], are input to the current control units 22A via the data communication units 14 and 21A. The current control units 22A control the currents flowing through the coils 9A so that they are 0 [A]. Consequently, no drive currents flow through the coils 9A, for which the current commands IrefA, which are 0 [A], are provided.

[0040] If, on the other hand, the thrust coefficients KA1 to KA5 are not zero, current commands IrefA are generated that are not 0 [A]. These current commands IrefA, which are not 0 [A], are input to the current control units 22A via the data communication units 14 and 21A. The current control units 22A control the currents flowing through the coils 9A so that they are not 0 [A]. Consequently, the drive currents flow through the coils 9A, which are supplied with current commands IrefA that are not 0 [A].

[0041] As can be understood from the above description, the driving currents flowing through coils 9A depend on the actual thrust coefficient distribution KA(x) of rotor 4 when the equations in formula (1) are used. Consequently, the number of coils through which the driving currents flow cannot be changed as desired if the equations in the Fig. The actual shear coefficient distribution KA(x) shown in Figure 3 is used.

[0042] Accordingly, in the first embodiment, instead of the one described in the Fig. The actual shear coefficient distribution KA(x) shown in the 3 is one in the Fig. The modified actual shear coefficient distribution KA(x) shown in Figure 4 was applied. Fig. 4 is the one in the Fig. The actual shear coefficient distribution KA(x) shown is indicated by a dashed line and the modified actual shear coefficient distribution KA(x) is indicated by a solid line. Fig. Figure 5 shows an exemplary configuration of a control device 1' using the modified actual thrust coefficient distribution K'A(x). In the Fig. 5 is the one in the Fig. The current command generation unit 13 shown in Figure 3 is replaced by a current command generation unit 13'. Furthermore, in the Fig. 5. The current commands IrefA (IrefA1 to IrefA5) are entered into the current control units 22A to modify the current commands IrefA (IrefA1 to IrefA5). This means that the current command generation unit 13' generates the current commands IrefA, which are the target current values, using a portion of the actual thrust characteristics determined by the characteristics of the coils 9 and the rotor 4. In the Fig. 5 are parts that belong to those in the Fig. 3 are identical or equivalent, are designated with the same reference symbols, and redundant descriptions are omitted appropriately. Iref'A1=K'A1 / (K'A12+K'A22+K'A32+K'A42+K'A52)×τref Iref'A2=K'A2 / (K'A12+K'A22+K'A32+K'A42+K'A52)×τref Iref'A3=K'A3 / (K'A12+K'A22+K'A32+K'A42+K'A52)×τref Iref'A4=K'A4 / (K'A12+K'A22+K'A32+K'A42+K'A52)×τref Iref'A5=K'A5 / (K'A12+K'A22+K'A32+K'A42+K'A52)×τref

[0043] In formula (2), K'A1 to K'A5 are shear coefficients determined from the modified shear coefficient distribution K'A(x). The modified shear coefficient distribution K'A(x) is a waveform representing modified shear characteristics generated using a portion of the actual shear coefficient distribution KA(x), which is the actual shear characteristic determined by the characteristics of the multiple coils 9 and the rotor 4. Fig. 5 The modified thrust coefficient distribution K'A(x) is generated by cutting off a part of the actual thrust coefficient distribution KA(x) which was determined by the characteristics of the coil 9A1 to 9A5 and the rotor 4A.

[0044] In particular, the modified shear coefficient distribution K'A(x) Fig. 5. The value of the thrust coefficient K'A1 corresponding to coil 9A1 and the value of the thrust coefficient K'A5 corresponding to coil 9A5 are "0". Consequently, the current command IrefA1, which is the target value of the drive current to be supplied to coil 9A1, and the current command IrefA5, which is the target value of the drive current to be supplied to coil 9A5, are current commands that are 0 [A] when calculated using formula (2). Thus, the number of coils 9A through which the drive currents flow is changed from five to three, and the number of coils 9A through which the drive currents flow is reduced.

[0045] It should be noted that the in the Fig. 4 and Fig. The modified shear coefficient distribution K'A(x) shown in Figure 5 is an example and is not limited to the waveform shown in these figures.

[0046] As described above, the use of the control device 1' according to the first embodiment allows a reduction in the number of coils through which the drive currents flow without connecting switches to the multiple coils 9 as described in patent literature 1.

[0047] Next, modifications to the configuration of the control device 1' according to the first embodiment are described. Fig. Figure 6 is a diagram showing an exemplary configuration of a control device 1" according to a first modification of the first embodiment. In the Fig. 6 is the one in the Fig. The thrust command generation unit 15 shown in Figure 5 is replaced by a thrust command generation unit 15", which is located in the Fig. The motion target value generation unit 11 shown in section 5 is replaced with a motion target value generation unit 11" and the one shown in the Fig. The current command generation unit 13' shown in Figure 5 has been replaced by a current command generation unit 13" in Figure 5. Fig. 6 is the one in the Fig. 5 existing position and velocity control units 12 omitted. In the Fig. 6 are parts that belong to those in the Fig. 5 are identical or equivalent, are designated with the same reference symbols, and redundant descriptions are omitted appropriately.

[0048] In the Fig. 6. In the case where the motion target values ​​yref generated by the motion target value generation unit 11" are considered to be the thrust commands τref, the motion target value generation unit 11 can be configured as the thrust command generation unit 15", as in the Fig. Figure 6 shows that the thrust commands τref, issued by the thrust command generation unit 15", can be input to the current command generation unit 13". The current command generation unit 13" generates current commands Iref'' using the thrust commands τref and outputs the current commands Iref'' to the data communication unit 14. Current commands Iref'A (Iref'A1 to Iref'A5) are input via the data communication units 14 and 21A to the current control units 22A. The current control units 22A control the currents IA1 to IA5, which are the drive currents to be supplied to the coils 9A1 to 9A5, such that the sensing values ​​of the currents IA1 to IA5 follow Iref''A1 to Iref'A5.

[0049] The control device 1' according to the first embodiment can be used as in the Fig. 7 shown, configured as shown. Fig. Figure 7 is a diagram showing an exemplary configuration of a control device 1''' according to a second modification of the first embodiment. In the Fig. 7 is the one in the Fig. The thrust command generation unit 15 shown in Figure 5 is replaced by a thrust command generation unit 15'''. The position and velocity control unit 12 and the current command generation unit 13', which are located in the Fig. 5 shown are for the drive device 2A in the Fig. 7 relocated and configured as a 25A''' position and velocity control unit and a 26A''' current command generation unit. In the Fig. 7 is the one in the Fig. The motion target value generation unit 11 shown in Figure 5 is replaced by a motion target value generation unit 11'''. This means that in the Fig. 7. The motion target value generation unit 11''' and the position and velocity control unit 25A''', which are components of the thrust command generation unit 15''', are arranged separately in the control device 1''' and the drive device 2A'''', respectively. Furthermore, in the Fig. 7 who are in the Fig. The data communication unit 14 shown in Figure 5 is replaced with a data communication unit 14''' and the one shown in the Fig. The data communication unit 21A shown in Figure 5 has been replaced by a data communication unit 21A'''. In the Fig. 7 are parts that belong to those in the Fig. 5 are identical or equivalent, are designated by the same reference symbols, and redundant descriptions are omitted appropriately.

[0050] In the Fig. 7. The motion target values ​​yref, generated by the motion target value generation unit 11''', are output to the data communication unit 14 to be sent to the drive device 2A. The position and velocity control unit 25A''' receives information about the motion target value yref via the data communication unit 21A'''. The position and velocity control unit 25A''' generates the thrust command τref such that the motion detection value y follows the motion target value yref, and outputs the thrust command τref to the current command generation unit 26A'''. The current command generation unit 26A''' generates current commands Iref''A (Iref"A1 to Iref"A5) based on the thrust command τref and the motion detection value yA of the runner 4A and outputs the current commands Iref''A (Iref''A1 to Iref''A5) to the current control units 22A.The current control units 22A control the currents IA1 to IA5, which are the drive currents to be supplied to the coils 9A1 to 9A5, so that the sensing values ​​of the currents IA1 to IA5 follow the current commands Iref''A1 to Iref''A5.

[0051] As described above, the conveying system according to the first embodiment is a conveying system comprising a runner and a conveying path along which the runner moves. The conveying system includes a drive unit that supplies drive currents to several coils arranged along the conveying path, and a thrust command generation unit that generates a thrust command, which is a command value for a thrust to be applied by the runner, based on a motion target value, which is a time-series motion target value that is input from an external source or generated internally. The conveying system also includes a current command generation unit that generates current target values, which are the target values ​​of drive currents to be supplied to the several coils, as current commands such that the thrust applied by the runner follows the thrust command.The current command generation unit generates the target current values ​​to be supplied to the multiple coils using a portion of actual thrust characteristics determined by the characteristics of the multiple coils and the rotor, in order to reduce the number of coils through which the drive currents flow. The conveyor system configured in this way allows for a reduction in the number of coils through which the drive currents flow without connecting switches to the multiple coils, as described in patent literature 1. This enables the provision of a conveyor system that simplifies circuit configuration and allows for control through simple processing.

[0052] The control device according to the first embodiment is a control device configured for use in a conveyor system with a runner, a conveyor path along which the runner moves, and a drive device that supplies drive currents to several coils arranged along the conveyor path. The control device comprises a thrust command generation unit that generates a thrust command, which is a thrust to be applied by the runner, based on a motion target value, which is a time-series motion target value that is input from an external source or generated internally. The control device also comprises a current command generation unit that generates current target values ​​as current commands, wherein the current target values ​​are the target values ​​of the drive currents to be supplied to the several coils such that the thrust applied by the runner follows the thrust command.The current command generation unit generates the target current values ​​to be supplied to the multiple coils using a portion of actual thrust characteristics determined by the characteristics of the multiple coils and the rotor, in order to reduce the number of coils through which the drive currents flow. The control device configured in this way allows a reduction in the number of coils through which the drive currents flow without connecting switches to the multiple coils, as described in patent literature 1. This enables the provision of a control device that simplifies circuit configuration and allows control through simple processing. Second embodiment.

[0053] In a second embodiment, a conveying system and a control device are described which are capable of solving a further problem while the problem in the first embodiment is solved. Fig. Figure 8 is a diagram illustrating the problem in the second embodiment. In the Fig. 8 are components that belong to those of the Fig. Items that are identical or equivalent are designated by the same reference symbols. In the following description, sections that overlap with the content described above are omitted as appropriate.

[0054] The Fig. Figure 8 shows a situation where the runners 4 are located next to each other on the straight measuring rail 6A, and shows runner 4A and the adjacent runner 4B. In the Fig. Figure 8 shows the waveform of the actual thrust coefficient distribution KA(x), which uses the characteristics of rotor 4A, represented by a solid line, and the waveform of an actual thrust coefficient distribution KB(x), which uses the characteristics of rotor 4B, represented by a dashed line. The actual thrust coefficient distribution KA(x) is used to generate the current commands Iref for the coils 9, through which the drive currents are to flow to move rotor 4A. The actual thrust coefficient distribution KB(x) is used to generate the current commands Iref for the coils 9, through which the drive currents are to flow to move rotor 4B.

[0055] As in the Fig. As shown in Figure 8, if rotor 4A and rotor 4B are located next to each other, the coils 9 for driving rotors 4A and 4B are also located next to each other. This means that the multiple coils 9A (a "first coil group," which will be described later) for driving rotor 4A are located next to multiple coils 9B (a "second coil group," which will be described later) for driving rotor 4B. In this description, the term "next to" refers to a coil located in the Fig. Figure 8 shows a situation where right-hand coils 9A4 and 9A5 of coils 9A1 to 9A5, which form a coil group for driving rotor 4A as one of the rotors, correspond to left-hand coils 9B1 and 9B2 of coils 9B1 to 9B5 (coils 9B3 to 9B5 are not shown), which form a coil group for driving rotor 4B as the other rotor. In this case, the thrust coefficients KA4 and KA5, which generate the current commands IrefA4 and IrefA5 of coils 9A4 and 9A5 for driving rotor 4A, coincide with the thrust coefficients KB1 and KB2, which generate the current commands IrefB1 and IrefB2 of coils 9B1 and 9B2 for driving rotor 4B. Accordingly, this situation can be considered a parallel operation.

[0056] In this description, any one of the multiple rotors 4 is sometimes referred to as a "first rotor," and a coil group consisting of the multiple coils 9 that drive the first rotor is sometimes referred to as a "first coil group." The rotor 4 located next to the first rotor is sometimes referred to as a "second rotor," and a coil group consisting of the multiple coils 9 that drive the second rotor is sometimes referred to as a "second coil group."

[0057] In particular, the current command IrefA5 of coil 9A4 and the current command IrefB2 of coil 9B1, which is the same coil as coil 9A4, can be expressed as in formulas (3) and (4) below using the formula (1) above. IrefA5=KA5 / (KA12+KA22+KA32+KA42+KA52)×τrefA IrefB2=KB2 / (KB12+KB22+KB32+KB42+KB52)×τrefB

[0058] In the above forms (3) and (4), τrefA is a thrust command for rotor 4A and τrefB is a thrust command for rotor 4B. Because the thrust commands τrefA and τrefB change over time, the current command IrefA5 for coil 9A5 and the current command IrefB2 for coil 9B2, which coincides with coil 9A5, do not always coincide. When these current commands IrefA5 and IrefB2 do not coincide, and the current command IrefA5, calculated using formula (3), is input to the current control unit 22A5 to allow the drive current to flow through coil 9A5 (9B2), the thrust generated at rotor 4B does not correspond to the thrust command τrefB. Furthermore, if the current command IrefB2, which is calculated using formula (4), is entered into the current control unit 22A5, the thrust generated at the rotor 4A does not match the thrust command τrefA.In the case where the thrust commands Iref are calculated using the actual thrust coefficient distributions KA(x) and KB(x) and the runners 4 are located next to each other, there is therefore a possibility that a thrust is not generated on one of the runners 4 in accordance with the thrust command τref, which causes a problem in that it is difficult to control all runners with high accuracy.

[0059] To solve this problem, in the second embodiment the control device 1' described in the first embodiment is used and the runners 4 are driven using the modified thrust coefficient distribution K'A(x) presented in the first embodiment.

[0060] Next, an operation is described that is carried out by the control device 1' according to the second embodiment. Fig. Figure 9 is a diagram illustrating the operation of the control device 1' according to the second embodiment. In the Fig. 9 are components that belong to those of the Fig. 5. Items that are identical or equivalent are designated with the same reference symbols. In the following description, sections that overlap with the content described above are omitted as appropriate.

[0061] In the Fig. Figure 9 shows the waveform of the modified thrust coefficient distribution K'A(x) as a solid line and the waveform of a modified thrust coefficient distribution K'B(x) as a dashed line. The modified thrust coefficient distribution K'A(x) is used to generate the current commands Iref for the coils 9 through which the drive currents for the rotor 4A are to flow. The modified thrust coefficient distribution K'B(x) is used to generate the current commands Iref for the coils 9 through which the drive currents for the rotor 4B are to flow.

[0062] As in the Fig. As shown in Figure 9, in a case where rotor 4A is located next to rotor 4B, the coils 9 that drive rotors 4A and 4B are also located next to each other. On the other hand, the use of the modified shear coefficient distributions K'A(x) and K'B(x) eliminates cases where the value of a shear coefficient K'A in the modified shear coefficient distribution K'A(x) and the value of a shear coefficient K'B in the modified shear coefficient distribution K'B(x) are not both zero. In other words, the shear coefficient K'A in the modified shear coefficient distribution K'A(x) and / or the value of the shear coefficient K'B in the modified shear coefficient distribution K'B(x) is always zero. Consequently, even in a case where the runners 4A and 4B are located next to each other, suitable thrust commands τref can be provided to the runners 4A and 4B, so that the runners 4A and 4B can be controlled with high accuracy.

[0063] In the Fig. Section 9 describes the cases in which the two rotors 4A and 4B are located next to each other, but the present invention is not limited to this example. The same description can apply to cases in which the rotors 4B and 4C are located next to each other, as well as to cases in which the rotors 4A and 4C are located next to each other. In the Fig. Section 9 describes the case where the two runners 4A and 4B are adjacent. However, the same description can apply to cases where three or more of the runners 4 are adjacent.

[0064] By using the method of the second embodiment, the current commands Iref can always be calculated using formula (2) and the modified thrust coefficient distributions K'A(x) and K'B(x), regardless of situations where two or more of the rotors 4 are located side by side. Accordingly, the use of the method of the second embodiment allows the current commands Iref to be calculated using only four simple arithmetic operations, eliminating the need for complicated calculations such as simultaneous equations. This provides an effect of reducing the computational effort and thus decreasing the operational load.

[0065] Furthermore, in the second embodiment of the method, the current commands Iref for all rotors 4 can be calculated using formula (2), which are the same equations, so that the modified thrust coefficient distributions K'(x) can be set to the same values ​​for all rotors 4. Consequently, the thrust commands generated for all rotors 4 have the same values, thus enabling the same control to be performed for all rotors 4.

[0066] As described above, in the conveying system and control device according to the second embodiment, the current command generation unit generates the target current values ​​to be supplied to the coils of the first coil group using a portion of the actual thrust characteristics determined by the characteristics of the coils of the first coil group and the first rotor to be driven by the first coil group. The current command generation unit generates the target current values ​​to be supplied to the coils of the second coil group using a portion of the actual thrust characteristics determined by the characteristics of the coils of the second coil group and the second rotor to be driven by the second coil group.Here, the first coil group is the group consisting of the multiple coils for driving the first rotor, and the second coil group is the group consisting of the multiple coils for driving the second rotor, located adjacent to the first coil group. By using modified thrust coefficient distributions—generated by using only a portion of the actual thrust characteristics rather than the entirety of the actual thrust data—it is possible to prevent different thrust commands from being issued to the same coil, which could otherwise control different rotors in a case where multiple rotors are located side by side. Consequently, even in a case where two or more rotors are located side by side, appropriate thrust commands can be issued to the rotors, allowing them to be controlled with high accuracy without the need for switches connected to the multiple coils.

[0067] In the second embodiment, the operation and its effects were described in the case of using the control device 1' and the drive device 2A, which are shown in the Fig. 5 are shown. However, operation is also possible using the control device 1" and the drive device 2A, which are shown in the Fig. Figure 6 shows the effects achieved in the second embodiment. Furthermore, operation using the control device 1''' and the drive device 2A''', which are shown in the Fig. Figure 7 shows the effects achieved in the second embodiment. Third embodiment.

[0068] A third embodiment describes a method for generating a modified shear coefficient distribution K"A(x) which is used when the conveying system 10 according to the third embodiment calculates the current commands Iref".

[0069] First, the modified shear coefficient distribution K'A(x) described in the first embodiment only needs to be a waveform obtained by truncating a portion of the actual shear coefficient distribution KA(x), and can therefore exhibit a higher degree of freedom in its generation. However, if the generated modified shear coefficient distribution K'A(x) is unsuitable, the rotor 4 cannot be controlled with high accuracy. The third embodiment presents a method for generating the modified shear coefficient distribution K'''A(x) that addresses this problem.

[0070] Fig. Figure 10 is a diagram to illustrate the problem in the third embodiment. In the Fig. 10 is the one in the Fig. The actual shear coefficient distribution KA(x) shown is indicated by a dashed line, and a modified shear coefficient distribution K"A(x), generated using the actual shear coefficient distribution KA(x), is indicated by a solid line. The Fig. The modified shear coefficient distribution K"A(x) shown in Figure 10 is an example of an unsuitable modified shear coefficient distribution. In the Fig. 10 represents the horizontal axis of the graph showing the waveform of the current commands Iref'', the position of the runner, and is an axis that coincides with the current command "0 (zero)." The same applies to the following drawings.

[0071] Although the in the Fig. When the modified thrust coefficient distribution K''A(x) shown in Figure 10 is generated using the actual thrust coefficient distribution KA(x), the values ​​of the thrust coefficients change discontinuously and steeply. Consequently, the current commands Iref'', generated using the modified thrust coefficient distribution K''''A(x), also change discontinuously and steeply. Furthermore, even when these current commands Iref are provided to the coils 9, the inductances of the coils 9 make it difficult to change the currents IA flowing through them steeply. As a result, the error between the currents IA flowing through the coils 9 and the current commands Iref'' increases, making it difficult to control the multiple rotors 4 with high accuracy.

[0072] Fig. Figure 11 is a diagram illustrating a modified thrust coefficient distribution used in the current command generation unit 13' of the third embodiment. The explanation here uses the control device 1' and the drive device 2A as described in the Fig. 5 or Fig. 10 are shown.

[0073] In the Fig. 11 is the one in the Fig. The actual shear coefficient distribution KA(x) shown in Figure 3 is indicated by a dashed line, and the modified shear coefficient distribution K'''A(x), which is generated using the actual shear coefficient distribution KA(x), is indicated by a solid line. The values ​​shown in the Fig. The modified shear coefficient distribution K'''A(x) shown in Figure 11 is an example of a suitable modified shear coefficient distribution.

[0074] The Fig. Figure 11 shows an example where a portion of the actual shear coefficient distribution KA(x) is truncated to be used for generation, resulting in continuous shear coefficient values. The term "continuous" used here means that the shear coefficient values ​​in the newly generated modified shear coefficient distribution K'''A(x) do not differ from the values ​​of the actual shear characteristics determined by the actual shear coefficient distribution KA(x). In the example of Fig. In sections 11 where the shear coefficient values ​​differ between the actual shear coefficient distribution KA(x) and the modified shear coefficient distribution K'''A(x), the shear coefficient values ​​in the modified shear coefficient distribution K'''A(x) are zero. This zeroing of the shear coefficient values ​​in the modified shear coefficient distribution K'''A(x) begins at the points where the actual shear coefficient distribution KA(x) intersects with zero. Consequently, the current commands Iref, generated using the modified shear coefficient distribution K'''A(x), change differently than in the case of the Fig. 10 steady and uniform. Accordingly, even when the currents flowing through the coils 9 are controlled using the current commands Iref" which are generated using the modified thrust coefficient distribution K'''A(x), the errors between the currents IA flowing through the coils 9 and the current commands Iref" can be reduced and the multiple rotors 4 can be controlled with high accuracy.

[0075] As described above, in the conveyor system and control device of the third embodiment, the current command generation unit generates the current commands using thrust coefficients with values ​​that do not deviate from the actual thrust characteristics determined by the characteristics of the multiple coils and the rotor. Consequently, the errors between the currents flowing through the coils and the current commands can be reduced, and the multiple rotors can be controlled with high accuracy.

[0076] In the third embodiment, the operation and its effect in the case of using the control device 1' and the drive device 2A, which are shown in the Fig. 5 or Fig. 10 are shown. However, operation can be carried out using the control device 1" and the drive device 2A, which are shown in the Fig. 6 are shown, or using the control device 1''' and the drive device 2A''', which are shown in the Fig. The procedures shown in section 7 can be carried out. This can provide the effects achieved in the first and second embodiments and the effect achieved in the third embodiment. Fourth embodiment.

[0077] In the first embodiment, the method for generating the current commands Iref using the modified thrust coefficient distribution K'A(x) is described. This distribution is generated using a portion of the actual thrust characteristics determined by the characteristics of the multiple coils and the rotor, and further using formula (2) above. In a fourth embodiment, a method for generating the current commands Iref''' using equations that differ from those in the first embodiment is described.

[0078] Fig. Figure 12 is a diagram illustrating the operation of a control device 1'''' according to the fourth embodiment. In the Fig. 12 is the one in the Fig. The current command generation unit 13' shown in Figure 5 has been replaced with a current command generation unit 13''''. Fig. Figure 12 shows the same actual shear coefficient distribution KA(x) as the Fig. 3. The Fig. Figure 12 also shows a virtual conductance distribution CA(x). The horizontal axis of the graph, which shows the waveform of the virtual conductance CA(x), represents the position of the runner and is an axis that coincides with the virtual conductance "0 (zero)." Furthermore, the Fig. 12. The waveform of the current commands, which is determined from the product of the actual thrust coefficient distribution KA(x) and the virtual conductance distribution CA(x). The waveform of the current commands is a waveform that represents the relationship between the rotor position, which represents the distance with respect to the center position of rotor 4, and the current commands. The virtual conductance distribution CA(x) is a waveform that represents the relationship between the rotor position, which represents the distance with respect to the center position of rotor 4, and the virtual conductance. The virtual conductance is a correction coefficient that varies in accordance with a rotor position. Fig. 12 are parts that belong to those in the Fig. 5. Identical or equivalent references are indicated by the same reference symbols, and redundant descriptions are omitted appropriately.

[0079] Next, a method for generating the current commands Iref''' in the fourth embodiment is described. The generation method is described below using the method described in the Fig. The actual shear coefficient distribution KA(x) shown in Figure 3 is described. However, the distribution shown in the figures can also be used. Fig. 4 and Fig. The modified shear coefficient distribution K'A(x) shown in Figure 5 can be used, or the one shown in the Fig. The modified shear coefficient distribution K'''A(x) shown in 11 can be used.

[0080] The current command generation unit 13'''' generates current target values ​​as the current commands Iref''' based on the thrust commands τref and the motion detection values ​​y, which represent the motion positions or motion velocities of the runners 4, where the current target values ​​are the target values ​​of the drive currents to be supplied to the multiple coils 9. Specifically, the current command generation unit 13'''' calculates current commands Iref''''A1 to Iref''''A5, which are the target values ​​of the drive currents to be supplied to coils 9A1 to 9A5, using formula (5) below. It should be noted that the current command generation unit 13'''' calculates the current commands Iref'''' for the respective coils 9 of each coil unit 3 included in the conveyor system 10. For simplicity, the calculation of the five current commands Iref''''A1 to Iref''''A5 is described here. Iref""A1=KA1⋅CA1 / (KA12⋅CA1+KA22⋅CA2+KA32⋅CA3+KA42⋅CA4+KA52⋅CA5)×τref Iref""A2=KA2⋅CA2 / (KA12⋅CA1+KA22⋅CA2+KA32⋅CA3+KA42⋅CA4+KA52⋅CA5)×τref Iref""A3=KA3⋅CA3 / (KA12⋅CA1+KA22⋅CA2+KA32⋅CA3+KA42⋅CA4+KA52⋅CA5)×τref Iref""A4=KA4⋅CA4 / (KA12⋅CA1+KA22⋅CA2+KA32⋅CA3+KA42⋅CA4+KA52⋅CA5)×τref Iref""A5=KA5⋅CA5 / (KA12⋅CA1+KA22⋅CA2+KA32⋅CA3+KA42⋅CA4+KA52⋅CA5)×τref

[0081] In formula (5), CA1 to CA5 are virtual conductivities and coefficients introduced to fit the values ​​of the current commands Iref'''A calculated by the current command generation unit 13''''. The virtual conductivities CA1 to CA5 can be determined from the virtual conductance distribution CA(x).

[0082] It is known that the relationship between the currents flowing through coils 9A1 to 9A5 and the thrust τ generated on the rotor 4 is expressed by the formula (6) below. τ=KA1⋅IA1+KA2⋅IA2+KA2⋅IA3+KA4⋅IA4+KA5⋅IA5

[0083] Although a detailed transformation of the formula is omitted, the current commands Iref''''A1 to Iref''''A5, calculated using formula (5), when substituting τ from formula (6) into τref in formula (5), allow the thrust τ generated at rotor 4 to be the thrust command τref, which is the target value of the thrust τ, regardless of the values ​​of the virtual conductivities CA1 to CA5. That is, even when the virtual conductivities CA1 to CA5 are introduced, the thrust τ generated at rotor 4 does not deviate from the thrust command τref.

[0084] According to the equations in formula (5), if the products of the thrust coefficients KA1 to KA5 and the virtual conductivities CA1 to CA5 are zero, the current commands Iref'''A are generated, which are 0 [A]. The current commands Iref'''A, which are 0 [A], are input to the current control units 22A via the data communication units 14 and 21A. The current control units 22A control the currents flowing through the coils 9A so that they are 0 [A]. Consequently, no drive currents flow through the coils 9A, to which the current commands Iref'''A, which are 0 [A], are provided.

[0085] Conversely, if the products of the thrust coefficients KA1 to KA5 and the virtual conductivities CA1 to CA5 are not zero, current commands Iref'''A are generated that are not 0 [A]. These non-0 [A] current commands Iref'''A are input to the current control units 22A via the data communication units 14 and 21A. The current control units 22A control the currents flowing through the coils 9A so that they have values ​​other than 0 [A]. Consequently, motive currents flow through the coils 9A, to which the non-0 [A] current commands Iref'''A are provided.

[0086] From the above description it can be understood that in the case where the equations in formula (5) are used, the number of coils through which the driving currents flow can be changed at will by adjusting the values ​​of the virtual conductivities CA1 to CA5, with which the thrust coefficients KA1 to KA5 are multiplied, and the number of coils through which the driving currents flow can be reduced without connecting switches to the multiple coils 9.This means that the generation of the current commands Iref'''A such that the number of coils through which drive currents flow is reduced, using the virtual conductivities CA1 to CA5, with which the thrust coefficients KA1 to KA5 are multiplied, is the generation of the current target values ​​that are provided to the multiple coils 9, using a part of the actual thrust characteristics determined by the characteristics of the multiple coils 9 and the rotor 4.

[0087] Furthermore, by using the virtual conductivity distribution CA(x), which allows the characteristics of the changes in values ​​obtained when the shear coefficients KA1 to KA5 are each multiplied by the virtual conductivities CA1 to CA5 to have values ​​that do not differ from the values ​​of the actual shear characteristics determined by the actual shear coefficient distribution KA(x), the current commands Iref" can be generated that change continuously and uniformly.

[0088] As described above, in the conveying system and control device according to the fourth embodiment, the current command generation unit generates the target current values ​​to be supplied to the multiple coils using the modified thrust characteristics. These characteristics are derived from the actual thrust characteristics, which are determined by the characteristics of the multiple coils and the rotor, and the correction coefficient, which varies according to the rotor's position. In other words, in the conveying system and control device according to the fourth embodiment, the current command generation unit generates the target current values ​​to be supplied to the multiple coils using a portion of the actual thrust characteristics determined by the characteristics of the multiple coils and the rotor.Consequently, the errors between the currents flowing through the coils and the current commands can be reduced, and the multiple rotors can be controlled with high accuracy.

[0089] In the fourth embodiment, the operation and its effect were described in the case where the control device 1 and the drive device 2A are used, which are described in the Fig. 3 are shown. However, operation can be carried out using the control device 1' and the drive device 2A, which are shown in the Fig. 5 and Fig. 9 are shown, or the operation can be carried out using the control device 1" and the drive device 2A, which are shown in the Fig. 6 are shown, or the operation can be carried out using the control device 1''' and the drive device 2A''', which are shown in the Fig. 7 are shown. Furthermore, operation with the control device 1' and the drive device 2A, which are shown in the Fig. The experiments shown in Figure 5 are carried out using the modified shear coefficient distribution K'''A(x) described in the third embodiment. This allows the effects achieved in the first to third embodiments and the effect achieved in the fourth embodiment to be provided.

[0090] Finally, with reference to the Fig. 13 and Fig. 14 describes a hardware configuration for implementing the functions of the control devices 1 to 1'''' and the drive devices 2A to 2H described above. Fig. Figure 13 is a block diagram showing an example of a hardware configuration implementing the functions of the control devices 1 to 1'''' and the drive devices 2A to 2H in the first to fourth embodiments. Fig. Figure 14 is a block diagram showing another example of a hardware configuration implementing the functions of the control devices 1 to 1'''' and the drive devices 2A to 2H in the first to fourth embodiments.

[0091] In the case where some or all of the functions of the control devices 1 to 1'''' and the drive devices 2A to 2H are implemented in the first to fourth embodiments, as in the Fig. As shown in Figure 13, a configuration can be used which includes a processor 300 that performs arithmetic operations, a memory 302 that stores a program to be read by the processor 300, and a communication circuit 304 that sends and receives signals.

[0092] The processor 300 is an example of an arithmetic mean. The processor 300 can be an arithmetic mean that is referred to as a microprocessor, a microcomputer, a central processing unit (CPU), or a digital signal processor (DSP). The memory 302 can be, for example, non-volatile or volatile semiconductor memory, such as random-access memory (RAM), read-only memory (ROM), flash memory, erasable programmable ROM (EPROM), or electrically erasable programmable ROM (EEPROM) (registered trademark), or magnetic storage, a floppy disk, optical storage, a CD, a MiniDisc, or a DVD (Digital Versatile Disc).

[0093] Memory 302 stores a program for executing the functions of the control devices 1 to 1'''' and the drive devices 2A to 2H in the first to fourth embodiments. Processor 300 sends and receives necessary information via communication circuit 304. Processor 300 executes the program stored in memory 302. Processor 300 refers to a table stored in memory 302. Consequently, the processing described above can be carried out. The results of the arithmetic operations performed by processor 300 can be stored in memory 302.

[0094] In the case where some of the functions of the control devices 1 to 1'''' and the drive devices 2A to 2H are implemented in the first to fourth embodiments, a Fig.The processing circuit 303 shown in Figure 14 can be used. The processing circuit 303 corresponds to a single circuit, a combined circuit, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a combination thereof. Information to be inputted to the processing circuit 303 and information to be output by the processing circuit 303 can be received or given via the communication circuit 304.

[0095] Part of the processing in the control devices 1 to 1'''' and the drive devices 2A to 2H can be carried out by the processing circuit 303, and the processing that is not carried out by the processing circuit 303 can be carried out by the processor 300 and the memory 302.

[0096] The configurations described in the above embodiments are an example and can be combined with other prior art. The embodiments can be combined with one another. The configurations can be partially omitted or modified without deviating from the underlying concept. Reference symbol list 1, 1', 1'', 1'''', 1'''' Control device; 2, 2A to 2H Drive device; 3, 3A to 3H coil unit; 4, 4A to 4C runners; 5.5A to 5C measuring rail head; 6, 6A, 6B straight measuring rail; 7 Data communication line; 7A, 7B Communication line; 8. Funding path; 9, 9A1 to 9A5, 9B1, 9B2 coil; 10 Conveyor system; 11 Movement target value generation unit; 12, 25A''' Position and speed control unit; 13, 13', 13'', 13'''', 26A''' Current command generation unit; 14, 21A, 21B data communication unit; 15, 15'', 15''' Thrust command generation unit; 17A, 17B Arrow; 20A, 20B drive unit; 22A, 22A1 to 22A5 power control unit; 23A, 23A1 to 23A5 current detector; 24A, 24B Detector communication unit; 40 permanent magnets; 300 processor; 302 storage locations; 303 Processing circuit; 304 Communication circuit. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2017 - 79 569

[0005] JP 2017 - 79 569 A

[0005]

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