JP7501474B2 - Item storage facilities - Google Patents

Description

The present invention relates to an item storage facility.

For example, in semiconductor factories and flat panel display factories, multiple processing steps are performed sequentially, so there are cases where an item storage facility with an internal transport device is provided for each process, and an external transport device is used to transport items between processes. An example of such an item storage facility is disclosed in JP 2001-130708 A (Patent Document 1).

The item storage facility (automated warehouse system 4) of Patent Document 1 includes storage shelves (racks 6) capable of storing items (cassettes 39), an entrance section (some stations 8) that receives items from an external transport device (rail-guided trolley 24), and an internal transport device (stacker cranes 12, 14). The entrance section has multiple holding positions (support positions 60, 62), and this entrance section with multiple holding positions functions as a buffer that temporarily holds the next item until the internal transport device returns after transporting the preceding item.

Providing an entry section that functions as a buffer in this way can improve to a certain degree the processing efficiency of the entire item transport facility, which includes an external transport device and multiple item storage facilities. For example, if an item is held in the entry section when the current transport process by the internal transport device is completed, the next transport process by the internal transport device can begin before the external transport device transports the next item, thereby improving processing efficiency. There is always a demand for improvements in this type of processing efficiency.

JP 2001-130708 A

Therefore, it is desirable to realize an item storage facility that can further improve the processing efficiency of the entire item transport facility.

The item storage facility according to the present disclosure includes:
A storage shelf having a plurality of storage sections for storing items;
a receiving section that holds the item received from an external conveying device that conveys the item outside the storage shelf;
an internal conveyance device that moves along a conveyance path set along a front surface of the storage shelf and conveys the item between the receiving section and the storage shelf;
a control system for controlling the external transport device and the internal transport device;
The maximum number of the items that can be held in the receiving section is defined as a holding upper limit number Nmax, and the number of the items that are actually held in the receiving section at each time point is defined as a holding item number Nr,
The control system sets an adjustment number A, which is variably set to an integer value equal to or greater than 0, to the upper limit number Nmax of held items as an operational buffer number (Nmax+A), and controls the external transport device so that the number of items being transported, which is the number of items being transported toward the storage section, is equal to or less than the operational buffer number minus the number of held items Nr (Nmax+A-Nr);
Furthermore, the control system sets the adjustment number A to a smaller value as the load on the internal transport device increases.

According to this configuration, the internal conveying device moves along the conveying path along the front of the storage shelf, and the items received from the external conveying device are stored in the storage shelf, and can be used for subsequent processing if necessary. At this time, the receiving section functions as a buffer, and the processing efficiency can be further improved by operating with an operating buffer number (Nmax+A; A is an adjustment number equal to or greater than 0) equal to or greater than the upper limit number Nmax, which is the maximum number of items that can be physically held in the receiving section. For example, if the adjustment number A is set to 1 or greater, even if the receiving section is already filled with items equal to the upper limit number Nmax, the external conveying device can convey items up to the adjustment number A toward the storage shelf (receiving section). If the conveying process of the internal conveying device is completed during that time, one of the items held in the receiving section can be conveyed to make space in the receiving section, so that the receiving section can receive the item conveyed in advance by the external conveying device. In this way, the processing efficiency can be further improved.
Furthermore, in this configuration, the adjustment number A is set to a smaller value as the load on the internal conveying device increases. Therefore, even if the internal conveying device is delayed in carrying out the goods from the receiving section, it is easy to avoid a situation in which the external conveying device becomes congested in front of the receiving section due to the delay. Therefore, it is easy to avoid a decrease in the processing efficiency of the entire goods conveying facility due to a congestion on the external conveying device.
From these factors, it is possible to realize an article storage facility that can further improve the processing efficiency of the article transport facility as a whole.

Further features and advantages of the technology disclosed herein will become more apparent from the following description of exemplary, non-limiting embodiments, which are described with reference to the drawings.

Overall layout diagram of an article transport facility according to an embodiment Schematic plan view of the item storage facility Perspective view of the item storage facility Schematic diagram of the control system FIG. 13 is a diagram showing the data structure of a transport command. FIG. 13 is a schematic diagram showing an example of a warehousing transport process; FIG. 13 is a schematic diagram showing an example of an in-shelf transport process; FIG. 13 is a schematic diagram showing an example of an in-shelf transport process; FIG. 13 is a schematic diagram showing an example of an in-shelf transport process; Schematic diagram showing an example of a transport process for processing FIG. 13 is a schematic diagram showing an example of a warehouse outbound transport process; Flowchart showing the procedure for adjusting the number of operational buffers Flowchart showing the procedure for controlling inventory priority FIG. 13 is a schematic diagram showing an example of internal transport load adjustment control. Flowchart showing the procedure for controlling internal transport load adjustment

An embodiment of an item storage facility will be described with reference to the drawings. In this embodiment, an item storage facility 1 provided in an item transport facility 100 that is installed to sequentially perform multiple processing steps in, for example, a semiconductor factory or a flat panel display factory will be described as an example.

As shown in FIG. 1, the item transport facility 100 includes an item storage facility 1, an external transport device 8, and a processing device 9. In this embodiment, multiple item storage facilities 1 are provided, an external transport device 8 is provided to travel around the multiple item storage facilities 1, and a processing device 9 is provided corresponding to each item storage facility 1. The item storage facility 1 and the corresponding processing device 9 make up one process, and the external transport device 8 that travels around the multiple item storage facilities 1 is responsible for transport between processes.

The external conveying device 8 is equipped with a plurality of conveying carriages 82 that travel along a specified travel path (external conveying path To). The external conveying device 8 of this embodiment is equipped with a circular track 81 installed along the external conveying path To, and a plurality of conveying carriages 82 that travel on the circular track 81. In this embodiment, the circular track 81 is installed on the floor. That is, the external conveying device 8 of this embodiment is equipped with a plurality of conveying carriages 82 that travel on the floor and are guided by tracks. The external conveying device 8 is also equipped with a fork-type transfer device supported by the conveying carriage 82. The external conveying device 8 transports the items 10 between the multiple item storage facilities 1 (between processes).

Examples of item 10 include semiconductor wafers used in the manufacture of semiconductor devices and reticles for processing. In this embodiment, these are transported in a container (e.g., a FOUP for semiconductor wafers, or a reticle pod for reticles). Therefore, hereinafter, when we say "item 10," we also mean the container that holds item 10.

The processing device 9 processes the item 10. In this embodiment, the processing device 9 has a delivery port Pp, and uses this delivery port Pp to transfer the item 10 to and from the internal transport device 3. The processing device 9 then performs various processes on the item 10 received from the internal transport device 3 at the delivery port Pp. The processing device 9 may be, for example, a cleaning device, a film forming device, an exposure device, an etching device, etc. The processing device 9 transfers the processed item 10 to the internal transport device 3 at the delivery port Pp. The delivery port Pp is located adjacent to the transport path (internal transport path Ti) of the internal transport device 3.

As shown in Figures 2 and 3, the item storage facility 1 includes a storage shelf 2, an internal transport device 3, an input section 4, and an output section 5. The item storage facility 1 also includes a control system 7 (see Figure 1). In this embodiment, the control system 7 is configured to individually control the multiple item storage facilities 1 and to centrally control the entire item transport facility 100.

The storage shelf 2 has a plurality of storage sections 23 for storing items 10. In this embodiment, the item storage facility 1 has a pair of storage shelves 2 (first storage shelf 2A and second storage shelf 2B) arranged opposite each other. The first storage shelf 2A and the second storage shelf 2B are arranged opposite each other with the internal transport device 3 between them. The first storage shelf 2A and the second storage shelf 2B each have a plurality of support columns 21 erected from the floor surface at a predetermined interval and a plurality of support parts 22 fixed to the support columns 21 at a predetermined interval. The space above the pair of support parts 22 fixed to the same height on the adjacent support columns 21 forms the storage section 23 for storing items 10. The first storage shelf 2A and the second storage shelf 2B each have storage sections 23 in multiple stages and multiple rows. Each storage section 23 is arranged adjacent to the transport path (internal transport path Ti) of the internal transport device 3 in a direction perpendicular to the transport path.

In this embodiment, the first storage shelf 2A and the second storage shelf 2B are installed with one end aligned. An entry section 4 and an exit section 5 are provided adjacent to the aligned ends. The entry section 4 is provided adjacent to the first storage shelf 2A, and the exit section 5 is provided adjacent to the second storage shelf 2B. In this embodiment, the second storage shelf 2B has a larger number of rows than the first storage shelf 2A. Therefore, the second storage shelf 2B is positioned to protrude further than the first storage shelf 2A at the end opposite the entry section 4 and the exit section 5. A processing device 9 is provided adjacent to the first storage shelf 2A and facing the second storage shelf 2B.

The internal transport device 3 is installed between a pair of storage shelves 2 (first storage shelf 2A and second storage shelf 2B) arranged opposite each other. The internal transport device 3 moves along an internal transport path Ti set along the front surface of the storage shelf 2, and transports items 10 between the receiving section 4 and the storage shelf 2, within the same storage shelf 2, between one storage shelf 2 and the other storage shelf 2, and between the storage shelf 2 and the unloading section 5. In this embodiment, the internal transport path Ti corresponds to the "transport path".

The article storage facility 1 of this embodiment also includes a pair of internal transport devices 3 (first internal transport device 3A and second internal transport device 3B) arranged along the internal transport path Ti. In this embodiment, the first internal transport device 3A corresponds to the "first transport unit", and the second internal transport device 3B corresponds to the "second transport unit". The first internal transport device 3A and the second internal transport device 3B are configured as stacker cranes, and each includes a traveling cart 32, a mast 33, a lifting platform 34, and a transfer device 35. The traveling cart 32 travels on a traveling rail 31 installed on the floor surface along the internal transport path Ti. The mast 33 is erected from the traveling cart 32. In this embodiment, a pair of masts 33 are provided separately on both sides of the internal transport path Ti on the traveling cart 32. The upper end of the mast 33 is guided by a guide rail 36 installed on the ceiling. The lifting platform 34 rises and falls along the pair of masts 33. The transfer device 35 is fixed to the lifting platform 34 and transfers the item 10.

In this embodiment, the first internal transport device 3A and the second internal transport device 3B are provided on a common running rail 31. That is, the running carriage 32 of the first internal transport device 3A and the running carriage 32 of the second internal transport device 3B are provided to run on the common running rail 31. The first internal transport device 3A is provided closer to the loading section 4 and the unloading section 5 than the second internal transport device 3B.

As shown in FIG. 2, the first internal transport device 3A transports the item 10 within a first transport range R1 including the receiving section 4 and at least a part of the storage section 23 of the storage shelf 2. The first transport range R1 is set to a range including the receiving section 4 and a part of the storage section 23 on the receiving section 4 side of the storage shelf 2. The first transport range R1 also includes the outgoing section 5 facing the receiving section 4. The second internal transport device 3B transports the item 10 within a second transport range R2 including at least a part of the storage section 23 of the storage shelf 2 but not including the receiving section 4. In this embodiment, the second transport range R2 is set to a range including at least a part of the storage section 23 of the storage shelf 2 and the processing device 9 arranged on the opposite side of the receiving section 4 and the outgoing section 5. The second transport range R2 is set to a range including a part of the storage section 23 on the processing device 9 side of the storage shelf 2 and the processing device 9.

The first and second conveying ranges R1 and R2 are set so that a portion of the first conveying range R1 and a portion of the second conveying range R2 overlap with each other. A portion of the first conveying range R1 on the processing device 9 side and a portion of the second conveying range R2 on the receiving section 4 and discharging section 5 side overlap with each other.

The receiving section 4 receives the items 10 from the external transport device 8 and holds the received items 10. In this embodiment, the receiving section 4 includes an input conveyor 41. The input conveyor 41 may be, for example, a roller conveyor, a slat conveyor, or a belt conveyor. In this embodiment, the receiving section 4 is configured to hold a plurality of items 10 in a stationary state. In this example, the input conveyor 41 constituting the receiving section 4 holds two items 10. In this case, the input conveyor 41 has two support positions 43, 44, and the maximum number of items 10 that can be held in the receiving section 4, that is, the upper limit number Nmax, is "2" (Nmax = 2).

The receiving conveyor 41 operates when an item 10 is supported at the support position 43 and an item 10 is not supported at the support position 44, and can transport the item 10 that was at the support position 43 to the support position 44. The support position 43 on the most upstream side in the transport direction is a position where the item 10 is received from the external transport device 8, and serves as a receiving port Pr. The support position 44 on the most downstream side in the transport direction is a position where the item 10 is handed over to the internal transport device 3 (first internal transport device 3A) when the item 10 is stored, and serves as a receiving port Pi. The receiving port Pi is located adjacent to the internal transport path Ti in a direction perpendicular to the internal transport path Ti.

The unloading section 5 holds the items 10 to be handed over to the external conveying device 8. The unloading section 5 holds the items 10 received from the internal conveying device 3 (first internal conveying device 3A) and hands over the items 10 to the external conveying device 8. In this embodiment, the unloading section 5 includes an unloading conveyor 51. The unloading conveyor 51 may be, for example, a roller conveyor, a slat conveyor, or a belt conveyor. In this embodiment, the unloading section 5 is configured to hold multiple items 10 in a stationary state. In this example, the unloading conveyor 51 constituting the unloading section 5 holds two items 10. In this case, the unloading conveyor 51 has two support positions 53 and 54, and the maximum number of items 10 that can be held in the unloading section 5 is "2".

The outgoing conveyor 51 operates when an item 10 is supported at the support position 53 and an item 10 is not supported at the support position 54, and can transport the item 10 that was at the support position 53 to the support position 54. The support position 53 on the most upstream side in the transport direction is a position that receives the item 10 from the internal transport device 3 (first internal transport device 3A) when the item 10 is unloaded, and is the outgoing port Po. The outgoing port Po is located adjacent to the internal transport path Ti in a direction perpendicular to the internal transport path Ti, and is located on the opposite side to the ingoing port Pi. The support position 54 on the most downstream side in the transport direction is a position that transfers the item 10 to the external transport device 8, and is the delivery port Ph.

The receiving port Pi and the shipping port Po are provided at one end of the first conveying range R1. The receiving port Pi and the shipping port Po are included only in the first conveying range R1, and are not included in the second conveying range R2. The delivery port Pp of the processing device 9 is provided at the end of the second conveying range R2 opposite the receiving port Pi and the shipping port Po. The delivery port Pp is included only in the second conveying range R2, and is not included in the first conveying range R1. Among the multiple storage sections 23 of the storage shelf 2, there are some that are included only in the first conveying range R1, some that are included only in the second conveying range R2, and some that are included in the overlapping range L of the first conveying range R1 and the second conveying range R2.

In an item storage facility 1 configured in this way, the internal transport device 3 performs incoming transport processing, in-shelf transport processing, processing transport processing, and outgoing transport processing.

The incoming transport process is a process of transporting an item 10 from the receiving section 4 to a specific storage section 23 of the storage shelf 2. In the incoming transport process, the item 10 supported at the support position 44 (incoming port Pi) of the receiving section 4 is transported by the first internal transport device 3A to a specific storage section 23 of the storage shelf 2 (first storage shelf 2A or second storage shelf 2B) and stored.

The intra-shelf transport process is a process of transporting an item 10 from a specific storage section 23 of a storage shelf 2 to another storage section 23 of the same or a different storage shelf 2. In the intra-shelf transport process, the item 10 stored in the specific storage section 23 of the source is transported to the specific storage section 23 of the destination by the first internal transport device 3A or the second internal transport device 3B. At this time, if the source or destination storage section 23 is included only in the first transport range R1, the target item 10 is transported by the first internal transport device 3A. If the source or destination storage section 23 is included only in the second transport range R2, the target item 10 is transported by the second internal transport device 3B. If both the source and destination storage sections 23 are included in the overlapping range L of the first transport range R1 and the second transport range R2, the target item 10 is transported by either the first internal transport device 3A or the second internal transport device 3B.

The processing transport process is a process of transporting items 10 between a specific storage section 23 of the storage shelf 2 and the processing device 9. In the processing transport process, the items 10 stored in the specific storage section 23 at the source are transported by the second internal transport device 3B to the delivery port Pp of the processing device 9. Alternatively, in the processing transport process, the processed items 10 supported at the delivery port Pp of the processing device 9 are transported by the second internal transport device 3B to the specific storage section 23 at the destination.

The outgoing transport process is a process of transporting an item 10 from a specific storage section 23 of the storage shelf 2 to the outgoing section 5. In the outgoing transport process, the item 10 stored in the specific storage section 23 of the storage shelf 2 (the first storage shelf 2A or the second storage shelf 2B) is transported by the first internal transport device 3A to the support position 53 (outgoing port Po) of the outgoing section 5 for outgoing.

As described above, the control system 7 individually controls the multiple item storage facilities 1 (internal conveying devices 3), and also centrally controls the entire item storage facility 100 including the external conveying device 8. For this reason, as shown in FIG. 4, the control system 7 includes an internal conveying control unit 71, an external conveying control unit 72, and a central control unit 73. For simplicity, FIG. 4 shows only an internal conveying control unit 71 corresponding to one item storage facility 1 (internal conveying device 3), but an internal conveying control unit 71 corresponding to each of the multiple item storage facilities 1 (internal conveying devices 3) is provided.

The internal transport control unit 71 controls the internal transport device 3. In this embodiment, the internal transport device 3 is equipped with a first internal transport device 3A and a second internal transport device 3B, and accordingly, the internal transport control unit 71 controls the first internal transport device 3A and the second internal transport device 3B. The internal transport control unit 71 controls the first internal transport device 3A and the second internal transport device 3B based on a transport command (here, a transport command within the process).

The transport command has a data structure as shown in FIG. 5, for example. Each transport command has information on the transport origin (transport start position), transport destination (transport completion position), and the internal transport device 3 to be used. In FIG. 5, "S1" represents the first storage shelf 2A, and "S2" represents the second storage shelf 2B. Furthermore, "(m,n)" following "S1" and "S2" represents the storage section 23 that is in the mth row from the entrance section 4 and exit section 5 and the nth row from the bottom. Note that "m" and "n" are each integers.

For example, transport command A-2 is a command for transporting from the receiving port Pi to the storage section 23 in the second tier of the first row of the first storage shelf 2A (see FIG. 6). Since both of these two positions are included in the first transport range R1, the first internal transport device 3A is assigned as the carrier of transport command A-2. The transport process based on this transport command A-2 is an example of the receiving transport process described above.

For example, transport command A-4 is a command for the source of transport to be the storage section 23 on the fourth level of the first row of the first storage shelf 2A, and the destination to be the storage section 23 on the seventh level of the fifth row of the second storage shelf 2B (see FIG. 7). As both of these two positions are included in the first transport range R1, the first internal transport device 3A is assigned as the carrier of transport command A-4. The transport process based on this transport command A-4 is an example of the intra-shelf transport process described above.

For example, transport command B-2 is a command for the source of transport to be the storage section 23 in the first tier of the tenth row of the second storage shelf 2B, and the destination to be the storage section 23 in the first tier of the fourth row of the second storage shelf 2B (see FIG. 8). Since both of these two positions are included in the second transport range R2, the second internal transport device 3B is assigned as the carrier of transport command B-2. The transport process based on this transport command B-2 is also an example of the intra-shelf transport process described above.

For example, transport command A-1 is a command to transport from the storage section 23 in the fifth stage of the fourth row of the first storage shelf 2A to the storage section 23 in the fifth stage of the sixth row of the first storage shelf 2A (see FIG. 9). Since both of these two positions are included in the overlapping range L of the first transport range R1 and the second transport range R2, either the first internal transport device 3A or the second internal transport device 3B can be the carrier of transport command A-1, but in this example, the first internal transport device 3A is assigned. The transport process based on this transport command A-1 is also an example of the intra-shelf transport process described above.

For example, the transport command B-1 is a command to transport from the storage section 23 in the third tier of the eighth row of the first storage shelf 2A to the transfer port Pp (see the solid arrow in FIG. 10). Both of these two positions are included in the second transport range R2, so the second internal transport device 3B is assigned to the carrier of the transport command B-1. The transport command B-3 is a command to transport from the transfer port Pp to the storage section 23 in the fifth tier of the eighth row of the second storage shelf 2B to the transfer destination (see the dashed arrow in FIG. 10). Both of these two positions are included in the second transport range R2, so the second internal transport device 3B is assigned to the carrier of the transport command B-3. The transport process based on these transport commands B-1 and B-3 is an example of the above-mentioned transport process for processing.

For example, transport command A-3 is a command for the source of transport to be the storage section 23 in the seventh level of the second row of the second storage shelf 2B, and the destination to be the outgoing port Po (see FIG. 11). Since both of these two positions are included in the first transport range R1, the first internal transport device 3A is assigned as the carrier of transport command A-3. The transport process based on this transport command A-3 is an example of the outgoing transport process described above.

In this embodiment, the first internal transport device 3A and the second internal transport device 3B are each configured to execute the transport processing in the order shown at the top of FIG. 5. In this example, the order of transport processing scheduled for the first internal transport device 3A is transport commands A-1, A-2, A-3, A-4, ..., and the order of transport processing scheduled for the second internal transport device 3B is transport commands B-1, B-2, B-3, .... These transport orders can be determined by prioritizing the processing efficiency of each of the first internal transport device 3A and the second internal transport device 3B, for example.

The external transport control unit 72 controls the external transport device 8. The external transport control unit 72 controls multiple transport carriages 82 traveling on a circular track 81 and the transfer device suspended and supported thereon. The external transport control unit 72 controls the transport carriages 82 and the transfer device based on a transport command (here, a transport command between processes). The transport command between processes has information on the source process (source item storage facility 1), the destination process (destination item storage facility 1), and the transport carriage 82 to be used. Based on this transport command between processes, the item 10 supported on the outgoing section 5 of the source process is transported to the incoming section 4 of the destination process by the designated transport carriage 82. At this time, multiple transport commands between processes can be executed simultaneously.

The overall control unit 73 controls the external transport control unit 72 and the internal transport control unit 71. For example, when transporting an item 10 between processes, the overall control unit 73 cooperatively controls the internal transport control unit 71 corresponding to the source item storage facility 1, the external transport control unit 72, and the internal transport control unit 71 corresponding to the destination item storage facility 1. The overall control unit 73 controls the internal transport control unit 71 corresponding to the item storage facility 1 so that the item 10 to be transported is supported on the delivery section 5 of the source item storage facility 1, controls the external transport control unit 72 to receive the item 10 supported on the delivery section 5, transport it to the destination item storage facility 1, and transfer it to the receiving section 4, and further controls the internal transport control unit 71 corresponding to the item storage facility 1 so that the item 10 supported on the receiving section 4 of the destination item storage facility 1 is stored on the storage shelf 2.

In order to improve the processing efficiency of the entire facility, the item transport equipment 100 of this embodiment controls each part by assuming that the receiving section 4 can hold more than the upper limit number Nmax of items 10, which is the physical buffer number. That is, the upper limit number Nmax plus the adjustment number A is set as the operational buffer number B (B = Nmax + A) (see Figure 2), and the receiving section 4 of the destination item storage equipment 1 is configured to accept items 10 in a number equal to or less than the operational buffer number B. The receiving section 4 of the destination item storage equipment 1 not only actually supports the upper limit number Nmax of items 10 that it can physically accept, but also assumes that the system virtually supports items 10 equal to or less than the adjustment number A, and the subsequent transport process is performed.

Here, the adjustment number A is a variably set integer value of 0 or more. It is preferable that the adjustment number A is an integer value of 1 or more. Even if the receiving section 4 of the destination item storage facility 1 is fully filled, items 10 equal to or less than this adjustment number A can be transported in advance to the receiving section 4. The adjustment number A is set based on the number of items 10 that can be transported by the internal transport device 3 (first internal transport device 3A) from the receiving section 4 to the storage shelf 2 until the items 10 transported in advance by the external transport device 8 reach the receiving section 4 of the destination item storage facility 1. From this perspective, it is preferable that the adjustment number A is realistically set to, for example, about 1 to 3.

Figure 2 shows an example in which "2" is added as the adjustment number A to the maximum holding number Nmax of "2", and "4" is set as the operational buffer number B, making it possible for up to four items 10 to be virtually received in the receiving section 4. When an item 10 is transported by the internal transport device 3 (first internal transport device 3A) from the receiving port Pi of the receiving section 4 to one of the storage sections 23 of the storage shelf 2, the receiving conveyor 41 operates to transfer the next item 10 to the receiving port Pi and form a receiving space for the item 10 transported in advance by the external transport device 8.

In this configuration, if the receiving section 4 is full of items 10 actually held in the destination item storage facility 1, the next item 10 cannot be transferred even if the external conveying device 8 conveys it. In this case, the receiving section 4 must wait until space becomes available, resulting in congestion on the external conveying device 8 and reducing the processing efficiency of the facility as a whole. Therefore, in the item conveying facility 100 of this embodiment, the control system 7 is configured to execute operational buffer number adjustment control, warehousing top priority control, and internal conveying load adjustment control, which will be described in detail below.

<Operation buffer number adjustment control>
The operation buffer number adjustment control is a control for adjusting the operation buffer number B under certain conditions. As described above, the control system 7 sets the number obtained by adding the adjustment number A, which is variably set to an integer value of 0 or more (preferably 1 or more), to the upper limit number of held items Nmax as the operation buffer number B (B = Nmax + A), and controls the item transport equipment 100 based on this operation buffer number B. Here, the number of items 10 actually held in the receiving section 4 at each time point is defined as the "number of held items Nr", and the number of items 10 being transported by the external transport device 8 toward the receiving section 4 is defined as the "number of items being transported Nt". At this time, the control system 7 controls the external transport device 8 so that the number of items being transported Nt is equal to or less than the number obtained by subtracting the number of held items Nr from the operation buffer number B (B - Nr = Nmax + A - Nr).

Based on this configuration, in the operational buffer number adjustment control, the control system 7 sets the adjustment number A to a smaller value as the load on the internal transport device 3 increases. In particular, the control system 7 sets the adjustment number A to a smaller value as the load on the first internal transport device 3A operating within the first transport range R1 including the storage section 4 increases.

As described above, the first internal transport device 3A is responsible for the incoming transport process, the in-shelf transport process, and the outgoing transport process. Therefore, when the load on the first internal transport device 3A increases (especially when the ratio of the in-shelf transport process and the outgoing transport process increases), the transport of the items 10 from the receiving section 4 to the storage shelf 2 (incoming transport process) is likely to be delayed. Therefore, by setting the adjustment number A to a smaller value as the load on the first internal transport device 3A increases, the number of items 10 transported in advance to the receiving section 4 by the external transport device 8 can be reduced according to the degree of the load on the first internal transport device 3A. Since the number of items 10 transported in advance is reduced, it is easier to avoid a situation in which the receiving section 4 is full when those items 10 arrive at the receiving section 4. Therefore, it is possible to suppress a decrease in the processing efficiency of the entire facility.

In this embodiment, the control system 7 determines the load on the first internal transport device 3A based on the number of transport commands for items 10 to the first internal transport device 3A. The control system 7 then determines that the load increases as the number of transport commands for items 10 to the first internal transport device 3A increases.

Here, the first internal conveying device 3A is solely responsible for the conveying of the item 10 whose origin or destination is within the first conveying range R1 (but neither is within the overlapping range L of the first conveying range R1 and the second conveying range R2), and therefore all of the corresponding conveying commands are commands to the first internal conveying device 3A. On the other hand, the first internal conveying device 3A and the second internal conveying device 3B are responsible for the conveying of the item 10 whose origin and destination are both within the overlapping range L of the first conveying range R1 and the second conveying range R2, and therefore only a portion of the corresponding conveying commands are commands to the first internal conveying device 3A. In this embodiment, in order to reduce calculation processing, the control system 7 considers that the conveying of the item 10 in the overlapping range L is equally shared between the first internal conveying device 3A and the second internal conveying device 3B, and considers half of the corresponding conveying commands to be commands to the first internal conveying device 3A.

That is, the control system 7 determines that the load on the first internal transport device 3A increases as the total number (hereinafter referred to as the "transport command number") of the number of transport commands for items 10 whose origin or destination is within the first transport range R1 and half the number of transport commands for items 10 whose origin and destination are both within the overlapping range L increases, and sets the adjustment number A to a smaller value as the load on the first internal transport device 3A increases. For example, in the example of FIG. 2, the adjustment number A, which was initially set to "2", is reset to "1" when the number of transport commands becomes equal to or greater than a first reference value, and is reset to "0" when the number of transport commands becomes equal to or greater than a second reference value that is greater than the first reference value. Accordingly, the operational buffer number B gradually decreases from "4" to "3" and then to "2".

By resetting the adjustment number A to a smaller number, the operational buffer number B (= Nmax + A) also becomes smaller, and the difference (= Nmax + A - Nr) between the number of items 10 actually held in the receiving section 4 (number of held items Nr) also becomes smaller. This difference corresponds to the number of items 10 that can be transported in advance to the receiving section 4 by the external transport device 8 at that time, but as this difference becomes smaller, it may be the case that the number of items 10 in question is already being transported. In such a case, the control system 7 is not to start transporting new items 10 by the external transport device 8 to the receiving section 4 while the number of items being transported Nt is equal to the number obtained by subtracting the number of held items Nr from the operational buffer number B (B - Nr = Nmax + A - Nr).

Eventually, as the warehousing transport process by the first internal transport device 3A progresses, the number of items being transported Nt becomes less than the number obtained by subtracting the number of held items Nr from the number of operational buffers B (B-Nr=Nmax+A-Nr). The control system 7 then starts the transport of new items 10 by the external transport device 8 toward the warehousing section 4. In this embodiment, the control system 7 starts the transport of new items 10 by the external transport device 8 as soon as the number of items being transported Nt becomes less than the number obtained by subtracting the number of held items Nr from the number of operational buffers B (Nmax+A-Nr).

Figure 12 is a flowchart showing the processing procedure for the operational buffer number adjustment control. The operational buffer number adjustment control is executed by the internal transport control unit 71, the external transport control unit 72, and the overall control unit 73 that constitute the control system 7 in cooperation with each other. In the operational buffer number adjustment control, the internal transport control unit 71 first determines the load (number of transport commands) of the first internal transport device 3A, and generates load information indicating the load (step #01). The generated load information is sent from the internal transport control unit 71 to the overall control unit 73.

Next, the overall control unit 73 sets the adjustment number A based on the load information received from the internal transport control unit 71 so that the adjustment number A becomes smaller as the load on the first internal transport device 3A increases (#02). Then, the overall control unit 73 transmits an inter-process transport command for the number of items 10 based on the operational buffer number B (B = Nmax + A) determined according to the set adjustment number A to the external transport control unit 72.

More specifically, the overall control unit 73 determines whether the number of items being transported at that time Nt is less than the difference (=Nmax+A-Nr) between the operational buffer number B (=Nmax+A) and the number of held items Nr (#03). If the number of items being transported Nt is less than the difference between the operational buffer number B and the number of held items Nr (#03: Yes), the external transport device 8 is allowed to transport new items 10 toward the storage section 4 (#04). In this case, the overall control unit 73 sends a new inter-process transport command to the external transport control unit 72, and the external transport control unit 72, which receives the command, controls the external transport device 8 based on the inter-process transport command.

On the other hand, if the number of items being transported Nt is equal to or greater than the difference between the number of operational buffers B and the number of held items Nr (actually, they are the same number) (#03: No), the external transport device 8 temporarily stops transporting new items 10 to the receiving section 4 (#05). For example, the overall control unit 73 puts on hold the transmission of a new inter-process transport command to the external transport control unit 72, or a new inter-process transport command is sent to the external transport control unit 72 and the operation of the external transport device 8 based on the inter-process transport command is put on hold. When the number of items being transported Nt becomes less than the difference between the number of operational buffers B and the number of held items Nr (#03: Yes), the hold is released and the external transport device 8 is allowed to transport new items 10 to the receiving section 4 (#04).

<In-stock priority control>
The warehousing top priority control is a control that performs the warehousing transport process with the highest priority under certain conditions with respect to the transport process by the internal transport device 3. In this embodiment, the control system 7 performs the warehousing priority control based on the total number of held goods Nr and the number of goods being transported Nt (hereinafter referred to as the "potential held goods number Np"). Here, the held goods number Nr is the number of goods 10 actually held in the warehousing section 4 as described above, and the number of goods being transported Nt is the number of goods 10 being transported to the warehousing section 4 by the external transport device 8. In the warehousing top priority control, when the potential held goods number Np is greater than the judgment threshold value Th, the control system 7 performs the warehousing transport process with priority over the outgoing transport process and the intra-shelf transport process among various transport processes by the internal transport device 3.

In this embodiment, of the first internal transport device 3A and the second internal transport device 3B that constitute the internal transport device 3, only the first internal transport device 3A is responsible for the warehouse transport process. Therefore, of the first internal transport device 3A and the second internal transport device 3B, the control system 7 executes warehouse-entry priority control only for the first internal transport device 3A.

In this embodiment, the judgment threshold value Th, which is the criterion for judging whether or not the top priority control for storing goods is to be executed, is set to the upper limit number Nmax, which is the maximum number of items 10 that can be held in the storing section 4. Therefore, in this embodiment, the top priority control for storing goods is executed when the number of potentially held items Np is greater than the upper limit number Nmax, in other words, when there is no space available in the storing section 4 at that time for at least one of all items 10 being transported by the external transport device 8.

As described above, in this embodiment, the first internal transport device 3A performs transport in an order that prioritizes, for example, processing efficiency; for example, in the example of FIG. 5, the order of transport commands A-1, A-2, A-3, A-4, ... is the planned order of transport processing. In the warehousing top priority control, the control system 7 changes this planned order of transport processing to perform warehousing priority control. For example, in the example of FIG. 5, the order of the transport processing based on transport command A-1 and the transport processing based on transport command A-2 is swapped, so that the warehousing transport processing based on transport command A-2 is performed with top priority.

By performing the incoming transport process with the highest priority, it becomes easier to quickly create space in the incoming section 4 for the external transport device 8 to receive the items 10 being transported. In other words, it becomes easier to avoid the incoming section 4 becoming full, and it is possible to suppress a decrease in the processing efficiency of the entire facility. The idea is to prioritize suppressing a decrease in the processing efficiency of the entire item transport facility 100, even if it means sacrificing some of the processing efficiency of the first internal transport device 3A of a particular item storage facility 1.

When the operating rate of the multiple transport cars 82 in the external transport device 8 is low, the impact on the entire facility is often small even if some of the transport cars 82 have to wait in front of one of the storage sections 4. For this reason, in this embodiment, the control system 7 is configured not to execute storage priority control when the operating rate of the multiple transport cars 82 in the external transport device 8 is equal to or lower than a specified operating rate threshold. As a result, when the processing efficiency of the entire item transport facility 100 is not a major issue, the processing efficiency of the first internal transport device 3A can be prioritized, as originally intended.

Here, the utilization rate of the transport vehicles 82 is the ratio (percentage) of the number of transport vehicles 82 to which inter-process transport commands are assigned to the total number of transport vehicles 82. The utilization rate threshold is set to a value near the upper limit at which subsequent transport vehicles 82 are unlikely to become congested even if one transport vehicle 82 waits for a certain period of time, specifically, a value of, for example, about 1% to 20%.

Figure 13 is a flowchart showing the processing procedure of the warehousing top priority control. The warehousing top priority control is executed by the internal transport control unit 71, the external transport control unit 72, and the general control unit 73 constituting the control system 7 in cooperation with each other. In the warehousing top priority control, the general control unit 73 first determines whether the operation rate of the multiple transport carts 82 in the external transport device 8 is greater than or equal to the operation rate threshold (#21). If the operation rate of the transport carts 82 is equal to or less than the operation rate threshold (#21: No), the warehousing top priority control ends as it is. On the other hand, if the operation rate of the transport carts 82 is greater than the operation rate threshold (#21: Yes), the general control unit 73 acquires the potential number of held items Np (#22). Specifically, the number of held items Nr is acquired from the internal transport control unit 71, and the number of items being transported Nt is acquired from the external transport control unit 72, and the potential number of held items Np is calculated by adding these.

Then, the overall control unit 73 judges whether or not to execute the warehousing priority control based on the number of potentially held items Np. Specifically, it is judged whether or not the number of potentially held items Np is greater than the judgment threshold value Th (#23). If the number of potentially held items Np is greater than the judgment threshold value Th (#23: Yes), the overall control unit 73 judges to execute the warehousing priority control. In this case, the overall control unit 73 sends a command to the internal transport control unit 71, and based on this, the scheduled order of the various transport processes by the first internal transport device 3A is changed, and the warehousing transport process is executed with the highest priority (#24). On the other hand, if the number of potentially held items Np is equal to or less than the judgment threshold value Th (#23: Yes), the transport processes by the first internal transport device 3A are executed in the scheduled order (#25).

<Internal transport load adjustment control>
The internal transport load adjustment control is a control for adjusting the balance of the transport loads of the first internal transport device 3A and the second internal transport device 3B constituting the internal transport device 3. In this embodiment, the internal transport load adjustment control performs a process (range adjustment process) for adjusting the range of the first transport range R1, which is the operating range of the first internal transport device 3A, under certain conditions based at least on the number of held articles Nr, which is the number of articles 10 held in the storage section 4. In this embodiment, the internal transport load adjustment control is performed based on the number (number of articles to be held Ne) obtained by adding the number of articles being transported Nt, which is the number of articles 10 being transported to the storage section 4 by the external transport device 8, to the number of held articles Nr. In the internal transport load adjustment control, the control system 7 performs a process of reducing the first transport range R1 as the number of articles to be held Ne increases, as a range adjustment process, thereby adjusting the balance of the transport loads of the first internal transport device 3A and the second internal transport device 3B.

In addition, in the internal transport load adjustment control (range adjustment process), the control system 7 increases the second transport range R2 in response to decreasing the first transport range R1. For example, the control system 7 reduces the first transport range R1 by transferring a portion of the first transport range R1 on the processing device 9 side to the second transport range R2, and increases the second transport range R2 by the amount that the first transport range R1 has become smaller.

As shown in FIG. 14, in this embodiment, the control system 7 can change the setting of the first conveying range R1 between a normal range R1n of normal size and a limited range R1l that is smaller than the normal range R1n. The control system 7 can change the setting of the second conveying range R2 between a normal range R2n of normal size and an extended range R2e that is larger than the normal range R2n. The difference in size between the normal range R1n and the limited range R1l in the first conveying range R1 and the difference in size between the normal range R2n and the extended range R2e in the second conveying range R2 are set to be equal to each other.

In the internal transport load adjustment control (range adjustment process), if the number of items to be held Ne is less than the upper limit number to be held Nmax, the control system 7 sets the first transport range R1 of the first internal transport device 3A to the normal range R1n and sets the second transport range R2 of the second internal transport device 3B to the normal range R2n. Note that this is the same range setting as in normal control.

In addition, in the internal transport load adjustment control (range adjustment process), the control system 7 sets the first transport range R1 of the first internal transport device 3A to the restricted range R1l and sets the second transport range R2 of the second internal transport device 3B to the extended range R2e when the number of items to be held Ne is equal to or greater than the upper limit number Nmax. By setting the first transport range R1 to the restricted range R1l when the number of items to be held Ne is equal to or greater than the upper limit number Nmax, the operating range of the first internal transport device 3A is reduced and the turnover rate is increased when the number of items to be held Ne is large, thereby facilitating the transport of items 10 from the storage section 4.

For example, the intra-shelf transport process based on the transport command A-1 shown in FIG. 5 (see FIG. 9) is no longer a transport process within the overlapping range L because the first transport range R1 is set to the limited range R1l and the second transport range R2 is set to the extended range R2e. Accordingly, the allocation of the intra-shelf transport process based on the transport command A-1 is changed from the first internal transport device 3A to the second internal transport device 3B. In this way, by narrowing the first transport range R1, the processing load of the first internal transport device 3A can be reduced, and the resulting spare capacity can be used to prioritize the execution of the storage transport process. This makes it easier to avoid a state in which the storage section 4 is full, and reduces a decrease in the processing efficiency of the item transport equipment 100 as a whole.

In this embodiment, the control system 7 does not perform range adjustment processing when the number of transport commands assigned to the second internal transport device 3B is equal to or greater than the command number threshold, regardless of the size of the number of items to be held Ne. The command number threshold is set to a value close to the upper limit at which the second internal transport device 3B can execute the assigned transport processing while leaving a certain amount of spare capacity, taking into consideration, for example, the size of the storage shelf 2 and the processing capacity of the second internal transport device 3B. By configuring the range adjustment processing to be performed only when there is a certain amount of spare capacity in the load of the second internal transport device 3B, it is possible to appropriately respond to the increase in load on the second internal transport device 3B that occurs as the second transport range R2 becomes larger.

Figure 15 is a flowchart showing the processing procedure for the internal transport load adjustment control. The internal transport load adjustment control is executed by the internal transport control unit 71 that constitutes the control system 7. In the internal transport load adjustment control, first, a magnitude relationship between the number of transport commands assigned to the second internal transport device 3B and the command number threshold is determined (#41). If the number of transport commands for the second internal transport device 3B is equal to or greater than the command number threshold (#41: No), the internal transport load adjustment control ends as is.

On the other hand, if the number of transport commands for the second internal transport device 3B is less than the command number threshold (#41: Yes), then the magnitude relationship between the number of items to be held Ne and the upper limit number to be held Nmax is determined (#42). If the number of items to be held Ne is less than the upper limit number to be held Nmax (#42: Yes), the first transport range R1 of the first internal transport device 3A is set to the normal range R1n, and the second transport range R2 of the second internal transport device 3B is set to the normal range R2n (#43). On the other hand, if the number of items to be held Ne is equal to or greater than the upper limit number to be held Nmax (#42: No), the first transport range R1 of the first internal transport device 3A is set to the limited range R1l, and the second transport range R2 of the second internal transport device 3B is set to the extended range R2e (#44).

Other embodiments
(1) In the above embodiment, an example has been described in which the external conveying device 8 starts conveying new items 10 in the operational buffer number adjustment control as soon as the number of items being conveyed Nt falls below the number (Nmax+A-Nr) obtained by subtracting the number of held items Nr from the number of operational buffers B. However, the present invention is not limited to such a configuration, and for example, the external conveying device 8 may start conveying new items 10 after a certain time has elapsed after the number of items being conveyed Nt falls below the number (Nmax+A-Nr) obtained by subtracting the number of held items Nr from the number of operational buffers B.

(2) In the above embodiment, in the storage top priority control, a configuration has been described as an example in which the judgment threshold Th is set to the upper limit number Nmax, which is the maximum number of items 10 that can be held in the storage section 4. However, the present invention is not limited to such a configuration, and the judgment threshold Th may be set to a value different from the upper limit number Nmax, for example, "upper limit number Nmax±1".

(3) In the above embodiment, an example has been described in which the potential number of held items Np is the sum of the number of held items Nr and the number of items being transported Nt in the top priority control for storing. However, the present invention is not limited to such a configuration, and for example, the potential number of held items Np may also include items for which inter-process transport commands have already been generated but which have not yet been transported. In this case, the potential number of held items Np can be defined as "the sum of the number of held items Nr, which is the number of items 10 held in the receiving section 4, and the number of transported items, which is the number of items 10 scheduled to be transported to the receiving section 4 by the external transport device 8."

(4) In the above embodiment, an example was described in which the warehousing priority control is not executed when the operation rate of the multiple transport vehicles 82 in the external transport device 8 is equal to or lower than the operation rate threshold value. However, the present invention is not limited to such a configuration, and the warehousing priority control may be executed uniformly regardless of the operation rate of the transport vehicles 82.

(5) In the above embodiment, an example was described in which the internal transport load adjustment control enlarges the second transport range R2 by the same amount as the first transport range R1 is reduced. However, the present invention is not limited to such a configuration, and the degree to which the first transport range R1 is reduced and the degree to which the second transport range R2 is increased may be different. Alternatively, only the first transport range R1 may be reduced without changing the size of the second transport range R2.

(6) In the above embodiment, an example has been described in which the first conveying range R1 and the second conveying range R2 are each switched in two stages in the internal conveying load adjustment control. However, the present invention is not limited to such a configuration, and for example, the first conveying range R1 and the second conveying range R2 may each be switched in three or more stages. In this case, the number of stages of switching the first conveying range R1 and the number of stages of switching the second conveying range R2 may be different from each other.

(7) In the above embodiment, a configuration has been described as an example in which internal transport load adjustment control is performed based on the number of items to be held Ne (the number of held items Nr, which is the number of items 10 held in the receiving section 4, plus the number of items being transported Nt, which is the number of items 10 being transported to the receiving section 4 by the external transport device 8). However, the configuration is not limited to this, and for example, internal transport load adjustment control may be performed based only on the number of held items Nr without considering the number of items being transported Nt.

(8) In the above embodiment, an example was described in which the internal transport load adjustment control (range adjustment process) is not executed when the number of transport commands assigned to the second internal transport device 3B is equal to or greater than the command number threshold. However, the present invention is not limited to such a configuration, and the internal transport load adjustment control (range adjustment process) may be executed uniformly regardless of the number of transport commands assigned to the second internal transport device 3B.

(9) In the above embodiment, a configuration in which all of the operational buffer number adjustment control, the warehousing top priority control, and the internal transport load adjustment control are executed has been described as an example. However, the present invention is not limited to such a configuration, and only one or two of these may be executed.

(10) In the above embodiment, a configuration in which the first internal transport device 3A and the second internal transport device 3B are provided on a common running rail 31 has been described as an example. However, the present invention is not limited to such a configuration, and for example, the first internal transport device 3A and the second internal transport device 3B may be provided on their own dedicated running rails 31 that are laid parallel to each other.

(11) In the above embodiment, the internal conveying device 3 has a first internal conveying device 3A and a second internal conveying device 3B. However, the present invention is not limited to such a configuration, and may be configured with only one internal conveying device 3. In this case, one internal conveying device 3 is responsible for the entire range of conveying processing from the receiving section 4 and the outgoing section 5 via the storage shelf 2 to the processing device 9, and it is also possible to directly convey the item 10 from the receiving section 4 to the processing device 9. In such a case, the process of directly conveying the item 10 from the receiving port Pi of the receiving section 4 to the delivery port Pp of the processing device 9 by the internal conveying device 3 is also considered to be included in the inbound conveying process. In addition, one internal conveying device 3 can directly convey the item 10 from the receiving section 4 to the outgoing section 5, and in such a case, the process of directly conveying the item 10 from the receiving section 4 to the outgoing section 5 by the internal conveying device 3 is also considered to be included in the inbound conveying process.

(12) In the above embodiment, an example has been described in which the storage section 4 and the delivery section 5 are each capable of physically holding two items 10. However, the present invention is not limited to such a configuration, and the number of items that the storage section 4 and the delivery section 5 can physically hold may be one or three or more. In this case, the number of items that the storage section 4 can physically hold and the number of items that the delivery section 5 can physically hold may be different from each other.

(13) In the above embodiment, an example was described in which the internal transport device 3 was configured as a stacker crane. However, the invention is not limited to such a configuration, and the internal transport device 3 may be configured as, for example, a multi-stage shuttle cart (a transport device having multiple transport cars that reciprocate along the front surface of the storage shelf 2 at heights corresponding to the respective stages of the storage shelf 2), etc.

(14) In the above embodiment, an example has been described in which the external transport device 8 is equipped with a tracked, floor-traveling transport cart 82. However, the present invention is not limited to such a configuration, and the external transport device 8 may be configured, for example, with a floor-traveling, trackless cart, or with a ceiling-transporting, tracked cart. When the external transport device 8 is configured with a ceiling-transporting, tracked cart, the external transport device 8 may be equipped with a hoist-type transfer device suspended from the transport cart 82.

(15) In the above embodiment, a configuration in which the external transport device 8 is equipped with a transfer device has been described as an example. However, the present invention is not limited to such a configuration, and the external transport device 8 may not be equipped with a transfer device, and a transfer device may be provided on the storage section 4 or the unloading section 5 side.

(16) In the above embodiment, the control system 7 is described as having an internal transport control unit 71, an external transport control unit 72, and an overall control unit 73 that cooperate with each other. However, the specific configuration of the control system 7 may be a combination of multiple control units, or a single control unit may be further subdivided. In addition, the control system 7 may further include other control units to enable other functions to be realized.

(17) The configurations disclosed in each of the above-described embodiments (including the above-described embodiments and other embodiments; the same applies below) can also be applied in combination with configurations disclosed in other embodiments, as long as no contradiction arises. As for other configurations, the embodiments disclosed in this specification are illustrative in all respects and can be modified as appropriate within the scope of the present disclosure.

[Overview of the embodiment]
To summarise the above, an item storage facility according to the present disclosure preferably comprises the following configurations.

An item storage facility, comprising:
A storage shelf having a plurality of storage sections for storing items;
a receiving section that holds the item received from an external conveying device that conveys the item outside the storage shelf;
an internal conveyance device that moves along a conveyance path set along a front surface of the storage shelf and conveys the item between the receiving section and the storage shelf;
a control system for controlling the external transport device and the internal transport device;
The maximum number of the items that can be held in the receiving section is defined as a holding upper limit number Nmax, and the number of the items that are actually held in the receiving section at each time point is defined as a holding item number Nr,
The control system sets an adjustment number A, which is variably set to an integer value equal to or greater than 0, to the upper limit number Nmax of held items as an operational buffer number (Nmax+A), and controls the external transport device so that the number of items being transported, which is the number of items being transported toward the storage section, is equal to or less than the operational buffer number minus the number of held items Nr (Nmax+A-Nr);
Furthermore, the control system sets the adjustment number A to a smaller value as the load on the internal transport device increases.

According to this configuration, the internal transport device moves along the transport path along the front of the storage shelf, and the items received from the external transport device are stored in the storage shelf, and can be used for subsequent processing if necessary. At this time, the receiving section functions as a buffer, and the number of operating buffers (Nmax+A; A is an adjustment number equal to or greater than 0) is equal to or greater than the upper limit number Nmax, which is the maximum number of items that can be physically held in the receiving section, thereby further improving processing efficiency. For example, if the adjustment number A is set to 1 or greater, even if the receiving section is already filled with the number of items equal to the upper limit number Nmax, the external transport device can transport up to the number of items equal to the adjustment number A toward the storage shelf (receiving section). If the transport processing of the internal transport device is completed during that time, one of the items held in the receiving section can be transported to free up space in the receiving section, and the receiving section can receive the item transported in advance by the external transport device. In this way, processing efficiency can be further improved.
Furthermore, in this configuration, the adjustment number A is set to a smaller value as the load on the internal conveying device increases. Therefore, even if the internal conveying device is delayed in carrying out the goods from the receiving section, it is easy to avoid a situation in which the external conveying device becomes congested in front of the receiving section due to the delay. Therefore, it is easy to avoid a decrease in the processing efficiency of the entire goods conveying facility due to a congestion on the external conveying device.
From these factors, it is possible to realize an article storage facility that can further improve the processing efficiency of the article transport facility as a whole.

In one embodiment,
It is preferable that the control system determines that the load increases as the number of transport commands for the internal transport device for transporting the articles increases.

With this configuration, the load on the internal transport device can be appropriately determined according to the number of item transport commands issued to the internal transport device. This allows the adjustment number A to be appropriately reset thereafter, improving the processing efficiency of the entire item transport facility.

In one embodiment,
It is preferable that the control system does not start transporting new items by the external conveying device toward the receiving section while the number of items being transported is equal to the number obtained by subtracting the number of held items Nr from the number of operational buffers (Nmax+A-Nr), and starts transporting new items by the external conveying device toward the receiving section after the number of items being transported becomes less than the number obtained by subtracting the number of held items Nr from the number of operational buffers (Nmax+A-Nr).

With this configuration, the number of items transported by the external transport device toward the receiving section can be appropriately limited according to the adjustment number A, which is set smaller as the load on the internal transport device increases. This makes it possible to more appropriately avoid situations in which the external transport device becomes congested just before the receiving section.

In one embodiment,
the internal transport device includes a first transport unit and a second transport unit;
The first transport unit transports the item within a first transport range that includes the receiving section and at least a part of the storage section of the storage shelf,
the second transport unit transports the item within a second transport range that includes at least a portion of the storage section of the storage shelf and does not include the receiving section;
a part of the first conveying range and a part of the second conveying range are set to overlap with each other,
It is preferable that the control system determines that the load increases as the total number of transport commands for the items whose source or destination is within the first transport range and half the number of transport commands for the items whose source and destination are both in the overlapping range of the first transport range and the second transport range increases.

According to this configuration, the first transport unit and the second transport unit work together to efficiently transport and process items within the item storage facility. In addition, the degree of load on the first transport unit, which is responsible for transporting items from the storage section, can be appropriately determined according to the number of transport commands, taking into account the relationship between the origin and destination positions of each transport command and the first and second transport ranges. This allows the adjustment number A to be reset more appropriately thereafter, further improving the processing efficiency of the item transport facility as a whole.

In one embodiment,
the control system includes an external transport control unit that controls the external transport device, an internal transport control unit that controls the internal transport device, and a general control unit that generalizes the external transport control unit and the internal transport control unit,
the internal transport control unit transmits load information indicating a load of the internal transport device to the overall control unit;
The overall control unit sets the adjustment number A based on the load information received from the internal transport control unit, and transmits to the external transport control unit a transport command for the number of items based on the operational buffer number (Nmax+A) determined according to the set adjustment number A;
It is preferable that the external transport control unit controls the external transport device based on the transport command from the general control unit.

With this configuration, the overall control unit takes the lead in sending and receiving the necessary information and commands between the internal transport control unit and the external transport control unit, allowing the adjustment number A to be set appropriately and the external transport device to be controlled appropriately.

The item storage facility according to the present disclosure should be able to achieve at least one of the above-mentioned effects.

1 Item storage facility 2 Storage shelf 2A First storage shelf 2B Second storage shelf 3 Internal transport device 3A First internal transport device (first transport unit)
3B Second internal transport device (second transport unit)
4 Storage section 5 Delivery section 7 Control system 8 External transport device 9 Processing device 10 Article 23 Storage section 71 Internal transport control unit 72 External transport control unit 73 General control unit 82 Transport cart Ti Internal transport path (transport path)
Pi: Receiving port Po: Delivery port Pp: Processing port (delivery section)
R1 First conveying range R1n Normal range R1l Limited range R2 Second conveying range R2n Normal range R2e Extended range L Overlap range B Number of operational buffers Nmax Upper limit number of held items A Adjustment number Nr Number of held items Np Potential number of held items Nt Number of items being conveyed Ne Number of items to be held

Claims (5)

A storage shelf having a plurality of storage sections for storing items;
a receiving section that holds the item received from an external conveying device that conveys the item outside the storage shelf;
an internal conveyance device that moves along a conveyance path set along a front surface of the storage shelf and conveys the item between the receiving section and the storage shelf;
a control system for controlling the external transport device and the internal transport device;
The maximum number of the items that can be held in the receiving section is defined as a holding upper limit number Nmax, and the number of the items that are actually held in the receiving section at each time point is defined as a holding item number Nr,
The control system sets the number obtained by adding an adjustment number A, which is variably set to an integer value equal to or greater than 0, to the upper limit number Nmax of holding space as the number of operating buffers (Nmax+A), and controls the external conveying device so that the number of items being conveyed, which is the number of items being conveyed toward the storage section, is equal to or less than the number obtained by subtracting the number of held items Nr from the number of operating buffers (Nmax+A-Nr);
Furthermore, the control system sets the adjustment number A to a smaller value as the load on the internal transport device increases. The item storage facility according to claim 1, wherein the control system determines that the load increases as the number of item transport commands to the internal transport device increases. The control system does not start the transport of new items by the external transport device toward the receiving section while the number of items being transported is equal to the number obtained by subtracting the number of held items Nr from the number of operational buffers (Nmax+A-Nr), and starts the transport of new items by the external transport device toward the receiving section after the number of items being transported becomes less than the number obtained by subtracting the number of held items Nr from the number of operational buffers (Nmax+A-Nr). The item storage facility according to claim 1 or 2. the internal transport device includes a first transport unit and a second transport unit;
The first transport unit transports the item within a first transport range that includes the receiving section and at least a part of the storage section of the storage shelf,
the second transport unit transports the item within a second transport range that includes at least a portion of the storage section of the storage shelf and does not include the receiving section;
a part of the first conveying range and a part of the second conveying range are set to overlap each other,
The item storage facility of any one of claims 1 to 3, wherein the control system determines that the load increases as the total number of transport commands for the items whose source or destination is within the first transport range and half the number of transport commands for the items whose source and destination are both in the overlapping range of the first transport range and the second transport range increases. the control system includes an external transport control unit that controls the external transport device, an internal transport control unit that controls the internal transport device, and a general control unit that generalizes the external transport control unit and the internal transport control unit,
the internal transport control unit transmits load information indicating a load of the internal transport device to the overall control unit;
The overall control unit sets the adjustment number A based on the load information received from the internal transport control unit, and transmits to the external transport control unit a transport command for the number of items based on the operational buffer number (Nmax+A) determined according to the set adjustment number A;
The article storage facility according to claim 1 , wherein the external transport control unit controls the external transport device based on the transport command from the general control unit.

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