Funding system

Abstract

A conveying system (1) comprises a plurality of conveying path units (11A, 11B, 11C, 11D, 11E, 11F, 11G, 11H) that form a conveying path (10) along which a conveyed body moves, the conveying path units each being connected by a common DC line. Each conveying path unit of the plurality of conveying path units (11A, 11B, 11C, 11D, 11E, 11G, 11H) comprises a drive unit that is supplied with power from the DC line in order to generate a driving force for moving the conveyed body. From one or two or more conveying path units to which the conveying body is not moved, the plurality of conveying path units (11A, 11B, 11C, 11D, 11E, 11G, 11H) at least one conveying path unit carries out a regeneration power supply to supply regeneration power generated in the plurality of conveying path units (11A, 11B, 11C, 11D, 11E, 11G, 11H) to the drive unit.

Description

Area

[0001] The present disclosure relates to a conveyor system that conveys an object. background

[0002] A conveyor system that conveys a workpiece is used in a production line that has implemented factory automation, such as a production line for assembling industrial products or a production line for packaging food products. In recent years, many conveyor systems have been used in which a conveyor path for conveying workpieces is divided into multiple zones, and a carrier on which a workpiece is placed is controlled to move by a control device arranged in each zone. Such a conveyor system is known as a conveyor system with excellent production efficiency.

[0003] Some conveyor systems use a linear motor that includes a carrier with a magnet and a conveyor path with a plurality of coils. Some conveyor systems using the linear motor control the current flowing through each coil using an inverter circuit, such as a full-bridge inverter circuit or a half-bridge inverter circuit. In such a conveyor system, it is important to appropriately process the regenerative power generated in the coils when the carrier is decelerated, either as consumption or regeneration.

[0004] Patent Literature 1 discloses a conveying system that includes a carrier having a magnetic element and a conveying path having a plurality of magnetic coil assemblies, and recovers the regeneration energy in an energy storage assembly provided at one or a plurality of points in the conveying path. Citation listPatent literature

[0005] Patent Literature 1: Disclosure of Japanese Patent Application No. 2019-170153 Overview of the inventionProblem to be solved by the invention

[0006] According to the technique disclosed in Patent Literature 1, it is necessary to install the energy storage device at each of the points in the conveying path where the carrier is decelerated. In a case where the point where the carrier is decelerated is not defined, the energy storage device must be installed at all points where the carrier can be decelerated. The more energy storage devices that need to be installed, the larger the size of the conveying system and the higher the production cost of the conveying system. Accordingly, according to the conventional technique of Patent Literature 1, there is a problem in that it is difficult to properly process the regenerative power.

[0007] The present disclosure has been made in view of the above, and it is an object thereof to obtain a conveying system capable of processing the regeneration power in an appropriate manner. Means of solving the problem

[0008] To solve the above-described problem and achieve the object, a conveying system according to the present disclosure includes a plurality of conveying path units forming a conveying path along which a conveying body moves, each of the conveying path units being connected to a common DC power line. Each conveying path unit of the plurality of conveying path units includes a drive unit to be supplied with power from the DC power line to thereby generate a driving force for moving the conveying body. Of one or two or more conveying path units to which the conveying body is not moved, at least one conveying path unit performs regenerative power supply for supplying regenerative power generated in the plurality of conveying path units. Effects of the invention

[0009] The conveying path unit according to the present disclosure achieves an effect of enabling appropriate processing of the regeneration power. Short description of the drawings Fig. 1 is a diagram showing an exemplary configuration of a conveyor system according to a first embodiment. Fig. 2 is a diagram showing an exemplary configuration of a conveyance path unit included in the conveyance system according to the first embodiment. Fig. 3 is a diagram for explaining regeneration control performed by the conveying system according to the first embodiment. Fig. 4 is a diagram for explaining an operation of each conveyance path unit included in the conveyance system according to the first embodiment. Fig. 5 is a diagram showing an exemplary embodiment of a conveyor system according to a second embodiment. Fig. 6 is a diagram for explaining an operation of each conveyance path unit included in the conveyance system according to the second embodiment. Fig. 7 is a diagram showing an exemplary configuration of the conveying path unit according to a modification of the second embodiment. Fig. 8 is a diagram showing an exemplary configuration of a controller included in the conveyor system according to a third embodiment. Fig. 9 is a diagram showing an exemplary configuration of a learning device included in the controller of the third embodiment. Fig. 10 is a flowchart showing a processing procedure of the learning device included in the controller of the third embodiment. Fig. 11 is a diagram showing an exemplary configuration of a position command generation unit included in the controller of the third embodiment. Fig. 12 is a flowchart showing a processing procedure of the position command generation unit and a coil drive command generation unit included in the controller of the third embodiment. Fig. 13 is a diagram showing an exemplary configuration of a control circuit according to the first to third embodiments. Fig. 14 is a diagram showing an exemplary configuration of a hardware circuit as a dedicated circuit according to the first to third embodiments. Description of embodiments

[0010] Hereinafter, a conveyor system according to each embodiment will be described in detail with reference to the drawings. First embodiment.

[0011] Fig. 1 is a diagram showing an exemplary configuration of a conveyor system 1 according to a first embodiment. The conveyor system 1 is a system used to convey an object. In the first embodiment, the conveyor system 1 conveys an object by moving a conveyor body on which the object is placed.

[0012] The conveyor system 1 includes a plurality of conveyor path units 11A, 11B, 11C, 11D, 11E, 11F, 11G, and 11H, a controller 12, a direct current (DC) power supply 13, and supports 16A, 16B, and 16C. In the following description, the conveyor path units 11A, 11B, 11C, 11D, 11E, 11F, 11G, and 11H are each referred to as a conveyor path unit 11 unless differentiated from each other.

[0013] The plurality of conveying path units 11 are coupled to one another and form a conveying path 10 along which the conveying body moves. The plurality of conveying path units 11 move the conveying body by applying a driving force to the conveying body. Each of the carriers 16A, 16B, and 16C is a conveying body. In the following description, the carriers 16A, 16B, and 16C are each referred to as a carrier 16 unless otherwise distinguished.

[0014] The one in the Fig. The conveying path 10 shown in Figure 1 is ring-shaped. This means that the Fig. 1 is a closed path. The conveyor path 10 of the conveyor system 1 can be an open path. This means that the conveyor path 10 of the conveyor system 1 can be a path with a starting point and an end point.

[0015] The conveying path units 11A, 11B, 11E, and 11F each constitute a linear conveying path unit 11, forming a linear path. The conveying path units 11C, 11D, 11G, and 11H each constitute a curved conveying path unit 11, forming a curved path and changing the direction of movement of the conveying body. The conveying path 10 may also include only the conveying path units 11 forming a curved path, without including the conveying path units 11 forming a linear path. Any shape can be implemented as the overall shape of the conveying path.

[0016] The carrier 16 is attached to a side surface of the conveying path 10. The carrier 16 moves along a guide rail provided on the side surface of the conveying path 10. The carrier 16 moves along the side surface of the conveying path 10 and stops on the side surface of the conveying path 10. The conveying system 1 according to the first embodiment is a linear motor with a moving magnet. The carrier 16 can move along a guide rail provided on an upper surface of the conveying path 10. The carrier 16 includes a permanent magnet constituting a moving element, a permanent magnet for a linear encoder, and a guide roller that moves by rotation on the guide rail. Fig. 1, the guide rail, the guide roller, the permanent magnet forming the moving element and the permanent magnet forming the linear encoder are not shown.

[0017] In the Fig. In the example shown in Figure 1, the conveyor system 1 comprises eight conveyor path units 11 and three carriers 16. There can be any number of conveyor path units 11 included in the conveyor system 1. This means that any number of conveyor path units 11 can form the conveyor path 10. The conveyor system 1 only needs to include a plurality of conveyor path units 11. Any number of carriers 16 can move along the conveyor path 10. The conveyor system 1 only needs to include one or a plurality of carriers 16.

[0018] The conveyor system 1 is not limited to a system including a linear motor and may be a system including a rotary motor. The conveyor system 1 may be a conveyor belt including a rotary motor and a belt rotated by the rotary motor. The conveyor belt moves a workpiece placed on the belt. The conveyor system 1 may be a roller conveyor including a plurality of rollers and a rotary motor that rotates the rollers. The roller conveyor moves a workpiece placed on the rollers.

[0019] The DC power supply 13 is connected to each conveyor path unit 11 via a DC power supply line 15. The DC power supply 13 is a power supply device or circuit that outputs a DC voltage. The DC power supply 13 supplies power to each conveyor path unit 11. The conveyor path units 11 share the DC power supply 13.

[0020] A DC line on a positive side and a DC line on a negative side run through the DC power supply line 15. The DC line on the positive side is called a P line. The DC line on the negative side is called an N line. The P line is connected to an anode of the DC power supply 13. The N line is connected to a cathode of the DC power supply 13. Hereinafter, the lines are referred to as PN lines when referring to both the P line and the N line. Each of the plurality of conveying path units 11 constituting the conveying path 10 is connected to a common DC line.

[0021] The conveyor system 1 has a configuration in which each conveyor path unit 11 is connected to the DC power supply 13 via a multi-drop connection. The connection type between the conveyor path units 11 and the DC power supply 13 is not limited to a multi-drop connection and may be a daisy-chain connection. In the Fig. In the example shown in Figure 1, the conveyor system 1 comprises one DC power supply, but the conveyor system 1 may also comprise two or more DC power supplies 13. This means that a plurality of power supply domains may be formed in the conveyor system 1.

[0022] The controller 12 is connected to each conveying path unit 11 via a data communication line 14. The controller 12 controls each of the plurality of conveying path units 11. The data communication line 14 includes a line connecting the controller 12 and the conveying path unit 11A, which is one of the plurality of conveying path units 11, and lines connecting the adjacent conveying path units 11 to each other. The conveying system 1 has a configuration in which each conveying path unit 11 is connected to the controller 12 through a daisy chain connection. A connection type between the conveying path units 11 and the controller 12 is not limited to the daisy chain connection. The connection type between the conveying path units 11 and the controller 12 may be a star connection in which each conveying path unit 11 is connected to the controller 12 via a communication interface.Alternatively, the conveyor system 1 may include a plurality of data communication lines 14, and each conveyor path unit 11 and the controller 12 may be directly connected to each other via the data communication line 14.

[0023] The controller 12 generates a position command specifying a position to which each carrier 16 is moved and generates a coil drive command based on the position command. The controller 12 outputs the coil drive command to each conveyor path unit 11. Each conveyor path unit 11 operates a coil of the conveyor path unit 11 in accordance with the coil drive command. The controller 12 controls the movement of each carrier 16 by outputting the coil drive command to each conveyor path unit 11. The coil drive command may, for example, correspond to a current command, a speed command, or a thrust command.

[0024] A direction of movement of each carrier 16 is a clockwise direction in the Fig. 1 or a counterclockwise direction in the Fig. 1. Of the directions of movement, the clockwise direction is in the Fig. 1 is defined as a forward direction. Of the directions of movement, the counterclockwise direction is in the Fig. 1 is defined as a reverse direction. An arrow 17A indicates the forward direction. An arrow 17B indicates the reverse direction.

[0025] A higher-level control device, such as a programmable logic controller, may be connected to the controller 12. The control device outputs a command for sequence control to the controller 12. A human-machine interface may be connected to the controller 12. The human-machine interface receives input from an operator. Furthermore, the human-machine interface outputs information indicating the state of the conveyor system 1 through a display or the like. The controller 12 may obtain operation information of the carrier 16 from the higher-level control device or the human-machine interface and generate the position command based on the operation information. The operation information is information indicating a schedule of movement of each of the plurality of carriers 16 on the conveyor path 10.

[0026] Next, a configuration of the conveying path unit 11 will be described. Here, the configuration of the conveying path unit 11 will be described using the straight conveying path unit 11 as an example. The curved conveying path unit 11 differs from the straight conveying path unit 11 in how the coils are arranged. The configuration of the curved conveying path unit 11 is similar to the configuration of the straight conveying path unit 11, except for the difference in how the coils are arranged.

[0027] The Fig. Fig. 2 is a diagram showing an exemplary embodiment of the conveying path unit 11 included in the conveying system 1 according to the first embodiment. Fig. Figure 2 shows the conveyor path unit 11 and permanent magnets 40 and 41 enclosed in the carrier 16. Permanent magnet 40 is a permanent magnet that forms a moving element. Permanent magnet 41 is a permanent magnet for a linear encoder.

[0028] The conveying path unit 11 comprises a plurality of coils 20. Each coil 20 functions as a drive unit to be supplied with power from the PN lines to thereby generate a driving force. Fig. In the example shown in Figure 2, the conveying path unit 11 includes nine coils 20. Any number of coils may be included in the conveying path unit 11. In the straight conveying path unit 11, the plurality of coils 20 are arranged in a straight line direction. In the curved conveying path unit 11, the plurality of coils 20 are arranged in a curved direction.

[0029] An inverter circuit 21 is connected to each of the coils of the conveyor path unit 11. The inverter circuit 21 includes switching elements and supplies power to the coil 20, where power conversion is performed by switching the switching elements. The switching elements are not shown. The inverter circuit 21 controls a current flowing through the coil 20. The inverter circuit 21 is a single-phase full-bridge inverter circuit or a single-phase half-bridge inverter circuit. The inverter circuit 21 may be a three-phase inverter circuit connected to three coils 20. Each of the coils 20 of the conveyor path unit 11 includes not only a pure inductance component but also a coil resistance.

[0030] Each inverter circuit 21 of the conveyor path unit 11 is connected between a P line 31, which is a positive wiring of the DC power supply line 15, and an N line 32, which is a negative wiring of the DC power supply line 15. Each inverter circuit 21 converts a direct current from the PN lines into an alternating current and supplies the alternating current to the coil 20. The inverter circuit 21 performs power conversion from a direct current power to an alternating current power by switching the switching elements.

[0031] With the power converted by the inverter circuit 21, the coil 20 generates an electromagnetic force that serves as a driving force for moving the carrier 16. A current sensor 22 is connected to each coil 20 of the conveying path unit 11. The current sensor 22 detects an actual coil current value, which is a current value of the current flowing through the coil 20. In the conveying path unit 11, a capacitor 23, which is an electrolytic capacitor, is connected between the P line 31 and the N line 32.

[0032] A current controller 24 is connected to the inverter circuit 21 and controls the inverter circuit 21. The current controller 24 calculates a voltage value to be applied to the coil 20 based on a current command value of the current flowing through the coil 20 and the actual value of the coil current detected by the current sensor 22. The current controller 24 transmits a pulse width modulation (PWM) signal obtained by comparing the calculated voltage value with a triangular waveform to the inverter circuit 21. The current controller 24 transmits the PWM signal to the inverter circuit 21, thereby causing the inverter circuit 21 to perform switching. Consequently, the current controller 24 applies a voltage to the coil 20, causing a current of a desired current value to flow through the coil 20.The current controller 24 may calculate the voltage value of the voltage to be applied to the coil 20 by performing proportional-integral-derivative (PID) control of the voltage to be applied to the coil 20 based on a deviation between the current command value and the actual current value.

[0033] The conveying path unit 11 includes a linear encoder 25, a processor 27, and a line voltage detection unit 33. The line voltage detection unit 33 detects a line voltage. The line voltage is a voltage of the PN line, which is a DC line, that is, a voltage between the P line 31 and the N line 32. The line voltage detection unit 33 outputs a detection result of the line voltage to the processor 27.

[0034] The linear encoder 25 is a detection unit for detecting a position of the carrier 16 on the conveying path unit 11. The linear encoder 25 is provided on the conveying path 10 through the plurality of conveying path units 11 that are connected to each other to form the conveying path 10. The processor 27 is a central processing unit (CPU). The processor 27 can be an arithmetic device, a processing device, a microprocessor, a microcomputer, or a digital signal processor (DSP).

[0035] The linear encoder 25 includes a plurality of position sensors 26. Each position sensor 26 is a sensor that detects a magnetic field, such as a Hall sensor or a magnetoresistive sensor. Each position sensor 26 detects a magnetic field of the permanent magnet 40 or a magnetic field of the permanent magnet 41. Here, the position sensor 26 is a Hall sensor to which two Hall elements are attached. A distance between the two Hall elements is a distance corresponding to half of a magnetic pole pitch of the permanent magnet 41. Each Hall element converts the magnetic field into an electrical signal and outputs the electrical signal. The electrical signal output from each Hall element changes with the movement of the carrier 16. The electrical signal output from one Hall element has a sine wave waveform. The electrical signal output from the other Hall element has a cosine wave waveform.

[0036] An analog-to-digital converter (ADC) included in the processor 27 detects the sine wave and the cosine wave. The processor 27 detects the position of the carrier 16 relative to the position sensor 26 by calculating the arctangent based on information about the sine wave and information about the cosine wave. Consequently, the processor 27 obtains position information indicating the position of the carrier 16.

[0037] In addition, the processor 27 obtains the detection result of the line voltage from the line voltage detection unit 33. The processor 27 controls the start of the regeneration power supply by the inverter circuit 21 and the stop of the regeneration power supply by the inverter circuit 21. The regeneration power supply will be described later.

[0038] The conveying path unit 11 includes a communication substation 28. The communication substation 28 is a communication substation located on one side of the conveying path unit 11. The data communication line 14 is connected to the communication substation 28. In a case where each conveying path unit 11 and the controller 12 are connected by a daisy chain connection, the communication substation 28 is configured to be capable of connecting two data communication lines 14. For each of the plurality of coils 20 included in the conveying path unit 11, the communication substation 28 receives from the controller 12 a current command indicating a current command value of a current to flow through the coil 20. The communication substation 28 obtains the position information obtained from the processor 27 based on an output from each of the plurality of position sensors 26 included in the linear scale 25.The communication substation 28 transmits the obtained position information to the controller 12.

[0039] For example, the communication substation 28 performs fixed-cycle communication, in which a current command is received and position information is transmitted in a fixed cycle. Instead of fixed-cycle communication, the communication substation 28 may perform the reception of the current command and the transmission of the position information aperiodically.

[0040] As described above, the conveying path unit 11 mainly has a function of performing excitation control of the coils 20 and a function of acquiring position information. All of the plurality of conveying path units 11 constituting the conveying path 10 similarly perform excitation control of the coils 20 and similarly perform position information acquisition.

[0041] Next, an operation of the conveyor system 1 is described, which is carried out by splitting the PN lines. It is assumed that the Fig. 1, for example, the carrier 16A and the carrier 16B are in a running state, such as a state of performing acceleration. In addition, it is assumed that the Fig. 1, the carrier 16C is in a regeneration state, such as a deceleration state. In such states, in a case where a regeneration power 16C is less than the sum of the running power of the carrier 16A and the running power of the carrier 16B, the regeneration power is consumed as the running power, and thus, a rise in the line voltage due to generation of the regeneration power is prevented.

[0042] On the other hand, in a case where the carrier 16A, the carrier 16B, and also the carrier 16C are in a regeneration state, the regeneration power generated in the carrier 16A, the carrier 16B, and the carrier 16C is not consumed, so the line voltage increases. Furthermore, even if one of the carriers 16A, 16B, and 16C is in the running power state and one of the carriers 16A, 16B, and 16C is in the regeneration state, and the regeneration power of the carrier 16 in the regeneration state is greater than the running power of the carrier 16 in the running power state, the line voltage increases. An excessive increase in the line voltage detrimentally affects the life of the capacitor 23 or results in damage to the capacitor 23. Accordingly, the conveyance system 1 according to the first embodiment performs regeneration control to consume regeneration power in the plurality of conveyance path units 11, as described below.

[0043] Here, the regeneration control performed by the conveyor system 1 will be described. In the conveyor system 1, one or two or more of the plurality of conveyor path units 11 to which the carrier 16 is not moved perform regeneration power supply to supply the coils 20 with regeneration power generated in the plurality of conveyor path units 11. Of the plurality of conveyor path units 11, one or two or more of the conveyor path units 11 to which the carrier 16 is not moved perform the regeneration power supply when the line voltage becomes greater than or equal to a preset first voltage threshold. The first voltage threshold is a value of the line voltage that serves as a reference for starting the regeneration control. The first voltage threshold is set in advance in each conveyor path unit 11 of the conveyor system 1.

[0044] The conveying path unit 11 that executes the regenerative power supply stops the regenerative power supply when the line voltage becomes less than or equal to a second voltage threshold. The second voltage threshold is a line voltage value that serves as a reference for stopping the regeneration control. The second voltage threshold is set in advance in each conveying path unit 11 of the conveying system 1. When the carrier 16 approaches the conveying path unit 11 that executes the regenerative power supply, the conveying path unit 11 stops the execution of the regenerative power supply. As described above, the conveying path unit 11 stops the regenerative power supply when the line voltage becomes less than or equal to the second voltage threshold or when the carrier 16 approaches the conveying path unit 11.

[0045] Here, as an example, we consider a case in which the Fig. 1, the carrier 16A begins to decelerate when the carrier 16B and the carrier 16C are stopped. The carrier 16B is stopped above the conveying path unit 11C and the conveying path unit 11D. The carrier 16C is stopped above the conveying path unit 11E and the conveying path unit 11F. The carrier 16A begins to decelerate at the conveying path unit 11A.

[0046] Fig. 3 is a diagram for explaining the regeneration control performed by the conveyor system 1 according to the first embodiment. Fig. 3 shows a time chart of a speed of the carrier 16 on the conveying path unit 11 in the regeneration state, a line voltage Vpn, a regeneration power W1, and a regeneration power W2. The regeneration power W1 is a regeneration power supplied to the coils 20 of the conveying path units 11 where no carrier 16 is located. The regeneration power W2 is a regeneration power supplied to the coils 20 of the conveying path units 11 where the carriers 16 are located. The speed of the Fig. 3 is the speed of the carrier 16A. The conveying path units 11 on which the carriers 16 are located are the conveying path units 11A, 11C, 11D, 11E, and 11F. The conveying path units 11 on which no carrier 16 is located are the conveying path units 11B, 11G, and 11H.

[0047] A voltage value Von is a first voltage threshold. A voltage value Voff is a second voltage threshold. Here, the voltage values ​​Von set in the respective conveying path units 11 of the conveying system 1 are the same. The voltage values ​​Voff set in the respective conveying path units 11 of the conveying system 1 are the same.

[0048] When the carrier 16A begins to decelerate at time t1, regenerative power is generated in the coils 20 of the conveying path unit 11A. When regenerative power is generated in the coils of the conveying path unit 11A, the line voltage Vpn begins to rise from time t1. The processor 27 of each conveying path unit 11 continuously monitors a result of the detection of the line voltage Vpn by the line voltage detection unit 33.

[0049] Assume that the line voltage Vpn, as in the Fig. 3, reaches the voltage value Von at time t2. The processor 27 of each of the conveying path units 11B, 11G, and 11H, where no carrier 16 is located, starts supplying regenerative power through the inverter circuit 21. The regenerative power W1 supplied to the coils 20 of each of the conveying path units 11B, 11G, and 11H begins to increase from zero at time t2.

[0050] In a case where the inverter circuit 21 performs the regeneration power supply, the current controller 24 performs current control such that a current corresponding to the rated current of the coil 20 continues to flow through the coil 20. The current flowing through the coil 20 is converted into heat by the coil resistance. The current is converted into heat by the coil 20, and thereby the regeneration power W1 is consumed by the coil 20.

[0051] The regeneration power W1 is consumed and as a result, the line voltage Vpn gradually decreases from the voltage value Von. Assume that the line voltage Vpn, as shown in the Fig. 3, from the line voltage Von drops at time t2 and the line voltage Vpn reaches the voltage value Voff at time t3. The processor 27 of each of the conveying path units 11B, 11G and 11H stops the regeneration power supply by the inverter circuits 21. In this Fig. In the example shown in Figure 3, the regeneration power W1 begins to increase at time t2, then remains at a constant value, and begins to decrease at time t3. After that, the regeneration power W1 becomes zero.

[0052] In the conveying path units 11A, 11C, 11D, 11E and 11F, where the carriers 16 are located, a movement of the carriers 16 and a stopping of the carriers 16 are carried out. In the Fig. 3, the regeneration power W2 supplied to the coils 20 of each of the conveying path units 11A, 11C, 11D, 11E and 11F remains at zero.

[0053] Fig. Fig. 4 is a diagram for explaining an operation of each conveying path unit 11 included in the conveying system 1 according to the first embodiment. Fig. 4 shows a table summarizing the presence or absence of the carrier 16 at each conveying path unit 11 and whether the regeneration power supply of each conveying path unit 11 is to be carried out in the case of the above example. Fig. 4, "A", "B", ...., and "H" in the "Conveyance Path Unit" column represent the conveyance path unit 11A, the conveyance path unit 11B, ...., and the conveyance path unit 11H, respectively. "Yes" in the "Regeneration Power Supply" column indicates that the regeneration power supply is being performed. "No" in the "Regeneration Power Supply" column indicates that the regeneration power supply is not being performed.

[0054] In a case where the carrier 16 is not detected by the linear encoder 25, the processor 27 of the conveyor path unit 11 detects that the carrier has not moved toward the conveyor path unit 11. In a case where the carrier is detected by the linear encoder 25, the processor 27 detects that the carrier 16 has moved toward the conveyor path unit 11. As shown in the Fig. As shown in Figure 4, each of the conveying path units 11B, 11G, and 11H to which the carrier 16 is not moved performs the regeneration power supply. Each of the conveying path units 11A, 11C, 11D, 11E, and 11F to which the carrier 16 is moved does not perform the regeneration power supply.

[0055] The conveyor system 1 prevents the line voltage Vpn from excessively rising above the voltage value Von by performing regenerative power supply in the conveyor path units 11 to which the carrier 16 is not approached. When the line voltage Vpn in the conveyor path units 11 performing regenerative power supply drops to the voltage value Voff, the conveyor system 1 stops the regenerative power supply to each conveyor path unit 11. The conveyor system 1 consumes the regenerative power generated in the plurality of conveyor path units 11 through this regeneration control. The conveyor system 1 can prevent an excessive rise in the line voltage Vpn.

[0056] In the above description, the voltage values ​​Von set in the respective conveying path units 11 of the conveying system 1 are the same, but the plurality of conveying path units 11 may include conveying path units 11 in which different voltage values ​​Von are set. Any voltage value Von may be set individually for each of the plurality of conveying path units 11.

[0057] In the above description, the voltage values ​​Voff set in the respective conveying path units 11 of the conveying system 1 are the same, but the plurality of conveying path units 11 may include conveying path units 11 in which different voltage values ​​Voff are set. Any voltage value Voff may be set individually for each of the plurality of conveying path units 11.

[0058] As described above, in the conveying system 1, the first voltage threshold and / or the second voltage threshold can be individually set for each of the plurality of conveying path units 11. The conveying system 1 can freely set the first voltage threshold and / or the second voltage threshold depending on a desired regeneration power supply mode to be achieved by the conveying path unit 11.

[0059] The straight conveying path units 11 and the curved conveying path units 11 differ in the number of phases of the coils 20, the resistance values ​​of the coils 20, the size of the casing of the conveying path unit 11, or the like. Accordingly, for example, the first voltage threshold and / or the second voltage threshold can be set to different values ​​between the straight conveying path units 11 and the curved conveying path units 11. By setting the first voltage threshold and / or the second voltage threshold individually for each of the plurality of conveying path units 11, the conveying system 1 can provide a regeneration power consumption suitable for each conveying path unit 11.

[0060] In the conveying path unit 11 where the number of phases of the coils 20 is large, the first voltage threshold may be lower than in the conveying path unit 11 where the number of phases of the coils 20 is small. Consequently, the conveying system 1 may prioritize the conveying path unit 11 having the coils 20 with a large number of phases for performing the regeneration power supply. It should also be noted that the number of phases of the coils 20 is the number of coils 20 provided in one conveying path unit 11. Fig. 2 shows the conveyor path unit 11 in which the number of phases of the coils 20 is nine.

[0061] In each conveying path unit 11 of the conveying system 1, a power threshold value, which is an upper limit of the regeneration power W1 allowed for supply to each coil 20, is set in advance. Here, the power threshold values ​​set in the respective conveying path units 11 of the conveying system 1 are the same. If the power supplied to each coil 20 of the conveying path unit 11 that executes the regeneration power supply exceeds a preset power threshold value, the conveying path unit 11 stops the execution of the regeneration power supply. For example, I can be used as the power threshold value. rate 2 ×R coil be set, where I rate represents the rated current of coil 20 and R coilrepresents the coil resistance of coil 20. A value obtained from an electronics thermal protection curve of each coil 20 can be set as the power threshold. The power threshold is not limited to these values ​​and can be set to any value. By stopping the regeneration power supply in the conveying path unit 11 when the power supplied to each coil 20 exceeds the power threshold, the conveying system 1 can prevent the regeneration power from being underconsumed due to overheating of the coil 20.

[0062] In the above description, the power thresholds set in the respective conveying path units 11 of the conveying system 1 are the same, but the plurality of conveying path units 11 may include conveying path units 11 in which different power thresholds are set. Any power threshold can be individually set for each of the plurality of conveying path units 11. The conveying system 1 can freely set the power threshold based on a desired regenerative power supply mode to be achieved by the conveying path unit 11. For example, the power thresholds may be set to different values ​​between the straight conveying path units 11 and the curved conveying path units 11.If the power threshold is individually set for each of the plurality of conveying path units 11, the conveying system 1 can provide a regeneration power supply suitable for the configuration of each conveying path unit 11.

[0063] It is assumed that in conveyor system 1, for example, the Fig. 1 moves from the conveying path unit 11A to the conveying path unit 11H during deceleration. When the entire carrier 16A has moved toward the conveying path unit 11H and the carrier 16A is not located at the conveying path unit 11A, the conveying path unit 11A starts the regenerative power supply. Alternatively, the conveying path unit 11H, which did not have a carrier 16 before the carrier 16A moved toward the conveying path unit 11H, stops the regenerative power supply when the carrier 16A starts to move toward the conveying path unit 11H. As described above, the conveying path units 11A and 11H perform switching between executing the regenerative power supply and stopping the regenerative power supply in response to the movement of the carrier 16A.The conveying path units 11 other than the conveying path units 11A and 11H also perform switching between executing the regenerative power supply and stopping the regenerative power supply in response to the movement of the carriers 16B and 16C. The conveying system 1 performs switching of the conveying path units 11 that execute the regenerative power supply in response to the movement of the carrier 16, thereby consuming the regenerative power generated in the plurality of conveying path units 11 while continuing to move the carriers 16.

[0064] During regenerative power supply, the inverter circuit 21 operates at a switching frequency lower than a switching frequency set when the driving force acts on the carrier 16. In other words, among the frequencies at which the inverter circuit 21 operates, the switching frequency at which switching is performed by the inverter 21 when regenerative power supply is performed is lower than the switching frequency at which switching is performed by the inverter 21 when the driving force acts on the carrier 16. Consequently, the conveying path unit 11 can reduce noise generated when regenerative power supply is performed with switching by the inverter 21.

[0065] According to the first embodiment, in the conveying system 1, one or two or more conveying path units to which the conveying body is not moved perform the regeneration power supply among the plurality of conveying path units 11. The conveying system 1 can consume the regeneration power even if a point at which the conveying body is decelerated is uncertain. Consequently, the conveying system 1 achieves an effect of enabling appropriate processing of the regeneration energy. Second embodiment.

[0066] In a second embodiment, an example will be described in which, among the conveying path units 11 where no carrier 16 is located, the conveying path units 11 adjacent to the conveying path units 11 where the carriers 16 are located are excluded from the conveying path units 11 that perform the regenerative power supply. In the second embodiment, when the carrier 16 moving at a certain conveying path unit 11 moves toward the adjacent conveying path unit 11 in one communication cycle, the carrier 16 can be moved smoothly. The communication cycle is a cycle of communication between the controller 12 and the conveying path units 11. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and configurations different from those in the first embodiment will be mainly described.

[0067] Fig. Fig. 5 is a diagram showing an exemplary configuration of a conveyor system 2 according to the second embodiment. In the conveyor system 2, processing by the controller 12 is different from that of the first embodiment. The configuration of the conveyor system 2 is similar to the configuration of the Fig. 1. The conveyor path units 11 each have a configuration corresponding to that shown in the Fig. 2 is similar to the configuration shown.

[0068] In the Fig. In the example shown in Figure 5, the conveyor system 2 comprises eight conveyor path units 11 and two supports 16. Any number of conveyor path units 11 can be included in the conveyor system 2. This means that any number of conveyor path units 11 can form the conveyor path 10. The conveyor system 2 only needs to comprise a plurality of conveyor path units 11. Any number of supports 16 can move along the conveyor path 10. The conveyor system 2 only needs to comprise one or a plurality of supports 16.

[0069] The communication substation 28 of each conveyor path unit 11 obtains the position information acquired by the processor 27 based on an output from each of the plurality of position sensors 26 included in the linear scale 25. The communication substation 28 transmits the acquired position information to the controller 12 via the data communication line 14.

[0070] The controller 12 receives the position information transmitted from the communication substations 28 of the conveying path units 11. The controller 12 combines the position information from the communication substations 28 of the conveying path units 11 to obtain position information indicating the position of each carrier 16 on the conveying path 10. Based on the position information indicating the position of each carrier 16 on the conveying path 10, the controller 12 determines the conveying path units 11 that should perform the regenerative power supply and the conveying path units 11 that should stop the regenerative power supply.

[0071] The plurality of conveying path units 11 includes a first conveying path unit and second conveying path units. The controller 12 excludes the first conveying path unit and the second conveying path units from the conveying path units 11 that are to perform the regenerative power supply. The plurality of conveying path units 11 includes the conveying path units other than the first conveying path unit and the second conveying path units, and the controller 12 designates these other conveying path units as the conveying path units 11 that are to perform the regenerative power supply. The first conveying path unit 11 is the conveying path unit 11 on which the carrier 16 as the conveying body is located. The second conveying path units are M conveying path units 11 and N conveying path units 11.The M conveying path units 11 are arranged in a first direction along the conveying path 10 adjacent to the first conveying path unit, and the N conveying path units 11 are arranged in a second direction adjacent to the first conveying path unit. The second direction, which is a direction along the conveying path 10, is opposite to the first direction. The first direction is a forward direction indicated by the arrow 17A. The second direction is a reverse direction indicated by the arrow 17B. Both M and N are integers of 1 or more. In the second embodiment, in the conveying path 10, one or two or more conveying path units 11 to which the carrier 16 is not moved perform the regeneration power supply.

[0072] Next, an operation of the conveyor system 2 in a case where the regeneration power supply is carried out will be described. Here, as an example, the operation of each conveyor path unit 11 in a case where the conveyor system 2 is in a state shown in the Fig. 5. If the conveyor system 2 is in the state shown in the Fig. 5, the carrier 16A is located on the conveying path unit 11A. The carrier 16B is located above the conveying path unit 11C and the conveying path unit 11D.

[0073] Fig. Fig. 6 is a diagram for explaining the operation of each conveying path unit 11 included in the conveying system 2 according to the second embodiment. The controller 12 detects the first conveying path units based on the acquired position information. Fig. In the example shown in Fig. 5, the conveying path unit 11A on which the carrier 16A is located and the conveying path units 11C and 11D on which the carrier 16B is located are the first conveying path units.

[0074] Next, the controller 12 detects the second conveyor path units based on the detected first conveyor path units. Here, M=1 and N=1 apply. In the Fig. In the example shown in Figure 5, each of the conveying path units 11B, 11E, and 11H is the second conveying path unit. The controller 12 excludes the conveying path units 11A, 11C, and 11D, which are the first conveying path units, and the conveying path units 11B, 11E, and 11H, which are the second conveying path units, from the conveying path units 11 that execute the regenerative power supply. The controller 12 transmits an instruction to stop the regenerative power supply to each of the conveying path units 11A, 11B, 11C, 11D, 11E, and 11H. The instruction to stop the regenerative power supply is, for example, a signal in which a flag indicating execution of the regenerative power supply is set to negative.

[0075] Next, the controller 12 detects, from the plurality of conveying path units 11 included in the conveying system 2, those conveying path units 11 that are different from the first conveying path units and the second conveying path units. Fig. In the example shown in FIG. 5, each of the conveying path units 11F and 11G is the conveying path unit 11 different from the first conveying path units and the second conveying path units. The controller 12 designates each of the conveying path units 11F and 11G as the conveying path unit 11 that executes the regenerative power supply. The controller 12 transmits an instruction to execute the regenerative power supply to each of the conveying path units 11F and 11G. The instruction to execute the regenerative power supply is, for example, a signal in which the flag indicating the execution of the regenerative power supply is set to positive.

[0076] The communication substation 28 of each of the conveying path units 11A, 11B, 11C, 11D, 11E, and 11H receives the instruction to stop the regeneration power supply sent from the controller 12. Each of the conveying path units 11A, 11B, 11C, 11D, 11E, and 11H enters a state where it does not perform the regeneration power supply in accordance with the instruction to stop the regeneration power supply. Each of the conveying path units 11C, 11D, 11E, and 11H performs a normal operation for applying a driving force to the carrier 16.

[0077] The communication substation 28 of each of the conveying path units 11F and 11G receives the instruction to execute the regenerative power supply sent from the controller 12. Each of the conveying path units 11F and 11G executes the regenerative power supply in accordance with the instruction to execute the regenerative power supply.

[0078] M, which is defined as the number of second conveying path units arranged adjacent to the first conveying path unit in the first direction, and N, which is defined as the number of second conveying path units arranged adjacent to the first conveying path unit in the second direction, are set in advance. M and / or N can be calculated based on the speed of the carrier 16 on the conveying path 10.

[0079] Here, an example of a method for calculating M and N based on the speed of the carrier 16 on the conveying path 10 is described. Here, a path length of the conveying path unit 11 is denoted by L, a maximum speed of the carrier 16 is denoted by Vmax, and a communication cycle of the communication between the controller 12 and the conveying path unit 11 is denoted by Tcyc. Both M and N are obtained by rounding up the decimal places of L / (Vmax×Tcyc).

[0080] As described above, in the second embodiment, the conveyor system 2 excludes not only the first conveyor path units where the carrier 16 is located, but also the second conveyor path units adjacent to the first conveyor path units from the conveyor path units 11 that perform the regenerative power supply. When the carrier 16 moving on the first conveyor path unit moves toward the adjacent second conveyor path unit, the carrier 16 moves toward the second conveyor path unit that performs the normal operation of applying the driving force to the carrier 16. Consequently, in the conveyor system 2, no carrier moves toward the conveyor path unit 11 that performs the regenerative power supply in the communication cycle, whereby the carrier 16 can be smoothly moved in a portion where the conveyor path units 11 are adjacent to each other.

[0081] In the above description, M and N are integers of 1 or more, however, M and / or N may be zero. That is, the second conveying path units only need to be at least one of the following: one or two or more conveying path units 11 arranged adjacent to the first conveying path unit in the first direction, and one or two or more conveying path units 11 arranged adjacent to the first conveying path unit in the second direction. The conveying system 2 can perform switching of M and N between zero and an integer of 1 or more for each communication cycle based on the moving direction of the carriers 16 for each communication cycle.

[0082] The controller 12 may exclude, among the plurality of conveying path units 11, the first conveying path unit as the conveying path unit 11 where the conveying body is located, and the second conveying path unit as one or two or more of the conveying path units 11 located adjacent to the first conveying path unit in the conveying path 10 moving direction of the conveying body from the conveying path units 11 that perform the regenerative power supply. The second conveying path unit, located adjacent to and downstream of the first conveying path unit in the moving direction, performs the normal operation of applying the driving force to the carrier 16. The conveying system 2 can smoothly move the carrier 16 in a section where the conveying path units 11 are adjacent to each other. In this case, the number of second conveying path units may be calculated based on the speed of the carrier 16 on the conveying path 10.

[0083] According to the second embodiment, the conveyor system 2 excludes the first conveyor path unit and the second conveyor path units from the conveyor path units 11 that perform the regenerative power supply, thereby performing the normal operation of applying the driving force to the carrier 16 in the first conveyor path unit and the second conveyor path units. Consequently, the conveyor system 2 can smoothly move the carrier 16. In addition, the conveyor system 2 performs the regenerative power supply in the conveyor path units 11 other than the first conveyor path unit and the second conveyor path units among the plurality of conveyor path units 11. Consequently, the conveyor system 2 can appropriately process the regenerative power.

[0084] Fig. 7 is a diagram showing an exemplary configuration of the conveying path unit 11 according to a modification of the second embodiment. The conveying path unit 11 according to the modification of the second embodiment includes a temperature sensor 34. The controller 12 determines the conveying path unit 11 to perform the regeneration power supply based on a temperature detection result by the temperature sensor 34 of each of the plurality of conveying path units 11.

[0085] In each of the conveying path units 11 that performs the regenerative power supply, the temperature inside the conveying path unit 11 rises due to the consumption of the regenerative power in the coils 20. The controller 12 compares the temperatures of the respective conveying path units 11 of the conveying system 2. The controller 12 determines one or two or more conveying path units 11 from the plurality of conveying path units 11 in ascending order of temperature as the conveying path units 11 that perform the regenerative power supply. Consequently, the conveying system 2 can equalize the temperatures of the respective conveying path units 11. By equalizing the temperatures of the respective conveying path units 11, it is possible to extend the service life of a component of each conveying path unit 11 that deteriorates under the influence of temperature.The controller 12 may determine in advance a temperature threshold to be compared with the detection result of the temperature by the temperature sensor 34 of each of the plurality of conveying path units 11, and determine, as the conveying path units 11 that perform the regeneration power supply, one or two or more conveying path units 11 in which the detection result of the temperature by the temperature sensor 34 is less than or equal to the temperature threshold. Third embodiment.

[0086] In a third embodiment, an example is described in which machine learning is applied to the generation of a position command issued by the controller 12 to each conveyor path unit 11. Based on the operating information of each carrier 16, the controller 12 generates a position command that increases the number of conveyor path units 11 performing regenerative power supply based on a trained model.

[0087] For example, assume that operation information is acquired indicating that the carrier 16 will reach a target position located 3 m from a current position two seconds after a certain time. In this case, any pattern can be used as a pattern of a position command for moving the carrier 16. One possible pattern is a pattern in which the carrier 16 is moved by trapezoidal acceleration / deceleration between the start point and the end point of two seconds. Examples of other patterns include a pattern in which the carrier 16 is moved by trapezoidal acceleration / deceleration for one second from the start point and the carrier 16 is stopped in the remaining one second, and a pattern in which the carrier 16 is stopped for one second from the start point and the carrier 16 is moved by trapezoidal acceleration / deceleration for the remaining one second.There are infinitely many patterns that can be used as the pattern for the position command.

[0088] The conveyor system 2 can increase the number of conveyor path units 11 that perform regenerative power supply in each control cycle by appropriately adjusting the position command pattern for each carrier 16. That is, in the conveyor system 2, if the number of conveyor path units 11 that perform regenerative power supply can be increased, a regenerative power by a conveyor path unit 11 can be reduced, thereby preventing an excessive temperature rise of the conveyor path unit 11. In the third embodiment, a position command that increases the number of conveyor path units 11 that perform regenerative power supply is derived by a machine learning method.

[0089] The configuration of the conveyor system 2 according to the third embodiment is similar to the configuration of the Fig. 5. The controller 12 of the conveyor system 2 according to the third embodiment obtains position information indicating the position of each carrier 16 on the conveyor path 10, similarly to the case of the second embodiment. The third embodiment differs from the second embodiment in that machine learning components are added to the controller 12.

[0090] Fig. Figure 8 is a diagram showing an exemplary configuration of the controller 12 included in the conveyor system 2 according to the third embodiment. The controller 12 includes a learning device 51, a trained model storage unit 52, a position command generation unit 53, and a reel drive command generation unit 54.

[0091] The learning device 51 learns a relationship between the operation information of each of the plurality of carriers 16 included in the conveyor system 2 and the position command that increases the number of conveyor path units 11, which increases the regenerative power supply. The operation information is information indicating a timing of the movement of each of the plurality of carriers 16 on the conveyor path 10. The position command indicates a position to which each carrier 16 is moved. The learning device 51 outputs a trained model that is a result of the learning. The trained model storage unit 52 stores the trained model.

[0092] For each of the plurality of carriers 16 included in the conveyor system 2, the position command generation unit 53 generates a position command indicating a position to which the carrier 16 is moved. The position command generation unit 53 reads a trained model from the trained model storage unit 52. The position command generation unit 53 infers a position command that increases the number of conveyor path units 11 that perform regenerative power supply by inputting the operation information to the trained model. The position command generation unit 53 generates the position command through this inference.

[0093] The reel drive command generation unit 54 generates a reel drive command based on the position command. The controller 12 controls the movement of each carrier 16 by outputting the reel drive command to each conveying path unit 11.

[0094] Fig. 9 is a diagram showing an exemplary configuration of the learning device 51 included in the controller 12 of the third embodiment. The learning device 51 includes a data acquisition unit 61 and a model generation unit 62. The data acquisition unit 61 acquires training data and generates a data set obtained by combining the training data. The training data is operation information and a position command. That is, the data acquisition unit 61 acquires training data including the operation information and the position command.

[0095] The model generation unit 62 generates a trained model using the training data. The model generation unit 62 generates a trained model to be used to infer a position command from the operating information based on the training data.

[0096] As a learning algorithm used by the model generation unit 62, a known algorithm such as supervised learning, unsupervised learning, or reinforcement learning can be used. As an example, a case where reinforcement learning is applied to a learning algorithm used by the model generation unit 62 will be described. Reinforcement learning is learning in which an action subject, as an agent, observes the current state in an environment and decides which action to take. The agent receives a reward from the environment by selecting an action and learns a strategy for obtaining a maximum reward over a series of actions. As representative methods of reinforcement learning, Q-learning, TD learning, and the like are known.For example, in a case of Q-learning, an action value table, which is a general update formula for an action value function Q(s,a), is expressed by the following formula (1). The action value function Q(s,a) represents an action value Q, which is a value of an action of selecting an action "a" given an environment "s". Formula 1: Q(st,at)←Q(st,at)+α(rt+1+γmaxaQ(st+1,at)−Q(st,at))

[0097] In formula (1), “s t “ an environment at time “t”. “a t “ represents an action at time “t”. The action “at” changes the environment to “s t+1 ". "r t+1 " represents a reward obtained by changing the environment. "γ" represents a discount factor. "α" represents a learning coefficient. The operating information is the environment "s t The position command is the action “a t “.

[0098] The update formula expressed by formula (1) increases an action value Q when an action value of the best action "a" at time "t+1" is greater than an action value Q of the action "a" executed at time "t", and decreases the action value Q when the opposite is true. In other words, the action value function Q(s,a) is updated so that the action value Q of an action "a" at time "t" approaches a best action value at time "t+1". Consequently, a best action value in a certain environment gradually propagates to action values ​​in previous environments.

[0099] The model generation unit 62 includes a reward calculation unit 63 and a function update unit 64. The reward calculation unit 63 calculates a reward based on the data set. The function update unit 64 updates a function for determining a position command in accordance with the reward calculated by the reward calculation unit 63.

[0100] Specifically, the reward calculation unit 63 calculates a reward "r" based on the number of conveying path units 11 performing regenerative power supply for each control cycle. For example, a reference number of conveying path units 11, which is a reference of the number of conveying path units 11 performing regenerative power supply, is determined in advance, and the reward calculation unit 63 increases the reward "r" in a case where the number of conveying path units 11 performing regenerative power supply is greater than the reference number. The reward calculation unit 63 increases the reward "r" by adding "1," which is a reward value. Note that the reward value is not limited to "1."On the other hand, the reward calculation unit 63 decreases the reward "r" in a case where the number of conveying path units 11 performing the regenerative power supply is smaller than the reference number. The reward calculation unit 63 decreases the reward "r" by adding "-1", which is a value of the reward. Note that the value of the reward is not limited to "-1". In addition, any number can be set as the reference number. For example, the reference number can be set by considering the magnitude of the regenerative power or the generation frequency of the regenerative power based on the total number of conveying path units 11 constituting the conveying system 2 and the total number of carriers 16 constituting the conveying system 2.

[0101] The function updating unit 64 updates a function, which is a model for determining a position command, in accordance with the reward calculated by the reward calculating unit 63. The function can be updated in accordance with the data set, such as by updating the action value table. The action value table is a data set in which any action and its action value are stored in the form of a table. For example, in the case of Q-learning, an action value function Q(s t , a t ), which is expressed by the above formula (1), is used as a function for determining the position command.

[0102] Fig. Fig. 10 is a flowchart showing a processing flow of the learning device 51 included in the controller 12 of the third embodiment. A reinforcement learning method for updating the action value function Q(s,a) will be described with reference to the flowchart of Fig. 10 described.

[0103] In step S11, the learning device 51 acquires operational information and a position command through the data acquisition unit 61. That is, the learning device 51 acquires training data. The data acquisition unit 61 collectively outputs a data set comprising the training data to the model generation unit 62.

[0104] In step S12, the learning device 51 calculates a reward through the reward generation unit 63. The reward calculation unit 63 calculates a reward for a combination of the operation information for each carrier 16 and a position command for each carrier 16. The reward calculation unit 63 increases or decreases the reward based on the number of conveyance path units 11 that perform the regenerative power supply for each control cycle.

[0105] In step S13, the learning device 51 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 51 updates the action value function Q(s t ,a t ) stored in the trained model storage unit 52.

[0106] In step S14, the learning unit 51 determines whether the action value function Q(s,a) has converged through the function updating unit 64. The function updating unit 64 determines that the action value function Q(s,a) has converged when the action value function Q(s,a) is no longer updated in step S13.

[0107] If the function updating unit 64 determines that the action value function Q(s,a) has not converged (step S14, No), the learning device 51 returns to step S11. On the other hand, the learning device 51 terminates the processes in accordance with the Fig. 10 when the function updating unit 64 determines that the action value function Q(s,a) has converged (step S14, Yes). Note that the learning device 51 may continue learning by returning the flow from step S13 to step S11 without making the determination in step S14. The trained model storage unit 52 stores a trained model that is the generated action value function Q(s,a).

[0108] In the third embodiment, the case where reinforcement learning is used for the learning algorithm used by the learning device 51 was described, however, learning methods other than reinforcement learning may also be used for the learning algorithm. The learning device 51 can perform machine learning using a known learning algorithm, such as deep learning, a neural network, genetic programming, inductive logic programming, or a support vector machine.

[0109] The Fig. 8 and Fig. The learning device 51 shown in Figure 9 is a device integrated into the controller 12. The learning device 51 may be a device external to the controller 12. The learning device 51, which is a device external to the controller 12, is included in the conveyor system 2. The learning device 51 may be a device connectable to the controller 12 via a network. The learning device 51 may be a device located in a cloud server.

[0110] The learning device 51 can learn the position command that increases the number of conveyor path units 11 that perform regenerative power supply according to a data set created for a plurality of conveyor systems 2. The learning device 51 can acquire training data from a plurality of conveyor systems 2 used at the same location, or can acquire training data from a plurality of conveyor systems 2 located at different locations. The training data can be collected from a plurality of conveyor systems 2 that operate independently of each other at a plurality of locations. After the collection of training data from such a plurality of conveyor systems 2 is started, a new conveyor system 2 can be added as a target from which training data is collected.In addition, after the collection of the training data from the plurality of conveyor systems 2 is started, some of the plurality of conveyor systems 2 may be excluded from the targets from which the training data is collected.

[0111] The learning device 51 that has trained one conveyor system 2 can train other conveyor systems 2 that are different from the one conveyor system 2. The learning device 51 that performs the learning for the other conveyor systems 2 can update the trained model by relearning the other conveyor systems 2.

[0112] Fig. 11 is a diagram showing an exemplary configuration of the position command generation unit 53 included in the controller 12 of the third embodiment. The position command generation unit 53 functions as an inference unit that infers a position command based on operational information. The position command generation unit 53 includes a data acquisition unit 65 and an inference unit 66.

[0113] The data acquisition unit 65 acquires inference data. The inference data is operational information about each of the plurality of carriers 16 included in the conveyor system 2. The inference unit 66 reads the trained model generated by the learning device 51 from the trained model storage unit 52. The inference unit 66 infers a position command by inputting the inference data into the trained model. The inference unit 66 outputs the position command, which is a result of the inference, to the reel drive command generation unit 54. The reel drive command generation unit 54 generates a reel drive command based on the position command.

[0114] Fig. 12 is a flowchart showing a processing procedure of the position command generation unit 53 and the coil drive command generation unit 54 included in the controller 12 of the third embodiment.

[0115] In step S21, the position command generation unit 53 acquires the operation information of each carrier 16 through the data acquisition unit 65. The data acquisition unit 65 outputs the acquired operation information to the inference unit 66.

[0116] In step S22, the position command generation unit 53 generates a position command by inputting the operation information of each carrier 16 into the trained model in the inference unit 66. In step S23, the inference unit 66 outputs the position command to the coil drive command generation unit 54. In step S24, the coil drive command generation unit 54 generates a coil drive command based on the position command. Accordingly, the position command generation unit 53 and the coil drive command generation unit 54 complete the processes in accordance with the Fig. 12. The controller 12 transmits the coil drive command generated by the coil drive command generation unit 54 to each conveying path unit 11 via the data communication line 14.

[0117] According to the third embodiment, the conveyor system 2 includes the learning device 51 and the position command generation unit 53, which is an inference device, so that it is possible to derive the position command that increases the number of conveyor path units 11 that perform the regenerative power supply. Consequently, the conveyor system 2 can process the regenerative power appropriately.

[0118] The example in which machine learning is used to generate the position command in the conveyor system 2 according to the second embodiment has been described. The machine learning described in the third embodiment can also be used to generate the position command in a case where regenerative power supply is performed in the conveyor path units 11 to which the carrier 16 is not moved, as in the first embodiment. The conveyor system 2 can generate the position command using a method other than machine learning.

[0119] Next, hardware implementing the controller 12 according to the first to third embodiments will be described. The controller 12 is implemented by a processing circuit. The processing circuit may be a processor circuit that executes software or a dedicated circuit.

[0120] In a case where the processing circuit is implemented by software, the processing circuit is, for example, a Fig. Control circuit shown in Figure 13. Fig. 13 is a diagram showing an exemplary configuration of a control circuit 80 according to the first to third embodiments. 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 to the control circuit 80 from the outside and outputs the data to the processor 82. The output unit 84 is an interface unit that outputs data from the processor 82 or the memory 83 to the outside of the control circuit 80.

[0121] In a case where the processing circuitry described in the Fig. 13, the controller 12 is implemented by software, firmware, or a combination of software and firmware. The software or firmware is described as a program and stored in the memory 83. The processing circuit implements functions of the controller 12 through the processor 82, which reads and executes a program stored in the memory 83. That is, the processing circuit includes the memory 83 for storing a program with which, as a result, a process of the controller 12 is executed. It is also noted that these programs can cause a computer to execute operations and methods of the controller 12.

[0122] The processor 82 is a CPU. The processor 82 may be a central processing device, a processing device, an arithmetic device, a microprocessor, a microcomputer, a processor, or a DSP. The memory 83 corresponds, for example, to a non-volatile or volatile semiconductor memory such as a random access memory (RAM), a read-only memory (ROM), a flash memory, an erasable programmable read-only memory (EPROM), or an electrically erasable programmable read-only memory (EEPROM, registered trademark), a magnetic memory, a floppy disk, an optical memory, a CD (compact disk), a minidisk, or a DVD (digital versatile disk).

[0123] Fig. 13 is an example of hardware in a case where the controller 12 is implemented by the processor 82 and the memory 83 for general purposes, but the controller 12 may be implemented by a dedicated hardware circuit. Fig. 14 is a diagram showing an exemplary configuration of a hardware circuit 85 as a dedicated circuit according to the first to third embodiments.

[0124] The hardware circuit 85 as a dedicated circuit includes the input unit 81, the output unit 84, and a processing circuit 86. The processing circuit 86 is a single circuit, a composite circuit, a programmable processor, a parallel programmable processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a circuit obtained by combining these. The functions of the controller 12 can be implemented separately by the processing circuit 86, or the functions can be implemented jointly by the processing circuit 86. The controller 12 can be implemented by combining the control circuit 80 and the hardware circuit 85.

[0125] The configurations described above in the respective embodiments are merely examples of the content of the present disclosure. The configurations of the respective embodiments can be combined with other known technology. The configurations of the respective embodiments can be combined as appropriate. Part of the configurations of the respective embodiments may be omitted or changed without departing from the gist of the present disclosure. List of reference symbols 1, 2 conveyor system; 10 funding path; 11, 11A, 11B, 11C, 11D, 11E, 11F, 11G, 11H Conveyor path unit; 12 Control; 13 DC power supply; 14 data communication line; 15 DC power supply line; 16, 16A, 16B, 16C carriers; 17A, 17B arrow; 20 coil; 21 inverter circuit; 22 current sensor; 23 capacitor; 24 power control; 25 linear encoders; 26 Position sensor; 27, 82 processor; 28 Communications substation; 31 P-line; 32 N-line; 33 Line voltage detection unit; 34 temperature sensor; 40, 41 permanent magnet; 51 learning device; 52 Storage unit for trained models; 53 Position command generation unit; 54 coil drive command generation unit; 61.65 data reference unit; 62 model generation unit; 63 Reward calculation unit; 64 Function Update Unit; 66 inference unit; 80 control circuit; 81 input unit; 83 storage; 84 output unit; 85 hardware circuit; 86 processing circuit. QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] JP 2019-170153

[0005]

Claims

[1] Conveyor system comprising: a plurality of conveyor path units forming a conveyor path along which a conveyor body moves, the conveyor path units each being connected to a common DC line, wherein each conveyor path unit of the plurality of conveyor path units comprises a drive unit to be supplied with power from the DC line to thereby generate a driving force for moving the conveyor body, and wherein, of one or two or more conveying path units to which the conveying body is not moved, of the plurality of conveying path units, at least one conveying path unit carries out a regeneration power supply for supplying regeneration power generated in the plurality of conveying path units to the drive unit. [2] Conveyor system according to claim 1, wherein the conveying path units each comprise a line voltage detecting unit for detecting a line voltage which is a voltage of the DC line, and wherein, of one or two or more conveying path units to which the conveying body is not moved, of the plurality of conveying path units, at least one conveying path unit performs regeneration power supply when the line voltage becomes greater than or equal to a preset first voltage threshold. [3] Conveyor system according to claim 2, wherein the conveying path units that perform the regeneration power supply stop the regeneration power supply when the line voltage becomes less than or equal to a second voltage threshold that is less than the first voltage threshold. [4] A conveyor system according to claim 3, wherein the first voltage threshold and / or the second voltage threshold is individually set for each of a plurality of conveyor path units. [5] The conveying system according to any one of claims 1 to 4, wherein when the conveying body moves toward the conveying path unit that executes the regenerative power supply, the conveying path unit stops the execution of the regenerative power supply. [6] The conveying system according to any one of claims 1 to 5, wherein the conveying path unit stops the execution of the regenerative power supply when power supplied to the drive unit of the conveying path unit that executes the regenerative power supply exceeds a preset power threshold. [7] A conveyor system according to claim 6, wherein the power threshold is individually set for each of a plurality of conveyor path units. [8] Conveyor system according to one of claims 1 to 7, wherein the conveying path is provided with a sensor unit for detecting a position of the conveying body, and wherein, of the plurality of conveying path units, a conveying path unit detected as a conveying path unit to which the conveying body is not moved by a result of detection by the sensor unit carries out the regeneration power supply. [9] Conveyor system according to one of claims 1 to 7, comprising: a controller for controlling each of the plurality of conveyor path units, wherein the controller determines the conveying path unit for executing the regeneration power supply based on position information indicating a position of the conveying body on the conveying path. [10] Conveyor system according to claim 9, wherein the plurality of conveying path units comprises a first conveying path unit and a second conveying path unit, wherein the first conveying path unit is the conveying path unit on which the conveying body is located, wherein the second conveying path unit is one or two or more of the conveying path units arranged in the conveying path adjacent to the first conveying path unit, and wherein the controller excludes the first conveying path unit and the second conveying path unit from the conveying path units for performing the regeneration power supply. [11] Conveyor system according to claim 10, wherein the number of second conveyor path units arranged in a first direction along the conveyor path next to the first conveyor path unit and / or the number of second conveyor path units arranged in a second direction opposite to the first direction along the conveyor path next to the first conveyor path unit is calculated based on a speed of the conveyor body on the conveyor path. [12] Conveyor system according to claim 9, wherein the plurality of conveying path units comprises a first conveying path unit and a second conveying path unit, wherein the first conveying path unit is the conveying path unit on which the conveying body is located, wherein the second conveying path unit is one or two or more of the conveying path units arranged in the conveying path in a direction of movement of the conveying body next to the first conveying path unit, and wherein the controller excludes the first conveying path unit and the second conveying path unit from the conveying path units for performing the regeneration power supply. [13] Conveyor system according to one of claims 10 to 12, wherein the number of the second conveying path units is calculated based on a speed of the conveying body on the conveying path. [14] Conveyor system according to one of claims 9 to 13, wherein the conveyor path units each comprise a temperature sensor, and wherein the controller determines the conveying path units for performing the regenerative power supply based on a result of detection of the temperature by the temperature sensor of each of the plurality of conveying path units. [15] Conveyor system according to one of claims 1 to 14, wherein the conveyor path units each comprise an inverter circuit for supplying power to the drive unit, in which power conversion is carried out by switching, and wherein the inverter circuit operates at a switching frequency lower than a switching frequency set when the driving force acts on the conveyor body during the regeneration power supply. [16] Conveyor system according to one of claims 1 to 15, wherein the conveyor body comprises a plurality of conveyor bodies, and wherein the conveyor system comprises: a learning device comprising: a data acquisition unit for acquiring training data comprising operation information and a position command, wherein the operation information is information indicating a timing of the movement of each of the conveyor bodies on the conveyor path, wherein the position command indicates, for each of a plurality of the conveyor bodies, a position to which the conveyor body is moved, and a model generation unit for generating a trained model based on the training data, wherein the trained model is to be used to infer the position command from the operation information. [17] Conveyor system according to one of claims 1 to 15, wherein the conveyor body comprises a plurality of conveyor bodies, and wherein the conveyor system comprises: a controller for controlling each of the plurality of conveying path units, the controller comprising a position command generating unit for generating a position command indicating, for each of a plurality of the conveying bodies, a position to which the conveying body is moved, wherein the position command generation unit comprises: a data acquisition unit for acquiring operation information, which is information indicating a timing of the movement of each of the conveying bodies on the conveying path; and an inference unit for inferring a position command by inputting the operation information into a trained model for inferring the position command from the operation information, wherein the position command indicates, for each of a plurality of the conveyor bodies, a position to which the conveyor body is moved. [18] Conveyor system according to one of claims 1 to 17, comprising: one or more conveyor bodies, wherein the drive unit comprises a coil to which power is to be supplied from the DC line to thereby generate an electromagnetic force which is the driving force, and wherein the conveyor body is provided with a permanent magnet.

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