Linear motor control device and linear conveyance system

Abstract

A linear motor control device (10) comprises: a controller unit (1) that controls energization to coils of fixed parts (3A to 3C) arranged so as to constitute a conveyance path, thereby causing a plurality of movable elements (4P to 4R) having permanent magnets to move on the conveyance path; a vibration information acquisition unit (6) that receives, from vibration sensors (5P to 5R) attached to the movable elements, vibration information including information pertaining to the vibration of a movable element and vibration sensor identification information for identifying the vibration sensors; and an individual identification unit (7) that identifies a movable element on the basis of the vibration information. The controller unit acquires and manages position information, which is information pertaining to the position of a movable element at startup, and causes a movable element to vibrate on the basis of the position information. The individual identification unit receives, from the controller unit, the position information pertaining to said movable element that the controller unit has caused to vibrate, and identifies said movable element on the basis of the position information and the vibration information.

Description

Linear motor control device and linear transport system

[0001] The present disclosure relates to a linear motor control device and a linear conveyance system that individually identify movers used in linear conveyance.

[0002] In factory automated production lines for assembling industrial products, etc., movable elements installed on the same transport route are individually controlled, and multiple processes are constructed on the same transport route, thereby realizing flexible equipment design.

[0003] For example, a linear conveyance system applied to a production line comprises a movable part with a permanent magnet, a fixed part with a coil, and a controller part that controls the position of the movable part. By mounting a jig prepared by the user on the movable part, this linear conveyance system makes it possible to move the jig and perform processing work simultaneously in parallel, thereby realizing reductions in the installation area of ​​the equipment and reductions in takt time.

[0004] In a linear transport system, multiple movers may be arranged within one transport path, and each mover may perform a different operation. In this case, the linear transport system identifies unique information (such as a serial number) assigned to each mover and then performs processing appropriate for each mover.

[0005] In the linear conveying system described in Patent Document 1, a wireless tag storing identification information of the mover is attached to the mover, and each mover is identified by reading the identification information from the wireless tag using a wireless tag reader installed along the conveying path.

[0006] Japanese Patent Application Laid-Open No. 2021-160841

[0007] However, with the technology of Patent Document 1, the number of wireless tag readers to be installed increases as the transport route becomes longer, which causes a problem of increasing the cost of identifying the mover.

[0008] The present disclosure has been made in view of the above, and has an object to provide a linear motor control device that can reduce the cost of identifying a mover.

[0009] To solve the above-mentioned problems and achieve the object, the linear motor control device of the present disclosure includes a controller unit that moves multiple movers having permanent magnets along a conveyance path by controlling the supply of current to coils of fixed units that are arranged to form a conveyance path. The linear motor control device of the present disclosure also includes a vibration information acquisition unit that receives vibration information from a vibration sensor attached to the mover, the vibration information including information on the vibration of the mover and vibration sensor identification information that identifies the vibration sensor, and an individual identification unit that identifies the mover based on the vibration information. The controller unit acquires and manages position information that is information on the position of the mover at startup and vibrates the mover based on the position information, and the individual identification unit receives from the controller unit the position information of the mover vibrated by the controller unit and identifies the mover based on the position information and vibration information.

[0010] The linear motor control device according to the present disclosure has the effect of reducing the cost for identifying the mover.

[0011] FIG. 1 is a diagram showing the configuration of a linear conveyance system equipped with a linear motor control device according to an embodiment; FIG. 2 is a flowchart showing the processing procedure for individual identification by the linear conveyance system according to an embodiment; FIG. 3 is a diagram showing an example of the configuration of a processing circuit provided in the linear motor control device according to an embodiment when the processing circuit is realized by a processor and a memory; and FIG. 4 is a diagram showing an example of a processing circuit provided in the linear motor control device according to an embodiment when the processing circuit is configured by dedicated hardware.

[0012] A linear motor control device and a linear conveyance system according to embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0013] 1 is a diagram showing the configuration of a linear conveyance system equipped with a linear motor control device according to an embodiment. The linear conveyance system 100 is a system that uses a linear motor to move a mover, which is a moving part, along a conveyance path. The linear conveyance system 100 is applied to, for example, a moving magnet type linear track system.

[0014] The linear transport system 100 includes a linear motor control device 10 and a linear transport mechanism 20. The linear transport mechanism 20 includes N (N is a natural number of 1 or more) control units, N fixed units (stators), M (M is a natural number of 1 or more) movers, and M vibration sensors. In this embodiment, a case where M is 2 or more will be described.

[0015] In this embodiment, a case where N and M are 3 will be described. That is, the linear conveyance system 100 includes a linear motor control device 10, three control units 2A to 2C, three fixed units 3A to 3C, three movers 4P to 4R, and three vibration sensors 5P to 5R. Note that the linear conveyance system 100 is not limited to a case where the number of fixed units and movable units is the same.

[0016] The linear motor control device 10 has a vibration information acquisition unit 6, an individual identification unit 7, and a controller unit 1. The controller unit 1 is connected to the individual identification unit 7. The vibration information acquisition unit 6 is also connected to the individual identification unit 7. The linear motor control device 10 vibrates the movers 4P to 4R in order at startup, and identifies the movers 4P to 4R based on the information obtained during the vibration.

[0017] In the embodiment, excitation is a process of vibrating the movers 4P to 4R by accelerating them at a specific acceleration. The linear motor control device 10 vibrates the movers 4P to 4R over a short distance for a short period of time so that the movers 4P to 4R do not collide with each other, and then stops them. The linear motor control device 10 accelerates the movers 4P to 4R at an acceleration of a specific magnitude, such as 2G (gravity), where 1G is the gravitational acceleration, and then stops the movers 4P to 4R. Below, a case will be described in which the controller unit 1 excites the movers 4P, 4Q, and 4R in this order, but the order of excitation may be any order.

[0018] Control units 2A to 2C are connected to controller unit 1. Control units 2A to 2C are also connected one-to-one to fixed units 3A to 3C, respectively. Control units 2A to 2C control fixed units 3A to 3C, respectively. That is, control unit 2A controls fixed unit 3A, control unit 2B controls fixed unit 3B, and control unit 2C controls fixed unit 3C.

[0019] The control units 2A to 2C have inverter units (not shown) for energizing the coils (not shown) provided in the fixed units 3A to 3C, and position detection units (not shown) for detecting the positions of the movers 4P to 4R. Each inverter unit controls the energization of the coils and detects the energizing current.

[0020] Control units 2A to 2C perform inverter control to energize the coils of fixed units 3A to 3C and detect the positions of movers 4P to 4R in accordance with instructions from controller unit 1. Control units 2A to 2C correspond one-to-one to fixed units 3A to 3C, respectively, and this correspondence does not change during control.

[0021] The position detection units of the control units 2A to 2C detect the magnetic fields emitted from the permanent magnets (not shown) of the movers 4P to 4R using, for example, Hall sensors (not shown) attached to the fixed units 3A to 3C, and perform position detection based on the detected magnetic fields. Note that the control units 2A to 2C may detect the positions of the movers 4P to 4R by any method.

[0022] Information on the positions of each of the movers 4P to 4R (hereinafter referred to as position information) detected by the position detection units of the control units 2A to 2C is transmitted to the controller unit 1, which then collectively manages the position information of each of the movers 4P to 4R.

[0023] The fixed units 3A to 3C are arranged along the direction of the path (transport path) along which the movers 4P to 4R move, i.e., along the movement direction. FIG. 1 shows a case in which the fixed unit 3B is arranged next to the fixed unit 3A, and the fixed unit 3C is arranged next to the fixed unit 3B. The fixed units 3A to 3C are equipped with coils for generating a moving magnetic field to drive the movers 4P to 4R. The moving magnetic field generated by the fixed units 3A to 3C corresponds to the order in which current is applied to the coils. In other words, a moving magnetic field is generated in accordance with the order in which current is applied to the coils, and the movers 4P to 4R move along the moving magnetic field.

[0024] The fixed units 3A to 3C individually drive each of the movers 4P to 4R by energizing the coils according to the position of each of the movers 4P to 4R. The fixed units 3A to 3C can drive each of the movers 4P to 4R at any position and speed within a range where the movers 4P to 4R do not collide with each other.

[0025] Furthermore, the fixed portions 3A to 3C have a holding mechanism (not shown) that holds the movers 4P to 4R, allowing the movers 4P to 4R to be driven along the fixed portions 3A to 3C without falling off. The fixed portions 3A to 3C are mechanically connected in series, allowing any path to be configured. That is, the fixed portions 3A to 3C are connected and arranged to configure a transport path along which the movers 4P to 4R move. Note that when there is only one fixed portion, that one fixed portion is arranged to configure the transport path along which the mover moves.

[0026] The fixed portions 3A to 3C can be shaped to match the shape of the transport path, and can be linear, curved, or other shapes. Note that the positional relationship between the movers 4P to 4R and the fixed portions 3A to 3C is not fixed one-to-one. For example, the mover 4P can move across the fixed portions 3A to 3C. Similarly, the movers 4Q and 4R can move across the fixed portions 3A to 3C.

[0027] Each of the movers 4P to 4R is equipped with a permanent magnet. The movers 4P to 4R move in response to an externally applied moving magnetic field. The linear conveyance system 100 can change the movement direction of the movers 4P to 4R and the thrust generated on the movers 4P to 4R by changing the direction and magnetic field strength of the moving magnetic field. The movers 4P to 4R are arranged along the movement direction of the movers 4P to 4R. FIG. 1 shows a case in which the mover 4Q is arranged next to the mover 4P, and the mover 4R is arranged next to the mover 4Q.

[0028] Vibration sensors 5P to 5R are attached to the movers 4P to 4R, respectively. Vibration sensor 5P detects vibration of mover 4P, vibration sensor 5Q detects vibration of mover 4Q, and vibration sensor 5R detects vibration of mover 4R.

[0029] The specifications of the vibration sensors 5P to 5R vary depending on the type of sensor. In this embodiment, a specific acceleration threshold is set for each of the vibration sensors 5P to 5R, and the vibration sensors 5P to 5R detect whether or not this acceleration threshold is exceeded. That is, the vibration sensors 5P to 5R detect the acceleration of each of the movers 4P to 4R, and determine whether the detected acceleration exceeds the acceleration threshold.

[0030] The vibration sensors 5P to 5R transmit vibration information including information on the vibration of the movers 4P to 4R and information identifying the vibration sensors 5P to 5R (hereinafter referred to as vibration sensor identification information) to the vibration information acquisition unit 6 of the linear motor control device 10.

[0031] The vibration information of the movers 4P to 4R is information indicating that the detected acceleration has exceeded an acceleration threshold (hereinafter referred to as excess information). When the detected acceleration has exceeded the acceleration threshold, the vibration sensors 5P to 5R transmit vibration information including the excess information and vibration sensor identification information to the vibration information acquisition unit 6.

[0032] In the linear conveyance system 100, the controller unit 1 vibrates the movers 4P to 4R in sequence, and the vibration sensors 5P to 5R transmit the vibration information in sequence to the vibration information acquisition unit 6. The vibration sensors 5P to 5R transmit the vibration information to the vibration information acquisition unit 6 by, for example, wireless communication.

[0033] The sensor specifications of the vibration sensors 5P to 5R are not limited to the above-mentioned sensor specifications, and other sensor specifications may be used. For example, the vibration sensors 5P to 5R may transmit vibration information to the vibration information acquisition unit 6 via wired communication.

[0034] The controller unit 1 independently controls the drive of each of the movers 4P to 4R. The controller unit 1 generates current commands to the control units 2A to 2C based on the operation profile of each of the movers 4P to 4R written by the user using an engineering tool or the like. In other words, the controller unit 1 generates current commands to the inverter unit to drive the movers 4P to 4R in accordance with the operation profile. The operation profile is defined by an operation program or the like created by the user.

[0035] Furthermore, the controller unit 1 acquires and manages the position information of each of the movers 4P to 4R detected by the control units 2A to 2C from the control units 2A to 2C. The controller unit 1 controls the drive of the movers 4P to 4R based on the position information of each of the movers 4P to 4R.

[0036] The controller unit 1 has the above-mentioned functions and is therefore able to perform overall control of the movers 4P to 4R, thereby enabling the controller unit 1 to arbitrarily and individually control each of the movers 4P to 4R while constantly understanding the position and state of each of the movers 4P to 4R.

[0037] Furthermore, at the time of startup, the controller unit 1 vibrates the movers 4P to 4R in order based on the position information of the movers 4P to 4R so that the acceleration becomes higher than the acceleration threshold (vibration threshold).

[0038] Although the controller unit 1 can acquire the position information of each of the movers 4P to 4R at startup, it cannot recognize which mover is at which position until it identifies the information unique to each of the movers 4P to 4R (mover-specific information such as a serial number) assigned to each of the movers 4P to 4R. In other words, the controller unit 1 cannot determine which mover is at which position and to which mover-specific information is assigned until the identification process for the movers 4P to 4R is complete. In the embodiment, the controller unit 1 executes the identification process for each of the movers 4P to 4R at startup.

[0039] In the linear conveyance system 100, there are multiple types of jigs mounted on the movers 4P to 4R, and it may be desired to move each jig in a different way depending on the type of jig. Also, in the linear conveyance system 100, there may be cases where it is desired to record information specific to each of the movers 4P to 4R (for example, production information such as the production phase and production quantity) and move each mover in a different way depending on the production information.

[0040] In these cases, the linear transport system 100 individually identifies the movers 4P to 4R and then executes control according to each of the movers 4P to 4R. The identification here does not simply identify the positions of the movers 4P to 4R, but identifies the movers 4P to 4R corresponding to the vibration sensors 5P to 5R by identifying, for example, vibration sensor identification information unique to the vibration sensors 5P to 5R. Hereinafter, identifying mover-specific information, which is information unique to the movers 4P to 4R, may be referred to as individual identification.

[0041] Generally, since movers are composed only of structural members and permanent magnets, it is difficult to embed information for individual identification in the movers themselves. Furthermore, since the positions of the movers 4P to 4R may be changed by the user after the power is turned off in the linear conveyance system 100, even if the positions of the movers 4P to 4R are associated with the identification information of the movers 4P to 4R and stored, the stored information often cannot be used the next time the system is started. For this reason, conventional linear conveyance systems can detect the coordinates of each mover at the time of start-up, but cannot identify individual movers.

[0042] For example, in a conventional linear transport system, a method is considered in which wireless tag readers installed along the transport route read identification information from wireless tags attached to movers. This method increases the number of wireless tag readers installed, raising costs, and also poses the risk of false detection of signals when movers are adjacent to each other.

[0043] When the linear conveying system 100 of the embodiment is started, it performs individual identification of the movers 4P to 4R using the vibration sensors 5P to 5R arranged on the movers 4P to 4R, thereby reducing the cost of identifying the movers. Furthermore, because the linear conveying system 100 performs individual identification of the movers 4P to 4R using the vibration sensors 5P to 5R arranged on the movers 4P to 4R, there is little risk of erroneous signal detection even when the movers 4P to 4R are adjacent to each other.

[0044] The vibration information acquisition unit 6 receives vibration information from the vibration sensors 5P to 5R. When the vibration information acquisition unit 6 receives vibration information from the vibration sensors 5P to 5R via wireless communication, the vibration information acquisition unit 6 has a wireless receiver.

[0045] In the linear conveyance system 100, the controller unit 1 vibrates the movers 4P to 4R in sequence, and the vibration information acquisition unit 6 receives vibration information in sequence from the vibration sensors 5P to 5R. That is, the vibration information acquisition unit 6 receives the vibration information in the following order: the vibration information of the mover 4P, the vibration information of the mover 4Q, and the vibration information of the mover 4R.

[0046] The vibration information acquisition unit 6 transmits the received vibration information to the individual identification unit 7. The vibration information acquisition unit 6 transmits the vibration information to the individual identification unit 7 in the order of vibration information from vibration sensor 5P, vibration information from vibration sensor 5Q, and vibration information from vibration sensor 5R.

[0047] The individual identification unit 7 receives vibration information including excess information and vibration sensor identification information from the vibration information acquisition unit 6. Furthermore, the individual identification unit 7 receives position information from the controller unit 1 at startup, which is information about the positions of the movers 4P to 4R excited by the controller unit 1. This position information is position information detected by the position detection units of the control units 2A to 2C at startup and transmitted to the controller unit 1.

[0048] When the controller unit 1 receives position information from the control units 2A to 2C, it has acquired the first position information, the second position information, and the third position information, but it does not know which of the movable elements 4P to 4R each piece of position information corresponds to.

[0049] The individual identification unit 7 receives the position information of the movers 4P to 4R in order from the controller unit 1. Here, the individual identification unit 7 receives the position information in the order of the position information of the mover 4P, the position information of the mover 4Q, and the position information of the mover 4R.

[0050] The individual identification unit 7 stores in advance information in which vibration sensor identification information and mover unique information are associated with each other (hereinafter referred to as mover correspondence information). In the mover correspondence information of the embodiment, the mover unique information of the mover 4P is associated with the vibration sensor identification information of the vibration sensor 5P. In the mover correspondence information, the mover unique information of the mover 4Q is associated with the vibration sensor identification information of the vibration sensor 5Q, and the mover unique information of the mover 4R is associated with the vibration sensor identification information of the vibration sensor 5R. Note that the mover correspondence information may be stored in a storage unit (not shown) or the like arranged outside the individual identification unit 7.

[0051] The individual identification unit 7 performs individual identification of the movers 4P to 4R based on the vibration information received from the vibration information acquisition unit 6, the information received from the controller unit 1 (position information corresponding to the driving status of the movers 4P to 4R), and the mover correspondence information.

[0052] For example, when the individual identification unit 7 receives first position information from the controller unit 1 and then receives vibration information of the vibration sensor 5P from the vibration information acquisition unit 6, the individual identification unit 7 determines that the vibration sensor 5P is located on the mover that stopped at the position corresponding to the first position information. Furthermore, the individual identification unit 7 determines that the vibration sensor 5P is located on the mover 4P based on the vibration sensor identification information and the mover correspondence information included in the vibration information of the vibration sensor 5P. As a result, the individual identification unit 7 determines that the mover that stopped at the position corresponding to the first position information is the mover 4P.

[0053] Similarly, when the individual identification unit 7 receives, for example, second position information from the controller unit 1, and then receives vibration information from the vibration sensor 5Q from the vibration information acquisition unit 6, it determines that the mover stopped at the position corresponding to the second position information is the mover 4Q.

[0054] Similarly, when the individual identification unit 7 receives, for example, third position information from the controller unit 1, and then receives vibration information from the vibration sensor 5R from the vibration information acquisition unit 6, it determines that the mover stopped at the position corresponding to the third position information is mover 4R.

[0055] In the linear conveyance system 100, after the individual identification unit 7 has individually identified one mover, the controller unit 1 vibrates the next mover. That is, in the linear conveyance system 100, the process of the controller unit 1 vibrating one mover and the process of the individual identification unit 7 individually identifying one mover are repeated.

[0056] In this embodiment, the controller unit 1 vibrates the mover 4P, and the individual identification unit 7 individually identifies the mover 4P. Then, the individual identification unit 7 transmits information to the controller unit 1 indicating that the mover corresponding to the first position information is the mover 4P. After that, the controller unit 1 vibrates the mover 4Q, and the individual identification unit 7 individually identifies the mover 4Q. Then, the individual identification unit 7 transmits information to the controller unit 1 indicating that the mover corresponding to the second position information is the mover 4Q. After that, the controller unit 1 vibrates the mover 4R, and the individual identification unit 7 individually identifies the mover 4R. Then, the individual identification unit 7 transmits information to the controller unit 1 indicating that the mover corresponding to the third position information is the mover 4R.

[0057] This allows the controller unit 1 to cause each of the identified movers 4P to 4R to operate in accordance with the mover 4P to 4R. The controller unit 1 can also select a memory address corresponding to each of the identified movers 4P to 4R and store information specific to each of the movers 4P to 4R (such as travel distance) in the memory address corresponding to the mover 4P to 4R. In this way, the linear motor control device 10 individually identifies the movers 4P to 4R and then executes control and information recording in accordance with each of the movers 4P to 4R.

[0058] The vibration sensors 5P-5R may transmit detected acceleration instead of excess information to the linear motor control device 10. In this case, the vibration sensors 5P-5R transmit vibration information including the detected acceleration and vibration sensor identification information to the vibration information acquisition unit 6. The individual identification unit 7 compares the detected acceleration included in the vibration information with an acceleration threshold value and determines whether the detected acceleration is higher than the acceleration threshold value. If the detected acceleration is higher than the acceleration threshold value, the individual identification unit 7 uses the vibration information including the detected acceleration to individually identify the movers 4P-4R.

[0059] Next, a description will be given of the individual identification processing procedure executed by the linear conveyance system 100. Fig. 2 is a flowchart showing the individual identification processing procedure executed by the linear conveyance system according to the embodiment.

[0060] When the linear conveyance system 100 is started up, the controller unit 1 receives position information of the movers 4P to 4R from the control units 2A to 2C and transmits it to the individual identification unit 7. As a result, the individual identification unit 7 acquires the position information of the movers 4P to 4R (step S10).

[0061] Immediately after the linear conveyance system 100 is started up, the controller unit 1 can detect that the three movers 4P to 4R are present at their respective coordinates, and can issue commands to each of the movers 4P to 4R, but is not able to individually identify these movers 4P to 4R. In other words, immediately after the linear conveyance system 100 is started up, the controller unit 1 can recognize that there are three movers and the positions of the three movers, but it cannot recognize which mover is at which position.

[0062] The controller unit 1 outputs a command (vibration command) to vibrate one of the three movers 4P to 4R. Based on the position information, the controller unit 1 outputs a vibration command to a control unit corresponding to the position information of the mover to be vibrated. As a result, the controller unit 1 vibrates one mover. That is, based on the position information, the controller unit 1 vibrates the mover corresponding to the position information so that the acceleration exceeds the acceleration threshold (step S20). The controller unit 1 outputs a vibration command to a control unit corresponding to, for example, first position information. As a result, the mover corresponding to the first position information vibrates. The controller unit 1 transmits the position information of the vibrated mover (here, the first position information) to the individual identification unit 7.

[0063] At this time, only the vibration sensor attached to the vibrating mover detects that the detected acceleration has become higher than the acceleration threshold value. Then, only the vibration sensor attached to the vibrating mover transmits vibration information including excess information indicating that the detected acceleration has become higher than the acceleration threshold value and vibration sensor identification information that identifies the vibration sensor to the vibration information acquisition unit 6. At this time, the vibration sensors attached to the mover that is not vibrating do not transmit vibration information to the vibration information acquisition unit 6.

[0064] The vibration information acquisition unit 6 receives the vibration information and transmits it to the individual identification unit 7. As a result, the individual identification unit 7 acquires the vibration information (step S30). The individual identification unit 7 performs individual identification of the mover based on the position information, vibration information, and mover correspondence information of the vibrated mover (step S40). For example, if the vibration information includes vibration sensor identification information of vibration sensor 5P, the individual identification unit 7 determines that the first mover vibrated in the first position information is mover 4P to which vibration sensor 5P is attached. The individual identification unit 7 transmits information indicating that the mover at the vibrated position is mover 4P to the controller unit 1.

[0065] The controller 1 determines whether or not all of the movers for which the position information has been acquired have been excited (step S50). If any of the movers have not been excited (step S50, No), the linear conveyance system 100 executes the processes of steps S20 to S50.

[0066] In this case, the controller unit 1 outputs a vibration command to vibrate one of the two movers that is not vibrating to the control unit corresponding to the position information of the mover that is to be vibrated. As a result, the controller unit 1 vibrates the mover corresponding to the position information so that the acceleration exceeds the acceleration threshold (step S20). Thereafter, processing similar to the processing of steps S30 to S50 described above is executed.

[0067] If none of the movers are being vibrated (No in step S50), the linear conveyance system 100 executes steps S20 to S50. The controller unit 1 outputs a vibration command to vibrate the remaining mover that is not being vibrated to the control unit corresponding to the position information of the mover to be vibrated. This causes the controller unit 1 to vibrate the mover corresponding to the position information so that the acceleration exceeds the threshold value (step S20). Thereafter, the same processes as those in steps S30 to S50 described above are executed.

[0068] In this way, the linear transport system 100 repeats the processes of steps S20 to S50 until all movers for which position information has been acquired are vibrated and individual identification of each mover is performed.

[0069] When the controller unit 1 determines that all movers for which position information has been acquired have been excited (Yes in step S50), the linear conveyance system 100 completes the individual identification process.

[0070] The linear motor control device 10 can associate information identifying the movers 4P-4R (such as a serial number) with vibration sensor identification information using the above-described procedure. This allows the linear motor control device 10 to manage information that associates information identifying the movers 4P-4R with vibration sensor identification information. Note that the linear motor control device 10 may also manage the movers 4P-4R using the vibration sensor identification information. Thereafter, the controller unit 1 executes individual control for each of the individually identified movers 4P-4R.

[0071] There is no limit to the number of movers that can be applied to the linear conveyance system 100. In the linear conveyance system 100, a vibration sensor is attached to each mover, and the vibration sensor identification information is set so that there is no duplication, so that the number of movers that the linear motor control device 10 performs individual identification on can be increased as desired.

[0072] In the linear conveying system 100, when the vibration sensors transmit vibration information to the linear motor control device 10 via wireless communication, the linear motor control device 10 only needs to be equipped with one wireless receiver regardless of the number of vibration sensors, thereby reducing the cost of identifying the movable element.

[0073] Furthermore, since the linear motor control device 10 detects the movers 4P to 4R based on vibration information from the vibration sensors 5P to 5R attached to the movers 4P to 4R, the adjacent distance between the movers 4P to 4R does not affect the detection accuracy of the movers 4P to 4R. Therefore, there is little risk of failure to detect the movers 4P to 4R when the movers 4P to 4R are adjacent to each other.

[0074] Furthermore, the information detected by the vibration sensors 5P to 5R is acceleration and does not depend on the amount of movement of the movers 4P to 4R, so that the movers 4P to 4R can be detected by minute movements of the movers 4P to 4R.

[0075] In the embodiment, a case where one vibration sensor is attached to each of the movers has been described, but a vibration sensor may be attached to only one of the movers. This method can be applied when the information on the arrangement of the movers is known and if one mover can be individually identified, then the other movers can also be individually identified.

[0076] In this case, the controller unit 1 outputs a vibration command to vibrate one of the three movers 4P-4R, causing that one mover to vibrate so that its acceleration exceeds the acceleration threshold. At this time, if the vibration information acquisition unit 6 has not received vibration information and the individual identification unit 7 has not acquired vibration information, the individual identification unit 7 will determine that a vibration sensor is not attached to the vibrated mover and will vibrate the other mover. The linear motor control device 10 repeats these processes until it receives vibration information.

[0077] When a mover to which a vibration sensor is attached vibrates, vibration information is transmitted from the vibration sensor to the linear motor control device 10. This vibration information includes vibration sensor identification information of the mover to which the vibration sensor is attached.

[0078] The individual identification unit 7 simultaneously acquires vibration information of the mover to which the vibration sensor is attached and position information of the vibrated mover, thereby detecting that a vibration sensor is attached to the vibrated mover.

[0079] For example, if a vibration sensor 5P is attached to the mover 4P, when the individual identification unit 7 acquires the vibration sensor identification information of the vibration sensor 5P, the individual identification unit 7 determines that the vibrated mover is attached with the vibration sensor 5P. As a result, the individual identification unit 7 can determine that the mover to which the vibration sensor 5P is attached is the mover 4P, and therefore that the mover 4P has been vibrated.

[0080] After this, the individual identification unit 7 can also identify the individual pieces of other movers based on the information on the arrangement of the movers. In this method, even if there are multiple movers, only one vibration sensor is required, which makes it possible to further reduce the cost of identifying the individual movers.

[0081] Note that when M is 3 or more, 2 to (M-1) vibration sensors may be attached to M movers. Furthermore, when M is 2, one vibration sensor may be attached to two movers. In these cases as well, the linear motor control device 10 identifies and individually identifies the one vibrated mover by repeating the process of vibrating one of the multiple movers. When 2 to (M-1) vibration sensors are attached to M movers, it is possible to identify the mover to which a vibration sensor is attached in a shorter time than when one vibration sensor is attached to M movers.

[0082] Note that the linear motor control device 10 may transmit vibration commands to multiple movers simultaneously when a vibration sensor is attached to only one mover. In this case, the linear motor control device 10 divides the movers into multiple groups and transmits vibration commands to each group simultaneously. When the linear motor control device 10 receives vibration information when transmitting a vibration command to a specific group, it determines that a vibration sensor is attached to this group. The linear motor control device 10 then further divides the movers in this group into multiple groups and transmits vibration commands to each group simultaneously. By repeating these processes, the linear motor control device 10 vibrates only the one mover to which a vibration sensor is attached and receives vibration information from the vibration sensor of this mover. In this way, the linear motor control device 10 identifies and individually identifies the mover to which a vibration sensor is attached.

[0083] The linear motor control device 10 can shorten the detection time by, for example, exciting the movers using a binary search. In this case, the linear motor control device 10 divides M movers into two groups. For example, if M is an even number, the linear motor control device 10 divides the movers into groups of (M / 2) movers each. The linear motor control device 10 then transmits an excitation command simultaneously to all movers in one group, and if vibration information cannot be received, transmits an excitation command simultaneously to all movers in the other group.

[0084] The linear motor control device 10 further divides the movers in the group from which it has received vibration information into two groups. For example, if (M / 2) is an even number, the linear motor control device 10 divides the movers into groups of (M / 4) movers each. The linear motor control device 10 then simultaneously transmits a vibration command to all movers in one group, and if it is unable to receive vibration information, simultaneously transmits a vibration command to all movers in the other group. By repeating this process, the linear motor control device 10 vibrates only one mover to which a vibration sensor is attached, and receives vibration information from the vibration sensor of this mover. In this way, the linear motor control device 10 identifies and individually identifies the mover to which the vibration sensor is attached.

[0085] Note that even when M is 3 or greater and 2 to (M-1) vibration sensors are attached to M movers, vibration commands may be sent simultaneously to multiple movers, just as in the case where a vibration sensor is attached to only one mover. In this case, too, the linear motor control device 10 divides the movers into multiple groups and sends vibration commands simultaneously to each group, just as in the case where a vibration sensor is attached to only one mover. The linear motor control device 10 repeats the process of sending vibration commands to each group, and the process of further dividing the movers in the group that received vibration information into multiple groups and sending vibration commands simultaneously to each group, thereby identifying and individually identifying the movers to which vibration sensors are attached.

[0086] Furthermore, the linear motor control device 10 may simultaneously vibrate multiple movers at different accelerations. The linear motor control device 10 vibrates a first mover of M movers at a first acceleration and a second mover at a second acceleration. The linear motor control device 10 may simultaneously vibrate three or more movers at different accelerations.

[0087] When multiple movers are vibrated simultaneously at different accelerations, each vibration sensor 5P-5R transmits the detected acceleration as excess information to the linear motor control device 10. The individual identification unit 7 of the linear motor control device 10 acquires information on the acceleration used to vibrate each mover (hereinafter referred to as acceleration information) along with position information from the controller unit 1. The individual identification unit 7 acquires, for example, a first acceleration as the acceleration information of the first mover and a second acceleration as the acceleration information of the second mover. The individual identification unit 7 individually identifies the movers based on the position information, acceleration information, and detected acceleration.

[0088] For example, when M is 2 or greater and first to m-th movers (m is a natural number from 2 to M) of the M movers correspond to the first to m-th position information, the controller unit 1 vibrates the first to m-th movers at the first to m-th accelerations. The controller unit 1 associates the first to m-th acceleration information corresponding to the first to m-th accelerations with the first to m-th position information and transmits them to the individual identification unit 7. That is, the controller unit 1 associates the first acceleration information corresponding to the first acceleration with the first position information and transmits them to the individual identification unit 7. Similarly, the controller unit 1 associates the m-th acceleration information corresponding to the m-th acceleration with the m-th position information and transmits them to the individual identification unit 7.

[0089] The first to mth accelerations are, for example, 1 G to mG. That is, the first acceleration is 1 G, the second acceleration is 2 G, and the mth acceleration is mG. Note that the first to mth accelerations may be any accelerations as long as they are different from each other.

[0090] Each vibration sensor attached to the first to mth movable elements detects the first to mth accelerations and transmits vibration information including these detected values ​​(the first to mth detected accelerations) to the linear motor control device 10.

[0091] The individual identification unit 7 receives, for example, from the controller unit 1, a combination of first position information and first acceleration information, and a combination of mth position information and mth acceleration information. The individual identification unit 7 also receives a first detected acceleration from a first vibration sensor attached to the first mover, and receives an mth detected acceleration from an mth vibration sensor attached to the mth mover. In this case, the individual identification unit 7 determines that the mover that stopped at a position corresponding to the first position information is a mover to which the first vibration sensor is attached. Similarly, the individual identification unit 7 determines that the mover that stopped at a position corresponding to the mth position information is a mover to which the mth vibration sensor is attached.

[0092] When individually identifying m movers simultaneously, the linear motor control device 10 vibrates the m movers at m different accelerations. Therefore, when individually identifying one mover in turn, the linear motor control device 10 only needs to vibrate one mover at one type of acceleration, but when individually identifying multiple movers simultaneously, the linear motor control device 10 vibrates the movers at the same number of types of acceleration as the number of movers to be individually identified simultaneously.

[0093] Note that when a vibration sensor is attached to only one mover, the linear motor control device 10 may divide the mover into multiple groups and simultaneously vibrate the mover at a different acceleration for each group. For example, the linear motor control device 10 divides the mover into three groups. The linear motor control device 10 then simultaneously executes the following processes: sending a vibration command to all movers in the first group to vibrate them at a first acceleration, sending a vibration command to all movers in the second group to vibrate them at a second acceleration, and sending a vibration command to all movers in the third group to vibrate them at a third acceleration.

[0094] When the linear motor control device 10 receives vibration information including the first detected acceleration, it determines that a vibration sensor is attached to the mover of the first group. Similarly, when the linear motor control device 10 receives vibration information including the second detected acceleration, it determines that a vibration sensor is attached to the mover of the second group, and when the linear motor control device 10 receives vibration information including the third detected acceleration, it determines that a vibration sensor is attached to the mover of the third group.

[0095] The linear motor control device 10 further divides the movers of a group having a vibration sensor attached thereto into a plurality of groups, and transmits a vibration command to each group to vibrate them at a different acceleration.

[0096] The linear motor control device 10 repeats the process of dividing the movable elements into multiple groups, the process of sending vibration commands to vibrate each group at different accelerations, the process of identifying the group to which a vibration sensor is attached, and the process of dividing the movable elements in the group to which a vibration sensor is attached into multiple groups.

[0097] By repeating these processes, the linear motor control device 10 vibrates only one mover to which a vibration sensor is attached and receives vibration information from the vibration sensor of this mover, thereby specifying and individually identifying the mover to which the vibration sensor is attached.

[0098] In this way, the linear transport system 100 identifies the individual movers 4P to 4R without using a wireless tag or a wireless tag reader, and therefore, even if the transport route is long, the individual movers 4P to 4R can be identified at low cost.

[0099] Furthermore, the linear conveyance system 100 individually identifies the movers 4P to 4R based on the detected acceleration of the movers 4P to 4R, and therefore can individually identify the movers 4P to 4R with a short movement distance of the movers 4P to 4R.

[0100] Furthermore, the linear conveying system 100 performs individual identification of the movers 4P to 4R using vibration sensors 5P to 5R arranged on the movers 4P to 4R, so that the movers 4P to 4R can be individually identified even if the movers 4P to 4R are adjacent to each other.

[0101] In this way, the linear conveying system 100 does not use wireless tags or wireless tag readers, and can individually identify the movers 4P to 4R even when the movers 4P to 4R are adjacent to each other, even with short movements of the movers 4P to 4R, so it can be applied to a wide range of use cases (how the linear conveying system 100 is used and how the movers 4P to 4R are moved).

[0102] Furthermore, even for linear conveying systems that do not have the function of individually identifying the movable element, the function of individual identification can be easily added to the linear conveying system by retrofitting a vibration sensor to the movable element and applying the linear motor control device 10.

[0103] Next, we will explain the hardware configuration of the linear motor control device 10. The linear motor control device 10 is realized by a processing circuit. The processing circuit may be a processor and memory that executes a program stored in memory, or may be dedicated hardware.

[0104] FIG. 3 is a diagram showing an example of the configuration of a processing circuit provided in a linear motor control device according to an embodiment, when the processing circuit is realized by a processor and a memory. The processing circuit 90 shown in FIG. 3 includes a processor 91 and a memory 92. When the processing circuit 90 is configured with the processor 91 and the memory 92, each function of the processing circuit 90 is realized by software, firmware, or a combination of software and firmware. The software or firmware is written as a control program and stored in the memory 92. The processing circuit 90 realizes each function by having the processor 91 read and execute the control program stored in the memory 92. In other words, the processing circuit 90 includes the memory 92 for storing the control program that results in the processing of the linear motor control device 10 being executed.

[0105] This control program can also be said to be a program for causing the linear motor control device 10 to execute each function realized by the processing circuit 90. This control program may be provided by a computer-readable recording medium on which the control program is recorded, or may be provided by other means such as a communication medium.

[0106] The control program can also be said to be a program that causes the linear motor control device 10 to execute the processes of steps S10 to S50 in Fig. 2. Here, the processor 91 is, for example, a CPU (Central Processing Unit), a processing device, an arithmetic device, a microprocessor, a microcomputer, or a DSP (Digital Signal Processor). The memory 92 is, for example, a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable ROM), or an EEPROM (Electrically EPROM), a magnetic disk, a flexible disk, an optical disk, a compact disk, a minidisk, or a DVD (Digital Versatile Disc).

[0107] FIG. 4 is a diagram illustrating an example of a processing circuit provided in a linear motor control device according to an embodiment, configured with dedicated hardware. The processing circuit 93 illustrated in FIG. 4 may be, for example, 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 processing circuit 93 may be partially implemented with dedicated hardware and partially implemented with software or firmware. In this way, the processing circuit 93 can realize each of the above-described functions using dedicated hardware, software, firmware, or a combination thereof.

[0108] In this way, in the linear motor control device 10 of this embodiment, the controller unit 1 vibrates the movers 4P-4R at startup, and the individual identification unit 7 identifies the movers 4P-4R based on the position information of the vibrated movers and the vibration information detected by the vibration sensor attached to the movers. This allows the linear motor control device 10 to reduce the cost of identifying the movers even when the transport path is long.

[0109] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, and parts of the configurations may be omitted or modified without departing from the spirit of the invention.

[0110] 1 Controller unit, 2A to 2C Control unit, 3A to 3C Fixed unit, 4P to 4R Movable element, 5P to 5R Vibration sensor, 6 Vibration information acquisition unit, 7 Individual identification unit, 10 Linear motor control device, 20 Linear transport mechanism, 90, 93 Processing circuit, 91 Processor, 92 Memory, 100 Linear transport system.

Claims

1. A linear motor control device comprising: a controller unit that moves multiple movers having permanent magnets along a conveying path by controlling the flow of electricity to coils of fixed units that are arranged to form the conveying path; a vibration information acquisition unit that receives vibration information from vibration sensors attached to the movers, the vibration information including vibration sensor identification information that identifies the vibration sensor; and an individual identification unit that identifies the movers based on the vibration information, wherein the controller unit acquires and manages position information that is information about the position of the movers at the time of startup, and vibrates the movers based on the position information, and the individual identification unit receives from the controller unit position information of the movers that the controller unit has vibrated, and identifies the movers based on the position information and the vibration information.

2. The linear motor control device according to claim 1, wherein the controller vibrates the movers in sequence, and the individual identification unit identifies the movers in sequence.

3. The linear motor control device according to claim 1, wherein the controller unit simultaneously vibrates the plurality of movers at different accelerations, thereby allowing the individual identification unit to simultaneously identify the plurality of movers.

4. A linear motor control device as described in any one of claims 1 to 3, characterized in that the controller unit divides the multiple movers into multiple groups and vibrates each group, so that the vibration information acquisition unit receives the vibration information from a vibration sensor attached to only one of the movers, and the individual identification unit identifies the group to which the vibration sensor is attached from among the multiple groups based on the vibration information, and identifies the mover from among the identified group.

5. A linear motor control device as described in claim 4, characterized in that the individual identification unit identifies the movers by repeating the following processes: the controller unit divides the multiple movers into multiple groups for the group identified by the individual identification unit and vibrates each group; the vibration information acquisition unit receives the vibration information from a vibration sensor attached to only one of the movers; and the individual identification unit identifies the group to which the vibration sensor is attached from among the multiple groups based on the vibration information.

6. A linear motor control device as described in any one of claims 1 to 5, characterized in that the vibration information acquisition unit receives the vibration information including excess information indicating that the acceleration of the vibration has become higher than an acceleration threshold, and the individual identification unit identifies the mover based on the vibration information including the excess information.

7. A linear motor control device as described in any one of claims 1 to 5, characterized in that the vibration information acquisition unit receives the vibration information including a detected acceleration indicating the acceleration of the vibration as information about the vibration, and the individual identification unit determines whether the detected acceleration is higher than an acceleration threshold, and if the detected acceleration is higher than the acceleration threshold, identifies the mover based on the vibration information including the detected acceleration.

8. The linear motor control device according to any one of claims 1 to 7, wherein the controller unit causes the identified mover to perform an operation corresponding to the mover.

9. The linear motor control device according to any one of claims 1 to 8, wherein the controller stores information specific to each identified mover.

10. A linear transport system comprising the linear motor control device according to any one of claims 1 to 9.

11. The linear transport system according to claim 10, further comprising a control unit that energizes the coil of the fixed unit in accordance with instructions from the controller unit, detects the position of the mover, and transmits the position of the mover to the controller unit as the position information.

12. The linear transport system according to claim 10 or 11, further comprising the mover and the vibration sensor.

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