Transport system

Abstract

The transport system includes a plurality of transport vehicles and a controller. The travel path has a first path, a second path, and a merging portion where the first path and the second path merge. The controller executes either a priority control for causing a transport vehicle traveling on one of a first route and a second route set as a priority route to pass through the confluence section preferentially than a transport vehicle traveling on the other route, or a non-priority control for causing a transport vehicle traveling on the other route to pass through the confluence section preferentially. The non-priority control is a control for causing the transport vehicle to pass through the confluence section so that the transport vehicle does not differ in quality due to which one of the first path and the second path is traveling, and when a jam of the transport vehicle occurs in a predetermined determination target area upstream of the confluence section in the first path or the second path. The controller executes non-priority control when the congestion of the transport vehicle does not occur in the determination target area, and executes priority control when the congestion of the transport vehicle does not occur in the determination target area.

Description

TECHNICAL FIELD

[0001] The present application relates to a transport system. BACKGROUND

[0002] As described in Patent Literature 1, a transport system (transport vehicle system) is known, which has a travel path having a first path, a second path having a standby section, and a merging section at which the first path and the second path merge, a plurality of transport vehicles that travel on the travel path, and a controller that controls travel of the plurality of transport vehicles. In the transport system, until a prescribed number of transport vehicles are stopped at the standby section of the second path, the transport vehicles traveling on the second path are caused to wait at the standby section, and the transport vehicles traveling on the first path are caused to continuously pass through the merging section.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: International Publication No. 2010 / 035411 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] However, in the above-described conventional system, until a prescribed number of transport vehicles are stopped at the standby section of the second path, the transport vehicles are stopped at the standby section. When the waiting time of the transport vehicles at the standby section is too long, the transport vehicles are left waiting at the standby section for a long time, and thus the transport efficiency is reduced. In order to prevent the waiting time of the transport vehicles at the standby section from becoming too long, a limit is set on the waiting time, and control is executed to cause the transport vehicles for which the waiting time becomes equal to or longer than the prescribed time to travel on other travel paths to bypass the merging section (Dead Lock Escape (DLE)). However, bypassing the merging section increases the travel distance of the transport vehicles, and as a result, the transport efficiency is reduced.

[0008] In order to address such a problem, control is executed by the controller to cause the transport vehicles traveling on the first path and the transport vehicles traveling on the second path to alternately pass through the merging section, so as to suppress the occurrence of the transport vehicles waiting at the standby section. However, the transport vehicles repeatedly start and stop, and as a result, the transport efficiency is reduced.

[0009] The present disclosure describes a transport system that can improve transport efficiency.

[0010] TECHNICAL MEANS FOR SOLVING THE PROBLEMS

[0011] The transport system of one embodiment of the present application includes: a plurality of transport vehicles that travel on travel paths to transport articles; and a controller that controls travel of the plurality of transport vehicles. The travel paths include a first path, a second path different from the first path, and a confluence portion at which the first path and the second path confluence. The controller performs either priority control or non-priority control. The priority control is control that gives priority to a transport vehicle that travels on one of the first path and the second path set as a priority path over a transport vehicle that travels on the other of the first path and the second path in passing through the confluence portion. The non-priority control is control that allows a transport vehicle to pass through the confluence portion without distinction as to which of the first path and the second path the transport vehicle travels on. When congestion of transport vehicles occurs in a predetermined determination target region on an upstream side of the confluence portion in the first path or the second path, the controller performs the non-priority control. When congestion of transport vehicles does not occur in the determination target region, the controller performs the priority control.

[0012] In the transport system, the controller performs the non-priority control when congestion of transport vehicles occurs in the determination target region. In the non-priority control, a transport vehicle is allowed to pass through the confluence portion without distinction as to which of the first path and the second path the transport vehicle travels on, and thus, it is possible to eliminate congestion of transport vehicles in the determination target region. In the transport system, the controller performs the priority control when congestion of transport vehicles does not occur in the determination target region. In the priority control, a transport vehicle that travels on one of the first path and the second path set as a priority path is given priority over a transport vehicle that travels on the other of the first path and the second path in passing through the confluence portion. Thus, when the transport vehicle that travels on one of the first path and the second path passes through the confluence portion, it is not necessary to wait until the transport vehicle that travels on the other of the first path and the second path passes through the confluence portion. As a result, the transport vehicle that travels on one of the first path and the second path can pass through the confluence portion without repeated start and stop. According to the above, it is possible to improve transport efficiency.

[0013] In the non-priority control, the transport vehicle that travels on the first path and the transport vehicle that travels on the second path can be alternately allowed to pass through the confluence portion. In this case, by alternately allowing the transport vehicle that travels on the first path and the transport vehicle that travels on the second path to pass through the confluence portion, it is possible to reliably eliminate congestion of transport vehicles in the determination target region.

[0014] The controller can determine that congestion of transport vehicles occurs in the determination target region when there are a predetermined number or more of transport vehicles that are positioned at a distance of a predetermined distance or less from a transport vehicle located in front of the own vehicle in the determination target region. In this case, it is possible to determine the presence or absence of congestion of transport vehicles on the basis of the number of transport vehicles that approach each other in the determination target region. Thus, it is possible to easily determine congestion of transport vehicles in the determination target region.

[0015] The carrier can also have a measurement unit that measures the distance to a carrier located in front of the carrier, and a travel control unit that stops the carrier when the distance is equal to or less than a predetermined distance. When the number of carriers stopped by the control of the travel control unit in the determination target area is equal to or more than a predetermined number, the controller determines that a carrier congestion has occurred in the determination target area. In this case, the presence or absence of a carrier congestion can be determined based on the number of carriers stopped by the control of the travel control unit in the determination target area. Thus, the carrier congestion in the determination target area can be more easily determined.

[0016] The determination target area can include a connection path connected to the merging portion, and a plurality of merging paths merging into the connection path. For example, when the connection path does not have a sufficient length, or the like, it can be difficult to determine the presence or absence of a congestion only from the travel conditions on the connection path. By considering not only the connection path but also the number of carriers on the plurality of merging paths, or the like, the congestion can be accurately determined regardless of the layout of the travel path.

[0017] Effects of the Invention

[0018] According to the present application, the carrying efficiency can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a general view of a carrying system according to an embodiment.

[0020] Figure 2 is a block diagram showing the functional structure of a controller and a carrier according to an embodiment.

[0021] Figure 3 is a view showing a procedure in the operation of a carrying system.

[0022] Figure 4 is a view showing a procedure after the procedure shown in Figure 3

[0023] Figure 5 is a view showing a procedure after the procedure shown in Figure 4

[0024] Figure 6 is a view showing a procedure after the procedure shown in Figure 5

[0025] Figure 7 is a view showing a procedure after the procedure shown in Figure 6

[0026] Figure 8 is a view showing a procedure after the procedure shown in Figure 7

[0027] ​​​​​Figure 9 is a view showing a procedure after the procedure shown in Figure 8 DETAILED DESCRIPTION

[0028] Embodiments of the present application will be described below with reference to the accompanying drawings. In addition, in the description of the drawings, the same reference numerals are applied to the same components, and repetitive description is omitted.

[0029] First, with reference to Figure 1 and Figure 2 , a summary of the conveyance system 1 will be described. As shown in Figure 1 , the conveyance system 1 constitutes a system that conveys articles (not shown). The articles are, for example, containers such as Front Opening Unified Pods (FOUPs) that house a plurality of semiconductor wafers. The articles can also be reticle pods that house glass substrates, or other general components, and the like. The conveyance system 1 has a track (travel path) 2, a plurality of conveyance vehicles 3, and a controller 4.

[0030] The track 2 is a predetermined travel road for the conveyance vehicles 3 to travel. The track 2 is, for example, laid near the ceiling space, i.e., the ceiling, of the head of a worker. The track 2 is, for example, suspended from the ceiling via a plurality of supports (not shown). The track 2 is formed by a plurality of path portions 20 being connected to each other. The track 2 has a merging portion 21 where a plurality of path portions 20 merge, and a branching portion 22 where one path portion 20 branches into a plurality of path portions 20. The layout of the track 2 (the shape, length, and arrangement of the path portions 20, and the positions of the merging portion 21 and the branching portion 22) is not particularly limited, and various layouts can be adopted.

[0031] The plurality of path portions 20 are, for example, constituted by a plurality of straight paths 23 and a plurality of curved paths 24. In the example shown in Figure 1 , the plurality of straight paths 23 include a plurality of first straight paths 27, a second straight path 28, and a third straight path 29 that extend in a constant direction. The second straight path 28 is arranged between the first straight path 27 and the third straight path 29. Although not shown, there are a plurality of straight paths that extend in a direction other than the constant direction (for example, in a direction orthogonal to the constant direction), as a whole of the track 2. In the present specification, the terms "upstream side" and "downstream side" are used with reference to the travel direction of the conveyance vehicles 3.

[0032] ​The curved paths 24 branch via a branch portion 22 of the middle of one of the straight paths 23 and merge via a merging portion 21 of the middle of the other straight path 23. The plurality of curved paths 24 includes an S-shaped path 25 and a U-shaped path 26. The S-shaped path 25 is a path for changing the straight path 23 on which the vehicle 3 travels without changing the traveling direction of the vehicle 3. In the present embodiment, the S-shaped path 25 links a first straight path 27 and a second straight path 28 to each other. The U-shaped path 26 is a path for changing the straight path 23 on which the vehicle 3 travels with changing the traveling direction of the vehicle 3. The U-shaped path 26 links the second straight path 28 and a third straight path 29 to each other. In the present embodiment, the U-shaped path 26 is located on the downstream side of the S-shaped path 25. Figure 1

[0033] Hereinafter, the merging portion 21 at which the U-shaped path 26 and the third straight path 29 merge will be referred to as a merging portion 21a, and the merging portion 21 at which the S-shaped path 25 and the second straight path 28 merge will be referred to as a merging portion 21b. Also, the branch portion 22 at which the second straight path 28 branches to the U-shaped path 26 will be referred to as a branch portion 22a, and the branch portion 22 at which the first straight path 27 branches to the S-shaped path 25 will be referred to as a branch portion 22b.

[0034] If the track 2 is described from a different viewpoint from the above description, the track 2 has a first path R1, a second path R2 different from the first path R1, and a merging portion 21 at which the first path R1 and the second path R2 merge. Both the first path R1 and the second path R2 are paths on the upstream side of the merging portion 21 and connected to the merging portion 21. The first path R1 merging into the merging portion 21a includes a connection path 51 connected to the merging portion 21a and a plurality of merging paths 52 merging into the connection path 51 at the merging portion 21b. The second path R2 merging into the merging portion 21a includes, for example, a portion of the third straight path 29 on the upstream side of the merging portion 21a.

[0035] In the present embodiment, the connection path 51 is constituted by the U-shaped path 26 and a portion of the second straight path 28 on the upstream side of the branch portion 22a and on the downstream side of the merging portion 21b. The plurality of merging paths 52 includes a portion of the second straight path 28 on the upstream side of the merging portion 21b. The plurality of merging paths 52 includes the S-shaped path 25 and a portion of the first straight path 27 on the upstream side of the branch portion 22b.

[0036] ​A plurality of stop points T are provided on track 2 to stop the transport vehicle 3. Stop points T are set at predetermined locations. Stop points T are set based on, for example, a plurality of dot marks (not shown) such as barcodes affixed at constant intervals along track 2. In the diagram, stop points T are represented by dashed circles on track 2.

[0037] The transport vehicle 3 travels along the track 2 in the direction of travel to transport items. The transport vehicle 3 transports items based, for example, on transport instructions assigned by the controller 4. These transport instructions include, for example, information related to the transfer of items from the transport source, travel along the path from the transport source to the transport destination, and the transfer of items to the transport destination. The transport vehicle 3 is configured to transport items to a port (not shown). The transport vehicle 3 is a roof-mounted unmanned vehicle. The transport vehicle 3 is also referred to, for example, as a traveling vehicle, transport trolley, or roof-mounted vehicle (roof-mounted trolley). The number of transport vehicles 3 in the transport system 1 is not particularly limited.

[0038] The transport vehicle 3, for example, includes a traveling unit (not shown), an θ-drive, a lateral conveying unit, a lifting drive, and a lifting platform. The traveling unit causes the transport vehicle 3 to travel along the track 2. The θ-drive causes the lifting drive to rotate in the horizontal plane to control the posture of the items. The lateral conveying unit laterally conveys the portion lower than the θ-drive relative to the track 2. The lifting drive causes the lifting platform, which holds the items, to rise and fall. A chuck is provided on the lifting platform, which is configured to freely grip or release items. However, the structure of the transport vehicle 3 can be appropriately modified.

[0039] like Figure 2 As shown, the transport vehicle 3 has a position acquisition unit 31, a measurement unit 32, and a travel control unit 33 as functional structures. The position acquisition unit 31 acquires position information indicating the position of the transport vehicle 3 on the track 2. The position acquisition unit 31 is composed, for example, of a reading unit that reads the point marks on the track 2 and an encoder. The position information includes, for example, information about the point marks obtained by the reading unit and information related to the travel distance after passing the point marks. The position acquisition unit 31 sends the acquired position information to the travel control unit 33.

[0040] The measuring unit 32 measures the distance between the vehicle (the transport vehicle 3 equipped with the measuring unit 32) and the transport vehicle 3 located in front of the vehicle. "In front" refers to the direction in which the transport vehicle 3 is traveling. The measuring unit 32 is, for example, a distance sensor that detects the interval between the vehicle and the transport vehicle 3 located in front of the vehicle. The measuring unit 32, for example, emits a laser beam towards the front of the vehicle and detects the reflected light reflected by the reflector of the transport vehicle 3 in front, thereby detecting the distance between the vehicle and the transport vehicle 3 in front of the vehicle. The measuring unit 32 sends the measured distance to the driving control unit 33.

[0041] The travel control section 33 is an electronic control unit constituted by a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and the like. The travel control section 33 can be constituted by software that loads a program stored in the ROM onto the RAM and executes the program by the CPU, for example. The travel control section 33 can also be constituted by hardware based on a circuit or the like.

[0042] The travel control section 33 controls various movements of the truck 3. The travel control section 33 controls the travel section and the measurement section 32. The travel control section 33 can communicate with the controller 4. The travel control section 33 can communicate with the controller 4 via a power supply line or the like of the track 2, for example, or via a communication line (a feeder line or the like) provided along the track 2 other than the power supply line. The travel control section 33 transmits a status report of the truck to the controller 4 when receiving a status inquiry from the controller 4.

[0043] The travel control section 33 determines whether the distance between the truck and the truck in front of the truck 3 is equal to or less than a prescribed distance based on the detection result of the measurement section 32. The prescribed distance is set in advance, for example, and can be appropriately changed. The travel control section 33 performs stop control to stop the truck by controlling the travel section when the distance is equal to or less than the prescribed distance. The travel control section 33 includes the position information acquired by the position acquisition section 31 and information indicating that the stop control is being performed in the status report and transmits the status report to the controller 4.

[0044] The travel control section 33 stores the layout of the track 2 in advance. The layout of the track 2 includes information indicating the positions of each path portion 20, each merging portion 21, and each branching portion 22. The travel control section 33 determines whether the truck wants to pass through the merging portion 21 based on the travel speed of the truck set in advance, the layout of the track 2, and the position information of the truck. The travel control section 33 determines that the truck wants to pass through the merging portion 21, for example, when the position at which the time required for travel to reach the merging portion 21 is less than a prescribed time.

[0045] The travel control section 33 determines whether the truck wants to pass through the branching portion 22 based on the travel speed of the truck set in advance, the layout of the track 2, and the position information of the truck. The travel control section 33 determines that the truck wants to pass through the branching portion 22, for example, when the position at which the time required for travel to reach the branching portion 22 is less than a prescribed time.

[0046] The travel control section 33 includes the merge passage permission request in the state report and transmits it to the controller 4 in the vicinity of the merge section 21 when the own vehicle wants to pass through the merge section 21. The travel control section 33 transmits the merge passage permission request to the controller 4, for example, at the timing when the distance from the own vehicle to the merge section 21 becomes equal to or less than a prescribed distance. The prescribed distance is set in advance, for example, as 8 m. The prescribed distance can be appropriately changed. The merge passage permission request is a signal that requests permission to pass through the merge section 21. The travel control section 33 causes the own vehicle to enter the merge section 21 by controlling the travel section when a merge passage permission response is received from the controller 4. The merge passage permission response is a signal that permits passage through the merge section 21. The travel control section 33 causes the own vehicle to stop at a stop point T in the vicinity of the merge section 21 and stand by by controlling the travel section when a merge passage permission response is not received from the controller 4. However, the position at which the own vehicle is caused to stop before passing through the merge section 21 can be appropriately changed.

[0047] The travel control section 33 includes the branch passage permission request in the state report and transmits it to the controller 4 in the vicinity of the branch section 22 when the own vehicle wants to pass through the branch section 22. The branch passage permission request is a signal that requests permission to pass through the branch section 22. The travel control section 33 causes the own vehicle to enter the branch section 22 by controlling the travel section when a branch passage permission response is received from the controller 4. The branch passage permission response is a signal that permits passage through the branch section 22. The travel control section 33 causes the own vehicle to stop at a stop point T in the vicinity of the branch section 22 and stand by by controlling the travel section when a branch passage permission response is not received from the controller 4. However, the position at which the own vehicle is caused to stop before passing through the branch section 22 can be appropriately changed.

[0048] The controller 4 is an electronic control unit constituted by a CPU, a ROM, a RAM, and the like. The controller 4 can be constituted by software that loads a program stored in the ROM onto the RAM and executes it by the CPU, for example. The controller 4 can also be constituted by hardware based on a circuit or the like.

[0049] The controller 4 has a vehicle control section 41, a congestion determination section 42, and a control switching section 43. The vehicle control section 41 communicates with a plurality of vehicles 3 in the own jurisdictional area to control the plurality of vehicles 3. The vehicle control section 41 controls the travel of the plurality of vehicles 3 by communicating with the travel control section 33 included in the vehicle 3. The vehicle control section 41 communicates with a higher-level controller (not shown) by wire or wirelessly. The vehicle control section 41 generates a transport instruction in accordance with a transport request given from the higher-level controller, for example, and distributes the transport instruction to the vehicle 3.

[0050] The vehicle control section 41 performs periodic communication with the plurality of vehicles 3 in the jurisdictional area. For example, the vehicle control section 41 sends a status query to the vehicles 3 in the jurisdictional area, and receives a status report from the vehicles 3 that received the status query. By performing this communication periodically in turn with the plurality of vehicles 3 in the jurisdictional area, the vehicle control section 41 can grasp the status of the plurality of vehicles 3 in the jurisdictional area.

[0051] The vehicle control section 41 performs lock control that permits or prohibits passage of the vehicles 3 through the merging section 21 when the vehicles 3 pass through the merging section 21. Specifically, the vehicle control section 41, in a case where a merging section passage permission request is received from a vehicle 3, when the setting of the merging lock area RG that includes the merging section 21 is not performed, sends a merging section passage permission response to the vehicle 3, and permits the vehicle 3 to pass through the merging section 21. The vehicle control section 41 permits the vehicle 3 to pass, and sets the merging lock area RG. The merging lock area RG is an area for prohibiting the vehicle 3 that did not receive the merging section passage permission response from entering a lock area (not shown) that includes the merging section 21.

[0052] The vehicle control section 41 cancels the merging lock area RG after the vehicles 3 that have passed through the merging section 21 pass the merging post. The merging post is a point (a location on the track 2) on the downstream side of the merging section 21. The merging post is, for example, a position set with a prescribed point mark on the downstream side of the merging section 21 as a reference. In the present embodiment, the merging post is set with a point mark of the position closest to the merging section 21 on the downstream side of the merging section 21 as a reference. The vehicle control section 41, in a case where the setting of the merging lock area RG is performed when a merging section passage permission request is received from a vehicle 3, does not send a merging section passage permission response to the vehicle 3, and causes the vehicle 3 to wait at the stop point T.

[0053] The transport vehicle control unit 41 performs either priority control or non-priority control. In priority control, the transport vehicle control unit 41 sets either the first path R1 or the second path R2 as the priority path. Priority control ensures that a transport vehicle 3 traveling on either the first path R1 or the second path R2, which is set as the priority path, passes through the merging section 21 before a transport vehicle 3 traveling on the other path. The method by which the transport vehicle control unit 41 sets the priority path will be described later. Non-priority control ensures that the transport vehicle 3 passes through the merging section 21 without prioritizing it based on whether it travels on the first path R1 or the second path R2. "Without prioritizing" means, for example, that no priority order is applied to the transport vehicles 3 passing through the merging section 21. In other words, non-priority control determines whether a transport vehicle 3 traveling on either the first path R1 or the second path R2, and a transport vehicle 3 traveling on the other path, are allowed to pass through the merging section 21 equally in terms of their travel path. In this embodiment, in non-priority control, the transport vehicle 3 traveling on the first path R1 and the transport vehicle 3 traveling on the second path R2 alternately pass through the merging section 21. Details regarding priority control and non-priority control will be described later.

[0054] Congestion determination unit 42 determines the designated target areas 61 and 62 (refer to) in the first path R1 or the second path R2 that are upstream of the merging point 21. Figure 1 Whether congestion of the transport vehicle 3 occurs. In this embodiment, each of the determination target areas 61 and 62 (hereinafter, sometimes referred to as "determination target areas") is set to be within 15m of the merging section 21 upstream of it. The determination target areas 61 and 62 can be preset, for example, or can be changed appropriately. The length of the determination target areas 61 and 62 can be set based on the aforementioned predetermined distance used in the stop control performed by the driving control unit 33. The length of the determination target areas 61 and 62 can be an integer multiple of the aforementioned predetermined distance, or it can be set to an integer multiple of the aforementioned predetermined distance plus the length of a predetermined number (threshold) of the transport vehicles 3 described later.

[0055] The determination object region 61 is set on the first path R1. The determination object region 61 includes the connecting path 51 included in the first path R1 and a plurality of merging paths 52. The determination object region 62 is set on the second path R2. The determination object region 62 includes the portion of the third straight path 29 included in the second path R2 located upstream of the merging section 21a.

[0056] The congestion determination unit 42 determines whether congestion of the trucks 3 occurs in the determination target region. In the present embodiment, the congestion determination unit 42 determines that congestion of the trucks 3 occurs in the determination target region when there are a predetermined number or more of trucks 3 that are located within a predetermined distance from the truck located in front of the own truck in the determination target region. The predetermined number is, for example, a threshold value that is set in advance and can be appropriately changed. The congestion determination unit 42 determines that congestion of the trucks 3 occurs in the determination target region when there are a predetermined number or more of trucks 3 that are stopped by the control of the travel control unit 33 in the determination target region.

[0057] The congestion determination unit 42 determines whether there are a predetermined number or more of trucks 3 that are stopped by the control of the travel control unit 33 in the determination target region on the basis of the status report that is periodically transmitted from the travel control unit 33. The period is, for example, 10 seconds, but can be appropriately changed. The period is, for example, set in advance. The congestion determination unit 42 performs the above-described congestion determination on the basis of the position information included in the status report and the information indicating the specified stop control.

[0058] The control switching unit 43 switches the control performed by the truck control unit 41 on the basis of the determination result of the congestion determination unit 42. The control switching unit 43 switches the control so that the truck control unit 41 performs the non-priority control when it is determined by the congestion determination unit 42 that congestion of the trucks 3 occurs in the determination target region. The control switching unit 43 switches the control so that the truck control unit 41 performs the priority control when it is determined by the congestion determination unit 42 that congestion of the trucks 3 does not occur in the determination target region.

[0059] Next, the operation of the truck system 1 of the present embodiment will be described with reference to Figures 3-9 The operation of the truck system 1 of the present embodiment will be described. In the present embodiment, the truck control unit 41 performs the non-priority control when the congestion determination unit 42 determines that congestion of the trucks 3 occurs in the determination target region. The truck control unit 41 performs the priority control when the congestion determination unit 42 determines that congestion of the trucks 3 does not occur in the determination target region. Figure 3 The operation of the truck system 1 of the present embodiment will be described. In the present embodiment, the truck control unit 41 performs the non-priority control when the congestion determination unit 42 determines that congestion of the trucks 3 occurs in the determination target region. The truck control unit 41 performs the priority control when the congestion determination unit 42 determines that congestion of the trucks 3 does not occur in the determination target region.

[0060] First, the congestion determination unit 42 determines whether congestion of the trucks 3 occurs in the determination target region. The congestion determination unit 42 determines that congestion of the trucks 3 does not occur in the determination target region when there are a predetermined number (the above-described threshold value) or more of trucks 3 that are stopped by the control of the travel control unit 33 in the determination target region. In the example shown in FIG. 6, the congestion determination unit 42 determines that congestion of the trucks 3 does not occur in the determination target region because there are six or more trucks 3 that are stopped by the control of the travel control unit 33 in the determination target region. Figure 3 In the examples shown in the following figures, the threshold value is set to six. In the example shown in FIG. 6, the congestion determination unit 42 determines that congestion of the trucks 3 does not occur in the determination target region because there are six or more trucks 3 that are stopped by the control of the travel control unit 33 in the determination target region. Figure 3In the determination target area 61, the number of the trolleys 3 stopped by the control of the travel control section 33 is three. In the determination target area 62, the number of the trolleys 3 stopped by the control of the travel control section 33 is two. As a result of the periodic congestion determination described above performed by the congestion determination section 42, the congestion determination section 42 determines that the congestion of the trolleys 3 does not occur in the determination target area.

[0061] Next, the control switching section 43 switches the control performed by the trolley control section 41 based on the determination result of the congestion determination section 42. Specifically, since the congestion determination section 42 determines that the congestion of the trolleys 3 does not occur in the determination target area, the control switching section 43 switches the control so that the trolley control section 41 performs the priority control.

[0062] Hereinafter, in the priority control, the trolley 3 that travels on one of the first path Rl and the second path R2 and that is given priority to pass through the merging section 21 with respect to the trolley 3 that travels on the other is referred to as a priority trolley 3a, and the trolley 3 that travels on the other is referred to as a standby trolley 3b. The path on which the priority trolley 3a travels among the first path Rl and the second path R2 is referred to as a "priority path", and the path on which the standby trolley 3b travels is referred to as a "standby path".

[0063] When the control switching section 43 switches the control performed by the trolley control section 41 from the non-priority control to the priority control, the trolley control section 41 sets one of the first path Rl and the second path R2 as the priority path and sets the other as the standby path. The trolley control section 41 sets, for example, the one on which the trolley 3 that receives the merging section pass permission request earliest from the timing at which the control is switched by the control switching section 43 among the first path Rl and the second path R2 as the priority path and sets the other as the standby path. Hereinafter, an example in which the trolley control section 41 sets the first path Rl as the priority path and sets the second path R2 as the standby path is described.

[0064] As described above, the trolley control section 41 performs the priority control in which the priority trolley 3a is given priority to pass through the merging section 21 with respect to the standby trolley 3b. Figure 4As shown, when the transport vehicle control unit 41 receives a merging section passage permission request from the priority transport vehicle 3a, it sends a merging section passage permission response to the priority transport vehicle 3a, allowing the priority transport vehicle 3a to pass, and sets a merging lock zone RG. After the priority transport vehicle 3a passes the merging point, the transport vehicle control unit 41 releases the merging lock zone RG. The control switching unit 43 switches the control, and initially, from receiving the merging section passage permission request until a predetermined time has elapsed, the transport vehicle control unit 41 repeatedly executes the same control. This predetermined time can be preset and can be changed appropriately. The transport vehicle control unit 41 does not send a merging section passage permission response to the standby transport vehicle 3b, causing the standby transport vehicle 3b to standby at the stop point T. As a result, the priority transport vehicle 3a traveling on the first path R1 continuously passes through the merging section 21.

[0065] When the specified time has elapsed, the transport vehicle control unit 41 sets the first path R1, which has been set as the priority path, as the standby path, and sets the second path R2, which has been set as the standby path, as the priority path. The transport vehicle control unit 41 repeatedly executes the above control, such as... Figure 5 As shown, the priority transport vehicle 3a traveling on the second path R2 continuously passes through the merging section 21. The transport vehicle control unit 41 alternately switches between the priority path and the standby path every time the predetermined time has elapsed.

[0066] Next, the actions taken when congestion occurs in the target area due to the transport vehicle 3 will be explained. Figure 6 The situation shown will be explained when the transport vehicle control unit 41 performs priority control.

[0067] exist Figure 6 In this case, the number of transport vehicles 3 that have stopped in the target area 61 under the control of the driving control unit 33 is 6. Therefore, the congestion determination unit 42 executes the results of the periodic congestion determination described above, and determines that congestion of transport vehicles 3 has occurred in the target area. Next, since the congestion determination unit 42 determines that congestion of transport vehicles 3 has occurred in the target area, the control switching unit 43 switches the control so that the transport vehicle control unit 41 performs non-priority control.

[0068] Hereinafter, in non-priority control, the transport vehicle 3 located upstream of and closest to the merging section 21 in both the first path R1 and the second path R2 will be referred to as the foremost transport vehicle 3c. When the control switching unit 43 switches the control performed by the transport vehicle control unit 41 from priority control to non-priority control, the transport vehicle control unit 41 sends a merging section clearance permission response to either the foremost transport vehicle 3c on the first path R1 or the foremost transport vehicle 3c on the second path R2. For example, the transport vehicle control unit 41 sends a merging section clearance permission response to the foremost transport vehicle 3c on the first path R1 or the second path R2 on a path where the congestion determination unit 42 has determined that a congestion has occurred and a determination target area has been set. Figure 6 In the example, when the control switching unit 43 switches the control, the transport vehicle control unit 41 sends a merging unit permission response to the foremost transport vehicle 3c on the first path R1.

[0069] like Figure 7 As shown, when the transport vehicle control unit 41 receives a merging passage permission request from the leading transport vehicle 3c on the first path R1, it sends a merging passage permission response to the leading transport vehicle 3c, allowing the leading transport vehicle 3c to pass, and sets a merging lock zone RG. After the leading transport vehicle 3c passes the merging post-point, the transport vehicle control unit 41 releases the merging lock zone RG. The transport vehicle control unit 41 does not send a merging passage permission response to the leading transport vehicle 3c on the second path R2, but instead keeps the leading transport vehicle 3c on the second path R2 waiting at the stop point T until the leading transport vehicle 3c on the first path R1 passes the merging post-point.

[0070] Next, as Figure 8 As shown, when the transport vehicle control unit 41 receives a merging passage permission request from the leading transport vehicle 3c on the second path R2, it sends a merging passage permission response to the leading transport vehicle 3c, allowing the leading transport vehicle 3c to pass, and sets a merging lock zone RG. After the leading transport vehicle 3c passes the merging post-point, the transport vehicle control unit 41 releases the merging lock zone RG. The transport vehicle control unit 41 does not send a merging passage permission response to the leading transport vehicle 3c on the first path R1, but instead keeps the leading transport vehicle 3c on the first path R1 waiting at the stop point T until the leading transport vehicle 3c on the second path R2 passes the merging post-point.

[0071] Next, as Figure 9 As shown, the transport vehicle control unit 41 performs the same process repeatedly, causing the first transport vehicle 3c traveling on the first path R1 and the first transport vehicle 3c traveling on the second path R2 to pass through the merging section 21 one by one and alternately.

[0072] In the transport system 1 of the present embodiment, when the transport vehicle control section 41 included in the controller 4 determines that congestion of the transport vehicles 3 occurs in the determination target region, non-priority control is executed. In the non-priority control, the transport vehicles 3 traveling on the first path Rl and the second path R2 are caused to pass through the merging section 21 alternately (see Figures 6-9 ). For example, when severe congestion occurs in the determination target region, the control to cause the transport vehicles 3 to pass through the merging section 21 can be automatically switched from the priority control to the non-priority control, and thus the time to relieve the congestion can be shortened. In addition, in order to prevent the standby time of the transport vehicles 3 on the upstream side of the merging section 21 from becoming too long, a limit can be set to the standby time, and the DLE can be executed when the standby time becomes equal to or longer than a predetermined time. In this case, the transport vehicles 3 in standby can advance relatively early, and thus the frequency of execution of the DLE can be reduced.

[0073] In addition, in the transport system 1, when the transport vehicle control section 41 included in the controller 4 determines that congestion of the transport vehicles 3 does not occur in the determination target region, priority control is executed. In the priority control, the transport vehicles 3 traveling on one of the first path Rl and the second path R2 pass through the merging section 21 preferentially with respect to the transport vehicles 3 traveling on the other (see Figures 3-5 ). Thus, when the transport vehicles 3 on one pass through the merging section 21, it is not necessary to wait until the transport vehicles 3 on the other pass through the merging section 21. As a result, the transport vehicles 3 on one can pass through the merging section 21 without repeating start and stop. According to the above, the transport efficiency can be improved.

[0074] In the non-priority control, the transport vehicles 3 traveling on the first path Rl and the second path R2 are caused to pass through the merging section 21 alternately (see Figures 6-9 ). Thus, by causing the transport vehicles 3 traveling on the first path Rl and the second path R2 to pass through the merging section 21 alternately, it is possible to reliably eliminate the congestion of the transport vehicles 3 in the determination target region.

[0075] The congestion determination section 42 included in the controller 4 determines that congestion of the transport vehicles 3 occurs in the determination target region when there are a predetermined number or more of the transport vehicles 3 whose distance from the transport vehicle 3 located in front of the own vehicle is equal to or shorter than a predetermined distance. Thus, it is possible to determine the presence or absence of congestion of the transport vehicles 3 based on the number of the transport vehicles 3 that approach each other in the determination target region (see Figure 3 ). Thus, it is possible to easily determine the congestion of the transport vehicles 3 in the determination target region.

[0076] The carrier 3 has a measurement unit 32 that measures the distance to the carrier 3 located in front of the own carrier, and a travel control unit 33 that stops the own carrier when the distance is equal to or less than a predetermined distance. The congestion determination unit 42 included in the controller 4 determines that congestion of the carriers 3 occurs in the determination target region when there are equal to or more than a predetermined number of carriers 3 stopped by the control of the travel control unit 33 in the determination target region. In this case, it is possible to determine the presence or absence of congestion of the carriers 3 based on the number of carriers 3 stopped by the control of the travel control unit 33 in the determination target region (see Figure 6 ). Therefore, it is possible to more easily determine congestion of the carriers 3 in the determination target region.

[0077] The determination target region 61 includes a connection path 51 connected to the merging portion 21, and a plurality of merging paths 52 merging into the connection path 51 (see Figure 1 ). For example, when the connection path 51 does not have a sufficient length, or the like, it can be difficult to determine the presence or absence of congestion only from the travel conditions on the connection path 51. By considering the number of carriers 3 on the plurality of merging paths 52 in addition to the connection path 51, it is possible to accurately determine congestion regardless of the layout of the travel path.

[0078] In the above, although the embodiment of the present application has been described, the present application is not limited to the above-described embodiment. For example, in the non-priority control, the carriers 3 traveling on the first path R1 and the carriers 3 traveling on the second path R2 can be alternately caused to pass through the merging portion 21 by equal to or more than a predetermined number at a time. The predetermined number is, for example, predetermined in advance and can be appropriately changed. In this case, the carrier control unit 41 repeatedly performs control to cause the foremost carrier 3c on the first path R1 to pass through the merging portion 21, and after a predetermined number of carriers 3 pass through the merging portion 21, repeatedly performs control to cause the foremost carrier 3c on the second path R2 to pass through the merging portion 21.

[0079] The non-priority control is control to cause the carriers 3 to pass through the merging portion 21 without giving priority to the carriers 3 traveling on either of the first path R1 and the second path R2, and various controls can be employed as the non-priority control. In the non-priority control, the carrier control unit 41 can cause the carriers 3 carrying articles to a specific carrying destination to pass through the merging portion 21 with priority over the carriers 3 carrying articles to carrying destinations other than the specific carrying destination based on the carrying instruction. In this case, for example, it is possible to quickly carry articles to a specific carrying destination where the demand for articles is high compared to other carrying destinations.

[0080] In the above-described embodiment, the vehicle control section 41 sets the first path Rl set as the priority path to the standby path and sets the second path R2 set as the standby path to the priority path at the timing at which a predetermined time elapses after the merging section passage permission request is initially received by the control switching section 43 switching control. However, the vehicle control section 41 can set the path set as the priority path to the standby path and set the path set as the standby path to the priority path at the timing at which it is determined that a predetermined condition (hereinafter referred to as "switching condition") is satisfied. Hereinafter, an example of the switching condition will be described.

[0081] The switching condition includes, for example, a first condition in which all of the priority vehicles 3a that have transmitted the merging section passage permission request to the vehicle control section 41 have passed the merging point and the merging lock area RG is released. This predetermined timing is set in advance, for example, and can be appropriately changed. As an example, the predetermined timing is a timing at which a predetermined time elapses in a case where the vehicle control section 41 does not receive a new merging section passage permission request from the priority vehicle 3a. In this case, for example, the travel control section 33 transmits the merging section passage permission request to the vehicle control section 41 with information that uniquely identifies the own vehicle, i.e., identification information, included therein. The vehicle control section 41 determines the priority vehicle 3a that has transmitted the merging section passage permission request to the vehicle control section 41 at the timing at which the predetermined time elapses, on the basis of the identification information. The vehicle control section 41 determines that the first condition is satisfied when all of the specified priority vehicles 3a have passed the merging point and the merging lock area RG is released.

[0082] The switching condition includes, for example, a second condition in which the number of the standby vehicles 3b that have transmitted the merging section passage permission request to the vehicle control section 41 and are standing at the stop point T is greater than a predetermined number. This predetermined number is set in advance, for example, and can be appropriately changed. As an example, the predetermined number is 3. In this case, for example, the vehicle control section 41 determines the standby vehicles 3b that have transmitted the merging section passage permission request to the vehicle control section 41 and are standing at the stop point T, on the basis of the identification information. The vehicle control section 41 determines that the second condition is satisfied when a new merging section passage permission request is received from a standby vehicle 3b other than the determined standby vehicles 3b in a state in which the number of the determined standby vehicles 3b is the predetermined number.

[0083] The switching conditions include, for example, a case where the control switching section 43 switches the control after a predetermined time (hereinafter, referred to as "third condition") elapses after the merging section passage permission request is initially received by the truck control section 41. In this case, the truck control section 41 determines that the third condition is satisfied when the control switching section 43 switches the control after the predetermined time elapses after the merging section passage permission request is initially received. The truck control section 41 can also use, for example, all of the first condition, the second condition, and the third condition as the switching conditions.

[0084] The truck control section 41 can also use, for example, only any one of the first condition, the second condition, and the third condition as the switching conditions. In addition, the truck control section 41 can also use, for example, the first condition, the second condition, and the third condition as appropriate as the switching conditions. In this case, the truck control section 41 can determine that the switching conditions are satisfied when it is determined that any one of the first condition, the second condition, and the third condition is satisfied, and can determine that the switching conditions are satisfied when it is determined that any two or more of the first condition, the second condition, and the third condition are satisfied. However, the contents of the switching conditions are merely an example, and can be changed as appropriate without departing from the spirit of the present application.

[0085] In addition, when at least one of the second condition and the third condition is used as the switching conditions, it can be configured such that even when the truck control section 41 determines that the second condition or the third condition is satisfied, the switching of the priority path and the standby path is not performed until the merging lock area RG is set after all of the priority trucks 3a that transmitted the merging section passage permission response pass the merging point.

[0086] In the above-described embodiment, the congestion determination section 42 determines whether congestion of the trucks 3 occurs in the determination target areas 61, 62. However, the congestion determination section 42 can determine whether congestion of the trucks 3 occurs in the determination target areas set on the non-priority path, and can not determine whether congestion of the trucks 3 occurs in the determination target areas set on the priority path.

[0087] In the above-described embodiment, the travel control section 33 stops the own truck when the distance measured by the measurement section 32 is equal to or shorter than the predetermined distance. However, the control is not limited to this, and the travel control section 33 can control the own truck (i.e., the truck 3 at the rear of the two trucks 3) to travel at a very small travel speed (deceleration) when the distance measured by the measurement section 32 is equal to or shorter than the predetermined distance (in the case where the two trucks 3 approach each other). In this case, an emergency stop distance shorter than the predetermined distance can be set.

[0088] In the above-described embodiments, although a ceiling-riding type of a transport vehicle is used as the transport vehicle 3, the transport vehicle 3 is not particularly limited. The transport vehicle 3 can be a ceiling-riding type of a shuttle vehicle. The transport vehicle 3 can be a rail type of a transport vehicle capable of traveling along a rail on a floor. The transport vehicle 3 can be a magnetic guidance type of a transport vehicle capable of traveling along a path constituted by a magnetic tape or the like. The transport vehicle 3 can be a laser guidance type of a transport vehicle capable of traveling along a decided path by laser guidance.

[0089] In the above-described embodiments, one or a plurality of other controllers that relay between the controller 4 and the transport vehicle 3 can be provided.

[0090] The configuration elements of the present application can be described as follows. [1]

[0092] A transport system in which, has: a plurality of transport vehicles that travel on a travel path to transport articles; and a controller that controls travel of the plurality of transport vehicles; the travel path has a first path, a second path different from the first path, and a confluence portion at which the first path and the second path confluence; the controller performs either of a priority control and a non-priority control, the priority control is control that causes the transport vehicles that travel in one of the first path and the second path set as a priority path to pass through the confluence portion preferentially to the transport vehicles that travel in the other, the non-priority control is control that causes the transport vehicles to pass through the confluence portion in a manner that does not give priority to either of the first path and the second path in which the transport vehicles travel, when congestion of the transport vehicles occurs in a prescribed determination target region that is more upstream than the confluence portion in the first path or the second path, the controller performs the non-priority control, when congestion of the transport vehicles does not occur in the determination target region, the controller performs the priority control. [2]

[0094] The transport system according to [1], in which, in the non-priority control, the transport vehicles that travel in the first path and the transport vehicles that travel in the second path are caused to pass through the confluence portion alternately. [3]

[0096] The transport system according to [1] or [2], in which, When the number of the tugs located within a predetermined distance from the tug located in front of the host vehicle is equal to or more than a predetermined number in the determination target area, the controller determines that the congestion of the tugs has occurred in the determination target area. [4]

[0098] The transport system according to [3], wherein the tug has: a measurement unit that measures a distance to the tug located in front of the host vehicle; and a travel control unit that stops the host vehicle when the distance is equal to or less than a predetermined distance; When the number of the tugs stopped by the control of the travel control unit is equal to or more than a predetermined number in the determination target area, the controller determines that the congestion of the tugs has occurred in the determination target area. [5]

[0100] The transport system according to any one of [1] to [4], wherein the determination target area includes: a connection path connected to the merging portion; and a plurality of merging paths merging into the connection path.

[0101] Explanation of reference numerals: 1: Transport system 2: Track (travel path) 3: Tug 4: Controller 21: Merging portion 32: Measurement unit 33: Travel control unit 51: Connection path 52: Merging path 61, 62: Determination target area R1: First path R2: Second path

Claims

1. A transport system, wherein a plurality of transport vehicles travel on a travel path to transport articles; and a controller controls travel of the plurality of transport vehicles; the travel path has a first path, a second path different from the first path, and a merging portion where the first path and the second path merge; the controller executes either of a priority control and a non-priority control, the priority control is a control that makes the transport vehicles traveling in one of the first path and the second path set as a priority path pass the merging portion preferentially over the transport vehicles traveling in the other, the non-priority control is a control that makes the transport vehicles pass the merging portion in a manner that does not give priority to the transport vehicles traveling in either of the first path and the second path, when congestion of the transport vehicles occurs in a prescribed determination target region on an upstream side of the merging portion in the first path or the second path, the controller executes the non-priority control, when congestion of the transport vehicles does not occur in the determination target region, the controller executes the priority control.

2. The transport system according to claim 1, wherein in the non-priority control, the transport vehicles traveling in the first path and the transport vehicles traveling in the second path are made to pass the merging portion alternately.

3. The transport system according to claim 1 or 2, wherein when there are a prescribed number or more of the transport vehicles whose distance from the transport vehicle located in front of the host vehicle is a prescribed distance or less in the determination target region, the controller determines that congestion of the transport vehicles occurs in the determination target region.

4. The transport system according to claim 3, wherein the transport vehicle has a measurement portion that measures the distance from the transport vehicle located in front of the host vehicle; and a travel control portion that stops the host vehicle when the distance is a prescribed distance or less; when there are a prescribed number or more of the transport vehicles stopped by the control of the travel control portion in the determination target region, the controller determines that congestion of the transport vehicles occurs in the determination target region.

5. The transport system according to claim 1 or 2, wherein the determination target region includes a connection path connected to the merging portion; and a plurality of merging paths that merge into the connection path. ​ ​

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