Transport vehicle system and transport vehicle control device

Abstract

A transport vehicle system according to the present invention includes a track having a plurality of branch portions and merging portions, a plurality of transport vehicles that travel along the track and that transport goods, a plurality of temporary placement spots that are disposed about the track and on which the goods are placed, and a transport vehicle controller that allocates transport commands to the transport vehicles. When an unknown cargo transport vehicle that is a transport vehicle that cannot complete transport of loaded goods is generated, the transport vehicle controller decides a temporary placement spot as a destination, on the basis of an unknown cargo transport destination table in which a plurality of temporary placement spots within a predetermined range from the unknown cargo transport vehicle are listed, and allocates an unknown cargo transport command to the unknown cargo transport vehicle, for conveying the goods to the determined temporary placement spot.

Description

Guided vehicle system and guided vehicle control device

[0001] The present disclosure relates to a guided vehicle system and a guided vehicle control device.

[0002] A known transport vehicle system includes a track having multiple branching and merging sections, multiple transport vehicles that travel along the track and transport items, and a transport vehicle controller that assigns transport commands to the transport vehicles (see, for example, Patent Document 1).

[0003] Patent No. 7306588

[0004] In the above-mentioned transport vehicle system, if an unknown load transport vehicle, which is a transport vehicle that cannot complete the transport of the loaded items for some reason, occurs, the items loaded on the unknown load transport vehicle (hereinafter also referred to as "unknown load") may be temporarily placed on a temporary storage area arranged along the track. However, in this case, for example, it may take a very long time to transport the unknown load to the temporary storage area, and there is a possibility that the unknown load cannot be temporarily stored efficiently.

[0005] The present disclosure aims to provide a transport vehicle system and a transport vehicle control device that can efficiently temporarily store items when an unknown cargo transport vehicle is unable to complete the transportation of loaded items.

[0006] (1) The transport vehicle system of the present disclosure comprises a track having multiple branching and merging sections, multiple transport vehicles that travel along the track and transport items, multiple temporary storage areas arranged around the track on which items are placed, and a transport vehicle controller that assigns transport commands to the transport vehicles.When an unknown load transport vehicle occurs, which is a transport vehicle that is unable to complete the transport of the loaded items, the transport vehicle controller determines the temporary storage area as the destination based on an unknown load transport destination table that lists multiple temporary storage areas within a specified range of the unknown load transport vehicle, and assigns an unknown load transport command to the unknown load transport vehicle to transport the items to the determined temporary storage area.

[0007] In this transport vehicle system, a temporary storage location outside a predetermined range from the unknown load transport vehicle is not set as the temporary storage location (i.e., the destination of the unknown load transport command), but the temporary storage location can be selected from multiple temporary storage locations within a predetermined range from the unknown load transport vehicle. This makes it possible to reduce the time required to transport an unknown load to a temporary storage location, for example, and to efficiently temporarily store the unknown load.

[0008] (2) In the transport vehicle system described in (1) above, when an unknown load transport vehicle occurs, the transport vehicle controller may perform a route search from the unknown load transport vehicle to multiple temporary storage areas, create an unknown load destination table, and determine the temporary storage area as the destination based on the created unknown load destination table. In this case, an unknown load destination table according to the situation when the unknown load transport vehicle occurs can be obtained.

[0009] (3) In the transport vehicle system described in (1) or (2) above, a maximum number of simultaneous transports is set for each of the multiple temporary storage areas in the unknown load transport destination table, and the transport vehicle controller assigns unknown load transport commands to multiple unknown load transport vehicles. If the destinations of the multiple assigned unknown load transport commands overlap with the same temporary storage area and the number of overlaps reaches the maximum number of simultaneous transports for the temporary storage area, when assigning the unknown load transport command to a new unknown load transport vehicle, a temporary storage area other than the temporary storage area that has reached the maximum number of simultaneous transports may be determined as the destination. In this case, it is possible to prevent multiple unknown loads from being temporarily stored in a specific temporary storage area, and to distribute the multiple unknown loads to multiple temporary storage areas.

[0010] (4) In the transport vehicle system described in any one of (1) to (3) above, the unknown load transport destination table lists multiple temporary storage areas for each unknown load transport vehicle, prioritized in order of proximity to the current location of the unknown load transport vehicle, and the transport vehicle controller may select the temporary storage areas as destination candidates in order of priority in the unknown load transport destination table. In this case, it is possible to temporarily store the unknown load in a temporary storage area that is closest to the current location of the unknown load transport vehicle.

[0011] (5) In the transport vehicle system described in any one of (1) to (4) above, if the transport vehicle is unable to complete an unknown load transport command to a temporary storage location determined based on the unknown load transport destination table, the transport vehicle controller may re-determine the temporary storage location as the destination based on the unknown load transport destination table and assign a new unknown load transport command to the unknown load transport vehicle to transport the item to the re-determined temporary storage location. Even if temporary storage cannot be completed using an unknown load transport command using the unknown load destination table, if various circumstances change thereafter, it may be possible to complete temporary storage using an unknown load transport command using the same unknown load destination table. The present disclosure takes such possibilities into account and enables efficient temporary storage of unknown loads.

[0012] (6) In the transport vehicle system described in any one of (1) to (5) above, the unknown load transport vehicle may be a transport vehicle that has failed to transport an item or a transport vehicle that has canceled the transport of an item while transporting the item, and for which a certain period of time has passed without a new transport command being assigned. The present disclosure makes it possible to efficiently temporarily store the unknown load of such an unknown load transport vehicle.

[0013] (7) A transport vehicle control device according to the present disclosure is a control device that controls transport vehicles in a transport vehicle system having a track with multiple branching and merging sections, multiple transport vehicles that travel along the track and transport items, and multiple temporary storage areas located around the track on which items are placed, and when an unknown load transport vehicle that is a transport vehicle that cannot complete the transport of the loaded items occurs, the control device determines the temporary storage area as a destination based on an unknown load transport destination table that lists multiple temporary storage areas within a predetermined range from the unknown load transport vehicle, and assigns an unknown load transport command to the unknown load transport vehicle to transport the items to the determined temporary storage area. Similar to the transport vehicle system described above, this transport vehicle control device also makes it possible to efficiently temporarily store unknown loads when an unknown load transport vehicle occurs.

[0014] According to the present disclosure, it is possible to provide a transport vehicle system and a transport vehicle control device that can efficiently temporarily store items when an unknown cargo transport vehicle occurs that is unable to complete the transport of the loaded items.

[0015] FIG. 1 is a schematic diagram showing an example layout of a guided vehicle system. FIG. 2 is a block diagram showing the functional configuration of the guided vehicle system. FIG. 3 is a block diagram showing an example hardware configuration of a guided vehicle controller. FIG. 4(a) is a diagram showing a first example of an unknown load delivery destination table. FIG. 4(b) is a diagram showing a second example of an unknown load delivery destination table. FIG. 5 is a schematic diagram showing another example layout of a guided vehicle system. FIG. 6(a) is a diagram showing a third example of an unknown load delivery destination table. FIG. 6(b) is a diagram showing a fourth example of an unknown load delivery destination table.

[0016] An embodiment will be described below with reference to the drawings. In the description of the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant description may be omitted.

[0017] As shown in Figure 1, the transport vehicle system 1 of this embodiment includes a track 10, a plurality of transport vehicles 2 running along the track 10, a temporary storage area P arranged around the track 10, and a transport vehicle controller 20 that assigns transport commands to the transport vehicles 2.

[0018] The track 10 is a transport path along which the transport vehicle 2 can travel in a predetermined travel direction. The track 10 is laid within a facility such as a factory. The track 10 is formed by connecting multiple path segments 11 to each other. The track 10 has multiple branching sections 12 where one path segment 11 branches into multiple path segments 11, and multiple merging sections 13 where the multiple path segments 11 merge.

[0019] The transport vehicle 2 is, for example, an automated guided vehicle that transports an article. The transport vehicle 2 is, for example, an overhead traveling vehicle, a tracked vehicle, or the like. As an example, the transport vehicle 2 is an overhead traveling automated guided vehicle that is capable of traveling along a track 10. For example, the transport vehicle 2 is an overhead traveling automated guided vehicle (OHT: Overhead Hoist Transport). As an example, the article transported by the transport vehicle 2 is a cassette (a so-called FOUP (Front Opening Unified Pod)) that contains multiple semiconductor wafers.

[0020] The temporary storage area P is a location where the transport vehicle 2 can temporarily store an item, and the item is placed there. The temporary storage area P serves as a buffer for temporarily storing the item. The temporary storage area P may be, for example, at least one of a stocker, an overhead buffer, and a conveyor. The temporary storage areas P are dispersedly arranged around the track 10. The number of items that can be temporarily stored at each temporary storage area P may be one or more.

[0021] 1 and 2, the transport vehicle controller 20 receives a transport command from a host controller 50. The transport vehicle controller 20 controls the travel of the transport vehicles 2 by allocating the transport command received from the host controller 50 to a transport vehicle 2 selected from among a plurality of transport vehicles 2.

[0022] The transport vehicle controller 20 determines a transport route of the transport command (i.e., a travel route from the current position of the transport vehicle 2 to the To point via the From point) by performing a route search using a predetermined route search algorithm (for example, a shortest route search algorithm such as the Dijkstra algorithm) based on link costs associated with the route portion 11, the branching section 12, and the merging section 13. The transport vehicle controller 20 assigns the transport command to the transport vehicle 2 for transport along the determined transport route.

[0023] The guided vehicle 2 to which the transport command is assigned travels toward the From point, grabs the item to be transported at the From point, transports the item toward the To point, and unloads the item at the To point. The route search algorithm for the route search is not particularly limited, and various algorithms may be used (the same applies to the route searches below). The guided vehicle controller 20 constitutes a guided vehicle control device that controls the guided vehicle 2 in the guided vehicle system 1.

[0024] 3, the transport vehicle controller 20 may be configured as a computer system including one or more processors 201 such as CPUs (Central Processing Units), one or more RAMs (Random Access Memories) 202 and one or more ROMs (Read Only Memories) 203 as main storage devices, an input device 204 such as a keyboard for an operator to input operations, an output device 205 such as a display that presents information to the operator, a communication module 206 for communicating with the transport vehicle 2, and an auxiliary storage device 207 such as an HDD and SSD. The transport vehicle controller 20 may be configured as a single computer device or as multiple computer devices (e.g., multiple sub-controllers).

[0025] Each function of the transport vehicle controller 20 is realized, for example, by loading a predetermined program into a memory such as RAM 202, operating the input device 204 and output device 205 under the control of the processor 201, operating the communication module 206, and reading and writing data in RAM 202 and the auxiliary storage device 207.

[0026] 1 and 2, when an unknown load transport vehicle 3 occurs, the transport vehicle controller 20 of this embodiment determines the temporary storage area P as the destination based on an unknown load transport destination table that lists multiple temporary storage areas P within a predetermined range from the unknown load transport vehicle 3, and assigns an unknown load transport command to the unknown load transport vehicle 3 to transport the item to the determined temporary storage area P. The transport vehicle controller 20 includes, as functional components, a table creation unit 21, a memory unit 22, a determination unit 23, and an allocation unit 24.

[0027] The unknown load transport vehicle 3 is a transport vehicle 2 that cannot complete the transport of the loaded items. The unknown load transport vehicle 3 is loaded with items (hereinafter, the items loaded on the unknown load transport vehicle 3 will also be referred to as "unknown load"). The unknown load transport vehicle 3 may be a transport vehicle 2 that failed to transport an item. The unknown load transport vehicle 3 may be a transport vehicle 2 that was canceled (aborted) during the transport of an item. The unknown load transport vehicle 3 may be a transport vehicle 2 that has not been assigned a new transport command (a state in which the transport vehicle controller 20 has not received the transport command from the upper controller 50) for a certain period of time or more. The unknown load transport vehicle 3 may be a transport vehicle 2 with an unknown destination, a transport vehicle 2 to which a command related to a To point has not been assigned, or a transport vehicle 2 that has lost the command related to the To point.

[0028] For example, the unknown load transport vehicle 3 may be a transport vehicle 2 that has stopped due to contact with another transport vehicle 2 or the like. Also, for example, the unknown load transport vehicle 3 may be a transport vehicle 2 that has repeatedly performed a loading or unloading operation without being able to complete it normally due to an error, and the number of repetitions has reached a certain number. Also, for example, the unknown load transport vehicle 3 may be a transport vehicle 2 in which a communication abnormality has occurred. Also, for example, the unknown load transport vehicle 3 may be a transport vehicle 2 that has timed out after a certain time has passed since receiving a transport command and has been unable to complete the command.

[0029] When an unknown load transport vehicle 3 occurs, the table creation unit 21 creates an unknown load transport destination table by searching for a route from the unknown load transport vehicle 3 to multiple temporary storage areas P. The table creation unit 21 can determine whether an unknown load transport vehicle 3 has occurred based on, for example, various information transmitted from the transport vehicle 2, etc.

[0030] As shown in FIG. 4 , the unknown load transport destination table TB is a table that lists multiple temporary storage areas P within a predetermined range from the unknown load transport vehicle 3. Specifically, the unknown load transport destination table TB is a table that lists multiple temporary storage areas P within a predetermined range, prioritized in order of proximity from the current location of the unknown load transport vehicle 3. The unknown load transport destination table TB is set for each unknown load transport vehicle 3. The predetermined range is not particularly limited and may be a range that is set in advance, or may be a range that is variable using, for example, the input device 204 (see FIG. 3 ). Proximity may mean a short distance along the route, a short time required to arrive, or a low link cost.

[0031] A maximum number of simultaneous transfers is set for each of the multiple temporary storage areas P in the unknown load transfer destination table TB. The maximum number of simultaneous transfers is the upper limit of the number of destinations that can be the destinations of multiple unknown load transfer commands at the same time. The maximum number of simultaneous transfers may be variable, for example, by the input device 204 (see Figure 3). A currently possible number of transfers (so-called capacity) is set for each of the multiple temporary storage areas P in the unknown load transfer destination table TB. The currently possible number of transfers is the remaining number that can be set as the destination of an unknown load transfer command. The currently possible number of transfers is the number obtained by subtracting the "number already set as the target value for an unknown load transfer command" from the "maximum number of simultaneous transfers."

[0032] The storage unit 22 is a database that stores various information related to the transport vehicle system 1. The storage unit 22 may be configured by a single database device or may be configured by multiple database devices. The storage unit 22 stores the unknown cargo destination table TB created by the table creation unit 21.

[0033] The determination unit 23 determines a temporary storage location P as the destination of the unknown load transport command based on the unknown load transport destination table TB created by the table creation unit 21 and stored in the storage unit 22. The determination unit 23 selects temporary storage locations P as destination candidates in descending order of priority in the unknown load transport destination table TB. The determination unit 23 determines the selected temporary storage location P as the destination candidate for the unknown load transport command.

[0034] The allocation unit 24 determines a transport route for transporting the unknown load to the determined temporary storage area P by performing a route search, and generates an unknown load transport command to transport the unknown load along the determined transport route and unload it at the temporary storage area P. The allocation unit 24 allocates the generated unknown load transport command to an unknown load transport vehicle 3. Note that the allocation unit 24 may generate the unknown load transport command using the route search results performed by the table creation unit 21.

[0035] In particular, in this embodiment, when unknown cargo transport commands are assigned to multiple unknown cargo transport vehicles 3, and the destinations of the multiple assigned unknown cargo transport commands overlap at the same temporary storage area P, and the number of overlaps reaches the maximum number of simultaneous transports at the temporary storage area P (when the ``currently possible number of transports'' becomes 0), when assigning the unknown cargo transport command to a new unknown cargo transport vehicle 3, the determination unit 23 determines a temporary storage area P other than the temporary storage area P that has reached the maximum number of simultaneous transports as the destination.

[0036] As an example, the determination unit 23 selects temporary storage units P as destination candidates in descending order of priority in the unknown load transport destination table TB. If the "currently possible transport number" of the selected temporary storage unit P as a destination candidate is 0, the determination unit 23 reselects the temporary storage unit P next in priority to the selected temporary storage unit P as a destination candidate. The determination unit 23 repeats this reselection until a temporary storage unit P whose "currently possible transport number" is not 0 becomes a destination candidate. Then, the determination unit 23 determines the selected destination candidate as the destination of the unknown load transport command.

[0037] Furthermore, if the unknown load transport vehicle 3 is unable to complete the unknown load transport command to the temporary storage location P determined based on the unknown load transport destination table TB, the determination unit 23 again determines the temporary storage location P as the destination based on the same unknown load transport destination table TB. In this case, the allocation unit 24 allocates a new unknown load transport command to the unknown load transport vehicle 3 to transport the item to the newly determined temporary storage location P.

[0038] Next, a processing example regarding allocation of an unknown load transport command in the transport vehicle system 1 will be described.

[0039] For example, as shown in Figure 1, when an unknown load transport vehicle 3A appears, an example will be described in which an unknown load transport command is generated by the transport vehicle controller 20 and assigned to the unknown load transport vehicle 3A. First, the table creation unit 21 executes a route search from the unknown load transport vehicle 3A to multiple temporary storage areas P within a predetermined range, and creates the unknown load transport destination table TB1 shown in Figure 4(a). The table creation unit 21 stores the created unknown load transport destination table TB1 in the memory unit 22.

[0040] The unknown load transport destination table TB1 lists three temporary storage areas PA, PB, and PC within a predetermined range from the unknown load transport vehicle 3A. In the unknown load transport destination table TB1, the temporary storage area PA closest to the unknown load transport vehicle 3A is given the first priority, the temporary storage area PB next closest to the unknown load transport vehicle 3A is given the second priority, and the temporary storage area PC next closest to the unknown load transport vehicle 3A is given the third priority. In the temporary storage areas PA, PB, and PC in the unknown load transport destination table TB1, the number of transports currently possible is the same as the maximum number of simultaneous transports.

[0041] The determination unit 23 selects candidate destinations for the unknown load transport command in order, starting with the temporary storage unit P with the highest priority in the created unknown load transport destination table TB1. In the example shown, the determination unit 23 selects the temporary storage unit PA with the highest priority and determines it as the destination of the unknown load transport command. The allocation unit 24 generates an unknown load transport command to transport the unknown load to the determined temporary storage unit PA, and allocates the generated unknown load transport command to the unknown load transport vehicle 3A. As a result, the unknown load transport vehicle 3A to which the unknown load transport command has been allocated transports the unknown load to the temporary storage unit PA, unloads it, and performs temporary storage, temporarily placing the unknown load at the temporary storage unit PA.

[0042] Next, an example will be described in which, for example, as shown in Figure 1, when an unknown load transport vehicle 3B appears, the transport vehicle controller 20 generates an unknown load transport command and assigns it to the unknown load transport vehicle 3B. First, the table creation unit 21 executes a route search from the unknown load transport vehicle 3B to multiple temporary storage areas P within a predetermined range, and creates the unknown load transport destination table TB2 shown in Figure 4(b). The table creation unit 21 stores the created unknown load transport destination table TB2 in the memory unit 22.

[0043] The unknown load transport destination table TB2 lists four temporary storage areas PJ, PK, PL, and PM within a predetermined range from the unknown load transport vehicle 3B. In the unknown load transport destination table TB2, the temporary storage area PJ closest to the unknown load transport vehicle 3B is given the first priority, the temporary storage area PK next closest to the unknown load transport vehicle 3B is given the second priority, the temporary storage area PL next closest to the unknown load transport vehicle 3B is given the third priority, and the temporary storage area PM next closest to the unknown load transport vehicle 3B is given the fourth priority. For the temporary storage areas PJ, PK, PL, and PM in the unknown load transport destination table TB2, the number of transports currently possible is the same as the maximum number of simultaneous transports.

[0044] The determination unit 23 selects candidate destinations for the unknown load transport command in order, starting with the temporary storage unit P with the highest priority in the created unknown load transport destination table TB2. In the example shown, the determination unit 23 selects the temporary storage unit PJ with the highest priority and determines it as the destination of the unknown load transport command. The allocation unit 24 generates an unknown load transport command to transport the unknown load to the determined temporary storage unit PJ, and allocates the generated unknown load transport command to the unknown load transport vehicle 3B. As a result, the unknown load transport vehicle 3B to which the unknown load transport command has been allocated transports the unknown load to the temporary storage unit PJ, unloads it, and performs temporary storage, temporarily placing the unknown load on the temporary storage unit PJ.

[0045] Next, for example, as shown in Figure 5, when multiple unknown load transport vehicles 3 are generated and multiple unknown load transport commands are generated by the transport vehicle controller 20 and assigned to each of the multiple unknown load transport vehicles 3, an example of assigning an unknown load transport command to an unknown load transport vehicle 3C will be explained.

[0046] First, the table creation unit 21 executes a route search from the unknown cargo transport vehicle 3C to a plurality of temporary storage areas P within a predetermined range, and creates the unknown cargo destination table TB3 shown in Figure 6(a). The table creation unit 21 stores the created unknown cargo destination table TB3 in the memory unit 22.

[0047] The unknown load transport destination table TB3 lists three temporary storage areas PA, PB, and PC within a predetermined range from the unknown load transport vehicle 3C. In the unknown load transport destination table TB3, the temporary storage area PA closest to the unknown load transport vehicle 3C is given the first priority, the temporary storage area PB next closest to the unknown load transport vehicle 3C is given the second priority, and the temporary storage area PC next closest to the unknown load transport vehicle 3C is given the third priority.

[0048] The temporary storage areas PA and PB in the unknown load transport destination table TB3 have already been used as destinations for unknown load transport commands for multiple other unknown load transport vehicles 3, and the current number of possible transports is 0. The temporary storage area PC in the unknown load transport destination table TB3 has already been used as a destination for unknown load transport commands for multiple other unknown load transport vehicles 3, but the number of uses has not yet reached the maximum number of simultaneous transports, and the current number of possible transports is 1.

[0049] The determination unit 23 selects candidate destinations for the unknown load transport command, starting with the temporary storage unit P with the highest priority in the created unknown load transport destination table TB3. In the example shown, since the current number of transports possible for the temporary storage units PA and PB is 0, the determination unit 23 selects the temporary storage unit PC with the highest priority and a currently available number of transports of 1 or more, and determines this as the destination of the unknown load transport command. The allocation unit 24 generates an unknown load transport command to transport the unknown load to the determined temporary storage unit PC, and allocates the generated unknown load transport command to the unknown load transport vehicle 3C. As a result, the unknown load transport vehicle 3C to which the unknown load transport command has been allocated transports the unknown load to the temporary storage unit PC, unloads it, and performs temporary storage, temporarily placing the unknown load on the temporary storage unit PC.

[0050] Next, for example, as shown in Figure 5, when multiple unknown load transport vehicles 3 are generated and multiple unknown load transport commands are generated by the transport vehicle controller 20 and assigned to each of the multiple unknown load transport vehicles 3, an example of assigning an unknown load transport command to an unknown load transport vehicle 3D will be explained.

[0051] First, the table creation unit 21 executes a route search from the unknown cargo transport vehicle 3D to a plurality of temporary storage areas P within a predetermined range, and creates an unknown cargo destination table TB4 shown in Figure 6(b). The table creation unit 21 stores the created unknown cargo destination table TB4 in the memory unit 22.

[0052] The unknown load transport destination table TB4 lists four temporary storage areas PA, PB, PC, and PD within a predetermined range from the unknown load transport vehicle 3D. In the unknown load transport destination table TB4, the temporary storage area PA closest to the unknown load transport vehicle 3D is given the first priority, the temporary storage area PB next closest to the unknown load transport vehicle 3D is given the second priority, the temporary storage area PC next closest to the unknown load transport vehicle 3D is given the third priority, and the temporary storage area PD next closest to the unknown load transport vehicle 3D is given the fourth priority.

[0053] The temporary storage areas PA, PB, and PC in the unknown load transport destination table TB4 have already been used as destinations for unknown load transport commands for multiple other unknown load transport vehicles 3, and the current number of possible transports is 0. The temporary storage area PD in the unknown load transport destination table TB4 has not been used as a destination for unknown load transport commands for multiple other unknown load transport vehicles 3, and the current number of possible transports is 5, which is the same as the maximum number of simultaneous transports.

[0054] The determination unit 23 selects candidate destinations for the unknown load transport command, starting with the temporary storage unit P with the highest priority in the created unknown load transport destination table TB4. In the example shown, since the current number of transports possible for the temporary storage units PA, PB, and PC is 0, the determination unit 23 selects the temporary storage unit PD with the highest priority and a currently available number of transports of 1 or more, and determines this as the destination of the unknown load transport command. The allocation unit 24 generates an unknown load transport command to transport the unknown load to the determined temporary storage unit PD and allocates the generated unknown load transport command to the unknown load transport vehicle 3D. As a result, the unknown load transport vehicle 3D to which the unknown load transport command has been allocated transports the unknown load to the temporary storage unit PD, unloads it, and performs temporary storage, temporarily placing the unknown load on the temporary storage unit PD.

[0055] 3, the auxiliary storage device 207 stores the transport vehicle control program 5, and by having the processor (computer) 201 execute the transport vehicle control program 5, each control of the transport vehicle 2 related to the above-mentioned unknown load transport command is performed. That is, the transport vehicle control program 5 is a program that controls the transport vehicle 2 in the transport vehicle system 1, and when an unknown load transport vehicle 3 occurs, causes the processor 201 to execute the steps of determining a temporary storage area P as a destination based on the unknown load transport destination table TB, and assigning an unknown load transport command to the unknown load transport vehicle 3 to transport the item to the determined temporary storage area P.

[0056] [Effects] As described above, the transport vehicle system 1 and the transport vehicle controller 20 can determine the temporary storage destination from among multiple temporary storage locations P within a predetermined range from the unknown load transport vehicle 3, rather than setting a temporary storage location P outside a predetermined range from the unknown load transport vehicle 3 as the temporary storage destination (i.e., the destination of the unknown load transport command). This makes it possible to reduce the time required to transport an unknown load to the temporary storage location P, for example, and to efficiently temporarily store the unknown load.

[0057] In the transport vehicle system 1, when an unknown load transport vehicle 3 occurs, the transport vehicle controller 20 executes a route search from the unknown load transport vehicle 3 to multiple temporary storage locations P, creates an unknown load transport destination table TB, and determines the temporary storage location P as the destination based on the created unknown load transport destination table TB. In this case, an unknown load transport destination table TB according to the situation when the unknown load transport vehicle 3 occurs can be obtained.

[0058] In the transport vehicle system 1, a maximum number of simultaneous transports is set for each of the multiple temporary storage areas P in the unknown load transport destination table TB. When unknown load transport commands are assigned to multiple unknown load transport vehicles 3, and the destinations of the multiple assigned unknown load transport commands overlap at the same temporary storage area P, and the number of overlaps reaches the maximum number of simultaneous transports for the temporary storage area, the transport vehicle controller 20 determines a different temporary storage area P from the temporary storage area P that has reached the maximum number of simultaneous transports as the destination when assigning an unknown load transport command to a new unknown load transport vehicle 3. In this case, it is possible to prevent multiple unknown loads from concentrating and being temporarily stored at a temporary storage area P that has exceeded the maximum number of simultaneous transports. It is possible to distribute multiple unknown loads to multiple temporary storage areas P for temporary storage. This makes it possible to reduce congestion of unknown load transport vehicles 3.

[0059] In the transport vehicle system 1, the unknown load transport destination table TB lists multiple temporary storage areas P for each unknown load transport vehicle 3, prioritized in order of proximity to the current location of the unknown load transport vehicle 3. The transport vehicle controller 20 selects temporary storage areas P as destination candidates in descending order of priority in the unknown load transport destination table TB. In this case, the unknown load can be temporarily stored in a temporary storage area P that is closest to the current location of the unknown load transport vehicle 3.

[0060] Here, when an unknown load transport command is issued using the unknown load transport destination table TB, the unknown load transport vehicle 3 may not be able to successfully complete temporary placement at the temporary storage location P for some reason. Even in this case, when various circumstances change thereafter, the unknown load transport vehicle 3 may be able to successfully complete temporary placement using an unknown load transport command using the same unknown load transport destination table TB. Therefore, even if the unknown load transport vehicle 3 is unable to complete the unknown load transport command to the temporary storage location P determined based on the unknown load transport destination table TB, the transport vehicle controller 20 of the transport vehicle system 1 does not erase the unknown load transport destination table TB but leaves it. Then, the transport vehicle controller 20 again determines the temporary storage location P as the destination based on the unknown load transport destination table TB and assigns a new unknown load transport command to the unknown load transport vehicle 3 to transport the item to the newly determined temporary storage location P. This makes it possible to efficiently temporarily store unknown loads, taking into account the above-mentioned possibilities.

[0061] In the transport vehicle system 1, the unknown load transport vehicle 3 is a transport vehicle that has failed to transport an item or a transport vehicle that has canceled the transport while transporting an item, and has not been assigned a new transport command for a certain period of time. In this embodiment, the unknown load of such an unknown load transport vehicle 3 can be efficiently temporarily stored.

[0062] [Modifications] As described above, one aspect of the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present invention.

[0063] In the above embodiment, there are no particular limitations on the number of guided vehicles 2 and the size of the area targeted by the guided vehicle controller 20. For example, the guided vehicle controller 20 may target an area including at least a portion of the track 10. Furthermore, for example, the guided vehicle controller 20 may target at least a portion of all guided vehicles 2 present on the track 10.

[0064] In the above embodiment, the table creation unit 21 creates the unknown cargo destination table TB for each unknown cargo transport vehicle 3, but this is not limiting. For example, each unknown cargo transport vehicle 3 may acquire the unknown cargo destination table TB from an external device via communication or the like. Also, for example, the unknown cargo destination table TB may be stored in advance for each transport vehicle 2.

[0065] In the above embodiment, a FOUP containing multiple semiconductor wafers is exemplified as an article transported by the transport vehicle 2, but the article is not limited to this and may be, for example, other containers containing glass wafers, reticles, etc., or other articles. Furthermore, the location where the transport vehicle system 1 is installed is not limited to a semiconductor manufacturing factory, and the transport vehicle system 1 may be installed in other facilities.

[0066] 1...transport vehicle system, 2...transport vehicle, 3, 3A, 3B, 3C, 3D...unknown cargo transport vehicle, 10...track, 12...branching section, 13...merging section, 20...transport vehicle controller (transport vehicle control device), P, PA, PB, PC, PD, PE, PF, PG, PH, PI, PJ, PK, PL, PM...temporary storage section, TB, TB1, TB2, TB3, TB4...unknown cargo destination table.

Claims

1. A transport vehicle system comprising: a track having a plurality of branching and merging sections; a plurality of transport vehicles that travel along the track and transport goods; a plurality of temporary storage areas that are arranged around the track and on which goods are placed; and a transport vehicle controller that assigns transport commands to the transport vehicles, wherein when an unknown load transport vehicle occurs that is a transport vehicle that is unable to complete the transport of the loaded goods, the transport vehicle controller determines the temporary storage area as a destination based on an unknown load transport destination table that lists a plurality of temporary storage areas within a specified range of the unknown load transport vehicle, and assigns an unknown load transport command to the unknown load transport vehicle to transport the goods to the determined temporary storage area.

2. The transport vehicle system of claim 1, wherein, when an unknown cargo transport vehicle occurs, the transport vehicle controller performs a route search from the unknown cargo transport vehicle to multiple temporary storage areas to create the unknown cargo destination table, and determines the temporary storage area as the destination based on the created unknown cargo destination table.

3. A maximum number of simultaneous transports is set for each of the multiple temporary storage areas in the unknown cargo transport destination table, and the transport vehicle controller, when the unknown cargo transport command is assigned to multiple unknown cargo transport vehicles, and the destinations of the multiple assigned unknown cargo transport commands overlap with the same temporary storage area and the number of overlaps reaches the maximum number of simultaneous transports for the temporary storage area, determines a temporary storage area other than the temporary storage area that has reached the maximum number of simultaneous transports as the destination when assigning the unknown cargo transport command to a new unknown cargo transport vehicle, a transport vehicle system as described in claim 1 or 2.

4. The unknown cargo destination table lists multiple temporary storage areas for each unknown cargo transport vehicle, prioritized in order of proximity to the current location of the unknown cargo transport vehicle, and the transport vehicle controller selects the temporary storage areas as destination candidates in order of priority in the unknown cargo destination table, as described in claim 1 or 2.

5. The transport vehicle system described in claim 1 or 2, wherein, if the unknown load transport vehicle is unable to complete the unknown load transport command to the temporary storage area determined based on the unknown load transport destination table, the transport vehicle controller re-determines the temporary storage area as the destination based on the unknown load transport destination table, and assigns a new unknown load transport command to the unknown load transport vehicle to transport the item to the newly determined temporary storage area.

6. A transport vehicle system as described in claim 1 or 2, wherein the unknown cargo transport vehicle is a transport vehicle that has failed to transport an item or a transport vehicle whose transport was canceled while transporting an item, and for which a certain period of time has passed without a new transport command being assigned.

7. A control device for controlling the transport vehicles in a transport vehicle system having a track with multiple branching and merging sections, multiple transport vehicles that travel along the track and transport items, and multiple temporary storage areas that are positioned around the track and on which items are placed, wherein, when an unknown load transport vehicle occurs, which is a transport vehicle that is unable to complete the transport of the loaded items, the transport vehicle control device determines the temporary storage area as a destination based on an unknown load transport destination table that lists multiple temporary storage areas within a specified range from the unknown load transport vehicle, and assigns an unknown load transport command to the unknown load transport vehicle to transport the items to the determined temporary storage area.

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