Conveyance system

Abstract

This conveyance system comprises a plurality of carts and a controller that controls the plurality of carts. The controller of the conveyance system performs periodic communication for periodically communicating with the plurality of carts in order, and when at least one of the plurality of carts is in a predetermined operation state, stops communication with the cart in periodic communication or decreases the frequency of communication with the cart in periodic communication.

Description

Transport System

[0001] One aspect of the present invention relates to a transport system.

[0002] A transport system including a plurality of carriages and a controller that controls the plurality of carriages is known. For example, Patent Document 1 discloses a technology of this type in which a controller sequentially and periodically communicates with the plurality of carriages (traveling vehicles).

[0003] Japanese Patent Application Laid-Open No. 2019-125000

[0004] In a system such as that described above, for example, as the number of trolleys increases, the cycle of periodic communication (so-called polling communication) between multiple trolleys in a sequential and periodic manner becomes longer, which may make it difficult to communicate sufficiently with each trolley.

[0005] An object of one aspect of the present invention is to provide a transport system that can shorten the cycle of periodic communication that sequentially and periodically communicates with a plurality of carriages.

[0006] A conveying system according to one aspect of the present invention is a conveying system comprising a plurality of carriages and a controller that controls the plurality of carriages, wherein the controller performs periodic communication with the plurality of carriages in sequence and periodically, and when at least one of the plurality of carriages is in a predetermined operating state, the controller stops communication with that carriage in the periodic communication or reduces the frequency of communication with that carriage in the periodic communication.

[0007] In this transport system, in periodic communication (hereinafter simply referred to as "periodic communication") between multiple carriages in a sequential and periodic manner, it is possible to reduce the time required for communication with carriages in a predetermined operating state, thereby shortening the period of periodic communication.

[0008] In the conveyance system according to one aspect of the present invention, the predetermined operating state may include a first operating state in which the carriage is stopped and performing an operation other than traveling, thereby reducing the time required for communication with the carriage in the first operating state in periodic communication.

[0009] In a conveyance system according to an aspect of the present invention, communication with a carriage in a first operating state in periodic communication may be stopped for a period based on the time required for operation in the first operating state. In this case, the period of periodic communication can be reduced by the period based on the time required for operation in the first operating state.

[0010] In the conveyance system according to one aspect of the present invention, the first operating state may include a transfer-in-progress state, which is a state in which the carriage starts transferring an item and ends immediately before the transfer-in-progress state. In this case, it is possible to reduce the time required for communication with the carriage in the transfer-in-progress state in periodic communication.

[0011] In the transport system according to one aspect of the present invention, the first operating state may include a charging state in which the cart starts charging and immediately before it finishes charging, thereby reducing the time required for communication with the cart in the charging state in the periodic communication.

[0012] In a conveyance system according to an aspect of the present invention, the first operating state may include a turning state that is a state from when a carriage starts to turn until just before the timing at which the carriage should issue a blocking control request that prohibits other carriages from entering a predetermined area that the carriage will enter after the turn. In this case, it is possible to reduce the time required for communication with a carriage in the turning state in periodic communication.

[0013] In the conveyance system according to one aspect of the present invention, the predetermined operating state may include a second operating state in which the carriage is stopped due to the influence of the operation of another carriage, in which case it is possible to reduce the time required for communication with the carriage in the second operating state in periodic communication.

[0014] In a transport system according to an aspect of the present invention, communication with a vehicle in the second operating state in periodic communication may be stopped while the vehicle is being affected by the operation of another vehicle or until immediately before the effect disappears. In this case, the period of periodic communication can be reduced by the period while the vehicle is being affected by the operation of another vehicle or until immediately before the effect disappears.

[0015] In the conveyance system according to one aspect of the present invention, the second operating state may include a transfer waiting state in which the carriage stops moving from when another carriage starts transferring an item until just before the other carriage finishes transferring an item. In this case, it is possible to reduce the time required for communication with the carriage in the transfer waiting state in the periodic communication.

[0016] In the transport system according to one aspect of the present invention, the second operating state may include a blocking wait state in which the carriage starts to stop traveling and immediately before it stops in accordance with blocking control, which is a control requested by the other carriage and prohibits carriages other than the other carriage from entering a predetermined area. In this case, it is possible to reduce the time required for communication with the carriage in the blocking wait state in periodic communication.

[0017] In a conveyance system according to an aspect of the present invention, the second operating state may include an area entry waiting state in which the carriage starts to stop traveling and immediately before it stops traveling in accordance with area vehicle number limiting control that prohibits the carriage from entering any of a plurality of traveling areas when the number of other carriages present in the area is equal to or greater than a specified number. In this case, it is possible to reduce the time required for communication with the carriage in the area entry waiting state in periodic communication.

[0018] In the transport system according to one aspect of the present invention, the predetermined operation state may include a third operation state in which the carriage performs a set operation indefinitely, thereby reducing the time required for communication with the carriage in the third operation state in periodic communication.

[0019] In the transport system according to one aspect of the present invention, the frequency of periodic communication with the carriage in the third operating state may be reduced. In this case, it is possible to increase the frequency of reducing the time required for communication with the carriage in the third operating state in the periodic communication.

[0020] In the transport system according to one aspect of the present invention, the third operating state may include a maintenance-in-progress state in which the carriage is in a maintenance mode, thereby reducing the time required for periodic communication with the carriage in the maintenance-in-progress state.

[0021] In the conveyance system according to one aspect of the present invention, the third operating state may include an error stopped state in which the carriage is stopped due to an error. In this case, it is possible to reduce the time required for communication with the carriage in the error stopped state in the periodic communication.

[0022] In the conveyance system according to one aspect of the present invention, the third operating state may include an idling stopped state in which the carriage is idling and stopped, thereby reducing the time required for communication with the carriage in the idling stopped state in the periodic communication.

[0023] The conveyance system according to one aspect of the present invention may include a lattice-shaped track on which a plurality of carriages travel. In this case, a so-called grid system can be configured. This makes it easier to freely select the travel route of the carriages, reduces congestion, and improves conveyance efficiency.

[0024] According to one aspect of the present invention, it is possible to provide a transport system that can shorten the period of periodic communication that sequentially and periodically communicates with a plurality of carriages.

[0025] FIG. 1 is a perspective view showing an example of a transport system according to an embodiment. FIG. 2 is a perspective view showing an example of a bogie in FIG. 1. FIG. 3 is a side view showing an example of the bogie in FIG. 1. FIG. 4 is a block diagram showing the transport system in FIG. 1. FIG. 5(a) is a flowchart showing the process of thinning out bogies in the process of being transferred. FIG. 5(b) is a flowchart showing the process of thinning out bogies in the process of being charged. FIG. 5(c) is a flowchart showing the process of thinning out bogies in the process of turning. FIG. 6(a) is a flowchart showing the process of thinning out bogies waiting for transfer. FIG. 6(b) is a flowchart showing the process of thinning out bogies waiting for blocking. FIG. 6(c) is a flowchart showing the process of thinning out bogies waiting to enter an area. FIG. 7(a) is a flowchart showing the process of thinning out bogies in the process of being maintained. FIG. 7(b) is a flowchart showing the process of thinning out bogies stopped due to an error. FIG. 7(c) is a flowchart showing the process of thinning out bogies stopped idling.

[0026] Hereinafter, an embodiment will be described with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals and redundant description will be omitted.

[0027] Fig. 1 is a perspective view showing an example of a transport system SYS according to an embodiment. Fig. 2 is a perspective view of a carriage V used in the transport system SYS of Fig. 1. Fig. 3 is a side view showing the carriage V of Fig. 2. Fig. 4 is a block diagram showing the transport system SYS of Fig. 1. In the drawings, the scales are appropriately changed for ease of explanation. In the following description, one direction along a horizontal plane is defined as the X direction, a direction perpendicular to the X direction and along the horizontal plane is defined as the Y direction, and a vertical direction is defined as the Z direction.

[0028] The transport system SYS is a grid system for transporting items M by carriages V in, for example, a clean room in a semiconductor manufacturing factory. The transport system SYS includes a first carriage V1 to an n-th carriage Vn (hereinafter collectively referred to as "carriages V") (see FIG. 4), a system controller 5 that controls the multiple carriages V, and rails R on which the multiple carriages V travel. In this embodiment, an example will be described in which the carriages V are overhead carriages. The carriages V move along the rails R of the transport system SYS. The rails R are the travel paths of the carriages V. The carriages V move along the rails R of the transport system SYS to transport items M such as FOUPs that store semiconductor wafers or reticle pods that store reticles. The carriages V may also be referred to as transport carriages, transport vehicles, traveling carriages, or traveling vehicles.

[0029] The rail R is laid on or near the ceiling of a building such as a clean room. The rail R is installed adjacent to, for example, a processing device, a stocker (automated warehouse), etc. The processing device is, for example, an exposure device, a coater developer, a film forming device, an etching device, etc., and performs various processes on semiconductor wafers in the article M transported by the cart V. The stocker stores the article M transported by the cart V. The rail R is an example of a track configuration. The rail R is a lattice-like track arranged in a lattice pattern in a plan view. The rail R is a rail that extends horizontally and is suspended. The rail R is a lattice-like rail having a plurality of first rails R1, a plurality of second rails R2, and a plurality of intersections R3.

[0030] The multiple first rails R1 each extend along the X direction. The multiple second rails R2 each extend along the Y direction. The rails R are formed in a grid shape in a plan view by the multiple first rails R1 and the multiple second rails R2. The rails R form multiple squares by the multiple first rails R1 and the multiple second rails R2. The intersections R3 are located at portions corresponding to intersections between the first rails R1 and the second rails R2. The intersections R3 are adjacent to the first rails R1 in the X direction and adjacent to the second rails R2 in the Y direction. The intersections R3 are connecting tracks that connect the first rails R1 and the second rails R2, connect first rails R1 to each other, and connect second rails R2 to each other. The intersection R3 is a track that is used when the bogie V runs along the first rail R1, when the bogie V runs along the second rail R2, and when the bogie V runs from the first rail R1 to the second rail R2 or from the second rail R2 to the first rail R1.

[0031] The rail R has a plurality of first rails R1 and a plurality of second rails R2 arranged in orthogonal directions, resulting in a plurality of grid cells 2 adjacent to each other in a plan view. One grid cell 2 corresponds to one square, and in a plan view, is a rectangular area surrounded by two first rails R1 adjacent to each other in the Y direction and two second rails R2 adjacent to each other in the X direction. Note that FIG. 1 shows only a portion of the rail R, and the rail R is formed with a similar configuration continuing from the illustrated configuration in the X and Y directions.

[0032] The first rail R1, the second rail R2, and the intersection R3 are suspended from a ceiling (not shown) by a suspension member H (see FIG. 1). The suspension member H has a first portion H1 for suspending the first rail R1, a second portion H2 for suspending the second rail R2, and a third portion H3 for suspending the intersection R3. The first portion H1 and the second portion H2 are each provided at two locations on either side of the third portion H3.

[0033] The first rail R1, the second rail R2, and the intersection R3 respectively have running surfaces R1a, R2a, and R3a on which running wheels 21 (described later) of the bogie V run. Gaps are formed between the first rail R1 and the intersection R3 and between the second rail R2 and the intersection R3. The gaps between the first rail R1 and the intersection R3 and between the second rail R2 and the intersection R3 are portions through which a connecting portion 30 (described later), which is part of the bogie V, passes when the bogie V runs on the first rail R1 and crosses the second rail R2, or when the bogie V runs on the second rail R2 and crosses the first rail R1. Therefore, the gaps between the first rail R1 and the intersection R3 and between the second rail R2 and the intersection R3 are wide enough to allow the connecting portion 30 to pass through. The first rail R1, the second rail R2, and the intersection R3 are arranged along the same horizontal plane.

[0034] The transport system SYS includes a communication system (not shown). The communication system is used for communication between the carriage V and the system controller 5. The carriage V and the system controller 5 are connected to each other so as to be able to communicate with each other via the communication system.

[0035] The following describes the configuration of the bogie V. As shown in Figures 2 to 4, the bogie V is provided so as to be able to travel along rails R. The bogie V has a main body 10, a traveling section 20, a connecting section 30, and a bogie controller 50.

[0036] The main body 10 is disposed below the rail R. The main body 10 is formed, for example, in a rectangular shape in a plan view. The main body 10 is formed to have dimensions that fit into one grid cell 2 (see FIG. 1 ) on the rail R in a plan view. This ensures space for the main body 10 to pass other carriages V traveling on the adjacent first rail R1 or second rail R2. The main body 10 includes an upper unit 17 and a transfer device 18. The upper unit 17 is suspended from the running part 20 via a connecting part 30. The upper unit 17 is, for example, rectangular in a plan view, and has four corners on its top surface 17a.

[0037] The main body 10 has four corners each having a running wheel 21, a connecting portion 30, and a direction change mechanism 34. In this configuration, the running wheels 21 arranged at the four corners of the main body 10 allow the main body 10 to be stably suspended and to travel stably.

[0038] The transfer device 18 moves horizontally relative to the traveling section 20 to transfer an item between the load port (loading table). The transfer device 18 is provided below the upper unit 17. The transfer device 18 is rotatable around a rotation axis AX1 in the Z direction. The transfer device 18 has an item holding section 13 that holds an item M below the rail R, an elevation drive section 14 that raises and lowers the item holding section 13 in the vertical direction, a lateral feed mechanism 11 that slides the elevation drive section 14 in the horizontal direction, and a rotating section 12 that holds the lateral feed mechanism 11. The load port is the destination or source of the cart V, and is the point where the item M is handed over to or from the cart V.

[0039] The article holding unit 13 suspends and holds the article M by gripping the flange portion Ma of the article M. The article holding unit 13 is, for example, a chuck having a claw portion 13a that is movable in the horizontal direction, and holds the article M by inserting the claw portion 13a below the flange portion Ma of the article M and raising the article holding unit 13. The article holding unit 13 is connected to a hanging member 13b such as a wire or a belt.

[0040] The lifting / lowering drive unit 14 is, for example, a hoist, and lowers the article holding unit 13 by paying out the hanging member 13b, and raises the article holding unit 13 by reeling in the hanging member 13b. The lifting / lowering drive unit 14 is controlled by the cart controller 50, and lowers or raises the article holding unit 13 at a predetermined speed. The lifting / lowering drive unit 14 is also controlled by the cart controller 50, and maintains the article holding unit 13 at a target height.

[0041] The lateral delivery mechanism 11 has a plurality of movable plates stacked in the Z direction, for example. The lowest movable plate is attached with a lifting drive unit 14. In the lateral delivery mechanism 11, the movable plates move in a horizontal plane in a direction perpendicular to the traveling direction of the carriage V, and the lifting drive unit 14 and the article holder 13 attached to the lowest movable plate move (slide) laterally in the direction perpendicular to the traveling direction of the carriage V.

[0042] The rotating unit 12 is provided between the lateral-discharging mechanism 11 and the upper unit 17. The rotating unit 12 has a rotating member 12a and a rotation drive unit 12b. The rotating member 12a is provided so as to be rotatable around an axis in the Z direction. The rotating member 12a supports the lateral-discharging mechanism 11. The rotation drive unit 12b is, for example, an electric motor, and rotates the rotating member 12a around the axis of rotation AX1. The rotating unit 12 rotates the rotating member 12a by the driving force from the rotation drive unit 12b, and can rotate the lateral-discharging mechanism 11 (the lifting drive unit 14 and the article holder 13) around the axis of rotation AX1. The cart V can transfer the article M to and from the load port by using a transfer device 18.

[0043] 2 and 3, the cart V may be provided with a cover W. The cover W surrounds the transfer device 18 and the article M held by the transfer device 18. The cover W is cylindrical with an open bottom end, and has a cutout at the portion where the movable plate of the lateral feeding mechanism 11 protrudes. The cover W has an upper end attached to the rotating member 12a of the rotating unit 12, and rotates around the rotation axis AX1 as the rotating member 12a rotates.

[0044] The traveling unit 20 has traveling wheels 21 and auxiliary wheels 22. The traveling wheels 21 are respectively arranged at the four corners of the top surface 17a of the upper unit 17 (main body 10). Each traveling wheel 21 is attached to an axle provided in the connecting unit 30. Each traveling wheel 21 is rotationally driven by the driving force of the traveling drive unit 33. Each traveling wheel 21 rolls on the rails R. Each traveling wheel 21 rolls on the running surfaces R1a, R2a, and R3a of the first rail R1, the second rail R2, and the intersection R3, causing the bogie V to travel. Note that the configuration is not limited to one in which all four traveling wheels 21 are rotationally driven by the driving force of the traveling drive unit 33, and it is also possible to configure one in which only some of the four traveling wheels 21 are rotationally driven.

[0045] The running wheels 21 are provided so as to be rotatable in the θZ direction around a rotation axis AX2. The running wheels 21 are rotated in the θZ direction by a direction-changing mechanism 34, which will be described later, thereby changing the running direction of the carriage V. The auxiliary wheels 22 are arranged one in front of and one behind the running wheels 21 in the running direction. Like the running wheels 21, each of the auxiliary wheels 22 is rotatable around an axle that is parallel or nearly parallel along the XY plane. The lower ends of the auxiliary wheels 22 are set to be higher than the lower ends of the running wheels 21. Therefore, when the running wheels 21 are running on the running surfaces R1a, R2a, R3a, the auxiliary wheels 22 do not come into contact with the running surfaces R1a, R2a, R3a. Furthermore, when the running wheel 21 passes through the gap between the first rail R1 and the intersection R3 and between the second rail R2 and the intersection R3, the auxiliary wheels 22 come into contact with the running surfaces R1a, R2a, R3a, thereby preventing the running wheel 21 from sinking. Note that the number of auxiliary wheels 22 provided per running wheel 21 is not limited to two, and for example, one running wheel 21 may be provided with one auxiliary wheel 22, or no auxiliary wheel 22 may be provided at all.

[0046] As shown in FIG. 2 , the coupling portion 30 couples the upper unit 17 of the main body 10 to the running portion 20. The coupling portions 30 are provided at the four corners of the top surface 17a of the upper unit 17 (main body 10). The coupling portions 30 allow the main body 10 to be suspended from the running portion 20 and positioned below the rails R. The coupling portion 30 includes a support member 31 and a connecting member 32. The support member 31 rotatably supports the rotation shafts of the running wheels 21 and the auxiliary wheels 22. The support member 31 maintains the relative positions of the running wheels 21 and the auxiliary wheels 22. The support member 31 is formed, for example, in a plate shape and has a thickness that allows it to pass through the gap between the first rail R1 and the intersection portion R3 and between the second rail R2 and the intersection portion R3.

[0047] The connecting member 32 extends downward from the support member 31 and is connected to the upper surface 17a of the upper unit 17 to hold the upper unit 17. The connecting member 32 has an internal transmission mechanism that transmits the driving force of the traveling drive unit 33, which will be described later, to the traveling wheels 21. This transmission mechanism may be configured to use a chain or a belt, or may be configured to use a gear train. The connecting member 32 is provided so as to be rotatable in the θZ direction about the pivot axis AX2. By rotating the connecting member 32 about the pivot axis AX2, the traveling wheels 21 can be rotated in the θZ direction around the pivot axis AX2 via the support member 31.

[0048] The coupling part 30 (see FIG. 2 ) is provided with a travel drive part 33 and a direction changing mechanism 34. The travel drive part 33 is attached to the connection member 32. The travel drive part 33 is a drive source that drives the travel wheels 21, and an electric motor or the like is used for example. The four travel wheels 21 are each driven by the travel drive part 33 and are drive wheels. The four travel wheels 21 are controlled by the bogie controller 50 so that they rotate at the same speed.

[0049] The direction-changing mechanism 34 rotates the connecting member 32 of the coupling unit 30 about the pivot axis AX2, thereby rotating the running wheels 21 in the θZ direction around the pivot axis AX2. By rotating the running wheels 21 in the θZ direction, the bogie V can be turned (switched from a first state in which the running direction is the X direction to a second state in which the running direction is the Y direction, or from the second state in which the running direction is the Y direction to the first state in which the running direction is the X direction). By rotating the direction-changing mechanism 34, the running wheels 21 and the auxiliary wheels 22 arranged at the four corners of the upper surface 17a each rotate within a range of 90 degrees in the θZ direction around the pivot axis AX2. The drive of the direction-changing mechanism 34 is controlled by the bogie controller 50. By rotating the running wheels 21 and the auxiliary wheels 22, the running wheels 21 transition from a state in which they are in contact with one of the first rail R1 and the second rail R2 to a state in which they are in contact with the other rail. This allows the travel direction of the carriage V to be switched between a first state in the X direction and a second state in the Y direction, i.e., the carriage V can turn. In this embodiment, when the carriage V turns, the carriage V stops traveling. The stopped traveling state refers to a state in which, for example, the article M to be transported is not moving.

[0050] The vehicle V is equipped with a position detection unit 38 that detects position information (see FIG. 4). The position detection unit 38 detects a position marker (not shown) that indicates the position information, thereby detecting the current position of the vehicle V. The position detection unit 38 detects the position marker in a non-contact manner. The position marker is installed in each grid cell 2 of the rail R.

[0051] The bogie controller 50 performs overall control of the bogie V. The bogie controller 50 is a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The bogie controller 50 may be configured as software in which a program stored in the ROM is loaded into the RAM and executed by the CPU. The bogie controller 50 may also be configured as hardware including electronic circuits or the like. The bogie controller 50 may be configured as a single device or multiple devices. When configured as multiple devices, these devices are connected via a communication network such as the Internet or an intranet to logically form a single bogie controller 50. In this embodiment, the bogie controller 50 is provided in the main body 10 (see FIG. 3 ), but may also be provided outside the main body 10.

[0052] The carriage controller 50 controls the traveling of the carriage V based on the transport command. The carriage controller 50 controls the traveling of the carriage V by controlling the traveling drive unit 33, the direction changing mechanism 34, etc. The carriage controller 50 controls, for example, the traveling speed, operations related to stopping, and operations related to direction changes. In response to a command from the system controller 5, the carriage controller 50 controls the traveling of the carriage V so as not to enter a traveling area, a blocking area, or a transfer area where a specified number or more carriages V exist (details will be described later).

[0053] The carriage controller 50 controls the transfer operation of the carriage V based on the transport command. The carriage controller 50 controls the transfer operation of the carriage V by controlling the transfer device 18, etc. The carriage controller 50 controls the load grabbing operation to grasp the item M to be placed at a specified load port and the unloading operation to lower the held item M to the specified load port. The carriage controller 50 periodically generates and updates status information (not shown). The status information is stored in the memory unit 51. The carriage controller 50 transmits the status information to the system controller 5. The status information includes, for example, information on the current position of the carriage V, information indicating the current status of the carriage V (normal or abnormal), the charge level of the carriage V, and information on the execution status (in execution, execution completed, execution failed) of various commands such as a transport command by the carriage V. When transferring the item M, the carriage controller 50 transmits a blocking control request to the system controller 5.

[0054] The system controller 5 is a computer including a CPU, ROM, RAM, etc. The system controller 5 can be configured as software in which a program stored in the ROM is loaded into the RAM and executed by the CPU, for example. The system controller 5 may also be configured as hardware including electronic circuits, etc. The system controller 5 may be configured as a single device or multiple devices. When the system controller 5 is configured as multiple devices, these devices are connected via a communication network such as the Internet or an intranet to logically form a single system controller 5. At least a portion of the various controls of the system controller 5 may be executed by the bogie controller 50.

[0055] The system controller 5 selects one of a plurality of carriages V capable of transporting the item M, and assigns a transport command to the selected carriage V. The transport command includes a travel command to cause the carriage V to travel to the load port, and a command to grab the item M placed at the load port or a command to unload the held item M to the load port.

[0056] The system controller 5 performs blocking control, which is an exclusive control that prohibits other bogies V from entering a blocking area (predetermined area) through which the bogie V passes. As a result, the traveling of other bogies V than the bogie V is controlled so that they do not enter a blocking area for which they are not granted permission to occupy, and for example, the bogies stop traveling and wait in front of the blocking area. For example, in response to a blocking control request from the bogie controller 50 of the bogie V, the system controller 5 starts blocking control and grants the bogie V permission to occupy the blocking area. For example, the blocking area is divided into grid cell 2 units corresponding to the squares of the rail R. The blocking area may be a predetermined area into which the bogie V enters after the bogie V makes a turn (changes direction).

[0057] When a carriage V transfers an item M between a load port and another carriage V, the system controller 5 performs transfer blocking control, which is an exclusive control that prohibits other carriages V from entering the transfer area required for the transfer. As a result, the travel of the other carriages V is controlled so that they do not enter the transfer area required for the transfer of the carriage V, and they stop traveling in front of the transfer area and wait. For example, based on a transport command assigned to the carriage V, the system controller 5 prohibits other carriages V from entering the transfer area of ​​the carriage V. The transfer area corresponds to the area occupied by the carriage V when transferring the item M in a plan view. For example, the transfer area is partitioned in units of grid cells 2 corresponding to the squares of the rail R.

[0058] The system controller 5 performs area vehicle number restriction control to prohibit entry into any of a plurality of travel areas when the number of bogies V present in that area is equal to or greater than a predetermined number. This controls the travel of the bogies V so that they do not enter a travel area where the predetermined number of bogies V or more is present. As a result, for example, a bogie V attempting to enter a travel area where the predetermined number of bogies V or more is present stops traveling and waits before the travel area. The system controller 5 can determine whether the number of bogies V present in a travel area is equal to or greater than a predetermined number, for example, based on current position information included in the status information of the plurality of bogies V. A travel area is an area in which the bogies V can travel and which includes rails R. A plurality of travel areas are set. The predetermined number is not particularly limited and may be any predetermined number. A travel area is one of a plurality of areas into which the entire area in which the bogies V can travel is divided.

[0059] When charging of the trolley V is required, the system controller 5 transmits a charging execution command to the trolley V, which is a command to charge the trolley V. The charging execution command causes the trolley V to stop traveling. Whether charging of the trolley V is required can be determined based on the status information of the trolley V. Furthermore, when performing maintenance on the trolley V, the system controller 5 transmits a maintenance mode execution command to the trolley V, which is a command to execute a maintenance mode. The maintenance mode is a mode for performing maintenance on the trolley V. In the maintenance mode, the trolley V is caused to travel at a low speed or to stop traveling. The maintenance is not particularly limited and includes various types of maintenance. For example, the maintenance mode may be a mode in which the trolley V is remotely traveled in response to a user operation.

[0060] When an error occurs in a bogie V, the system controller 5 transmits an error stop command to the bogie V, which is a command to stop the traveling of the bogie V in which the error occurs. Whether or not an error has occurred in the bogie V can be determined based on the state information of the bogie V. Furthermore, when the system controller 5 is to stop the traveling of the bogie V in an idling state, it transmits an idling stop command to the bogie V, which is a command to stop the traveling of the bogie V in an idling state. The idling state is a state in which a bogie V that is not traveling maintains a state in which it can immediately respond to the start of traveling.

[0061] Here, the system controller 5 of this embodiment performs periodic communication (hereinafter also referred to as "polling communication") in which it communicates sequentially and periodically with a plurality of vehicle V. In polling communication, the system controller 5 targets a plurality of vehicle V present within the control range of the system controller 5, and communicates with some or all of the plurality of vehicle V sequentially one by one, and repeats this sequential communication. When at least one of the plurality of vehicle V is in a predetermined operating state, the system controller 5 stops communication with that vehicle V in the polling communication, or performs polling thinning processing to reduce the frequency of communication with that vehicle V in the polling communication.

[0062] The predetermined operating state of the vehicle V that is the target of the polling thinning process is a first operating state in which the vehicle V stops traveling and is performing an operation other than traveling. The system controller 5 suspends communication with the vehicle V in the first operating state in polling communication for a period based on the time required for operation in the first operating state.

[0063] The first operating state includes a transfer-in-progress state, which is a state in which the stopped carriage V starts transferring the item M until just before it finishes transferring the item M. That is, in the polling thinning-out process, the thinning-out process of the carriage in the transfer-in-progress state shown in FIG. 5( a) is periodically and repeatedly executed.

[0064] In the process of thinning out the in-transfer vehicles, it is determined whether or not there is a in-transfer vehicle V in the in-transfer state among the multiple vehicle V targeted for polling communication (step S11). For example, the determination of whether or not a vehicle V is in-transfer may be made based on the status information of the vehicle V. For example, the determination of whether or not a vehicle V is in-transfer may be made based on a transport command assigned to the vehicle V by the system controller 5. For example, the determination of whether or not a vehicle V is in-transfer may be made based on information or a command from a higher-level controller (not shown). Immediately before the end of the transfer in the in-transfer state refers to, for example, 100 ms before the end timing of the transfer. Note that "immediately before" is not particularly limited and refers to a timing a predetermined period earlier (the same applies below). The status information of the vehicle V may include information regarding the transfer time of the vehicle V according to the load port to be transferred (the start timing, end timing, and time required for the transfer).

[0065] If the answer is NO in step S11, the processing for this cycle is terminated, and the process proceeds to step S11 in the next cycle. On the other hand, if the answer is YES in step S11, communication with the vehicle in the process of transfer in the polling communication is stopped (step S12). In other words, in step S12, the vehicle in the process of transfer is thinned out from the multiple vehicle V that are the target of the polling communication. As a result, in the polling communication, communication is performed sequentially and periodically with the multiple vehicle V excluding the vehicle in the process of transfer.

[0066] The first operating state includes a charging state in which the stopped vehicle V starts charging and immediately before the charging ends. That is, in the polling thinning process, the thinning process of the charging vehicle shown in FIG. 5(b) is periodically and repeatedly executed.

[0067] In the process of thinning out charging trolleys, it is determined whether or not a charging trolley V that is in a charging state is present among the multiple trolleys V that are the targets of polling communication (step S21). For example, the determination of whether or not a trolley V is a charging trolley may be made based on the status information of the trolley V. For example, the determination of whether or not a trolley V is a charging trolley may be made based on a charging execution command sent by the system controller 5 to the trolley V. For example, the determination of whether or not a trolley V is a charging trolley may be made based on information or a command from a higher-level controller (not shown). The status information of the trolley V may include information regarding the start timing of charging the trolley V, the end timing of charging, and the period required for charging (e.g., 5 minutes), etc.

[0068] If the answer is NO in step S21, the processing for this cycle ends, and the process proceeds to step S21 in the next cycle. On the other hand, if the answer is YES in step S21, communication with the charging vehicle in the polling communication is stopped (step S22). In other words, in step S22, the charging vehicle is thinned out from the multiple vehicle V that are the target of the polling communication. As a result, communication is performed sequentially and cyclically with the multiple vehicle V excluding the charging vehicle in the polling communication.

[0069] The first operating state includes a turning state, which is a state from when the vehicle V starts turning until just before the timing when the vehicle V should request blocking control to prohibit other vehicles V from entering a predetermined area (blocking area) that the vehicle V will enter after the turn. That is, in the polling thinning process, the turning vehicle thinning process shown in FIG. 5(c) is periodically and repeatedly executed. The timing of the request for blocking control may be before the turn operation is completed, thereby eliminating time loss. The timing of the request for blocking control may also be after the turn operation is completed.

[0070] In the process of thinning out turning bogies, it is determined whether or not a turning bogie that is in a turning state is present among the multiple bogies V that are the targets of polling communication (step S31). For example, the determination of whether or not a bogie V is a turning bogie may be made based on the status information of the bogie V. For example, the determination of whether or not a bogie V is a turning bogie may be made based on a transport command assigned to the bogie V by the system controller 5. For example, the determination of whether or not a bogie V is a turning bogie may be made based on information or a command from a higher-level controller (not shown). The status information of the bogie V may include information regarding the start timing of the turn of the bogie V, the end timing of the turn, the period required for the turn, and the request timing for blocking control of the bogie V.

[0071] If the answer is NO in step S31, the processing for this cycle is terminated, and the process proceeds to step S31 in the next cycle. On the other hand, if the answer is YES in step S31, communication with the turning vehicle in the polling communication is stopped (step S32). In other words, in step S32, turning vehicles are thinned out from the multiple vehicles V that are the targets of polling communication. As a result, in the polling communication, communication is performed sequentially and cyclically with the multiple vehicles V excluding the turning vehicle.

[0072] Furthermore, the predetermined operating state of the vehicle V that is the target of the polling thinning process is a second operating state in which the vehicle V is stopped from traveling due to the influence of the operation of another vehicle V. The system controller 5 suspends communication with the vehicle V in the second operating state in polling communication while the influence of the operation of the other vehicle V is occurring or until immediately before the influence disappears. Hereinafter, the vehicle V that is the target for which communication is suspended is also referred to as the "own vehicle V."

[0073] The second operating state includes a transfer waiting state in which the vehicle V stops traveling from the time when the other vehicle V starts transferring the article until just before the other vehicle V finishes transferring the article. That is, in the polling thinning process, the thinning process of the vehicle waiting for transfer shown in FIG. 6( a) is periodically repeated.

[0074] In the process of thinning out the carriages waiting for transfer, it is determined whether or not a carriage waiting for transfer, which is the carriage V itself, is present among the multiple carriages V that are the targets of polling communication (step S41). For example, the determination of whether or not the carriage V itself is a carriage waiting for transfer may be made based on status information of the carriage V itself and the other carriages V. For example, the determination of whether or not the carriage V itself is a carriage waiting for transfer may be made based on a command for blocking control for transfer. For example, the determination of whether or not the carriage V itself is a carriage waiting for transfer may be made based on information or a command from a higher-level controller (not shown). The status information of the carriage V itself and the other carriages V may include the start timing of the transfer of the other carriage V, the end timing of the transfer of the other carriage V, the time required for the transfer of the other carriage V, the start timing of the stop of travel of the carriage V itself, and the end timing of the stop of travel of the carriage V itself.

[0075] If the answer is NO in step S41, the processing for this cycle is terminated, and the process proceeds to step S41 in the next cycle. On the other hand, if the answer is YES in step S41, communication with the vehicles waiting for transfer in the polling communication is stopped (step S42). In other words, in step S42, the vehicles waiting for transfer are thinned out from the multiple vehicles V that are the target of the polling communication. As a result, in the polling communication, communication is performed sequentially and periodically with the multiple vehicles V excluding the vehicles waiting for transfer.

[0076] The second operating state includes a blocking waiting state, which is a state from when the own bogie V starts to stop traveling until immediately before it ends, in accordance with the blocking control of a bogie V other than the other bogie V, which is a control requested by the other bogie V. That is, in the polling thinning process, the thinning process of the blocking-waiting bogies shown in FIG. 6(b) is periodically and repeatedly executed.

[0077] In the process of thinning out bogies waiting for blocking, it is determined whether or not a bogie waiting for blocking, which is the own bogie V and is in a state of waiting for blocking, exists among the multiple bogies V that are the targets of polling communication (step S51). For example, the determination of whether or not the own bogie V is a bogie waiting for blocking may be made based on status information of the own bogie V and the other bogies V. For example, the determination of whether or not the own bogie V is a bogie waiting for blocking may be made based on a command related to blocking control. For example, the determination of whether or not the own bogie V is a bogie waiting for blocking may be made based on a command from a higher-level controller (not shown). The status information of the own bogie V and the other bogies V may include whether or not the other bogies V have requested blocking control, the start timing and end timing of the own bogie V's stopping of travel, etc.

[0078] If the answer is NO in step S51, the processing for this cycle is terminated, and the process proceeds to step S51 in the next cycle. On the other hand, if the answer is YES in step S51, communication with the carts waiting for blocking in the polling communication is stopped (step S52). In other words, in step S52, carts waiting for blocking are thinned out from the multiple carts V that are the targets of the polling communication. As a result, communication is performed sequentially and periodically with the multiple carts V excluding the carts waiting for blocking in the polling communication.

[0079] The second operating state includes an area entry waiting state, which is a state from when the vehicle V starts to stop traveling until just before it ends, in accordance with area vehicle number limiting control that prohibits entry into any of a plurality of traveling areas when the number of other vehicles V present in the area is equal to or greater than a specified number. That is, in the polling thinning process, the thinning process of vehicles waiting to enter the area shown in FIG. 6(c) is periodically repeated.

[0080] In the process of thinning out the bogies waiting to enter the area, it is determined whether or not the host bogie V, a bogie waiting to enter the area, exists among the multiple bogies V that are the targets of polling communication (step S51). For example, the determination of whether or not the host bogie V is a bogie waiting to enter the area may be made based on status information of the host bogie V and the other bogies V. For example, the determination of whether or not the host bogie V is a bogie waiting to enter the area may be made based on a command related to area vehicle count limit control. For example, the determination of whether or not the host bogie V is a bogie waiting to enter the area may be made based on a command from a higher-level controller (not shown). The status information of the host bogie V and the other bogies V may include whether or not area vehicle count limit control is in effect, information on the current position of the host bogie V, information on the current positions of the other bogies V, etc.

[0081] If the answer is NO in step S61, the processing for this cycle is terminated, and the process proceeds to step S61 in the next cycle. On the other hand, if the answer is YES in step S61, communication with vehicles waiting to enter the area in the polling communication is stopped (step S62). In other words, in step S62, the vehicles waiting to enter the area are thinned out from the multiple vehicles V that are the targets of the polling communication. As a result, communication is performed sequentially and periodically with the multiple vehicles V excluding the vehicles waiting to enter the area in the polling communication.

[0082] Furthermore, the predetermined operating state of the vehicle V that is the target of the polling thinning process is a third operating state in which the vehicle V is performing a set operation indefinitely. The system controller 5 reduces the frequency of communication with the vehicle V in the third operating state in polling communication.

[0083] The third operating state includes a maintenance-in-progress state in which the carriage V is in the maintenance mode. That is, in the polling thinning-out process, the thinning-out process of the carriage under maintenance shown in FIG. 7A is periodically and repeatedly executed.

[0084] In the process of thinning out the under-maintenance carriages, it is determined whether or not there is a under-maintenance carriage V that is in a maintenance state among the multiple carriages V that are the target of polling communication (step S71). For example, the determination of whether or not the carriage V is a under-maintenance carriage may be made based on the status information of the carriage V. For example, the determination of whether or not the carriage V is a under-maintenance carriage may be made based on a maintenance mode execution command sent by the system controller 5. For example, the determination of whether or not the carriage V is a under-maintenance carriage may be made based on a command from a higher-level controller (not shown). The status information of the carriage V may include information on whether or not the carriage V is executing the maintenance mode, etc.

[0085] If the answer is NO in step S71, the processing for this cycle is terminated, and the process proceeds to step S71 in the next cycle. On the other hand, if the answer is YES in step S71, the frequency of communication with the vehicle under maintenance in the polling communication is reduced (step S72). In other words, in step S72, the vehicle under maintenance is thinned out from the multiple vehicle V that are the target of the polling communication so that the frequency of communication with the vehicle under maintenance is reduced. As a result, in the polling communication, communication is performed sequentially and cyclically with the multiple vehicle V with the reduced frequency of communication with the vehicle under maintenance. For example, in step S72, the frequency of communication with the vehicle under maintenance is reduced so that communication with the vehicle under maintenance is performed once every five seconds in the polling communication.

[0086] The third operating state includes an error stopped state in which the vehicle V is stopped due to an error. That is, in the polling thinning process, the error stopped vehicle thinning process shown in FIG. 7B is periodically and repeatedly executed.

[0087] In the process of thinning out bogies stopped due to an error, it is determined whether or not there is an error-stopped bogie that is a bogie V in an error-stopped state among the multiple bogies V that are the target of polling communication (step S81). For example, the determination of whether or not a bogie V is an error-stopped bogie may be made based on the status information of the bogie V. For example, the determination of whether or not a bogie V is an error-stopped bogie may be made based on an error stop command sent by the system controller 5. For example, the determination of whether or not a bogie V is an error-stopped bogie may be made based on a command from a higher-level controller (not shown). The status information of the bogie V may include information on whether or not the status of the bogie V is abnormal, and whether or not the bogie V has stopped traveling.

[0088] If the answer is NO in step S81, the processing for this cycle is terminated, and the process proceeds to step S81 in the next cycle. On the other hand, if the answer is YES in step S81, the frequency of communication with the error-stopped vehicle in the polling communication is reduced (step S82). In other words, in step S82, the error-stopped vehicle is thinned out from the multiple vehicle V that are the target of the polling communication so that the frequency of communication with the error-stopped vehicle is reduced. As a result, in the polling communication, communication is performed sequentially and periodically with the multiple vehicle V with the frequency of communication with the error-stopped vehicle reduced. For example, in step S82, the frequency of communication with the error-stopped vehicle is reduced so that communication with the error-stopped vehicle is performed once every 10 seconds in the polling communication.

[0089] The third operating state includes an idling stopped state in which the vehicle is idling and stopped. That is, in the polling thinning process, the thinning process of idling stopped vehicles shown in FIG. 7( c) is periodically repeated.

[0090] In the process of thinning out idling bogies, it is determined whether or not there is an idling bogie V that is in an idling state among the multiple bogies V that are the targets of polling communication (step S91). For example, the determination of whether or not a bogie V is an idling bogie may be made based on the status information of the bogie V. For example, the determination of whether or not a bogie V is an idling bogie may be made based on an idling stop command transmitted by the system controller 5. For example, the determination of whether or not a bogie V is an idling bogie may be made based on a command from a higher-level controller (not shown). The status information of the bogie V may include information on whether or not the bogie V is in an idling state and whether or not the bogie V is stopped from traveling.

[0091] If the answer is NO in step S91, the processing for this cycle is terminated, and the process proceeds to step S91 in the next cycle. On the other hand, if the answer is YES in step S91, the frequency of communication with idling bogies in polling communication is reduced (step S92). In other words, in step S92, idling bogies are thinned out from the multiple bogies V that are the targets of polling communication so that the frequency of communication with idling bogies is reduced. As a result, in polling communication, communication is performed sequentially and periodically with the multiple bogies V with the reduced frequency of communication with idling bogies. For example, in step S92, the frequency of communication with idling bogies is reduced so that communication with idling bogies is performed once every five seconds in polling communication.

[0092] As described above, in the transport system SYS, the polling thinning process can stop or reduce the frequency of polling communication with a vehicle V in a predetermined operating state. This makes it possible to thin out communication with a vehicle V in a predetermined operating state in polling communication, thereby reducing the time required for communication with the vehicle V in the predetermined operating state. Therefore, it is possible to shorten the period of polling communication, that is, one cycle time of polling communication (see the formula below). As a result, for each necessary vehicle V (a vehicle V not in a predetermined operating state), for example, the notification communication speed (bps) can be increased, enabling smooth control. One cycle time = t·N t: response time per vehicle, N: number of vehicles targeted for polling communication

[0093] In the transport system SYS, the predetermined operating state includes a first operating state in which the carriage V stops traveling and performs an operation other than traveling. In this case, it is possible to reduce the time required for communication with the carriage V in the first operating state in polling communication.

[0094] In the transport system SYS, communication with the carriage V in the first operation state in polling communication is stopped for a period based on the time required for operation in the first operation state. In this case, the cycle of polling communication can be reduced by the period based on the time required for operation in the first operation state.

[0095] In the transport system SYS, the first operating state includes a transferring state. In this case, it is possible to reduce the time required for communication with a transferring vehicle in polling communication. In the transport system SYS, the first operating state includes a charging state. In this case, it is possible to reduce the time required for communication with a charging vehicle in polling communication. In the transport system SYS, the first operating state includes a turning state. In this case, it is possible to reduce the time required for communication with a turning vehicle in polling communication.

[0096] In the transport system SYS, the predetermined operating state includes a second operating state in which a carriage V stops traveling due to the influence of the operation of another carriage V. In this case, it is possible to reduce the time required for communication with a carriage V in the second operating state in polling communication.

[0097] In the transport system SYS, communication with a vehicle V in the second operating state in polling communication is stopped while the influence of the operation of another vehicle V is occurring or until immediately before the influence disappears. In this case, the cycle of polling communication can be reduced for the period while the influence of the operation of another vehicle V is occurring or until immediately before the influence disappears.

[0098] In the transport system SYS, the second operating state includes a waiting state for transfer. In this case, it is possible to reduce the time required for communication with a vehicle waiting for transfer in polling communication. In the transport system SYS, the second operating state includes a waiting state for blocking. In this case, it is possible to reduce the time required for communication with a vehicle waiting for blocking in polling communication. In the transport system SYS, the second operating state includes a waiting state for area entry. In this case, it is possible to reduce the time required for communication with a vehicle waiting to enter the area in polling communication.

[0099] In the transport system SYS, the predetermined operation state includes a third operation state in which the carriage V performs a set operation indefinitely. In this case, it is possible to reduce the time required for communication with the carriage V in the third operation state in polling communication.

[0100] In the transport system SYS, the frequency of polling communication with a vehicle V in the third operating state is reduced. In this case, it is possible to increase the frequency of polling communication, reducing the time required for communication with a vehicle V in the third operating state. In addition, in this case, since polling communication with a vehicle V in the third operating state is not stopped, communication with the vehicle V can be maintained, which is effective in returning the vehicle V from the third operating state to the normal operating state.

[0101] In the transport system SYS, the third operation state includes a maintenance in progress state. In this case, it is possible to reduce the time required for communication with a vehicle that is under maintenance in polling communication. In the transport system SYS, the third operation state includes an error stopped state. In this case, it is possible to reduce the time required for communication with a vehicle that is under error stopped in polling communication. In the transport system SYS, the third operation state includes an idling stopped state. In this case, it is possible to reduce the time required for communication with a vehicle that is under idling stopped in polling communication.

[0102] The transport system SYS is equipped with rails R on which multiple carriages V run, forming a so-called grid system. This makes it easier to freely select the travel route of the carriages V, thereby reducing congestion and improving transport efficiency.

[0103] A simulation was performed on the transport system SYS described above to verify the reduction rate of the polling communication cycle. As a result of the simulation, it was confirmed that the polling communication cycle could be reduced by more than 30% (approximately 31%).

[0104] Whether or not the polling thinning process is being executed in the polling communication can be confirmed, for example, based on the log of the system controller 5. In the transport system SYS, execution and stop of the polling thinning process may be selected, for example, by a user's operation input via the operation input unit, and the execution and stop of the polling thinning process may be controlled according to the result of the selection.

[0105] Although the embodiments have been described above, one aspect of the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the invention.

[0106] In the above embodiment, the predetermined operating state is not particularly limited. The predetermined operating state may include at least one of a first operating state, a second operating state, and a third operating state, or may include other operating states. Furthermore, the information used to determine whether the bogie V is in the predetermined operating state is not particularly limited, and various information may be used.

[0107] In the above embodiment, the first operating state is not particularly limited. The first operating state may include at least one of a transfer-in-progress state, a charging state, and a turning state, or may further include other states. In the above embodiment, the second operating state is not particularly limited. The second operating state may include at least one of a transfer-in-progress state, a blocking-in-progress state, and an area entry-progression-progression state, or may further include other states. In the above embodiment, the third operating state is not particularly limited. The third operating state may include at least one of a maintenance-in-progress state, an error-stopped state, and an idling-stopped state, or may further include other states.

[0108] In the above embodiment, a grid system is used as the transport system SYS, but the transport system SYS is not limited to a grid system. For example, an AGV (Automated Guided Vehicle) may be used as the transport system, or various known systems that travel on a grid-like travel path may be used. In the above embodiment, the carriage V holds the article M below the rail R, but the main body 10 may be disposed above the rail R and hold the article M above the rail R.

[0109] 2...grid cell, 5...system controller (controller), 13...article holding unit, 18...transfer device, 20...traveling unit, 21...traveling wheel, M...article, R...rail (grid track), SYS...transport system, V...cart (own cart, other cart).

Claims

1. A transport system comprising a plurality of carriages and a controller for controlling the plurality of carriages, wherein the controller performs periodic communication between the plurality of carriages in sequence and periodically, and when at least one of the plurality of carriages is in a predetermined operating state, the controller stops communication with that carriage in the periodic communication, or reduces the frequency of communication with that carriage in the periodic communication.

2. The conveying system according to claim 1, wherein the predetermined operating state includes a first operating state in which the carriage is stopped and performing an operation other than traveling.

3. The transport system according to claim 2, wherein communication with the carriage in the first operating state in the periodic communication is stopped for a period based on the time required for operation in the first operating state.

4. A conveying system according to claim 2 or 3, wherein the first operating state includes a transfer-in-progress state, which is a state in which the carriage starts transferring an item and ends immediately before the transfer is completed.

5. A transport system according to any one of claims 2 to 4, wherein the first operating state includes a charging state, which is a state in which the carriage starts charging and ends charging immediately before the end of charging.

6. A conveying system as claimed in any one of claims 2 to 5, wherein the first operating state includes a turning state which is a state from when the carriage starts to turn until just before the timing when the carriage should request blocking control to prohibit other carriages from entering a specified area into which the carriage will enter after the turn.

7. A conveying system according to any one of claims 1 to 6, wherein the predetermined operating state includes a second operating state in which the carriage is stopped due to the influence of the operation of another carriage.

8. A conveying system as described in claim 7, wherein communication with the carriage in the second operating state in the periodic communication is stopped while an influence caused by the operation of the other carriage is occurring or until just before the influence disappears.

9. A conveying system as described in claim 7 or 8, wherein the second operating state includes a transfer waiting state in which the other carriage stops moving from the time it starts transferring an item until just before it finishes transferring the item.

10. A conveying system as claimed in any one of claims 7 to 9, wherein the second operating state includes a blocking waiting state, which is a state in which the carriage starts to stop traveling and immediately before it stops, in accordance with blocking control requested by the other carriage, which prohibits the carriage other than the other carriage from entering a specified area.

11. A conveying system as claimed in any one of claims 7 to 10, wherein the second operating state includes an area entry waiting state, which is a state in which the carriage starts to stop traveling and immediately before it stops, in accordance with area number restriction control that prohibits entry into any of a plurality of traveling areas when the number of other carriages present in that area is equal to or greater than a specified number.

12. A transport system according to any one of claims 1 to 11, wherein the predetermined operating states include a third operating state in which the carriage performs a set operation indefinitely.

13. The transport system according to claim 12, wherein the frequency of communication between the carriage in the third operating state and the carriage in the periodic communication is reduced.

14. A transport system according to claim 12 or 13, wherein the third operating state includes a maintenance in progress state in which the carriage is in a maintenance mode.

15. A conveyance system according to any one of claims 12 to 14, wherein the third operating state includes an error stopped state in which the carriage is stopped due to an error.

16. A transport system according to any one of claims 12 to 15, wherein the third operating state includes an idling stopped state in which the carriage is idling and stopped.

17. A transport system according to any one of claims 1 to 16, comprising a lattice-like track on which a plurality of said carriages run.

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