Conveying system

Abstract

A conveying system (1) includes: a plurality of conveying path units (11A-11H) constituting a conveying path (10) for a conveying body to move, each of which includes a plurality of drive units that generate thrust for moving the conveying body by flowing current; and a controller (12) including a current command generator that generates current commands for controlling current flowing through the plurality of drive units. The plurality of conveying path units (11A-11H) each control the current flowing through the plurality of drive units in accordance with the current commands. The current command generator generates a current command that sets all of the plurality of drive units of each conveying path unit (11A-11H) as the target of current control in each control cycle when generating the current command.

Description

Technical Field

[0001] The present invention relates to a conveying system for conveying objects. Background Art

[0002] Conveyor systems for transporting workpieces are commonly used in production lines that incorporate factory automation, such as those used to assemble industrial products or package food. In recent years, conveyor systems have become increasingly common. These systems divide the workpiece transport path into multiple sections, with a cart carrying the workpieces driven by control devices located in each section. This conveyor system is known as one of the most efficient conveyor systems.

[0003] Patent document 1 discloses a conveying system using a linear motor. The conveying system disclosed in Patent document 1 includes: a trolley having a magnet; and a plurality of coil units arranged in a conveying path. Each coil unit has a plurality of coils. The conveying system disclosed in Patent document 1 generates a thrust for moving the trolley by the interaction between the current flowing in the coil and the magnetic field generated by the magnet. According to Patent document 1, a switch is connected to each coil unit, and the supply of current to the coil and the interruption of the current flowing to the coil are switched by opening and closing the switch. The conveying system disclosed in Patent document 1 detects the position of the trolley in the conveying path and selects a coil unit that is in a position where it can apply thrust to the trolley. The conveying system disclosed in Patent document 1 supplies current to the selected coil unit by closing the switch, and interrupts the current to the coil units other than the selected coil unit by opening the switch.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-79569 Summary of the Invention

[0005] In the conveying system disclosed in Patent Document 1, a switch is provided independently of the current controller that controls the current flowing to the coil. The conveying system disclosed in Patent Document 1 requires a switch, and the circuit structure becomes correspondingly complex. In addition, in the conveying system disclosed in Patent Document 1, it is necessary to generate and output an opening and closing instruction for controlling the switch independently of the current instruction input to the current controller. According to the technology of Patent Document 1, since the opening and closing instruction is generated and output independently of the current instruction, the processing for controlling the conveying system becomes complicated. As described above, the conveying system disclosed in Patent Document 1 has the following problems: the circuit structure becomes complicated, and the processing for controlling the conveying system becomes complicated.

[0006] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a conveying system that can simplify the circuit configuration and realize control by simple processing.

[0007] To address the aforementioned issues and achieve the objectives, the conveying system of the present invention comprises: a plurality of conveying path units forming a conveying path for moving a conveying body, each of which includes a plurality of drive units that generate thrust for moving the conveying body by flowing current; and a controller including a current command generator that generates current commands for controlling the current flowing through the plurality of drive units. Each of the plurality of conveying path units controls the current flowing through each of the plurality of drive units in accordance with the current commands. The current command generator generates a current command for each control cycle in which all of the plurality of drive units in each conveying path unit are subject to current control.

[0008] Effects of the Invention

[0009] The transport system according to the present invention has the effect of simplifying the circuit configuration and enabling control by simple processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a diagram showing a configuration example of a transportation system according to the first embodiment.

[0011] Figure 2 This is a diagram showing a configuration example of a transport path unit included in the transport system according to the first embodiment.

[0012] Figure 3 This is a diagram showing a configuration example of a track controller included in the transport system according to the first embodiment.

[0013] Figure 4 This is a flowchart showing a processing procedure performed by the current command generator of the transmission system according to the first embodiment.

[0014] Figure 5 This is a diagram showing an example of the relationship between the position of the vehicle and the thrust constant of the coil in the first embodiment.

[0015] Figure 6 This is a diagram showing an example of calculation results of current commands obtained by the transmission system according to the first embodiment.

[0016] Figure 7 This is a diagram showing a configuration example of a transport path unit included in a transport system according to a second embodiment.

[0017] Figure 8 This is a diagram showing an example of a thrust command used when generating a current command for each coil in the conveying system according to the second embodiment.

[0018] Figure 9This is a diagram showing a configuration example of a track controller included in a transportation system according to a third embodiment.

[0019] Figure 10 This is a diagram showing a configuration example of a learning device included in a transportation system according to a third embodiment.

[0020] Figure 11 This is a flowchart showing the processing procedure of the learning device included in the transportation system according to the third embodiment.

[0021] Figure 12 This is a diagram showing a configuration example of a vehicle position controller included in a conveying system according to a third embodiment.

[0022] Figure 13 This is a flowchart showing the processing procedure of the vehicle position controller included in the conveying system according to the third embodiment.

[0023] Figure 14 This is a diagram showing a configuration example of a control circuit according to the first to third embodiments.

[0024] Figure 15 This is a diagram showing a configuration example of a dedicated hardware circuit according to the first to third embodiments. DETAILED DESCRIPTION

[0025] Hereinafter, the transportation system according to the embodiment will be described in detail with reference to the drawings.

[0026] Implementation method 1.

[0027] Figure 1 1 is a diagram showing a configuration example of a conveyance system 1 according to Embodiment 1. The conveyance system 1 is a system used when conveying an object. In Embodiment 1, the conveyance system 1 conveys the object by moving a conveyance body on which the object is placed.

[0028] The conveyor system 1 includes multiple conveyor path units 11A-11H, a controller 12, a direct current (DC) power supply 13, and carriages 17A, 17B, and 17C. The controller 12 controls the multiple conveyor path units 11A-11H. The controller 12 includes a motion controller 19 and a track controller 20. In the following description, the conveyor path units 11A-11H are not distinguished from each other and are referred to as conveyor path units 11.

[0029] Multiple conveyor path units 11 are connected to form a conveyor path 10 along which a conveyor moves. These conveyor path units 11 impart power to the conveyor, thereby moving it. The conveyor elements are referred to as carts 17A, 17B, and 17C. In the following description, carts 17A, 17B, and 17C are not distinguished from one another and are referred to as carts 17.

[0030] Figure 1 The conveying path 10 shown is annular. Figure 1 The transport path 10 shown is a closed path. The transport path 10 of the transport system 1 may also be an open path. In other words, the transport path 10 of the transport system 1 may be a path having a starting point and an end point.

[0031] Conveyor path units 11A, 11B, 11E, and 11F are linear conveyor path units 11 that form a straight path. Conveyor path units 11C, 11D, 11G, and 11H are curved conveyor path units 11 that form a curved path, changing the direction of travel of the conveyed object. Conveyor path 10 may not include linear conveyor path units 11, but may consist solely of curved conveyor path units 11. The overall shape of conveyor path 10 may be arbitrary.

[0032] The trolley 17 is installed on the side of the conveying path 10. The trolley 17 moves along the guide rail provided on the side of the conveying path 10. The trolley 17 moves on the side of the conveying path 10 and stops on the side of the conveying path 10. The conveying system 1 involved in Embodiment 1 is a moving magnet type linear motor. The trolley 17 can move along the guide rail provided on the upper surface of the conveying path 10. The trolley 17 has a permanent magnet constituting a movable part, a permanent magnet for a linear scale, and a guide roller that moves on the guide rail by rotating. Figure 1 In the figure, the guide rail, the guide roller, the permanent magnet constituting the movable member, and the permanent magnet for the linear scale are omitted.

[0033] The traveling direction of each vehicle 17 is Figure 1 In the clockwise direction or Figure 1 The counterclockwise direction of the direction. Figure 1 Set the clockwise direction in the direction of travel to the positive direction. Figure 1 The counterclockwise direction in FIG is defined as the reverse direction. Arrow 18A indicates the positive direction. Arrow 18B indicates the reverse direction.

[0034] exist Figure 1In the example shown, the conveyor system 1 includes eight conveyor path units 11 and three carts 17. The number of conveyor path units 11 included in the conveyor system 1 is arbitrary. In other words, the number of conveyor path units 11 that constitute the conveyor path 10 is arbitrary. The conveyor system 1 may simply include a plurality of conveyor path units 11. The number of carts 17 that move along the conveyor path 10 is arbitrary. The conveyor system 1 may simply include one or more carts 17.

[0035] The conveying system 1 is not limited to systems with linear motors and may also be a system with rotary motors. The conveying system 1 may be a belt conveyor having a rotary motor and a conveyor belt rotated by the rotary motor. The belt conveyor moves workpieces placed on the conveyor belt. The conveying system 1 may be a roller conveyor having multiple rollers and a rotary motor that rotates the rollers. The roller conveyor moves workpieces placed on the rollers.

[0036] The DC power supply 13 is connected to each transport path unit 11 via a DC power bus 16. The DC power supply 13 is a power supply device or a power supply circuit that outputs a DC voltage. The DC power supply 13 supplies power to each transport path unit 11. Each transport path unit 11 shares the DC power supply 13.

[0037] The positive-side DC bus and the negative-side DC bus pass through the DC power supply bus 16. The positive-side DC bus is called the P bus. The negative-side DC bus is called the N bus. The P bus is connected to the positive terminal of the DC power supply 13. The N bus is connected to the negative terminal of the DC power supply 13. Hereinafter, when referring specifically to both the P bus and the N bus, they will be referred to as the PN bus. The multiple conveyor path units 11 that constitute the conveyor path 10 are each connected to the common PN bus.

[0038] The conveying system 1 has a structure in which each conveying path unit 11 is connected to a DC power supply 13 by a multi-branch connection. The connection method between each conveying path unit 11 and the DC power supply 13 is not limited to a multi-branch connection, and a daisy chain connection may also be used. Figure 1 In the example shown, the transport system 1 includes one DC power supply 13 , but the transport system 1 may include multiple DC power supplies 13 . That is, the transport system 1 may include multiple power supply domains.

[0039] The track controller 20 is connected to each conveying path unit 11 via a data communication line 15. The data communication line 15 is composed of a line connecting the track controller 20 and one of the multiple conveying path units 11, namely the conveying path unit 11A, and a line connecting the conveying path units 11 adjacent to each other. The conveying system 1 has a structure in which each conveying path unit 11 is connected to the track controller 20 by a daisy chain connection. The connection method of each conveying path unit 11 and the track controller 20 is not limited to a daisy chain connection. The connection method of each conveying path unit 11 and the track controller 20 may also be a star connection in which each conveying path unit 11 is connected to the track controller 20 via a communication hub. Alternatively, the conveying system 1 may have a plurality of data communication lines 15, and each conveying path unit 11 and the track controller 20 may be directly connected via the data communication line 15.

[0040] The motion controller 19 is connected to the track controller 20 via the data communication line 14. The motion controller 19 periodically generates a position command indicating a position to move the vehicle 17. The motion controller 19 transmits the generated position command to the track controller 20. Details of the track controller 20 will be described later.

[0041] Figure 1 The transport system 1 shown has one motion controller 19 and one track controller 20. The transport system 1 has two or more track controllers 20, each of which can be connected to the motion controller 19. One or two or more transport path units 11 are connected to each track controller 20. The communication protocol between the motion controller 19 and the track controller 20 and the communication protocol between the track controller 20 and the transport path unit 11 can be the same or different.

[0042] A control device higher in level than the controller 12, such as a programmable logic controller, can be connected to the motion controller 19. This control device outputs instructions for sequence control to the motion controller 19. A human-machine interface can also be connected to the motion controller 19. This human-machine interface receives input from the operator. Furthermore, this human-machine interface outputs information indicating the status of the conveying system 1 through a display or the like. The motion controller 19 can obtain operating information of the trolley 17 from the higher-level control device or human-machine interface and generate position commands based on this operating information. The operating information is information indicating the schedule for the movement of each of the multiple trolleys 17 in the conveying path 10.

[0043] Next, the structure of the transport path unit 11 will be described. This description will use a linear transport path unit 11 as an example. The arrangement of the coils in the curved transport path unit 11 differs from that in the linear transport path unit 11. Aside from this difference in coil arrangement, the structure of the curved transport path unit 11 is identical to that of the linear transport path unit 11.

[0044] Figure 2 1 is a diagram showing a configuration example of the transport path unit 11 included in the transport system 1 according to the first embodiment. Figure 2 1 and 2 show permanent magnets 30 and 31 included in the transport path unit 11 and the carriage 17. The permanent magnet 30 is a permanent magnet constituting a movable element, and the permanent magnet 31 is a permanent magnet for a linear scale.

[0045] The conveyance path unit 11 includes multiple coils 21a-21i. In the following description, coils 21a-21i are not distinguished individually and are referred to as coils 21. Each coil 21 functions as a drive unit that generates thrust by flowing current. Each coil 21 generates electromagnetic force, which serves as thrust, through the interaction between the current and the magnetic field generated by the permanent magnet 30.

[0046] exist Figure 2 In the example shown, the conveying path unit 11 includes nine coils 21. The number of coils 21 included in the conveying path unit 11 is arbitrary. In a linear conveying path unit 11, the coils 21 are arranged in a straight line. In a curved conveying path unit 11, the coils 21 are arranged in a curved line.

[0047] The inverter circuit 22 is connected to each coil 21 of the transmission path unit 11. The inverter circuit 22 includes a switching element and supplies power to the coil 21 after power conversion by turning the switching element on and off. The switching element is not shown in the figure. The inverter circuit 22 controls the current flowing through the coil 21. The inverter circuit 22 is a single-phase full-bridge inverter circuit or a single-phase half-bridge inverter circuit. The inverter circuit 22 can be a three-phase inverter circuit connected to the three coils 21. Each coil 21 of the transmission path unit 11 contains not only a pure inductance component but also coil resistance.

[0048] Each inverter circuit 22 of the transmission path unit 11 is connected between the P bus and the N bus. Each inverter circuit 22 converts DC power from the PN bus into AC power and supplies the AC power to the coil 21. The inverter circuit 22 performs power conversion from DC power to AC power by turning on and off the switching element.

[0049] The coils 21 are supplied with power converted by the inverter circuit 22, thereby generating thrust, or electromagnetic force, that moves the carriage 17. Current sensors 23 are connected to each coil 21 of the conveyance path unit 11. The current sensors 23 detect the actual coil current value, or the current flowing through the coils 21. Furthermore, within the conveyance path unit 11, a capacitor 24, an electrolytic capacitor, is connected between the P bus and the N bus.

[0050] A current controller 25, which controls the inverter circuit 22, is connected to each inverter circuit 22 of the conveyance path unit 11. The current controller 25 calculates the voltage value applied to the coil 21 based on the current command value for the current flowing through the coil 21 and the actual coil current value detected by the current sensor 23. The current controller 25 transmits a pulse width modulation (PWM) signal to the inverter circuit 22, obtained by comparing the calculated voltage value with a triangular wave. The current controller 25 switches the inverter circuit 22 on and off by transmitting the PWM signal to the inverter circuit 22. This allows the current controller 25 to apply a voltage to the coil 21 sufficient to cause a desired current value to flow through the coil 21. The current controller 25 can calculate the voltage value applied to the coil 21 by performing PID (Proportional Integral Differential) control of the voltage applied to the coil 21 based on the deviation between the current command value and the actual coil current value.

[0051] The arrangement interval of the plurality of coils 21 in the traveling direction of the vehicle 17 is represented by L. coil . L coil It can be said that it is the distance between the center positions of the coils 21 adjacent to each other in the transport path unit 11. carrier L is the length of the trolley 17 in the direction of travel of the trolley 17. coil L carrier Thus, each vehicle 17 can obtain thrust through the interaction of magnetic fluxes generated by two or more coils 21 .

[0052] The length of the permanent magnet 30 in the traveling direction of the carriage 17 is represented by L. magnet . L magnet It is the length from one end of the permanent magnet 30 to the other end of the permanent magnet 30 in the direction of travel of the trolley 17. Figure 2 As shown, when N poles and S poles are alternately arranged, L magnet It is the length of the entire permanent magnet 30 in the direction of travel of the carriage 17, which includes all the magnetic poles. magnet The length of the space is also included.

[0053] L magnet L carrier Short. Due to L magnet L carrier The short length ensures space between the permanent magnet 30 of one cart 17 and the permanent magnet 30 of the other cart 17 when the two carts 17 approach each other. Ensuring space between the permanent magnet 30 of one cart 17 and the permanent magnet 30 of the other cart 17 prevents the permanent magnet 30 of one cart 17 and the permanent magnet 30 of the other cart 17 from being located above a single coil 21. The permanent magnet 30 located above a single coil 21 is the permanent magnet 30 of a single cart 17, allowing the calculation of the current command for generating magnetic flux through a single coil 21 to be performed for a single cart 17. In contrast, if the calculation of the current command for generating magnetic flux through a single coil 21 needs to be performed for both carts 17, the calculation of the current command becomes complicated.

[0054] According to the first embodiment, in the conveying system 1, L magnet L carrier By shortening the current command for generating magnetic flux in one coil 21, the calculation of the current command can be made into the calculation for one vehicle 17. Therefore, the transport system 1 can prevent the calculation of the current command from becoming complicated.

[0055] The conveyor path unit 11 includes a linear scale 26, a processor 28, and a communication slave station 29. The linear scale 26 is a detection unit that detects the position of the carriage 17 on the conveyor path unit 11. The conveyor path 10 is formed by connecting multiple conveyor path units 11, and the linear scale 26 is provided on the conveyor path 10. The processor 28 is a CPU (Central Processing Unit). The processor 28 may also be an arithmetic device, a processing device, a microprocessor, a microcomputer, or a DSP (Digital Signal Processor).

[0056] The linear scale 26 has a plurality of position sensors 27. Each position sensor 27 is a sensor that detects a magnetic field, such as a Hall sensor or a magnetoresistive sensor. Each position sensor 27 detects the magnetic field of the permanent magnet 30 or the magnetic field of the permanent magnet 31. Here, the position sensor 27 is a Hall sensor equipped with two Hall elements. The interval between the two Hall elements is an interval equivalent to half the magnetic pole pitch of the permanent magnet 31. Each Hall element converts the magnetic field into an electrical signal and outputs the electrical signal. The electrical signal output by each Hall element changes as the trolley 17 moves. The waveform of the electrical signal output by one Hall element becomes a sin wave. The waveform of the electrical signal output by the other Hall element becomes a cos wave.

[0057] The electrical signals from each position sensor 27 of the linear scale 26 are input to the processor 28. The AD (Analog to Digital) converter in the processor 28 detects the sin wave and the cos wave. The processor 28 calculates arctan based on the information of the sin wave and the cos wave, thereby detecting the position of the trolley 17 relative to the position sensor 27. Thus, the processor 28 obtains the position sensor information indicating the relative position of the trolley 17 relative to the position sensor 27. In addition, Figure 2 In FIG. 1 , illustration of communication lines for electrical signals between each position sensor 27 and the processor 28 is omitted.

[0058] The communication slave station 29 is a communication slave station on the transport path unit 11 side. The data communication line 15 is connected to the communication slave station 29. When each transport path unit 11 and the track controller 20 are connected via a daisy chain, the communication slave station 29 is configured to connect the two wires that constitute the data communication line 15. The communication slave station 29 receives current commands from the track controller 20, indicating command values ​​for the current flowing through each of the multiple coils 21 included in the transport path unit 11. The communication slave station 29 transmits the current commands to each of the multiple current controllers 25 in the transport path unit 11. As a result, the transport path unit 11 controls the current flowing through each of the multiple coils 21 according to the current commands.

[0059] The communication slave station 29 acquires the position sensor information from the processor 28 , and transmits the acquired position sensor information to the track controller 20 .

[0060] The communication slave station 29 receives the current command in a constant cycle and performs periodic communication to transmit the position sensor information. Alternatively, the communication slave station 29 may receive the current command and transmit the position sensor information aperiodically instead of performing the periodic communication.

[0061] As described above, the transport path unit 11 mainly controls the energization of the coil 21 and acquires position sensor information. The plurality of transport path units 11 constituting the transport path 10 similarly controls the energization of the coil 21 and similarly acquires position sensor information.

[0062] Next, the structure of the track controller 20 will be described. Figure 3 This figure shows a configuration example of the track controller 20 included in the conveying system 1 according to Embodiment 1. The track controller 20 includes a vehicle position controller 41 , a current command generator 42 , a position information generator 43 , a communication slave station 44 , and a communication master station 45 .

[0063] The communication slave station 44 is a communication slave station on the track controller 20 side. The communication slave station 44 receives position commands from the motion controller 19. In the first embodiment, the communication slave station 44 receives position commands for the carriages 17A, 17B, and 17C of the conveyance path unit 11. The communication slave station 44 receives position commands for each carriage 17 of the conveyance path unit 11 and outputs the received position commands to the carriage position controller 41.

[0064] The communication master station 45 is the communication master station on the track controller 20 side. The communication master station 45 receives position sensor information from the communication slave stations 29 of each conveyor path unit 11. In other words, the communication master station 45 receives position sensor information acquired by the processor 28 of each conveyor path unit 11. The communication master station 45 outputs the received position sensor information to the position information generator 43.

[0065] The position information generator 43 obtains position sensor information from each conveyance path unit 11 and calculates the position of each carriage 17 based on the obtained position sensor information. The position information generator 43 generates position information indicating the actual position of the carriage 17 in the conveyance path 10. In the first embodiment, the position information generator 43 generates position information indicating the actual position of the carriages 17A, 17B, and 17C in the conveyance path 10. The position information generator 43 generates position information for each carriage 17 in the conveyance system 1 and outputs the generated position information to the carriage position controller 41 and the current command generator 42.

[0066] The trolley position controller 41 obtains a position command and position information for each trolley 17. The trolley position controller 41 generates a thrust command for each trolley 17 based on the difference between the position command and the position information. In the first embodiment, the trolley position controller 41 generates a thrust command for trolley 17A based on the difference between the position command for trolley 17A and the position information for trolley 17A. The trolley position controller 41 generates a thrust command for trolley 17B based on the difference between the position command for trolley 17B and the position information for trolley 17B. The trolley position controller 41 generates a thrust command for trolley 17C based on the difference between the position command for trolley 17C and the position information for trolley 17C. The trolley position controller 41 outputs the generated thrust command to the current command generator 42.

[0067] The current command generator 42 obtains thrust commands and position information for each trolley 17. Based on the thrust commands and position information, the current command generator 42 generates current commands for controlling the currents flowing through the multiple coils 21. For each control cycle in which the track controller 20 generates current commands, the current command generator 42 generates current commands for all of the multiple coils 21 in each transport path unit 11. The term "control cycle" here refers to the period from the generation of the trolley 17 position information by the position information generator 43 to the generation of current commands for the coils 21 in each transport path unit 11 by the current command generator 42. That is, the current command generator 42 of the first embodiment generates current commands for all of the multiple coils 21 in each transport path unit 11 for each control cycle. The current command generator 42 outputs the generated current commands to the communication master station 45. The communication master station 45 transmits the current commands to the communication slave stations 29 of the transport path units 11. In the following description, a group of current instructions for each of the plurality of coils 21 included in the transport path unit 11 is referred to as a current instruction bundle. The communication master station 45 transmits the current instruction bundle to the communication slave stations 29 of each transport path unit 11 .

[0068] The current command generated by the current command generator 42 includes a current command for setting the current flowing through the coil 21 to zero. Generating a current command for setting all of the multiple coils 21 in each transport path unit 11 to be the subject of current control includes setting the current command value for at least one of the multiple coils 21 to zero.

[0069] Next, the details of the processing performed by the current command generator 42 will be described. Figure 4 1 is a flowchart showing the processing procedure performed by the current command generator 42 of the conveying system 1 according to the first embodiment. Figure 4 , the sequence of processing executed by the current command generator 42 for each control cycle is shown.

[0070] In step S1, the current command generator 42 generates the current command beam I based on the thrust command of the vehicle 17A and the position information of the vehicle 17A. cmdA Calculation is performed. Current command beam I cmdA The current command generator 42 generates a current command bundle I which is a set of current commands for all coils 21 of each transport path unit 11. cmdA .

[0071] In step S2, the current command generator 42 generates the current command beam I based on the thrust command of the vehicle 17B and the position information of the vehicle 17B. cmdB Calculation is performed. Current command beam I cmdB The current command generator 42 generates a current command bundle I which is a collection of current commands for all coils 21 of each transport path unit 11. cmdB .

[0072] In step S3, the current command generator 42 generates the current command beam I based on the thrust command of the vehicle 17C and the position information of the vehicle 17C. cmdC Calculation is performed. Current command beam I cmdC The current command generator 42 generates a current command bundle I which is a collection of current commands for all coils 21 of each transport path unit 11. cmdC .

[0073] In step S4, the current command generator 42 uses the current command bundle I calculated in steps S1 to S3 to generate the current command bundle I cmdA , I cmdB , I cmdC , calculates the current command for each coil 21 of each conveying path unit 11. The current command generator 42 generates each current command bundle I cmdA , I cmdB , I cmdC The current instructions for the same coils 21 are added together, thereby making the current instruction I for each coil 21 of each conveying path unit 11 tot As described above, the current command generator 42 obtains a current command for each vehicle 17 for each coil 21 , and generates a current command for each coil 21 by adding the current commands for each vehicle 17 for each coil 21 .

[0074] The current command generator 42 generates a current command I for all the coils 21 of each transport path unit 11. tot The current command bundle I cmd Current command beam I cmd This is a set of current instructions for generating thrust to move all the carts 17A, 17B, and 17C of the transport system 1. The current instruction generator 42 outputs the generated current instruction bundle I cmd The above is the end of the current instruction generator 42. Figure 4 The current command generator 42 repeats the process for each control cycle. Figure 4 The processes involved are shown in the order shown.

[0075] Here, the current instruction bundle I implemented by the current instruction generator 42 is cmdA , I cmdB , I cmdC In the following description, the current instruction for each coil 21 of each conveying path unit 11 for generating the thrust for moving the trolley 17A is denoted as “I cmdA _Aa". "I cmdA "Aa" in "_Aa" indicates a current command for the coil 21a of the transport path unit 11A. Regarding each coil 21 other than the coil 21a of the transport path unit 11A, the current command for each coil 21 is also labeled in the same manner as in the case of the coil 21a of the transport path unit 11A.

[0076] Figure 5 : is a diagram showing an example of the relationship between the position of the carriage 17 and the thrust constant of the coil 21 in the first embodiment. Figure 5 The graph in FIG shows the relationship between the distance x based on the center position of the coil 21 in the direction of travel of the trolley 17 and the thrust constant k(x) of the coil 21. The thrust constant k(x) represents the ratio of the thrust received by the trolley 17 to the current flowing through the coil 21. Figure 5 In the equation, the vertical axis represents the thrust constant k(x), and the horizontal axis represents the distance x. Figure 5 In , the unit of the thrust constant k(x) becomes N / A. Figure 5 In the following description, the center position of the coil 21 is assumed to be the center position of the coil 21 in the direction of travel of the vehicle 17. The center position of the vehicle 17 is assumed to be the center position of the vehicle 17 in the direction of travel of the vehicle 17.

[0077] exist Figure 5 For reference, the diagram shows the case where the front end of the carriage 17 in its travel direction is aligned with the center position of the coil 21. As the center position of the carriage 17 approaches the center position of the coil 21, a large thrust can be generated with a small current, depending on the relationship between the position of the coil 21 and the phase of the permanent magnet 30. The magnitude of the thrust varies depending on the relationship between the position of the coil 21 and the phase of the permanent magnet 30.

[0078] The length L from the front end of the trolley 17 to the center of the trolley 17 is carrier / 2, the thrust constant becomes zero when the distance x from the center position of the coil 21 to the center position of the carriage 17 is longer than L. carrier / 2 long, even if the current flows through the coil 21, no thrust can be applied to the trolley 17. Figure 5 The graph shown is an example. The relationship between the position of the carriage 17 and the thrust constant of the coil 21 changes depending on the arrangement of the permanent magnets 30 .

[0079] In the following description, the thrust constant k(x) for each coil 21 of each conveyance path unit 11 is denoted as "kAa(x)." The "Aa" in "kAa(x)" indicates the thrust constant k(x) for coil 21a of conveyance path unit 11A. The thrust constant k(x) for each coil 21 other than coil 21a of conveyance path unit 11A is also denoted using the same principles as for coil 21a of conveyance path unit 11A.

[0080] In the following description, the center position of each coil 21 in each transport path unit 11 is indicated as "pAa." The "Aa" in "pAa" indicates the center position of coil 21a in transport path unit 11A. The center position of each coil 21 other than coil 21a in transport path unit 11A is also indicated using the same principles as for coil 21a in transport path unit 11A.

[0081] The current command I for each coil 21 of each transport path unit 11 for generating a thrust to move the carriage 17A is cmdA _Aa、I cmdA _Ab、···、I cmdA _Hh, I cmdA _Hi is expressed by the following formula: τA represents the thrust command τ of the cart 17A. xA represents the distance x from the center position of the coil 21 to the center position of the cart 17A, and represents the actual position of the cart 17A relative to the coil 21.

[0082] I cmdA _Aa=kAa(xA-pAa)×τA / {kAa(xA-pAa) 2 +kAb(xA-pAb) 2 +···+kHh(xA-pHh) 2 +kHi(xA-pHi) 2}

[0083] I cmdA _Ab=kAb(xA-pAb)×τA / {kAa(xA-pAa) 2 +kAb(xA-pAb) 2 +···+kHh(xA-pHh) 2 +kHi(xA-pHi) 2}

[0084] ···

[0085] I cmdA _Hh=kHh(xA-pHh)×τA / {kAa(xA-pAa) 2 +kAb(xA-pAb) 2 +···+kHh(xA-pHh) 2 +kHi(xA-pHi) 2}

[0086] I cmdA _Hi=kHi(xA-pHi)×τA / {kAa(xA-pAa) 2 +kAb(xA-pAb) 2 +···+kHh(xA-pHh) 2 +kHi(xA-pHi) 2}

[0087] Generally speaking, when a thrust command τ and a thrust constant k(x) are given, there are countless sets of current commands for each coil 21 that realize the given thrust command τ. The current command I obtained by the above formula is cmdA _Aa、I cmdA _Ab、···、I cmdA _Hh, I cmdA The group of _Hi is the group that minimizes the sum of the squares of the currents flowing through the coil 21. That is, according to the above formula, the current command I that can minimize the copper loss of the coil 21 is obtained. cmdA _Aa、I cmdA _Ab、···、I cmdA _Hh, I cmdA _Hi.

[0088] The current command generator 42 generates each current command I cmdA _Aa、I cmdA _Ab、···、I cmdA _Hh, I cmdA _Hi is collected, thereby generating a current instruction bundle I related to the trolley 17A cmdA .

[0089] The current instruction generator 42 generates a current instruction bundle I related to the vehicle 17B. cmdB and the current command beam I associated with the trolley 17C cmdC , also with respect to the current instruction beam I of the trolley 17A cmdA The same calculation is performed for the case of Figure 4 In the sequence shown, the current command beam I cmdA , current command beam I cmdBand current command beam I cmdC The calculation is performed in the order of the current instruction bundle I cmdA , I cmdB , I cmdC The order of calculation is arbitrary.

[0090] Next, the current command I for each coil 21 of each transport path unit 11 for generating a thrust to move the carriages 17A, 17B, and 17C will be described. tot An example of a method for performing calculations. The current instruction generator 42 uses the current instruction bundle I cmdA , I cmdB , I cmdC , the current instruction I for each coil 21 of each conveying path unit 11 tot In the following description, the current command I for each coil 21 of each conveying path unit 11 is tot Marked as "I tot _Aa". "I tot "Aa" in "_Aa" indicates a current instruction I for the coil 21a of the transport path unit 11A. tot Regarding each coil 21 other than the coil 21a of the transport path unit 11A, the current instruction I for each coil 21 is also set in the same manner as in the case of the coil 21a of the transport path unit 11A. tot Mark.

[0091] The current instruction I for each coil 21 of each conveying path unit 11 is set to tot _Aa、I tot _Ab、···、I tot _Hh, I tot _Hi is expressed by the following formula.

[0092] I tot _Aa=I cmdA _Aa+I cmdB _Aa+I cmdC _Aa

[0093] I tot _Ab=I cmdA _Ab+I cmdB _Ab+I cmdC _Ab

[0094] ···

[0095] I tot _Hh=I cmdA _Hh+I cmdB _Hh+I cmdC _Hh

[0096] I tot _Hi=I cmdA _Hi+I cmdB _Hi+I cmdC _Hi

[0097] Figure 6 : is a diagram showing an example of the calculation result of the current instruction obtained by the transmission system 1 according to the first embodiment. Figure 6 The current command I obtained by the above calculation method is shown in FIG. tot _Aa、I tot _Ab、···、I tot _Hh, I tot Example of calculation result of _Hi.

[0098] like Figure 5 As shown, the distance x from the center position of the coil 21 to the center position of the carriage 17 is L carrier When the thrust constant k(x) is approximately zero, the current flowing in the coil 21 hardly contributes to the thrust of the vehicle 17. cmdA When Aa is a value other than zero, I cmdB _Aa、I cmdC _Aa each becomes approximately zero, and in fact I tot _Aa=I cmdA As described above, each coil 21 can apply thrust to substantially one vehicle 17 , and it can be said that one coil 21 does not apply thrust to two or more vehicles 17 at the same time.

[0099] In addition, the conveying system 1 is Figure 1 In the state shown, for example, there is no distance x greater than L in the transport path unit 11B. carrier / 2 short coil 21. If one of the coils 21 included in the transport path unit 11B, namely the coil 21d, is used as an example, the current command I tot _Bd is calculated in the following way.

[0100] I tot _Bd

[0101] =I cmdA _Bd+I cmdB _Bd+I cmdC _Bd

[0102] =0×τA / {kAa(xA-pAa) 2 +kAb(xA-pAb) 2 +···+kHh(xA-pHh) 2 +kHi(xA-pHi)2}

[0103] +0×τB / {kAa(xA-pAa) 2 +kAb(xA-pAb) 2 +···+kHh(xA-pHh) 2 +kHi(xA-pHi) 2}

[0104] +0×τC / {kAa(xA-pAa) 2 +kAb(xA-pAb) 2 +···+kHh(xA-pHh) 2 +kHi(xA-pHi) 2}

[0105] =0

[0106] As mentioned above, in the absence of distance x greater than L carrier In the case of a coil 21 that is shorter than 1 / 2, the current command value for the coil 21 is calculated to be zero. That is, the current command generator 42 generates a current command that sets the current command value to zero for the coil 21 at a position other than the position where thrust can be applied to the vehicle 17.

[0107] As described above, the current command generator 42 generates the current commands I 21a, 21b, ..., 21i for all the coils 21a, 21b, ..., 21i of the transport path units 11A, 11B, ..., 11H. tot _Aa、I tot _Ab、···、I tot _Hh, I tot The current command generator 42 generates a current command for making all of the plurality of coils 21 of each transport path unit 11 the target of current control in all control cycles when controlling the plurality of transport path units 11 .

[0108] The current command generator 42 generates the current command I tot _Aa、I tot _Ab、···、I tot _Hh, I tot _Hi is the current instruction bundle I cmd The current instruction generator 42 generates the current instruction bundle I cmd Output to the communication master station 45. For example, the communication master station 45 outputs the current instruction beam I cmd The current command I tot _Aa、I tot _Ab、···、I tot_Ai is sent to the communication slave station 29 of the transport path unit 11A. The communication master station 45 sends the current instruction bundle I cmd The current command I tot _Ha, I tot _Hb、···、I tot _Hi is transmitted to the communication slave station 29 of the transport path unit 11H. As described above, the communication master station 45 transmits the current command to the communication slave station 29 of each transport path unit 11.

[0109] According to the first embodiment, the current command generator 42 of the conveying system 1 generates a current command for each of the multiple coils 21 of each conveying path unit 11 during each control cycle when controlling the multiple conveying path units 11. The conveying system 1 issues current commands to all coils 21, including coils 21 in positions capable of applying thrust to the carriage 17 and coils 21 in positions other than those capable of applying thrust to the carriage 17. The conveying system 1 eliminates the need for switches to switch between supplying and shutting off current to the coils 21, simplifying the circuit configuration. Furthermore, the conveying system 1 eliminates the need for generating and outputting on / off commands to the switches in addition to the current commands, enabling control using a simple program.

[0110] When selecting a coil 21 to be supplied with current from among the multiple coils 21 in each transport path unit 11, a current command is calculated only for the selected coil 21. In contrast, in the first embodiment, the current command generator 42 uniformly generates current commands for all coils 21 in each transport path unit 11. This eliminates the need for selecting coils 21 and calculating current commands only for the selected coils 21. This allows the transport system 1 to control each transport path unit 11 using a simple procedure.

[0111] The current command generator 42 generates current commands that set the current command value to zero for the coils 21 at locations other than those where thrust can be applied to the cart 17. Even if induced currents are generated in the coils 21 at locations other than those where thrust can be applied to the cart 17, the conveyance system 1 can still adjust the current to zero by canceling out the induced currents. This eliminates the need for processing based on the presence or absence of the cart 17 at locations where thrust can be applied, simplifying the processing sequence.

[0112] As described above, the transport system 1 has the effect of being able to simplify the circuit configuration and realize control by simple processing.

[0113] Implementation method 2.

[0114] In the first embodiment, the current command generator 42 determines a current command associated with each cart 17 for each coil 21, and adds the current commands associated with each cart 17 for each coil 21 to generate a current command associated with each coil 21. In the second embodiment, the current command generator 42 selects one cart 17 closest to the coil 21 among the plurality of carts 17, determines a current command to impart thrust to the selected cart 17, and generates a current command associated with each coil 21. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description will focus on the components that differ from the first embodiment.

[0115] Figure 7 1 is a diagram showing a configuration example of the transport path unit 11 included in the transport system 1 according to the second embodiment. Figure 7 FIG shows a part of the structure of the transport path unit 11 and two carriages 17A and 17B. Figure 7 FIG. 1 shows a case where two carts 17A and 17B are present in one of the plurality of conveying path units 11 of the conveying system 1, namely, the conveying path unit 11A. Figure 7 As shown, in addition to the case where two carriages 17 exist in one conveyance path unit 11 , there are also cases where one carriage 17 exists in one conveyance path unit 11 and where no carriage 17 exists in one conveyance path unit 11 .

[0116] exist Figure 7 In the state shown, the trolley 17 that is closest to the center of the coil 21a in the direction of travel of the trolley 17 is the trolley 17A. The current command generator 42 uses the thrust command τ related to the trolley 17A, i.e., τA, and the distance x related to the trolley 17A, i.e., xA, to generate the current command I for the coil 21a of the conveying path unit 11A using the following formula. tot _Aa is calculated.

[0117] Itot_Aa

[0118] =I cmdA _Aa

[0119] =kAa(xA-pAa)×τA / {kAa(xA-pAa) 2 +kAb(xA-pAb) 2 +···+kHh(xA-pHh) 2 +kHi(xA-pHi) 2}

[0120] In with Figure 7In the case where the situation shown is different, if the carriage 17 is present at a position far from the center position of the coil 21a, Figure 5 The relationship shown holds that kAa(xA−pAa)=0. In this case, the coil 21 a does not generate a thrust that can be applied to the vehicle 17 .

[0121] exist Figure 7 In the state shown, for example, the trolley 17 that is closest to the center position of the coil 21e in the direction of travel of the trolley 17 is the trolley 17B. The current command generator 42 uses the thrust command τ related to the trolley 17B, i.e., τB, and the distance x related to the trolley 17B, i.e., xB, to generate the current command I for the coil 21e of the conveying path unit 11A using the following formula. tot _Ae is calculated.

[0122] I tot _Ae

[0123] =I cmdA _Ae

[0124] =kAe(xB-pAe)×τB / {kAa(xB-pAa) 2 +kAb(xB-pAb) 2 +···+kHh(xB-pHh) 2 +kHi(xB-pHi) 2}

[0125] exist Figure 7 In the state shown, for example, the trolley 17 that is closest to the center of the coil 21d in the direction of travel of the trolley 17 is the trolley 17A. The current command generator 42 uses the thrust command τ related to the trolley 17A, i.e., τA, and the distance x related to the trolley 17A, i.e., xA, to generate the current command I for the coil 21d of the conveying path unit 11A using the following formula. tot _Ad performs calculations.

[0126] I tot _Ad

[0127] =I cmdA _Ad

[0128] =kAd(xA-pAd)×τA / {kAa(xA-pAa) 2 +kAb(xA-pAb) 2 +···+kHh(xA-pHh) 2 +kHi(xA-pHi) 2}

[0129] exist Figure 7In the state shown, a portion of the carriage 17B still exists on the coil 21d. However, the distance x from the center position of the coil 21d to the center position of the carriage 17 is longer than the distance from the front end of the carriage 17B to the center position of the carriage 17B. Figure 5 The relationship shown in FIG. 1 shows that the thrust constant of the thrust that the coil 21d can apply to the trolley 17B is substantially zero. The magnetic flux generated by the coil 21d hardly contributes to the movement of the trolley 17B, so the current command I based on τA and xA related to the trolley 17A can be cmdA _Ad is directly set as the current instruction I for the coil 21d tot _Ad.

[0130] Figure 8 : is a diagram showing an example of a thrust command used when generating a current command for each coil 21 in the conveying system 1 according to the second embodiment. Figure 8 About Figure 7 The illustrated state of each coil 21a-21i shows cart 17 closest to the center of coil 21 and the thrust command τ used when generating the current command. Regarding coils 21a-21d, cart 17 closest to the center of coil 21 is cart 17A. The thrust command τ used when generating the current command for each coil 21a-21d is τA. Regarding coils 21e-21i, cart 17 closest to the center of coil 21 is cart 17B. The thrust command τ used when generating the current command for each coil 21e-21i is τB.

[0131] As described above, the current command generator 42 selects one of the multiple carts 17 closest to the coil 21 for each coil 21, calculates a current command to impart thrust to the selected cart 17, and thereby generates a current command for each coil 21. Similar to the current command for each coil 21 of the transport path unit 11A, the current command generator 42 also calculates the current command for each coil 21 of each transport path unit 11B-11H.

[0132] The current command generator 42 generates a current command bundle I which is a collection of current commands for the coils 21 of the transport path units 11. cmd The current instruction generator 42 generates the current instruction bundle I cmd Output to the communication master station 45. For example, the communication master station 45 outputs the current instruction beam I cmd The current command I tot _Aa、I tot _Ab、···、I tot_Ai is sent to the communication slave station 29 of the transport path unit 11A. The communication master station 45 sends the current instruction bundle I cmd The current command I tot _Ha, I tot _Hb、···、I tot _Hi is transmitted to the communication slave station 29 of the transport path unit 11H. As described above, the communication master station 45 transmits the current command to the communication slave station 29 of each transport path unit 11.

[0133] According to the second embodiment, the current command generator 42 of the transport system 1 generates a current command for each control cycle when controlling the plurality of transport path units 11, targeting all of the plurality of coils 21 of each transport path unit 11 for current control. This simplifies the circuit configuration of the transport system 1 and enables control using simple processing.

[0134] Furthermore, the current command generator 42 selects one of the multiple carts 17 closest to the coil 21 for each coil 21 and calculates a current command for imparting thrust to the selected cart 17. Since the current command generator 42 calculates the current command corresponding to the selected cart 17 for each coil 21, the amount of calculation can be reduced compared to calculating the current command corresponding to each of the multiple carts 17 for each coil 21. Consequently, the conveying system 1 can reduce the amount of calculation required for control.

[0135] Implementation method 3.

[0136] In the third embodiment, a thrust command is corrected based on a thrust command correction value, and an example of applying machine learning to the calculation of the thrust command correction value is described. In the third embodiment, the same reference numerals are assigned to the same components as in the first or second embodiment, and the description will focus on the components that differ from the first or second embodiment.

[0137] In each conveyor path unit 11, the coils 21 are arranged at regular intervals. However, the continuity of the arrangement of the coils 21 is interrupted at the connection points between conveyor path units 11 within the conveyor path 10. Therefore, a cogging torque different from the cogging torque generated between the coils 21 within each conveyor path unit 11 is generated at the connection points between conveyor path units 11, causing the cogging torque to fluctuate. Since the conveyor path units 11 are often assembled by the user, assembly errors between conveyor path units 11 are prone to occur. Therefore, it is difficult to pre-determine a correction value for correcting the cogging torque at the connection points between conveyor path units 11. In actual situations, when the correction value is determined after the conveyor path 10 is assembled, the cogging torque at the connection points between conveyor path units 11 must be measured with high precision, which increases the time required to assemble the conveyor path 10.

[0138] In the third embodiment, the thrust command correction value calculated by machine learning is calculated to correct the thrust command, thereby achieving highly accurate correction of the cogging torque and reducing the man-hours required for assembling the conveyor path 10. In the third embodiment, the thrust command correction value is used to correct the thrust command.

[0139] Figure 9 This figure shows an example configuration of a track controller 50 included in the conveying system 1 according to Embodiment 3. The track controller 50 includes a current command generator 42, a position information generator 43, a communication slave station 44, a communication master station 45, a vehicle position controller 51, a learning device 52, and a trained model storage unit 53.

[0140] The trolley position controller 51 obtains a position command and position information for each trolley 17 . Based on the difference between the position command and the position information, the trolley position controller 51 generates a thrust command for each trolley 17 . Furthermore, the trolley position controller 51 obtains a trained model from the trained model storage unit 53 and calculates a thrust command correction value based on the trained model and the position information for each trolley 17 . The trolley position controller 51 uses the thrust command correction value to correct the thrust command and outputs the corrected thrust command to the current command generator 42 .

[0141] The learning device 52 acquires position information and thrust command correction values ​​for each vehicle 17. The learning device 52 learns thrust command correction values ​​that enable highly accurate correction of cogging torque. The learning device 52 outputs a trained model as a result of the learning. The trained model storage unit 53 stores the trained model.

[0142] Figure 10This figure shows an example of the structure of the learning device 52 included in the conveying system 1 according to Embodiment 3. The learning device 52 includes a data acquisition unit 61 and a model generation unit 62. The data acquisition unit 61 acquires learning data and creates a data set that combines the learning data. The learning data is the position information and thrust command correction value of each trolley 17. In other words, the data acquisition unit 61 acquires learning data including the position information and the thrust command correction value. The data acquisition unit 61 acquires the position information from the position information generator 43. The data acquisition unit 61 acquires the thrust command correction value from the trolley position controller 51.

[0143] The model generation unit 62 generates a trained model using the learning data. Based on the learning data, the model generation unit 62 generates a trained model for use in estimating the thrust command correction value from the position information. The model generation unit 62 outputs the generated trained model. The trained model is stored in the trained model storage unit 53. Alternatively, the model generation unit 62 can read a previously generated trained model from the trained model storage unit 53 and update the trained model by relearning it using the learning data.

[0144] As the learning algorithm used by the model generation unit 62, well-known algorithms such as teacher learning, teacherless learning or reinforcement learning can be used. As an example, the case of applying reinforcement learning in the learning algorithm used by the model generation unit 62 is described. Reinforcement learning is an intelligent agent, i.e., an action subject, in a certain environment observing the current state and deciding the action to be taken. The intelligent agent obtains rewards from the environment by selecting actions, and learns the countermeasures that obtain the most rewards through a series of actions. As representative methods of reinforcement learning, Q-learning and TD-learning are known. For example, in the case of Q-learning, the general update formula of the action value function Q(s, a), i.e., the action value table, is expressed by the following formula (1). The action value function Q(s, a) represents the value of the action of selecting action "a" based on the environment "s", i.e., the action value Q.

[0145] [Formula 1]

[0146] Q(s t ,a t )←Q(s t ,a t )+α(r t+1 +γmax a Q(s t+1 ,a t )-Q(s t ,a t )) ...(1)

[0147] In formula (1), “s t " represents the environment at time "t". t " indicates the action at time "t". t ", the environment becomes "s t+1 ". "r t+1 " represents the reward brought by the change of its environment. "γ" represents the discount rate. "α" represents the learning coefficient. In the third embodiment, the position information is the environment "s t ”. In addition, the thrust command correction value is the action “a t ”.

[0148] The update formula expressed by equation (1) states that if the action value of the best action "a" at time "t+1" is greater than the action value Q of action "a" performed at time "t," then action value Q is increased; otherwise, action value Q is decreased. In other words, the action value function Q(s, a) is updated so that the action value Q of action "a" at time "t" approaches the best action value at time "t+1." Thus, the best action value in a given environment is propagated to the action value in the previous environment.

[0149] The model generation unit 62 includes a reward calculation unit 63 and a function update unit 64. The reward calculation unit 63 calculates rewards based on the data set. The function update unit 64 updates the function for determining the thrust command correction value according to the rewards calculated by the reward calculation unit 63.

[0150] Specifically, the reward calculation unit 63 calculates the reward "r" based on the degree of fluctuation of the speed of the trolley 17. The degree of fluctuation of the speed of the trolley 17 is obtained, for example, based on the position information of the trolley 17. For example, when the degree of fluctuation of the speed of the trolley 17 becomes smaller, the reward calculation unit 63 increases the reward "r". The reward calculation unit 63 assigns a value of "1" to the reward, thereby increasing the reward "r". In addition, the value of the reward is not limited to "1". On the other hand, when the degree of fluctuation of the speed of the trolley 17 becomes larger, the reward calculation unit 63 decreases the reward "r". The reward calculation unit 63 assigns a value of "-1" to the reward, thereby decreasing the reward "r". In addition, the value of the reward is not limited to "-1".

[0151] The function updating unit 64 updates the function used as a model to determine the thrust command correction value according to the reward calculated by the reward calculating unit 63. The function can be updated according to the data set, for example, by updating the action value table. The action value table is a data set that associates any action with its action value and stores it in the form of a table. For example, in the case of Q learning, the action value function Q(s) represented by the above formula (1) is updated.t , a t ) is used as a function for determining the thrust command correction value.

[0152] Figure 11 3 is a flowchart showing the processing procedure of the learning device 52 included in the transportation system 1 according to the third embodiment. Figure 11 Flowchart of , illustrating the reinforcement learning method for updating the action-value function Q(s, a).

[0153] In step S11, the learning device 52 acquires the position information and thrust command correction value of each vehicle 17 through the data acquisition unit 61. In other words, the learning device 52 acquires learning data. The data acquisition unit 61 outputs a data set obtained by integrating the learning data to the model generation unit 62.

[0154] In step S12, the learning device 52 calculates a reward using the reward calculation unit 63. The reward calculation unit 63 calculates a reward for a combination of the position information of each vehicle 17 and the thrust command correction value associated with each vehicle 17. The reward calculation unit 63 increases or decreases the reward based on the degree of fluctuation in the speed of the vehicle 17.

[0155] In step S13, the learning device 52 updates the action value function through the function updating unit 64. The function updating unit 64 updates the action value function Q(s, a) based on the reward calculated in step S12. The learning device 52 updates the action value function Q(s, a) stored in the trained model storage unit 53. t , a t ) to update.

[0156] In step S14, the learning device 52 determines whether the action-value function Q(s, a) has converged via the function updating unit 64. The function updating unit 64 determines that the action-value function Q(s, a) has converged by not updating the action-value function Q(s, a) in step S13.

[0157] If it is determined that the action value function Q(s, a) does not converge (step S14, No), the learning device 52 returns the sequence to step S11. On the other hand, if it is determined that the action value function Q(s, a) converges (step S14, Yes), the learning device 52 ends the process. Figure 11 The processing involved in the sequence shown. Alternatively, the learning device 52 may not perform the judgment in step S14 but instead return from step S13 to step S11 to continue learning. The trained model storage unit 53 stores the generated action-value function Q(s, a), i.e., the trained model.

[0158] In the third embodiment, reinforcement learning is applied to the learning algorithm used by the learning device 52. However, learning algorithms other than reinforcement learning may also be applied to the learning algorithm. The learning device 52 can perform machine learning using a well-known learning algorithm other than reinforcement learning, such as deep learning, neural networks, genetic programming, inductive logic programming, or support vector machines.

[0159] Figure 9 and Figure 10 The learning device 52 shown is a device built into the track controller 50. The learning device 52 may also be a device external to the track controller 50. The learning device 52, which is a device external to the track controller 50, constitutes the conveyor system 1. The learning device 52 may be a device that can be connected to the track controller 50 via a network. The learning device 52 may also be a device that exists on a cloud server.

[0160] The learning device 52 can learn the relationship between position information and thrust command correction values ​​based on a data set created for multiple conveyor systems 1. The learning device 52 can obtain learning data from multiple conveyor systems 1 used in the same location, or it can also obtain learning data from multiple conveyor systems 1 used in different locations. Learning data can also be collected from multiple conveyor systems 1 operating independently of each other in multiple locations. After the collection of learning data from multiple conveyor systems 1 is started, a new conveyor system 1 can be added to the objects from which the learning data is collected. In addition, after the collection of learning data from multiple conveyor systems 1 is started, some of the multiple conveyor systems 1 can be excluded from the objects from which the learning data is collected.

[0161] The learning device 52 that has learned about a particular transport system 1 can also learn about other transport systems 1 besides the transport system 1. The learning device 52 that has learned about the other transport system 1 can update the trained model by relearning about the other transport system 1.

[0162] Figure 12 This figure shows an example configuration of the vehicle position controller 51 included in the conveying system 1 according to Embodiment 3. The vehicle position controller 51 includes a thrust command generator 71, a thrust command corrector 72, a data acquisition unit 73, and an estimation unit 74. The data acquisition unit 73 and the estimation unit 74 function as an estimation device that estimates a thrust command correction value based on the position information of each vehicle 17.

[0163] The thrust command generator 71 obtains the position command for each vehicle 17 and the position information for each vehicle 17. The thrust command generator 71 generates a thrust command for each vehicle 17 based on the difference between the position command for each vehicle 17 and the position information for each vehicle 17. The thrust command generator 71 outputs the generated thrust command to the thrust command correction unit 72.

[0164] The data acquisition unit 73 acquires inference data. The inference data is position information for each of the multiple vehicles 17 included in the conveying system 1. The data acquisition unit 73 acquires the position information from the position information generator 43. The inference unit 74 reads the trained model generated by the learning device 52 from the trained model storage unit 53. The inference unit 74 inputs the inference data into the trained model, thereby inferring the thrust command correction value. The inference unit 74 outputs the thrust command correction value, which is the inference result, to the thrust command correction unit 72. The thrust command correction unit 72 uses the thrust command correction value to correct the thrust command for each vehicle 17. The thrust command correction unit 72 outputs the corrected thrust command.

[0165] Figure 13 This is a flowchart showing the processing procedure of the vehicle position controller 51 included in the conveying system 1 according to Embodiment 3. The vehicle position controller 51 obtains the position command and position information of each vehicle 17 via the thrust command generator 71. The thrust command generator 71 generates a thrust command for each vehicle 17 based on the position command and position information.

[0166] In step S21, the vehicle position controller 51 acquires the position information of each vehicle 17 via the data acquisition unit 73. The data acquisition unit 73 outputs the acquired position information to the estimation unit 74. In step S22, the vehicle position controller 51 inputs the position information into the trained model via the estimation unit 74, thereby generating a thrust command correction value. The estimation unit 74 outputs the generated thrust command correction value to the thrust command correction unit 72.

[0167] In step S23, the trolley position controller 51 corrects the thrust command using the thrust command correction value through the thrust command correction unit 72. In step S24, the trolley position controller 51 outputs the thrust command corrected by the thrust command correction unit 72. Figure 13 The current command generator 42 generates a current command based on the thrust command obtained by the vehicle position controller 51 and the position information of each vehicle 17 .

[0168] According to the third embodiment, the conveying system 1 uses the learning device 52 to learn a thrust command correction value that enables highly accurate correction of cogging torque. The conveying system 1 uses the carriage position controller 51, which includes a data acquisition unit 73 and an estimation unit 74, to estimate the thrust command correction value that enables highly accurate correction of cogging torque. The conveying system 1 corrects the thrust command based on the estimated thrust command correction value, thereby achieving highly accurate correction of cogging torque and reducing the number of steps required to assemble the conveying path 10.

[0169] Next, the hardware that realizes the track controllers 20 and 50 according to Embodiments 1 to 3 will be described. The track controllers 20 and 50 are realized by a processing circuit. The processing circuit may be a circuit in which a processor executes software, or a dedicated circuit.

[0170] In the case where the processing circuit is implemented by software, the processing circuit is, for example, Figure 14 The control circuit shown. Figure 14 This figure shows an example configuration of a control circuit 80 according to Embodiments 1 to 3. The control circuit 80 includes an input unit 81, a processor 82, a memory 83, and an output unit 84. The input unit 81 is an interface circuit that receives data input from outside the control circuit 80 and provides it to the processor 82. The output unit 84 is an interface circuit that transmits data from the processor 82 or the memory 83 to the outside of the control circuit 80.

[0171] The processing circuit is Figure 14 In the case of the control circuit 80 shown, the track controllers 20 and 50 are implemented using software, firmware, or a combination of software and firmware. The software or firmware is described as a program and stored in a memory 83. The processing circuit has a processor 82 read out and execute the program stored in the memory 83, thereby realizing the various functions of the track controllers 20 and 50. In other words, the processing circuit includes a memory 83 for storing the program that ultimately executes the processing of the track controllers 20 and 50. Furthermore, these programs can be said to cause the computer to execute the procedures and methods of the track controllers 20 and 50.

[0172] Processor 82 is a CPU. Processor 82 may also be a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, a processor, or a DSP. Memory 83 may be, for example, a nonvolatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), or EEPROM (registered trademark) (Electrically Erasable Programmable Read Only Memory), a magnetic disk, a floppy disk, an optical disk, a compact disk, a minidisc, or a DVD (Digital Versatile Disc).

[0173] Figure 14 This is an example of hardware in which the track controllers 20 and 50 are realized by a general-purpose processor 82 and a memory 83 . However, the track controllers 20 and 50 may be realized by a dedicated hardware circuit. Figure 15 This is a diagram showing a configuration example of a dedicated hardware circuit 85 according to the first to third embodiments.

[0174] The dedicated hardware circuit 85 includes an input unit 81, an output unit 84, and a processing circuit 86. The processing circuit 86 may be 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 combination thereof. The functions of the track controllers 20 and 50 may be implemented by the processing circuit 86 according to their functional categories, or the functions may be aggregated and implemented by the processing circuit 86. Furthermore, the track controllers 20 and 50 may be implemented by combining the control circuit 80 and the hardware circuit 85.

[0175] Figure 1 The motion controller 19 shown is implemented by a processing circuit similar to the track controllers 20 and 50. The processing circuit implementing the motion controller 19 is Figure 14 The control circuit 80 shown, or Figure 15 Dedicated hardware circuit 85 is shown.

[0176] The specific manner of dispersing or combining the components of the transport system 1 according to the first to third embodiments is not limited to the manner described in the first to third embodiments. All or part of the components of the transport system 1 may be functionally or physically dispersed or combined in any unit. For example, Figure 1The controller 12 shown is not limited to being separated into the motion controller 19 and the track controller 20, and may be implemented by a single device.

[0177] The structures shown in the above embodiments illustrate an example of the content of the present invention. The structures of the embodiments can be combined with other known technologies. The structures of the embodiments can also be appropriately combined with each other. A part of the structure of the embodiments can be omitted or changed without departing from the scope of the present invention.

[0178] Description of the label

[0179] 1 conveying system, 10 conveying path, 11, 11A-11H conveying path unit, 12 controller, 13 DC power supply, 14, 15 data communication line, 16 DC power bus, 17, 17A, 17B, 17C trolley, 18A, 18B arrow, 19 motion controller, 20, 50 track controller, 21, 21a-21i coil, 22 inverter circuit, 23 current sensor, 24 capacitor, 25 current controller, 26 linear scale, 27 position sensor, 28, 82 processor, 29 , 44 communication slave site, 30, 31 permanent magnet, 41, 51 trolley position controller, 42 current command generator, 43 position information generator, 45 communication master site, 52 learning device, 53 trained model storage unit, 61, 73 data acquisition unit, 62 model generation unit, 63 feedback calculation unit, 64 function update unit, 71 thrust command generator, 72 thrust command correction unit, 74 inference unit, 80 control circuit, 81 input unit, 83 memory, 84 output unit, 85 hardware circuit, 86 processing circuit.

Claims

1. A conveying system, characterized in that: have: a plurality of conveying path units constituting a conveying path for a conveying body to move, each having a plurality of driving parts for generating a thrust for moving the conveying body by flowing current; and a controller including a current command generator for generating a current command for controlling the current flowing through the plurality of drive units; Each of the plurality of conveying path units controls the current flowing in each of the plurality of driving parts according to the current command. The current command generator generates a current command for setting all of the plurality of drive units of each of the transport path units as targets for current control in each control cycle when generating the current command. The plurality of conveying path units apply the thrust to each of the plurality of conveying bodies, thereby causing each of the plurality of conveying bodies to move. The current command generator obtains a current command related to each of the transport bodies for each of the drive units, and adds the current commands related to the transport bodies for each of the drive units to generate a current command related to each of the drive units. There are multiple conveying bodies, The conveying body is provided with a permanent magnet. The driving unit includes a coil that generates an electromagnetic force serving as the thrust due to interaction between an electric current and a magnetic field generated by the permanent magnet.

2. The conveying system according to claim 1, characterized in that The arrangement interval of the plurality of driving units in the traveling direction of the conveyor is shorter than the length of the conveyor in the traveling direction.

3. The conveying system according to claim 2, characterized in that The length of the permanent magnet in the traveling direction of the conveyor is shorter than the length of the conveyor in the traveling direction.

4. The conveying system according to any one of claims 1 to 3, characterized in that The controller generates a thrust command for the conveying body based on a position command indicating a position to move the conveying body and position information indicating a detection result of the position of the conveying body, and generates the current command based on the thrust command and the position information.

5. The conveying system according to claim 4, characterized in that have: a data acquisition unit that acquires learning data including a correction value used for correction of the thrust command and the position information; as well as a model generating unit that generates a trained model used for estimating the correction value from the position information based on the learning data, The controller corrects the thrust command based on the correction value inferred by using the trained model, The current command generator generates the current command based on the corrected thrust command and the position information.

6. The conveying system according to claim 1, characterized in that The current command generator sets a current command value for at least one of the plurality of drive units to zero.

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