Linear conveyor device and method for controlling linear conveyor device

Abstract

In this linear conveyor device (100), a first control driver (151) controls a first rotor (321) and a second rotor (322) when both the first rotor (321) and the second rotor (322) are positioned above a first control coil (112a) connected to the first control driver (151). And a propulsive force reduction control for controlling the current of the first control coil so as to reduce the propulsive force applied by the first control coil to the first mover and the second mover.

Description

Technical Field

[0001] This invention relates to a linear conveyor device and a control method for the linear conveyor device, and more particularly to a linear conveyor device with a sliding element and a control method for the linear conveyor device. Background Technology

[0002] Previously, linear conveyor devices with sliding elements were known. Such linear conveyor devices are disclosed, for example, in International Publication No. 2020 / 225862.

[0003] International Publication No. 2020 / 225862 discloses a linear conveyor system (linear conveyor device) comprising: multiple sliding members, each having a mover of a linear motor; multiple electromagnets arranged in a predetermined direction as stators; and multiple servo units that apply a propulsive force to the movers of the linear motors by controlling the current of the multiple electromagnets. In this linear conveyor system, the multiple servo units control the current of several of the multiple electromagnets respectively.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2020 / 225862 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] Although not explicitly stated in Patent Document 1, in the linear conveyor system described in Patent Document 1, when two linear motor movers are simultaneously located above the electromagnet of the controlled object controlled by a servo unit, the propulsive force applied to one of the two linear motor movers is also applied to the other. Therefore, the minimum distance between the sliding members is sometimes determined such that the two linear motor movers are not simultaneously located above the electromagnet of the controlled object controlled by a servo unit. Specifically, the minimum distance between the sliding members is sometimes determined such that the two linear motor movers do not approach a distance smaller than the length of the electromagnet of the controlled object controlled by a servo unit. In this case, there is an undesirable situation where the minimum distance between the sliding members becomes relatively large, so it is desirable to reduce the minimum distance between the sliding members.

[0009] The present invention was made to solve the problems described above. One object of the present invention is to provide a linear conveyor device and a control method for the linear conveyor device that can reduce the minimum distance between sliding members.

[0010] Technical solutions for solving the problem

[0011] To achieve the above objectives, a linear conveyor apparatus according to a first aspect of the present invention comprises: a first sliding member having a first mover; a second sliding member having a second mover; a stator having a plurality of coils arranged along a predetermined direction; and a plurality of control drivers, each connected to a control coil among the plurality of coils, which apply a propulsive force along the predetermined direction to the first mover and the second mover by controlling the current of the control coil to which it is connected. When both the first mover and the second mover are located above the first control coil to which it is connected, the first control driver performs propulsive force reduction control by controlling the current of the first control coil to reduce the propulsive force applied by the first control coil to the first mover and the second mover.

[0012] In the linear conveyor apparatus of the first aspect of the present invention, as described above, the first control driver is configured to control the current of the first control coil to reduce the propulsion force exerted by the first control coil on the first and second movers when both the first and second movers are located above the first control coil to which they are connected, thereby reducing the propulsion force exerted by the first control coil on the first and second movers. Therefore, even when both the first and second movers are located above the first control coil, the influence of the first control coil can be reduced, and thus the first and second movers can be brought closer together to a distance smaller than the length of the first control coil. As a result, the minimum distance between the sliding members (between the first and second sliding members) can be reduced.

[0013] In the linear conveyor device of the first aspect described above, it is preferable that the first control driver reduces the propulsion force by preventing current from flowing through the first control coil when both the first and second movers are located above the first control coil. With this configuration, the influence of the first control coil can be easily reduced even when both the first and second movers are located above the first control coil, thus easily reducing the minimum distance between the sliding members (between the first and second sliding members).

[0014] In the linear conveyor device of the first aspect described above, it is preferable that the second control driver connected to the second control coil adjacent to the first control coil, when the first control driver performs thrust reduction control, increases the current of the second control coil to compensate for the decrease in thrust of one of the control movers, either the first or the second mover, located above the second control coil, caused by the thrust reduction control. With this configuration, the decrease in thrust caused by the thrust reduction control can be compensated, thus suppressing a decrease in the conveying speed of the first and second slide members. As a result, an increase in the conveying time of the first and second slide members can be suppressed.

[0015] In this case, it is preferable that the second control driver, when the first control driver performs thrust reduction control, increases the current of the second control coil to maintain thrust by compensating for the decrease in thrust caused by the thrust reduction control of the control mover. With this configuration, the decrease in thrust caused by the thrust reduction control can be compensated for, and thrust can be maintained, thus easily suppressing the decrease in the conveying speed of the first and second sliders. As a result, the increase in the conveying time of the first and second sliders can be easily suppressed.

[0016] In the aforementioned structure for compensating for the reduction in thrust, it is preferable that the second control actuator controls the current of the second control coil based on the overlap between the control mover and the first control coil to compensate for the reduction in thrust caused by the thrust reduction control. With this configuration, the current of the second control coil can be increased based on the overlap between the control mover and the first control coil, which is related to the reduction in thrust caused by the thrust reduction control, thus enabling high-precision compensation for the reduction in thrust.

[0017] In this case, it is preferable that the second control driver obtains the multiplier of the current command for the second control coil based on the overlap amount, and controls the increase of the current in the second control coil based on the obtained multiplier of the current command for the second control coil, so as to compensate for the reduction in thrust caused by the thrust reduction control of the control mover. If configured in this way, the current in the second control coil can be increased based on the multiplier of the current command obtained according to the overlap amount, so the reduction in thrust caused by the thrust reduction control can be easily and accurately compensated.

[0018] In the linear conveyor apparatus of the first aspect described above, it is preferable to further include a position detection unit for detecting the positions of the first mover and the second mover, and the first control driver performs thrust reduction control when the position detection unit detects that both the first mover and the second mover are above the first control coil. With this configuration, thrust reduction control can be performed when the position detection unit reliably detects that both the first mover and the second mover are above the first control coil.

[0019] In the linear conveyor device of the first aspect described above, it is preferable that the control coil is composed of one or more three-phase coils, and the first control driver performs thrust reduction control when both the first mover and the second mover are located above the first control coil composed of one or more three-phase coils. With this configuration, when using a control coil composed of one or more three-phase coils, where the minimum distance between the sliding members (between the first and second sliding members) tends to increase due to its large length, the minimum distance between the sliding members can be effectively reduced.

[0020] In the linear conveyor device of the first aspect described above, it is preferable that the control coil is composed of one phase of a three-phase coil, and the first control driver performs thrust reduction control when both the first mover and the second mover are located above the first control coil composed of one phase of the three-phase coil. With this configuration, when using a control coil composed of one phase of a three-phase coil, where the minimum distance between the sliding members (between the first and second sliding members) is easily reduced due to its short length, the minimum distance between the sliding members can be further reduced.

[0021] To achieve the above objective, in a control method for a linear conveyor apparatus according to a second aspect of the present invention, the linear conveyor apparatus includes: a first sliding member having a first mover; a second sliding member having a second mover; and a stator having a plurality of coils arranged along a predetermined direction. The control method for the linear conveyor apparatus includes the following steps: applying a propulsive force along a predetermined direction to the first mover and the second mover by controlling the current of the plurality of coils; and, when both the first mover and the second mover are located above a predetermined control coil among the plurality of coils, performing a propulsive force reduction control step of controlling the current of the predetermined control coil to reduce the propulsive force applied by the predetermined control coil to the first mover and the second mover.

[0022] In the control method of the linear conveyor device of the second aspect of the present invention, as described above, a step is provided in which, when both the first and second movers are located above a predetermined control coil among a plurality of coils, the current of the predetermined control coil is controlled to reduce the propulsion force exerted by the predetermined control coil on the first and second movers. Therefore, even when both the first and second movers are located above the predetermined control coil, the influence of the predetermined control coil can be reduced, thus allowing the first and second movers to approach each other within a distance less than the length of the predetermined control coil. As a result, a control method for a linear conveyor device that minimizes the spacing between the sliding members (between the first and second sliding members) is provided.

[0023] Invention Effects

[0024] According to the present invention, as described above, the minimum distance between the sliding elements can be reduced. Attached Figure Description

[0025] Figure 1 This is a schematic top view illustrating a linear conveyor device according to one embodiment of the present invention.

[0026] Figure 2 This is a schematic cross-sectional view showing the conveying section and sliding member of a linear conveyor device according to an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram illustrating the slider, coil, and control driver of a linear conveyor device according to an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram illustrating the control of the sliding element of a linear conveyor device according to an embodiment of the present invention.

[0029] Figure 5 This is a schematic diagram illustrating the operation of a sliding member of a linear conveyor device according to an embodiment of the present invention.

[0030] Figure 6 This is a flowchart illustrating the control processes related to the control of a slider according to an embodiment of the present invention.

[0031] Figure 7 It is used for explanation Figure 6 The flowchart details the processing of step S5.

[0032] Figure 8 This is a schematic diagram illustrating the control of the sliding member of a linear conveyor device according to a modified embodiment of the present invention. Detailed Implementation

[0033] Hereinafter, embodiments embodying the present invention will be described with reference to the accompanying drawings.

[0034] Reference Figures 1 to 5 The configuration of a linear conveyor device 100 according to one embodiment of the present invention will be described.

[0035] (Composition of a linear conveyor system)

[0036] The linear conveyor device 100 of this embodiment is configured to convey a transport object placed on a sliding member 30 along the conveyor section 1 and the conveyor section 2. Furthermore, the transport object conveyed by the linear conveyor device 100 is operated at multiple conveying positions. Operations on the transport object are performed by a robot or an operator.

[0037] like Figure 1As shown, the linear conveyor device 100 includes a conveying section 1, a conveying section 2, a transfer conveying section 3, a transfer conveying section 4, and a sliding member 30. Additionally, the linear conveyor device 100 includes a main controller 40.

[0038] Conveying section 1 includes multiple linear conveyor modules 10. Conveying section 2 includes multiple linear conveyor modules 10. The multiple linear conveyor modules 10 are connected in series to form the conveying path of the sliding member 30. The sliding member 30 is conveyed in the X direction in conveying section 1 and conveying section 2, and is conveyed from conveying section 1 (2) to conveying section 2 (1) in the Y direction by means of transfer conveying section 3 and transfer conveying section 4. That is, the sliding member 30 is conveyed cyclically between conveying section 1, transfer conveying section 3, conveying section 2, and transfer conveying section 4.

[0039] like Figure 2 As shown, the linear conveyor module 10 includes a stator 11, a magnetic sensor 12, a guide rail 13, and a cover 14. The magnetic sensor 12 is an example of a "position detection unit" within the protected area.

[0040] like Figure 1 As shown, the transfer conveying unit 3 and the transfer conveying unit 4 include a conveying mechanism 20 for conveying the sliding member 30 in the X direction and a moving mechanism for moving the conveying mechanism 20 in the Y direction. The conveying mechanism 20 has a stator 11 and a magnetic sensor 12. The moving mechanism has a guide rail and a ball screw mechanism.

[0041] like Figure 2 As shown, the slider 30 includes a slider body 31, a mover 32, a guide block 33, and a magnetic ruler 34. Multiple sliders 30 are provided. Furthermore, the multiple sliders 30 are configured to move independently on the conveying section 1, conveying section 2, transfer conveying section 3, and transfer conveying section 4.

[0042] Conveying units 1 and 2 are configured to move the slider 30 along the X direction. Furthermore, conveying units 1 and 2 are arranged substantially parallel to each other. Conveying unit 1 conveys the slider 30 in the X2 direction, and conveying unit 2 conveys the slider 30 in the X1 direction. Conveying units 1 and 2 are fixedly mounted on the frame. That is, the stator 11 and guide rail 13 of conveying units 1 and 2 are fixedly mounted.

[0043] The transfer conveying unit 3 is positioned adjacent to the conveying units 1 and 2 in the X2 direction. Furthermore, the transfer conveying unit 4 is positioned adjacent to the conveying units 1 and 2 in the X1 direction.

[0044] The stator 11 has multiple coils 111 arranged along the X direction and consisting of multiple three-phase coils (see reference). Figure 3 The slider 30 is moved by supplying current to multiple coils 111. The stator 11 is arranged along the X direction.

[0045] The magnetic sensor 12 is configured to detect the magnetism of the magnetic scale 34. Specifically, the magnetic sensor 12 is arranged facing the magnetic scale 34 of the slider 30 in the Y direction. The magnetic sensor 12 is configured to detect the position of the mover 32 (slider 30) by detecting the magnetism of the magnetic scale 34. In addition, multiple magnetic sensors 12 are arranged at intervals along the X direction.

[0046] The guide rails 13 are configured to extend along the X direction. A pair of guide rails 13 are spaced apart in the Y direction. The guide rails 13 are aligned between adjacent linear conveyor modules 10 in the X direction in a manner that allows the sliding members 30 to engage. The guide blocks 33 of the sliding members 30 engage with the guide rails 13 in a manner that allows them to move along the X direction.

[0047] The cover 14 is provided to cover the top of the stator 11, the magnetic sensor 12, and the guide rail 13. That is, the cover 14 is configured so that the top of the stator 11, the magnetic sensor 12, and the guide rail 13 are not exposed even when the slider 30 is not present.

[0048] The sliding body 31 is configured to hold the object to be conveyed. Furthermore, viewed from the X direction, the sliding body 31 is arranged to surround the cover 14 of the conveying section 1 and the conveying section 2. A mover 32, a guide block 33, and a magnetic scale 34 are mounted on the sliding body 31.

[0049] The mover 32 is arranged such that the stator 11 is clamped in the Y direction. The mover 32 has a permanent magnet and a back yoke for retaining the permanent magnet.

[0050] The guide block 33 is configured to move along the guide rail 13. The guide block 33 has multiple balls that circulate along the direction of movement.

[0051] The magnetic scale 34 is provided on the slider 30 in a manner that extends along the X direction. In addition, the magnetic scale 34 is provided for detecting the position of the mover 32 (slider 30).

[0052] The main controller 40 is configured to control the various parts of the linear conveyor device 100. The main controller 40 controls the power supplied to the stator 11 and controls the movement of the sliding member 30. Furthermore, the main controller 40 controls the driving of the moving mechanisms of the transfer conveyor section 3 and the transfer conveyor section 4, and controls the movement of the conveyor mechanism 20. The main controller 40 includes a CPU (central processing unit), memory, etc.

[0053] (Coil control)

[0054] like Figure 3As shown, the linear conveyor module 10 includes multiple control drivers 15. The multiple control drivers 15 control the current of multiple coils 111 based on control signals from the main controller 40. Each of the multiple control drivers 15 includes circuitry for controlling the current.

[0055] Multiple control actuators 15 are electrically connected to control coils 112, which are the objects of their control, in multiple coils 111. Each control actuator 15 applies a propulsive force along the X-direction to the mover 32 by controlling the current in its control coil 112. Each control actuator 15 obtains a current command for the control coil 112 based on control signals (position and speed commands) from the main controller 40, and controls the current in the control coil 112 based on the obtained current command.

[0056] In this embodiment, the control coil 112 is composed of multiple (two) three-phase coils. That is, the control coil 112 is composed of six coils 111: two U-phase coils 111, two V-phase coils 111, and two W-phase coils 111. The multiple three-phase coils constituting the control coil 112 are connected in series with each other.

[0057] Reference Figure 4 The thrust reduction control of this embodiment will be described below. Hereinafter, the control driver 15 performing the thrust reduction control will be referred to as the first control driver 151. The control coil 112 connected to the first control driver 151 will be referred to as the first control coil 112a. One of the two sliders 30 will be referred to as the first slider 301, and the other as the second slider 302. The mover 32 of the first slider 301 will be referred to as the first mover 321, and the mover 32 of the second slider 302 will be referred to as the second mover 322. The control coil 112 adjacent to the first control coil 112a will be referred to as the second control coil 112b, and the control driver 15 connected to the second control coil 112b will be referred to as the second control driver 152.

[0058] In this embodiment, as Figure 4As shown, when both the first mover 321 and the second mover 322 are above the first control coil 112a to which the first control driver 151 is connected, the first control driver 151 performs thrust reduction control to reduce the thrust exerted by the first control coil 112a on the first mover 321 and the second mover 322. Specifically, when both the first mover 321 and the second mover 322 are above the first control coil 112a, the first control driver 151 performs thrust reduction control in a manner that prevents current from flowing through the first control coil 112a. At this time, the first slider 301 (first mover 321) and the second slider 302 (second mover 322) can be brought close together to become the minimum distance P between the sliders 301 (between the first slider 301 and the second slider 302). The minimum distance P is the distance between the centers of the first slider 301 and the second slider 302 when the first slider 301 and the second slider 302 are closest. The minimum spacing P is the distance D between the end faces of the first mover 321 and the second mover 322, which is less than the length L1 of the first control coil 112a.

[0059] Furthermore, in this embodiment, the first control driver 151 performs thrust reduction control when the magnetic sensor 12 detects that both the first mover 321 and the second mover 322 are above the first control coil 112a. Additionally, in this embodiment, the first control driver 151 performs thrust reduction control when both the first mover 321 and the second mover 322 are above the first control coil 112a, which is composed of multiple three-phase coils.

[0060] Furthermore, in this embodiment, the second control driver 152, connected to the second control coil 112b adjacent to the first control coil 112a, increases the current in the second control coil 112b when the first control driver 151 performs thrust reduction control. This compensates for the reduction in thrust of one of the first movers 321 and 322 located above the second control coil 112b to which it is connected, caused by the thrust reduction control. Specifically, when the first control driver 151 performs thrust reduction control, the second control driver 152 increases the current in the second control coil 112b to maintain thrust by compensating for the reduction in thrust of the control mover caused by the thrust reduction control.

[0061] Furthermore, in this embodiment, the second control driver 152 controls the current of the second control coil 112b based on the overlap A between the control mover and the first control coil 112a, in order to compensate for the reduction in propulsion force caused by the propulsion force reduction control of the control mover. Specifically, the second control driver 152 obtains the multiplier of the current command of the second control coil 112b based on the overlap A, and controls the current of the second control coil 112b to increase based on the obtained multiplier of the current command of the second control coil 112b, in order to compensate for the reduction in propulsion force caused by the propulsion force reduction control of the control mover. At this time, the second control driver 152 obtains the multiplier of the current command of the second control coil 112b that maintains the propulsion force of the first mover 321 by the following formula (1).

[0062] MA={(A / L2)×2+1}···(1)

[0063] in,

[0064] MA: Current command multiplier;

[0065] A: The amount of overlap between the control rotor and the first control coil 112a;

[0066] L2: The total length of mover 32.

[0067] For example, a second control actuator 152 controls the first actuator 321, which acts as a control actuator. Figure 4 The second control driver 152 on the left side obtains the overlap A between the first mover 321 (which is a control mover) and the first control coil 112a based on the position information of the first mover 321 obtained by the magnetic sensor 12, and obtains the multiplier of the current command of the second control coil 112b to which it is connected based on the obtained overlap A. At this time, the second control driver 152 obtains the multiplier of the current command of the second control coil 112b to maintain the propulsion force of the first mover 321 by the above formula (1). Furthermore, the second control driver 152 performs control to increase the current of the second control coil 112b based on the current command that increases by the multiplier of the obtained current command. As a result, the propulsion force of the first mover 321 is maintained.

[0068] As a specific example, when the overlap A is 10mm and the total length L2 of the mover 32 (first mover 321) is 100mm, the current command multiplier is 1.2. Furthermore, the current command multiplier can also be obtained by adjusting the electrical angle of the three-phase coils.

[0069] Additionally, for example, a second control actuator 152 that controls the second actuator 322 as a control actuator ( Figure 4The second control driver 152 on the right side obtains the overlap A between the second mover 322 (which is a control mover) and the first control coil 112a based on the position information of the second mover 322 obtained by the magnetic sensor 12, and obtains the multiplier of the current command of the second control coil 112b to which it is connected based on the obtained overlap A. At this time, the second control driver 152 obtains the multiplier of the current command of the second control coil 112b to maintain the propulsion force of the second mover 322 by the above formula (1). Furthermore, the second control driver 152 performs control to increase the current of the second control coil 112b based on the current command that increases by the multiplier of the obtained current command. As a result, the propulsion force of the second mover 322 is maintained.

[0070] As a specific example, when the overlap A is 30mm and the total length L2 of the mover 32 (first mover 321) is 100mm, the current command multiplier is 1.6. Furthermore, the current command multiplier can also be obtained by adjusting the electrical angle of the three-phase coils.

[0071] Reference Figure 5 An example of the operation of the slider 30, which is accompanied by a reduction in propulsion force, will be explained. Here, an example of the operation in which the two sliders 30 move in the same direction with a minimum distance P will be explained.

[0072] like Figure 5 As shown, with only one mover 32 positioned above the control coil 112, normal slider control is performed. That is, the current to the control coil 112 is controlled by a current command equal to 1.

[0073] Furthermore, when both movers 32 (first mover 321 and second mover 322) are positioned above the control coil 112 (first control coil 112a), thrust reduction control is performed. That is, the current to the first control coil 112a is controlled by the first control driver 151 connected to the first control coil 112a, thereby reducing the thrust exerted by the first control coil 112a on the first mover 321 and the second mover 322. Specifically, the current to the first control coil 112a is controlled by the first control driver 151 in a manner that prevents current from flowing through the first control coil 112a.

[0074] Furthermore, by using a second control driver 152 connected to a second control coil 112b adjacent to the first control coil 112a, the current of the second control coil 112b is increased to compensate for the reduction in propulsion force of the control mover located above the second control coil 112b to which the second control driver 152 is connected, caused by the propulsion force reduction control. Specifically, the overlap A between the control mover and the first control coil 112a is obtained by the second control driver 152, and a multiplier of the current command for the second control coil 112b is obtained based on the obtained overlap A. At this time, the overlap A, which varies according to the movement of the first mover 321 and the second mover 322, is obtained sequentially, and a multiplier of the current command for the second control coil 112b is obtained sequentially. Therefore, the increase in the current of the second control coil 112b changes according to the movement of the first mover 321 and the second mover 322. For example, in Figure 5 In the second control coil 112b on the left side, the overlap A gradually decreases according to the movement of the first mover 321, therefore the multiplier of the current command of the second control coil 112b gradually decreases, and the increase in current of the second control coil 112b varies in a gradually decreasing manner. Additionally, for example, in... Figure 5 In the second control coil 112b on the right, the overlap A gradually increases according to the movement of the second mover 322. Therefore, the multiplier of the current command of the second control coil 112b gradually increases, and the increase in the current of the second control coil 112b changes in a gradually increasing manner.

[0075] Furthermore, when only one mover 32 is positioned above the control coil 112, normal slider control is performed. That is, the current to the control coil 112 is controlled by a current command of 1 times the rated current. While performing this control, the slider 30 is operated in conjunction with the thrust reduction control.

[0076] Furthermore, although an example of two sliders 30 moving in the same direction with a minimum distance P has been described, the operation of the sliders 30 with thrust reduction control is not limited to this. For example, the operation of the sliders 30 with thrust reduction control also occurs when the two sliders 30 move in opposite directions from the minimum distance P state. Additionally, the operation of the sliders 30 with thrust reduction control also occurs when one slider 30 approaches another slider 30 with the two sliders 30 at a minimum distance P. Furthermore, the operation of the sliders 30 with thrust reduction control also occurs even when the two sliders 30 are not at a minimum distance P, but when the two movers 32 are located above a control coil 112.

[0077] (Control processing related to the control of the slider)

[0078] Reference Figure 6 and Figure 7 The flowchart illustrates the control processes related to the control of the slider 30. Furthermore, each process in the flowchart is performed by the control driver 15.

[0079] like Figure 6 As shown, firstly, in step S1, it is determined whether the two sliders 30 (movers 32) are located above the control coil 112 to which they are connected. If it is determined that the two sliders 30 (movers 32) are located above the control coil 112 to which they are connected, the process proceeds to step S2. Then, in step S2, thrust reduction control is performed. Then, in step S3, the adjacent control driver 15 (second control driver 152) is notified that thrust reduction control is in progress. In steps S2 and S3, control driver 15 functions as first control driver 151.

[0080] Furthermore, in step S2, if it is determined that neither of the two sliders 30 (movers 32) is above the control coil 112 to which it is connected, proceed to step S4. Then, in step S4, it is determined whether one slider 30 (mover 32) is above the control coil 112 to which it is connected. If it is determined that one slider 30 (mover 32) is above the control coil 112 to which it is connected, proceed to step S5. Then, in step S5, slider control is implemented. The details of slider control will be described later.

[0081] Furthermore, in step S4, if it is determined that a slider 30 (mover 32) is not located above the control coil 112 to which it is connected, the process proceeds to step S6. Then, in step S6, it is determined that slider control will not be performed.

[0082] Reference Figure 7 The details of the slider control in step S5 will be explained.

[0083] like Figure 7 As shown, firstly, in step S11, a current command for the control coil 112 is obtained. Then, in step S12, it is determined whether the adjacent control driver 15 is under thrust reduction control. If it is determined that the adjacent control driver 15 is under thrust reduction control, the process proceeds to step S13. Then, in step S13, a multiplier greater than 1 is obtained based on the overlap amount A. Then, after passing through step S13, in step S14, the current command is multiplied by a multiplier greater than 1, and in step S15, slider control is performed based on the current command multiplied by a multiplier greater than 1. In steps S13, S14, and S15, the control driver 15 functions as a second control driver 152.

[0084] Additionally, in step S12, if it is determined that the adjacent control driver 15 is not under thrust reduction control, the process proceeds to step S16. Then, in step S16, a multiplier of the current command is obtained. Then, following step S16, in step S14, the current command is multiplied by the multiplier, and in step S15, slider control (normal slider control) is performed based on the current command multiplied by the multiplier.

[0085] (Effects of this implementation method)

[0086] In this embodiment, the following effects can be achieved.

[0087] In this embodiment, as described above, the first control driver 151 is configured to control the current of the first control coil 112a to reduce the thrust exerted by the first control coil 112a on the first control driver 151 when both the first mover 321 and the second mover 322 are located above the first control coil 112a to which the first control driver 151 is connected. Therefore, even when both the first mover 321 and the second mover 322 are located above the first control coil 112a, the influence of the first control coil 112a can be reduced, thus allowing the first mover 321 and the second mover 322 to approach each other within a distance smaller than the length L1 of the first control coil 112a. As a result, the minimum distance P between the sliders 30 (between the first slider 301 and the second slider 302) can be reduced.

[0088] Furthermore, reducing the minimum distance P between the sliders 30 can improve space efficiency. For example, if the minimum distance P between the sliders 30 is large, it is sometimes impossible to arrange adjacent processes close together, resulting in a larger distance between processes. In contrast, by reducing the minimum distance P between the sliders 30, adjacent processes can be arranged closer together, reducing the distance between processes. Additionally, for example, if the minimum distance P between the sliders 30 is large, it is sometimes impossible to arrange the sliders 30 waiting for work close to each other, resulting in a larger waiting space for the sliders 30. In contrast, by reducing the minimum distance P between the sliders 30, the sliders 30 waiting for work can be arranged close to each other, reducing the waiting space for the sliders 30. Furthermore, by improving space efficiency, the linear conveyor device 100 can be made more compact.

[0089] Furthermore, in this embodiment, as described above, the first control driver 151 performs thrust reduction control in a manner that prevents current from flowing through the first control coil 112a when both the first mover 321 and the second mover 322 are located above the first control coil 112a. Therefore, even when both the first mover 321 and the second mover 322 are located above the first control coil 112a, the influence of the first control coil 112a can be easily reduced, thus making it easy to reduce the minimum distance P between the sliders 30 (between the first slider 301 and the second slider 302).

[0090] Furthermore, in this embodiment, as described above, the second control driver 152, connected to the second control coil 112b adjacent to the first control coil 112a, controls the current of the second control coil 112b to increase when the first control driver 151 performs thrust reduction control. This compensates for the decrease in thrust of one of the control movers 321 and 322 located above the second control coil 112b caused by the thrust reduction control. Therefore, the decrease in thrust caused by the thrust reduction control can be compensated, thus suppressing the reduction in the conveying speed of the first slider 301 and the second slider 302. As a result, the increase in the conveying time of the first slider 301 and the second slider 302 can be suppressed.

[0091] Furthermore, in this embodiment, as described above, when the first control driver 151 performs thrust reduction control, the second control driver 152 controls the current of the second control coil 112b to increase the thrust by compensating for the decrease in thrust caused by the thrust reduction control of the control mover. Therefore, by compensating for the decrease in thrust caused by the thrust reduction control to maintain the thrust, the decrease in the conveying speed of the first slider 301 and the second slider 302 can be easily suppressed. As a result, the increase in the conveying time of the first slider 301 and the second slider 302 can be easily suppressed.

[0092] Furthermore, in this embodiment, as described above, the second control driver 152 controls the increase of the current in the second control coil 112b based on the overlap A between the control mover and the first control coil 112a, in order to compensate for the reduction in thrust caused by the thrust reduction control. Therefore, by increasing the current in the second control coil 112b based on the overlap A between the control mover and the first control coil 112a, which is related to the reduction in thrust caused by the thrust reduction control, it is possible to compensate for the reduction in thrust caused by the thrust reduction control with high precision.

[0093] Furthermore, in this embodiment, as described above, the second control driver 152 obtains the multiplier of the current command for the second control coil 112b based on the overlap amount A, and controls the increase of the current in the second control coil 112b based on the obtained multiplier of the current command for the second control coil 112b, in order to compensate for the reduction in thrust caused by the thrust reduction control of the control mover. Therefore, the current in the second control coil 112b can be increased based on the multiplier of the current command obtained according to the overlap amount A, thus enabling easy and high-precision compensation for the reduction in thrust caused by the thrust reduction control.

[0094] Furthermore, in this embodiment, as described above, a magnetic sensor 12 is also provided for detecting the positions of the first mover 321 and the second mover 322. The first control driver 151 performs thrust reduction control when the magnetic sensor 12 detects that both the first mover 321 and the second mover 322 are above the first control coil 112a. Therefore, thrust reduction control can be performed when the magnetic sensor 12 reliably detects that both the first mover 321 and the second mover 322 are above the first control coil 112a.

[0095] Furthermore, in this embodiment, as described above, the control coil 112 is composed of multiple three-phase coils. When the first control driver 151 is positioned above both the first mover 321 and the second mover 322, which are both composed of multiple three-phase coils, it performs thrust reduction control. Therefore, when using a control coil composed of multiple three-phase coils, where the minimum distance P between the sliders 30 (between the first slider 301 and the second slider 302) tends to be large due to its long length, the minimum distance P between the sliders 30 can be effectively reduced.

[0096] (Modified example)

[0097] Furthermore, the embodiments disclosed herein should be considered illustrative rather than restrictive in all respects. The scope of the invention is not indicated by the description of the embodiments above, but by the scope of the claims, and includes all modifications (variations) within the scope and meaning of the claims.

[0098] For example, in the above embodiment, an example of thrust reduction control is shown in which current does not flow through the first control coil, but the present invention is not limited thereto. For example, if the thrust applied by the first control coil to the first and second movers is reduced, thrust reduction control can also be performed by allowing current to flow through the first control coil.

[0099] Furthermore, in the above embodiments, an example was shown where the current of the second control coil was increased to maintain the thrust by compensating for the decrease in thrust caused by the thrust reduction control of the control rotor; however, the present invention is not limited thereto. For example, if the decrease in thrust caused by the thrust reduction control of the control rotor is compensated for, the current of the second control coil may be increased by an amount smaller than that required to maintain the thrust.

[0100] Furthermore, while the above embodiment illustrates an example of using a magnetic sensor as a position detection unit, the present invention is not limited thereto. For example, components other than a magnetic sensor may be used as the position detection unit.

[0101] Furthermore, in the above embodiments, an example is shown where the control coil is composed of two three-phase coils, but the present invention is not limited thereto. For example, the control coil may also be composed of one or more three-phase coils. Additionally, as... Figure 8 As shown in the variant example, the control coil 112 can also be composed of one phase of a three-phase coil. In this case, the first control driver 151 performs thrust reduction control when both the first mover 321 and the second mover 322 are located above the first control coil 112a composed of one phase of the three-phase coil. Thus, when using the control coil 112 composed of one phase of the three-phase coil, which is easy to reduce the minimum distance P between the sliders 30 (between the first slider 301 and the second slider 302) due to its short length, the minimum distance P between the sliders 30 can be further reduced.

[0102] Furthermore, in the above embodiment, an example was shown where the first control driver performs thrust reduction control regardless of the overlap between the first control coil and the first or second mover, when both the first and second movers are located above the first control coil to which the first control driver is connected. However, the present invention is not limited to this. For example, the first control driver may also be configured to perform thrust reduction control when the overlap between the first control coil to which the first control driver is connected and the first or second mover is greater than a predetermined value.

[0103] Furthermore, in the above embodiment, an example was shown where the second control driver increases the current of the second control coil based on the overlap between the control mover and the first control coil, but the present invention is not limited thereto. For example, when the first slider approaches the second slider, the second control driver corresponding to the first slider may increase the current of the second control coil by an amount greater than the increase based on the overlap between the control mover and the first control coil. Alternatively, the second control driver corresponding to the second slider may increase the current of the second control coil by an amount smaller than the increase based on the overlap between the control mover and the first control coil. Therefore, when the first slider approaches the second slider, the risk of interference between the first and second sliders can be reduced.

[0104] Furthermore, in the above embodiments, for ease of explanation, a process-driven process that processes sequentially according to a processing flow was used to illustrate the control processing, but the present invention is not limited to this. In the present invention, control processing can also be performed using an event-driven process that executes processing on an event-by-event basis. In this case, it can be performed entirely as an event-driven process, or it can be performed as a combination of event-driven and process-driven processes.

[0105] Explanation of reference numerals in the attached figures

[0106] 11. Stator;

[0107] 12. Magnetic sensor (position detection unit);

[0108] 15. Control driver;

[0109] 100 linear conveyor system;

[0110] 111 coil;

[0111] 112 Control coil;

[0112] 112a First control coil;

[0113] 112b Second control coil;

[0114] 151 First control driver;

[0115] 152 Second control driver;

[0116] 301 First sliding member;

[0117] 302 Second sliding member;

[0118] 321 First mover;

[0119] 322 Second mover;

[0120] A. Overlap amount.

Claims

1. A linear conveyor device, comprising: The first sliding member has a first moving element; The second slider has a second mover; The stator has multiple coils arranged in a specified direction; as well as Multiple control actuators are connected to control coils among the multiple coils, and by controlling the current in the control coils to which they are connected, they apply a propulsive force along the predetermined direction to the first and second movers. When both the first mover and the second mover are located above the first control coil to which the first control driver is connected, the first control driver performs thrust reduction control to control the current of the first control coil so as to reduce the thrust applied by the first control coil to the first mover and the second mover.

2. The linear conveyor device according to claim 1, wherein, The first control driver performs the thrust reduction control in a manner that prevents current from flowing through the first control coil when both the first mover and the second mover are above the first control coil.

3. The linear conveyor device according to claim 1, wherein, A second control driver connected to a second control coil adjacent to the first control coil controls the current of the second control coil to increase the thrust reduction control when the first control driver performs the thrust reduction control, in order to compensate for the reduction in thrust of one of the first and second movers located above the second control coil caused by the thrust reduction control.

4. The linear conveyor device according to claim 3, wherein, When the first control driver performs the thrust reduction control, the second control driver increases the current of the second control coil to maintain thrust by compensating for the reduction in thrust of the control mover caused by the thrust reduction control.

5. The linear conveyor device according to claim 3, wherein, The second control driver controls the current of the second control coil to increase based on the overlap between the control mover and the first control coil, in order to compensate for the reduction in thrust of the control mover caused by the thrust reduction control.

6. The linear conveyor device according to claim 5, wherein, The second control driver obtains the multiplier of the current command of the second control coil based on the overlap amount, and controls the current of the second control coil to increase based on the obtained multiplier of the current command of the second control coil, so as to compensate for the reduction in thrust of the control mover caused by the thrust reduction control.

7. The linear conveyor device according to claim 1, wherein, The linear conveyor device also includes a position detection unit for detecting the positions of the first mover and the second mover. The first control driver performs the thrust reduction control when the position detection unit detects that both the first mover and the second mover are above the first control coil.

8. The linear conveyor device according to claim 1, wherein, The control coil consists of one or more three-phase coils. The first control driver performs the thrust reduction control when both the first mover and the second mover are located above the first control coil, which is composed of one or more of the three-phase coils.

9. The linear conveyor device according to claim 1, wherein, The control coil consists of one phase of a three-phase coil. The first control driver performs the thrust reduction control when both the first mover and the second mover are located above the first control coil, which is composed of one phase of the three-phase coil.

10. A control method for a linear conveyor device, the linear conveyor device comprising: a first slider having a first mover; a second slider having a second mover; and a stator having a plurality of coils arranged along a predetermined direction, wherein, The control method for the linear conveyor device includes the following steps: By controlling the current in the plurality of coils, a propulsive force is applied to the first mover and the second mover along the predetermined direction; and When both the first mover and the second mover are located above a predetermined control coil among the plurality of coils, thrust reduction control is performed to control the current of the predetermined control coil so as to reduce the thrust applied by the predetermined control coil to the first mover and the second mover.

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