Conveying system

Abstract

A delivery system according to the present invention is provided with delivery vehicles and a control device. The delivery vehicles deliver goods by traveling along routes. The control device controls the delivery vehicles. Destinations of the delivery vehicles include processing locations and storage locations. The control device carries out preliminary processes and a route shutdown process when shutting down target routes. The preliminary processes include at least one from among (1) a process for allowing only some delivery vehicles to pass through target routes, (2) a process for using the delivery vehicles to shunt goods located in a restricted zone to an active zone, and (3) a process for permitting a delivery whose destination is a processing location in a restricted zone and prohibiting a delivery whose destination is a storage location in a restricted zone. The root shutdown process is carried out after the preliminary processes and is for prohibiting travel by delivery vehicles along target routes.

Description

Technical Field

[0001] The present invention mainly relates to a conveying system for conveying articles by a carrier vehicle.

Background Art

[0002] The conveying system of Patent Document 1 includes a traveling path, a carrier vehicle that travels along the traveling path, and a control device that controls the carrier vehicle. The control device can execute a route-down process on a part of the traveling path. The control device controls the carrier vehicle so as not to pass through the route-down traveling path.

Prior Art Documents

Patent Documents

[0003] [[ID=2']]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When executing the route-down process, various processes are required along with the route-down process. For example, a process of changing the route of the carrier vehicle may be required. Also, a process of also bringing down the conveyance port destinations related to the route-down traveling path may be required. Therefore, the processing load of the control device becomes high when executing the route-down process.

[0005] The present invention has been made in view of the above circumstances, and its main object is to provide a conveying system capable of suppressing the processing load of the control device when executing the route-down process. Means and Effects for Solving the Problems

[0006] The problems to be solved by the present invention are as described above. Next, the means for solving this problem and its effects will be described.

[0007] In view of the present invention, a transport system having the following configuration is provided. That is, the transport system comprises a transport vehicle and a control device. The transport vehicle transports articles by traveling along a track. The control device controls the transport vehicle. The destination of the transport vehicle includes a processing location, which is a location for handing over the articles to a processing device, and a storage location, which is a location for temporarily storing the articles. When the control device brings down a target route, which is a route selected from a plurality of routes on the track, it performs pre-processing and route down processing. The pre-processing is, (1) A process of moving the item located in the closed area, which is the area that will be closed due to the downtime of the target route, to the effective area, which is the area that will not be closed before and after the downtime of the target route, using the transport vehicle. (2) The process includes at least one of which is to permit transport with the processing location in the closed area as the destination and to prohibit transport with the storage location in the closed area as the destination. The route down process is a process performed after the preprocessing and is a process that prohibits the transport vehicle from traveling along the target route.

[0008] This allows for the closure of the target route in stages, thereby reducing the processing load on the control unit.

[0009] A second aspect of the present invention provides a transport system having the following configuration: The transport system comprises a transport vehicle and a control device. The transport vehicle transports articles by traveling along a track. The control device controls the transport vehicle. The destinations of the transport vehicle include a processing position, which is a position for handing over the articles to a processing device, and a storage position, which is a position for handing over the articles to a storage rack for temporary storage. When the control device moves down a target route, which is a route selected from a plurality of routes on the track, A pre-processing step is performed to allow only some of the transport vehicles to pass through the target route. If an alternative route that avoids the target route exists, the transport vehicles are driven to their destination via a route that does not pass through the target route. If no alternative route that avoids the target route exists, the transport vehicles are driven to their destination via a route that passes through the target route. The control device is a process performed after the pre-processing, and performs a route down process that prohibits the transport vehicle from traveling along the target route.

[0010] As a result, The target route can be closed in stages. Therefore, the processing load on the control unit can be reduced. Furthermore, The frequency with which transport vehicles travel along the designated route can be reduced, while still allowing them to travel along the designated route if it is essential.

[0011] In the transport system described above, the pre-processing includes a process of moving the articles located in the closed area to the effective area using the transport vehicle, and it is preferable that the control device moves all the articles from the closed area to the effective area after a destination has been secured for all the articles to be moved from the closed area to the effective area.

[0012] This allows items to be evacuated smoothly after the evacuation destination has been set.

[0013] In the aforementioned transport system, the article is preferably a container for holding the object to be transported.

[0014] This reduces the likelihood of containers remaining in the closed area, thus suppressing the decrease in transport efficiency after the route-down process. [Brief explanation of the drawing]

[0015] [Figure 1] A schematic plan view of a transport system according to one embodiment of the present invention. [Figure 2] Front view of the transport system. [Figure 3] A schematic plan showing the closed area and the open area after the target route has been defined. [Figure 4] A flowchart illustrating the process from receiving a route down reservation instruction to executing the route down process. [Figure 5] A table showing the contents of the first pre-processing, second pre-processing, and route-down processing. [Modes for carrying out the invention]

[0016] Next, embodiments of the present invention will be described with reference to the drawings.

[0017] The conveying system 1 shown in Fig. 1 is provided in a facility such as a semiconductor manufacturing factory or a warehouse, and conveys an article 50. The article 50 conveyed by the conveying system 1 is a container that houses wafers (semiconductor wafers). Specifically, the container is a FOUP (Front-Opening Unified Pod) or a wafer cassette. Note that the article 50 may be a reticle pod that houses reticles. Also, when the conveying system 1 is provided in a warehouse, the article 50 is a commodity or a part stored in the warehouse, etc.

[0018] As shown in Figs. 1 and 2, the conveying system 1 includes a management control device (control device) 10, a carrier vehicle 20, and a track 30.

[0019] The management control device 10 is a computer having an arithmetic device such as a CPU and a storage device such as an HDD, an SSD, or a flash memory. By reading and executing a program stored in the storage device, the management control device 10 can execute various controls related to the conveyance and processing of the article 50. The management control device 10 generates a conveyance command based on information received from a higher-level control device, and assigns the conveyance command to the carrier vehicle, thereby instructing the carrier vehicle 20 to convey the article 50.

[0020] The carrier vehicle 20 is an OHT (Overhead Hoist Transfer). The carrier vehicle 20 is a vehicle that travels unmanned along a track 30 suspended from the ceiling to convey the article 50. As shown in Fig. 2, the carrier vehicle 20 includes a communication device 21, a drive control device 22, a motor 23, wheels 24, and a conveyance unit 25.

[0021] The communication device 21 is a wireless communication module for performing wireless communication with the outside. The communication device 21 can communicate with the management control device 10 that controls the transport system 1. The drive control device 22 is a computer having an arithmetic unit such as a CPU and a storage device such as an HDD, an SSD, or a flash memory. The drive control device 22 can execute various controls related to the transport vehicle 20 by reading and executing a program stored in the storage device. The drive control device 22 operates the motor 23 based on, for example, a transport command received from the management control device 10. The motor 23 generates a driving force for running the transport vehicle 20 using the electric power supplied via the track 30. The driving force generated by the motor 23 is transmitted to the wheels 24 via a transmission mechanism. Thereby, the transport vehicle 20 runs along the track 30. The transport unit 25 has, for example, a hand that can switch between a state of holding the article 50 and a state of releasing the holding of the article 50, and can receive and deliver the article 50.

[0022] In the semiconductor manufacturing factory, a storage shelf 31 and a processing device 101 are provided. The storage shelf 31 and the processing device 101 are arranged in the vicinity of the track 30. The transport vehicle 20 can deliver the article 50 to the storage shelf 31 and the processing device 101, or receive the article 50 from the storage shelf 31 and the processing device 101.

[0023] The storage shelf 31 is a part for temporarily storing the article 50. The storage shelf 31 of the present embodiment is arranged at a position adjacent to the track 30 in plan view. The storage shelf 31 temporarily stores the article 50 waiting for processing by the processing device 1 or temporarily stores the article 50 to be transported to another location. The position where the transport vehicle 20 delivers the article 50 to the storage shelf 31 is referred to as a storage position. With the direction of running along the track 30 as the front-rear direction, the direction orthogonal to the front-rear direction in plan view is the left-right direction. The storage shelf 31 is arranged, for example, outside the left-right direction of the track 30.

[0024] The processing unit 101 has a load port (processing position) 102 that receives articles 50 from the transport vehicle 20. The processing unit 101 takes in the articles 50 that the transport vehicle 20 has placed in the load port 102 and performs processing (for example, one step in manufacturing a semiconductor device) on the wafer contained in the articles 50. The load port 102 is positioned to overlap with the track 30 in a plan view, but it may be positioned at a different location.

[0025] A transfer assist device may be provided adjacent to the processing device 101. The assist device temporarily stores the items 50 awaiting processing by the processing device 101. The transfer assist device takes in the items 50 received from the transport vehicle 20 and stores them temporarily. Then, after the processing device 101 is ready to process, the transfer assist device hands over the items 50 to the processing device 101. The position where the transport vehicle 20 hands over the items 50 to the transfer assist device is the position for handing over the items 50 to the processing device 101, and therefore corresponds to the processing position.

[0026] Next, we will explain the root down process with reference to Figures 3 to 5.

[0027] Route down processing refers to shutting down a portion of the track 30, for example, for maintenance purposes. Types of maintenance include maintenance of the track 30, and maintenance related to power supply via the track 30. Alternatively, if communication or control between the management control device 10 and the transport vehicle 20 is temporarily suspended, the track 30 included in the area where communication or control is suspended is shut down. The transport vehicle 20 cannot travel on the shut-down route. In detail, the management control device 10 sets the destination and route of the transport vehicle 20 so that the transport vehicle 20 does not travel on the shut-down route. Hereinafter, the route to be shut down will be referred to as the "target route".

[0028] Next, we will explain closed areas and active areas. In the transport system 1, areas that are scheduled to be closed (closed areas) may occur when the route down process is executed. When an area is closed, the transport vehicle 20 cannot travel outside the closed area, nor can the transport vehicle 20 travel into the closed area from the outside. For example, as shown in Figure 3, if there are two target routes, the area enclosed by the two target routes becomes the closed area. On the other hand, areas that are active both before and after the execution of the route down process (areas that are not closed) are called active areas.

[0029] If the control unit 10 immediately executes the route down process after receiving an instruction to do so, it will be necessary to change the destination or route of all affected transport vehicles 20. This would increase the processing load on the control unit 10 during the execution of the route down process, potentially delaying other controls performed by the control unit 10. Furthermore, items 50 in the closed area during the execution of the route down process will be unusable after the process is completed. As a result, the wafer transport efficiency may decrease.

[0030] In this regard, the management control device 10 of this embodiment performs pre-processing before executing the root down process. This distributes the processing load of the management control device 10. As a result, delays in other controls performed by the management control device 10 can be reduced. The pre-processing will be described in detail below.

[0031] When a route shutdown is required, the administrator sets the target route and start time using their terminal or PC. This sends an instruction to the management control device 10 to schedule a route shutdown. The administrator may also directly operate the management control device 10 to schedule a route shutdown. Alternatively, the administrator may instruct the management control device 10 to schedule a route shutdown according to a pre-created schedule.

[0032] The management control device 10 determines whether or not it has received an instruction for route down reservation processing (S101). If the management control device 10 has received an instruction for route down reservation processing, it registers the target route and start time for the route down processing (S102).

[0033] Next, the management control device 10 performs the first preprocessing (S103). In this embodiment, the preprocessing is divided into two stages: the first preprocessing and the second preprocessing. As shown in Figure 5, the first preprocessing includes "1. Route matching," "2. Item evacuation," and "3. Transport command matching." Note that the order in which "1. Route matching," "2. Item evacuation," and "3. Transport command matching" of the first preprocessing are performed is not limited, and at least two of the processes may be performed simultaneously.

[0034] "1. Route handling" is a process to gradually prohibit the transport vehicle 20 from traveling along the target route. By reducing the frequency of this process, the number of transport vehicles 20 affected when the route down process is executed decreases, thereby reducing the processing load on the management control device 10.

[0035] In the first pre-processing step, "1. Route Matching," the cost of traveling along the target route is increased. Cost is a parameter commonly used when performing route searching. The management control device 10 searches for a route that minimizes the cost from the starting point to the destination and sets it for the transport vehicle 20. In principle, the cost increases as the distance traveled increases. Also, the cost of passing through locations that are undesirable is set to a higher value than the cost of passing through other locations. Therefore, by making the cost of traveling along the target route significantly higher than the cost of passing through other routes, the frequency with which the transport vehicle 20 travels along the target route can be reduced.

[0036] Specifically, if an alternative route exists that bypasses the target route, the transport vehicle 20 will be configured to travel along the alternative route. On the other hand, if no alternative route exists, the transport vehicle 20 will be configured to travel along the target route to its destination. The management control device 10 also lists the transport vehicles 20 that travel from the active area to the closed area via the target route as targets for monitoring. This list is used in the second pre-processing step.

[0037] Furthermore, the process of increasing the cost of traversing the target route in "1. Route Management" is just one example, and it can be replaced with other processes that allow only some of the transport vehicles 20 to traverse the target route. For example, it may be possible to allow transport vehicles 20 whose destination is a point within the closed area to traverse the target route, while prohibiting transport vehicles 20 whose destination is a point outside the closed area from traversing the target route.

[0038] "2. Relocation of items" is the process of relocating items located in the closed area to the active area. If the route-down process is performed while items 50 are located in the closed area, the number of usable items 50 decreases, thus reducing the wafer transport efficiency. Furthermore, it may be necessary to register that items 50 have become unusable, which increases the processing load on the management control device 10. If workers have to carry these items 50 to the active area, it is time-consuming. In this regard, by having the transport vehicle 20 move the items 50 to the active area before the route-down process is performed, the number of usable items 50 after the route-down process does not decrease as much, thus maintaining wafer transport efficiency. In addition, the processing load on the management control device 10 during the route-down process can be reduced. Furthermore, it is less time-consuming compared to the method of carrying items 50 manually.

[0039] In the first pre-processing step, "2. Evacuation of Items," the items 50 located in the closed area are identified first. The control device 10 controls the transport of the items 50 using the transport vehicle 20 based on the position of the transport vehicle 20 and the position of the items 50. Therefore, the control device 10 can identify the items 50 located in the closed area based on the information used in this control. Next, the control device 10 secures the same number of evacuation locations as the number of identified items 50. Evacuation locations are storage shelves 31 in the active area where no other items 50 are located and which are not destinations for other items 50. If this type of evacuation location exists, the control device 10 secures the evacuation location by blocking it. Blocking means setting the transport vehicle 20 so that it does not place other items 50 there.

[0040] "3. Transport Command Response" is a process that gradually reduces the number of transport commands that originate from or destined for a closed area. This reduces the number of transport vehicles 20 affected when route down processing is performed, thereby reducing the processing load on the management control device 10.

[0041] In "3. Responding to Transport Commands" of the first pre-processing, all transport commands are authorized. In other words, the conditions regarding transport commands are the same before and after the first pre-processing. Therefore, the management control device 10 can generate transport commands with a departure or destination of any location and assign them to the transport vehicle 20 based on the information received from the higher-level control device.

[0042] The control device 10 determines whether it is time to transition to the second preprocessing after starting the execution of the first preprocessing (S104). The control device 10 determines that it is time to transition to the second preprocessing when, for example, a predetermined time has passed before the start time of the route down processing. Alternatively, the condition for transitioning to the second preprocessing may be that the evacuation locations for all items 50 have been secured in the first preprocessing.

[0043] The control device 10 executes the second preprocessing when it determines that it is time to transition to the second preprocessing (S105). The second preprocessing includes "1. Route matching", "2. Item evacuation", and "3. Transport command matching". The order in which "1. Route matching", "2. Item evacuation", and "3. Transport command matching" of the second preprocessing are performed is not limited. However, it is preferable to perform "3. Transport command matching" after performing "2. Item evacuation". Also, at least two processes may be performed simultaneously.

[0044] In the second pre-processing step, "1. Route Response," travel along the target route by the transport vehicle 20 is prohibited in principle. Travel along the target route by the transport vehicle 20 is permitted only for those transport vehicles 20 listed in the list created in the first pre-processing step. Since the transport vehicles 20 listed are located in a closed area, they will become inoperable after the route down processing is performed. Therefore, it is permitted for the transport vehicle 20 to move from a closed position to an active position.

[0045] Furthermore, if "1. Route handling" and "2. Evacuation of goods" of the second pre-processing are performed in parallel, the transport vehicle 20 is permitted to travel along the target route for "2. Evacuation of goods." Also, if "1. Route handling" and "3. Transport command handling" are performed in parallel, the transport vehicle 20 is permitted to travel along the target route for "3. Transport command handling." However, "1. Route handling" may be performed after "2. Evacuation of goods" and "3. Transport command handling" are completed.

[0046] The management control device 10 executes a process to prohibit driving on the target route. Then, if the above permitted situation occurs, the management control device 10 temporarily permits driving on the target route by performing a cancellation process or abort process.

[0047] In the second pre-processing step, "2. Evacuation of items," the items 50 for which evacuation destinations were secured in the first pre-processing step are evacuated. In other words, in this embodiment, the evacuation of items 50 begins after evacuation destinations have been secured for all items 50 to be evacuated in the second pre-processing step. Specifically, the management control device 10 instructs the transport vehicle 20 to retrieve the items 50 located in the closed area and to transport the items 50 to the evacuation destinations secured in the first pre-processing step. After the evacuation of all items 50 in the closed area is completed, the management control device 10 notifies the higher-level control device of this fact.

[0048] In "3. Responding to Transport Commands" of the second pre-processing, transport commands that target the storage location in the closed area are not permitted. Specifically, the control device 10 shuts down or blocks the point (port) corresponding to the storage location in the closed area to prevent the storage location in the closed area from becoming the destination. Transport commands that target the processing location in the closed area are permitted. This is because the purpose of the semiconductor factory is for the processing device 101 to process the wafer, so transporting the items 50 to the processing location is a high priority. In "2. Evacuating Items" of the second pre-processing, transport is carried out with the storage location as the destination in order to retrieve the items 50 in the closed area. Therefore, in the second pre-processing, it is preferable to perform "3. Responding to Transport Commands" after performing "2. Evacuating Items".

[0049] The control device 10 determines whether it is time to transition to the route down process after starting the execution of the second pre-processing (S106). For example, the control device 10 determines that it is time to transition to the route down process when the start time for the route down process arrives. If no start time for the route down process is set, the condition for transitioning to the route down process may be that all items 50 have been evacuated in the second pre-processing.

[0050] The management control device 10 executes the route down process when it determines that it is time to proceed with the route down process (S107). During the route down process, travel along the target route is prohibited without exception. Furthermore, all transports that originate from or end at a closed location are not permitted. Specifically, the management control device 10 prevents the closed area from becoming the origin or destination of the transport vehicle 20 by downing or blocking all points (ports) located within the closed area. This completes the route down process. The route down process continues until another command is received to release the down of the target route.

[0051] As described above, the transport system 1 of this embodiment comprises a transport vehicle 20 and a management control device 10. The transport vehicle 20 transports articles 50 by traveling along a track 30. The management control device 10 controls the transport vehicle 20. The destinations of the transport vehicle 20 include a processing position, which is a position for handing over the articles 50 to a processing device, and a storage position, which is a position for handing over the articles 50 to a storage rack 31 for temporarily storing the articles 50. When the management control device 10 brings down a target route, which is a route selected from a plurality of routes on the track, it performs pre-processing and route down processing. The pre-processing includes at least one of the following: (1) processing to allow only some of the transport vehicles 20 to pass through the target route; (2) processing to move articles 50 located in a closed area, which is an area that is to be closed by the downing of the target route, to an effective area, which is an area that is not closed before and after the downing of the target route, using the transport vehicle 20; or (3) processing to permit transport to a processing position in the closed area and prohibit transport to the storage position in the closed area. Route down processing is a process performed after pre-processing, and it prohibits the transport vehicle 20 from traveling along the target route.

[0052] This allows for the closure of the target route to be carried out in stages. Therefore, the processing load on the management control device 10 can be reduced.

[0053] In the transport system 1 of this embodiment, the management control device 10 processes a process to allow only some of the transport vehicles 20 to pass through the target route. If there is an alternative route that avoids the target route, the management control device 10 causes the transport vehicles 20 to travel to the destination via a route that does not pass through the target route. If there is no alternative route that avoids the target route, the management control device 10 causes the transport vehicles 20 to travel to the destination via a route that passes through the target route.

[0054] This reduces the frequency with which the transport vehicle 20 passes through the target route, while still allowing it to pass through the target route when necessary.

[0055] In the transport system 1 of this embodiment, the pre-processing includes a process of moving the articles 50 located in the closed area to the effective area using the transport vehicle 20. After a destination has been secured for all the articles 50 to be moved from the closed area to the effective area, all the articles 50 are moved from the closed area to the effective area.

[0056] This allows the item 50 to be evacuated after the evacuation destination has been set, thus enabling a smooth evacuation of the item 50.

[0057] In the transport system 1 of this embodiment, the article 50 is a container (FOUP) that holds the wafer, which is the object to be transported.

[0058] This reduces the likelihood of containers remaining in the closed area, thus suppressing the decrease in transport efficiency after the route-down process.

[0059] Although preferred embodiments of the present invention have been described above, the above configuration can be modified as follows, for example.

[0060] The flowchart shown in the above embodiment is an example, and some processes may be omitted, some processes may be modified, or new processes may be added. For example, the preprocessing may be treated as a single process instead of being divided into first preprocessing and second preprocessing. In this case, "1. Route handling" would involve either increasing the cost of traveling along the target route or, in principle, prohibiting travel along the target route. "2. Evacuation of goods" would involve moving the transport vehicle 20 whenever an evacuation site is secured.

[0061] The management control device 10 may perform only one of the following preprocessing steps: "1. Route matching," "2. Item evacuation," and "3. Transport command matching." Even in this case, the processing load on the management control device 10 can be reduced compared to immediately performing route down processing.

[0062] In the first preprocessing step "1. Route matching" of the above embodiment, the cost of traveling along the target route is increased. Alternatively, a different setting for route searching may be changed. For example, the system may be set to perform a route search with the target route as untravelable, and if a route exists that reaches the destination from the starting point, that route is set. If no route exists that reaches the destination from the starting point, the system may set the target route as travelable and perform a route search again. Even with this setting, the frequency with which the transport vehicle 20 travels along the target route can be reduced.

[0063] In the above embodiment, an OHT was used as an example of the transport vehicle 20, but the present invention can also be applied to other vehicles, such as an AGV (Automated Guided Vehicle) or a suspended crane. [Explanation of Symbols]

[0064] 1. Conveying System 10. Control and Management System (Control Device) 20 transport vehicles 30 orbits 101 Processing Unit 102 Load port (processing location)

Claims

1. A transport vehicle that moves along a track to transport goods, A control device for controlling the transport vehicle, Equipped with, The destination of the transport vehicle includes a processing location, which is a location for transferring the article to the processing device, and a storage location, which is a location for transferring the article to a storage rack for temporary storage. The control device is When bringing down the target route, which is a route selected from among multiple routes on the aforementioned orbit, (1) A process of moving the items located in the closed area, which is the area that will be closed due to the downtime of the target route, to an effective area, which is the area that will not be closed before and after the downtime of the target route, using the transport vehicle; or (2) A process of permitting transport with the processing location in the closed area as the destination and prohibiting transport with the storage location in the closed area as the destination. This process is performed after the aforementioned pre-processing, and includes a route down process that prohibits the transport vehicle from traveling along the target route, A transport system characterized by performing the following actions.

2. A transport vehicle that transports goods by traveling along a track, A control device for controlling the transport vehicle, Equipped with, The destination of the transport vehicle includes a processing location, which is a location for transferring the article to the processing device, and a storage location, which is a location for transferring the article to a storage rack for temporary storage. When the control device lowers a target route, which is a route selected from a plurality of routes on the track, it performs a preprocessing to allow only some of the transport vehicles to pass through the target route. If there is an alternative route that avoids the aforementioned target route, the transport vehicle will be driven to its destination via a route that does not pass through the aforementioned target route. If there is no alternative route that avoids the aforementioned target route, the transport vehicle will be driven to its destination via the route that passes through the aforementioned target route. The control device is a process performed after the pre-processing, and is characterized by performing a route down process that prohibits the transport vehicle from traveling along the target route.

3. A transport system according to claim 1, The aforementioned pre-processing includes a process of moving the article located in the closed area to the effective area using the transport vehicle, The control device is characterized in that, after a destination has been secured for all items to be moved from the closed area to the effective area, it moves all of the items from the closed area to the effective area.

4. A transport system according to claim 3, The transport system is characterized in that the aforementioned article is a container for containing an object to be transported.

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