JP2002326707A - Automated storage and retrieval warehouse - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem with a conventional method for assigning shelves to articles to be put in storage in accordance with the order of priority in an automated storage and retrieval warehouse, that the shelves of low priority are not used when the quantity of inventory is small, so that it is difficult to find the abnormality of the shelves of low priority in early period. SOLUTION: This automated storage and retrieval warehouse having a plurality of shelves respectively provided with the order of priority, and a stacker crane capable of transferring the articles to the shelves, can arbitrarily select a first mode (a) for transferring the article to the shelf of the highest priority among the vacant shelves in putting the articles in storage, and a second mode (b) for (1) transferring the articles to the shelf of the highest priority among the shelves of the priority lower than that of the shelf on which the article has been transferred last time, and (2) transferring the articles to the shelf of the highest priority among all of vacant shelves, when the articles has been transferred to the shelf of the lowest priority last time, or when the shelves having the priority lower than the shelf on which the article has been transferred last time do not exist.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has a plurality of shelves,
The present invention relates to a technology of an automatic warehouse that automatically searches for empty shelves according to a predetermined priority and stores goods.

[0002]

2. Description of the Related Art Conventionally, when an article is placed at a storage entrance, empty shelves are searched according to a predetermined priority order.
Automatic warehouses for storing articles are known. This automatic warehouse is provided with, for example, an entrance for ceiling transport vehicles provided at the upper part and an entrance for floor transport vehicles provided at the lower part of the automatic warehouse, and the priority order is relatively high in the frequency of entry. Based on the entrance, the shelf closest to the entrance is set to have the highest priority, such as the shelf closest to the entrance, the second shelf next to the entrance, and so on. ing. Then, when the articles are actually stored, the articles are transferred to the shelf having the highest priority among the empty shelves.

[0003]

However, such a conventional automatic warehouse has the advantage that the time required for storage can be shortened by storing the goods in the order closer to the entrance, but only the shelves with high priority are frequently used. Will be used. Furthermore, the number of shelves in the automated warehouse (storage inventory capacity) is determined with a margin so as to be larger than the maximum value of the number of articles to be stocked in the warehouse (maximum stock number) in the system. Low shelves, especially those near the bottom, may not be used at all. Therefore, when there is an abnormality in a high priority shelf, it can be found immediately through a phenomenon such as not operating at the time of use, but even when there is an abnormality in a low priority shelf, it is small and the maximum inventory is small. Is
In many cases, abnormalities cannot be found because they are not actually used.

[0004] When introducing such an automatic warehouse system, it is practical to start with a small one at first, and gradually increase the scale while confirming normal operation. It is about to be taken. Considering the above circumstances, if an abnormality occurs on a shelf with a low priority, it will not be used in the early stage of the system, which is small and has a small maximum number of inventories. When the number of shelves increases and low-priority shelves are used, there is a possibility that a defect of the shelves will be found.

[0005] In general, the loss when the system is stopped due to, for example, the occurrence of an abnormality in the shelf is greater as the system is larger. Therefore, there has been a demand for a configuration capable of confirming that a low-priority shelf can be used normally even while the system is small and the stock quantity is small.

[0006]

The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

That is, according to the present invention, there is provided an automatic warehouse having a plurality of shelves each assigned a unique priority, and a stacker crane capable of transferring articles to the shelves. A first warehousing mode in which articles are transferred to the highest priority shelf among empty shelves when warehousing, and b) a priority order of shelves to which articles were previously transferred when warehousing. Items are transferred to the empty highest priority shelf among lower priority shelves, and the shelf where the last item was transferred is the lowest priority shelf, or the previous item was transferred. If all the shelves with lower priorities than the shelves that have been set are not empty, the second storage mode of transferring the goods to the shelves with the highest priority among all shelves, which can be freely switched, Things.

According to a second aspect of the present invention, there is provided a means for predicting and calculating a future work amount of the stacker crane, and when the work amount is larger than a predetermined value, the first storage mode is set. Is automatically switched to the second storage mode.

In the third aspect, the second storage mode is performed using a dummy article.

[0010]

Next, embodiments of the present invention will be described. FIG. 1 is a side view showing an overall configuration of an automatic warehouse according to an embodiment of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a rear view thereof. FIG. 4 is a block diagram showing the configuration of the control system.

As shown in FIG. 1, the automatic warehouse 1 includes a plurality of shelves 4 for storing cassettes w conveyed by a ceiling carrier 2 and a floor carrier 3, and a stacker for transferring the cassettes w to the respective shelves 4. A crane 5 and an automatic warehouse controller (control device) 6 for issuing a transfer command to a crane controller 51 (FIG. 4) for controlling the stacker crane 5 are provided. As shown in FIGS. 1 to 3, the shelves 4 are provided side by side on racks that are erected on both front and rear sides of the passage of the stacker crane 5, and are managed by the automatic warehouse controller 6. A product or a semi-finished product is stored in the cassette w, transported in this state, or stored in the automatic warehouse 1. Alternatively, when the product or semi-finished product is sent to a processing device (not shown) arranged on the transport path of the overhead transport vehicle 2 or the floor transport vehicle 3, the product or semi-finished product is taken out of the cassette w and the processing corresponding to each device is performed. Will be

The stacker crane 5 includes a traveling carriage 53 having a turntable 52 for loading and unloading a cassette w in and out of the car along with wheels and a drive unit, a mast 54 standing on the turntable 52, and a mast 54. An elevating table 55 that moves up and down along with 54 is provided, and the elevating table 55 is provided with a scalar arm 56 as a transfer device.

The overhead transport vehicle 2 is controlled by a ceiling transport vehicle controller 21 shown in FIG. 4 and is configured to transport a cassette w between a plurality of automatic warehouses 1. The ceiling transport vehicle 2 includes a main body including wheels, a secondary conductor of a linear motor, and the like, a mounting table 22 on which the cassette w is mounted, and a connecting portion connecting the main body and the mounting table 22. The vehicle travels inside a rail 7 described below, and the mounting table 22 is arranged outside the rail 7. The body is provided with two mounting tables 22 so that two cassettes w can be transported simultaneously.

The rail 7 has a running surface in which the main body of the overhead transport vehicle 2 travels, and a slit is provided on the upper surface along the longitudinal direction thereof to allow the connection of the ceiling transport vehicle 2 to move. I have. In addition to the running surface, a temporary conductor of a linear motor, a suction device for sucking dust generated inside the rail, and the like are arranged inside the rail 7. Two rails 7 are provided above and below.

The on-floor transport vehicle 3 is controlled by a on-floor transport vehicle controller 31 (FIG. 4) and is configured to transport the cassette w between various processing units (not shown) and the automatic warehouse 1. The floor carrier 3 has a transfer device such as a robot hand 32 or a scalar arm, and a cassette w.
Are provided, and four cassettes w at the maximum can be transported at the same time.

At the upper part of the automatic warehouse 1, an entrance / exit port 8 for entry / exit by the overhead transport vehicle 2 is provided.
A stocking unit 11 and a stocking unit 12 are arranged side by side along the traveling direction of the overhead carrier 2 for each rail 7. A transfer device 9 is provided in each of the storage unit 11 and the storage unit 12.

In the lower part of the automatic warehouse 1, an entry / exit port 10 for entry / exit by the on-floor carrier 3 traveling on the floor is provided. Are provided in each case. The cassette w placed by the robot hand 32 is provided in each of the storage unit 13 and the storage unit 14.
Is provided to a position where the sheet can be transferred to and from the stacker crane 5. Conveyor 1
5 is controlled by a conveyor controller 151 (FIG. 4) which receives a command from the automatic warehouse controller 6.

The automatic warehouse controller 6 is configured to be able to switch between two modes of a "short time storage mode" and "all shelf storage mode" as described later. The cassette w is stored in each shelf 4 by the stacker crane 5. A unique priority is assigned to each of the shelves 4, and a memory 61 of the automatic warehouse controller 6 serves as a priority table 62 shown in FIG.
Is stored. The empty information 63 indicating whether or not the cassette w is in each shelf 4 is transmitted to the automatic warehouse controller 6.
Is written on the hard disk 64.

The priority assigned to each shelf 4 is as follows:
In FIGS. 2 and 3, each shelf is indicated by a numeral attached to the position. Note that shelves with high priorities are given small numbers, and shelves with low priorities are given large numbers. As is clear from this, the priority order of the shelf 4 close to the frequently used entrance / exit port 8 for the overhead transport vehicle entrance / exit port 8 is as follows.
The priority is set higher than the priority of the shelf 4 located far away.

A case where the cassette w is stored in the automatic warehouse from the overhead transport vehicle 2 will be described below mainly with reference to FIG. System controller 1 managing production status
A transfer command is sent from 6 to the overhead transport vehicle controller 21, and the overhead transport vehicle controller 21 controls the overhead transport vehicle 2 in accordance with the transport instruction and stops at the target automatic warehouse 1. When the overhead transport vehicle 2 stops in front of the target storage unit 11, a photoelectric sensor (not shown) operates, and the transfer device controller 91 shown in FIG. The cassette w is mounted on the storage unit 11 from the mounting table 22. At this time, the barcode attached to the cassette w is read by a barcode reader (not shown),
Cassette information such as the type of the cassette w is sent from the transfer device controller 91 to the automatic warehouse controller 6.

The automatic warehouse controller 6 checks whether or not the cassette w is a transport instruction cassette based on the received cassette information. If it is confirmed that it is, depending on whether it is "short time storage mode" or "all shelf storage mode",
As will be described later, the transfer destination empty shelf 4 is determined by a different method, and the cassette w is stored in the transfer destination shelf 4.

In the "short-time warehousing mode", the automatic warehouse controller 6 assigns the shelf having the highest priority (numbered "1" in FIG. 2) according to the priority order table 62 stored in the memory 61. It is determined by checking the free space information 63 on the hard disk 64 whether or not the free shelf is empty. If the free space is not empty, the next highest priority shelf ("2" in FIG. 2) is assigned. To see if the shelf is empty. If the shelf is not empty, the next highest priority shelf is examined, and so on until the empty shelf is found, so that the highest priority shelf is available. 4 can be determined. This determination method is the same as the conventional method of determining the transfer destination of the cassette in the automatic warehouse.

When the empty shelves 4 to which the data is to be transferred are determined, the automatic warehouse controller 6 sets the storage unit 1 on which the cassette w is placed.
1 to transport the cassette w to the empty shelf 4
A transfer command is sent to the crane controller 51. The crane controller 51 that has received the transport command causes the stacker crane 5 to travel to the target storage unit 11 and the cassette w
Is received from the storage unit 11. Then, the stacker crane 5 is moved to the empty shelf 4 at the transfer destination determined as described above, and the cassette w is stored in the shelf 4. The automatic warehouse controller 6 reports that the shelf 4 is no longer an empty shelf.
Write to the space information 63.

On the other hand, when the storage mode is the “all shelves storage mode”, the automatic warehouse controller 6 also stores the priority 65 of the previously stored shelves in the memory 6 in addition to the priority table 62.
1 is stored. Then, the automatic warehouse controller 6 determines whether or not a shelf one level lower than the stored order of the last storage shelf is vacant.
It is determined by examining the above empty information 63, and if it is not empty, it is checked whether the next lower shelf is empty. If the shelf is not empty, the next lower shelf is checked, and so on, by repeating this process until a vacant shelf is found for a shelf that has never been received, and so on. Among the shelves lower than the order of the shelves, the shelves 4 having the highest free priority can be determined.

It should be noted that the shelf stored last time is the lowest shelf (FIG. 3).
, The search process is performed from the shelf with the highest priority among all the shelves (that is, the shelf with “1” shown in FIG. 2), and High shelf 4 is determined. Even when there are no empty shelves in the lower ranks of the shelves that have been received last time, the search process is performed from the shelf with the highest priority among all shelves (that is, the shelf “1” shown in FIG. 2). , The shelf 4 having the highest priority is determined.

When the empty shelves 4 to which the cassettes are to be transferred are determined, the automatic warehouse controller 6 operates the storage unit 1 on which the cassette w is placed.
1 to transport the cassette w to the empty shelf 4
A transfer command is sent to the crane controller 51. The crane controller 51 that has received the transport command causes the stacker crane 5 to travel to the target storage unit 11 and the cassette w
Is received from the storage unit 11. Then, the stacker crane 5 is moved to the empty shelf 4 at the transfer destination determined as described above, and the cassette w is stored in the shelf 4. The automatic warehouse controller 6 reports that the shelf 4 is no longer an empty shelf.
Write to the space information 63. Further, the priority order of the shelf 4 of the transfer destination is written into the memory 61 again (6.
5) At the time of the next storage, the priorities of the previous storage racks can be read.

The difference between the two modes described above will be described with reference to specific examples shown in FIGS. In FIG. 5 and subsequent figures, each shelf is schematically indicated by a chain-line rectangle, and the numeral at the lower right thereof indicates the priority of each shelf. Consider a state in which all shelves 4 of the automatic warehouse are empty as shown in FIG. 5, and in this state, three cassettes w
It is assumed that an instruction for sequentially storing 1, w2, and w3 has been transmitted from the system controller 16 to the automatic warehouse controller 6. In this case, the automatic warehouse controller 6 assigns the first cassette w1 to the priority order “1” as shown in FIG. 5 → FIG. 6 → FIG. 7 in any of the “short time storage mode” and “all shelf storage mode”. , The second cassette w2 is stored in the shelf of priority "2", and the third cassette w3 is stored in the shelf of priority "3".

Next, it is assumed that a command to retrieve the first cassette w1 is transmitted from the system controller 16 to the automatic warehouse controller 6. in this case,
Regardless of the “short-time storage mode” or “all-shelf storage mode”, the automatic warehouse controller 6 takes out the first cassette w1 on the shelf having the priority “1” as shown in FIG. As a result, the shelf with the priority “1” and the shelf with the priority “4” or later become empty shelves.

"Short time storage mode""All shelf storage mode"
The difference appears when the instruction to store the fourth cassette w4 next is sent to the automatic warehouse controller 6.

FIG. 9 shows the difference between the transfer destinations in both modes in the above case. As shown in FIG. 9, in the "short time storage mode", the transfer destination of the fourth cassette is set. In order to determine a shelf, the automatic warehouse controller 6 sequentially checks whether or not a shelf is empty from the shelf having the priority "1". In this case, since the shelf having the priority "1" is vacant, the fourth cassette w4 is stored in this shelf. This mode is advantageous in that the transfer destination of the cassette w is preferentially assigned to the shelf near the entrance, so that the storage time is reduced, the operating time of the stacker crane 5 is reduced, and the working efficiency is improved. is there.

On the other hand, in the "all shelves storage mode", the automatic warehouse controller 6 operates the shelf having the next lower priority order ("3") than the shelf ("3") of the previously received shelf, that is, the shelf having the priority order "4". Then, it is checked sequentially whether the shelf is empty or not. In this case, since the shelf of priority "4" is vacant, the fourth cassette w4 is stored in this shelf. The cassette is next stored in the shelf with the priority "1" after it is stored in the shelf with the lowest priority (the shelf with the priority "111" in this embodiment). .

In the "all shelves storage mode", there is a feature that even if the maximum stock number is a small number, shelves are always stored in a low-priority shelf as long as storage and retrieval are repeated. Therefore, even when the maximum stock quantity is small, not only the shelves with high priority but also the shelves with low priority are used evenly, and it can be confirmed whether or not the operation is normally performed on all shelves.

The switching between the two modes described above may be performed by switching means such as a dial or switch (not shown) provided on the operation panel, or may be automatically switched by software.

For example, when a command to store a large number of cassettes w in a short time is received, the mode is switched to the “short-time storage mode” in order to shorten the storage time by the stacker crane 5, If the stacker crane 5 has room for operation, such as when only the cassette w is stored, automatic control may be performed to switch to the “all shelves storage mode”. As a specific example,
When the automatic warehouse controller 6 temporarily buffers the incoming and outgoing commands from the system controller 16 and counts the number of incoming and outgoing commands currently buffered, and the count value exceeds a certain value. In this case, the “short-time warehousing mode” may be set, and if the value is below a certain value, the “all-shelf warehousing mode” may be set. Note that the method of counting the buffered amount of the incoming / outgoing command is an example, and the point is that the amount of work required to operate the stacker crane 5 in the future is somehow predicted and calculated, and based on that, What is necessary is just to change the mode.

Further, for example, the “all-shelf storage mode” may be set at the beginning of use of the automatic warehouse, and the mode may be switched to the “short-time storage mode” when all the shelves have been fully stored. In this case, there is an advantage that the initial failure of all shelves can be checked and confirmed at the beginning of the system.

In the "all shelves storage mode", it is effective to use an empty cassette (dummy cassette) instead of the cassette w containing a normal product. This is because when using shelves that are used less frequently in the “all shelves storage mode”, the shelves are likely to malfunction, and the abnormal operation during transfer may damage the product inside the cassette. There is a greater risk of the situation. Therefore,
By using a dummy cassette, loss in the event of an abnormality can be minimized.

[0037]

The present invention is configured as described above.
The following effects are obtained.

That is, an automatic warehouse having a plurality of shelves each assigned a unique priority and a stacker crane capable of transferring articles to the shelves, wherein: A first storage mode in which the goods are transferred to the highest priority shelf among empty shelves when the goods are stored, and b) the priority of the shelf to which the goods were previously transferred when the goods are stored. Of the shelves with lower priorities, the goods are transferred to the empty highest priority shelves, and if the shelf on which the previous goods were transferred is the lowest priority shelf, or the previous goods are moved. If all shelves with lower priorities than the loaded shelves are not vacant, the second warehousing mode of transferring articles to the vacant highest priority shelves of all shelves can be freely switched. Therefore, in the second warehousing mode, the maximum stock quantity is small. Even if, as long as they repeat the GR / unloading will be always be someday receipts to lower priority shelf. Therefore, even when the maximum stock quantity is small, not only high priority shelves but also low shelves are used equally, and it is possible to use all shelves while confirming whether or not operation is performed normally. it can. Therefore, by using the useful second storage mode and the normal first storage mode properly in accordance with the situation and use, it is possible to construct a more reliable automatic warehouse system.

According to a second aspect of the present invention, there is provided means for predicting and calculating the future work amount of the stacker crane, and when the work amount is larger than a predetermined value, the first storage mode is switched to the first storage mode. In such a case, the mode is automatically switched to the second storage mode, so that in the second storage mode, the stacker crane must be moved to a distant shelf inevitably. In view of
When the workload is low, check the normal operation of all shelves in the automated warehouse as a second receiving mode, while
When there is a lot of work, the first storage mode is a rationalized mode in which items are preferentially stored in empty shelves near the entrance, and the stacker crane is used efficiently to quickly store goods. It becomes possible to use various modes.

According to a third aspect of the present invention, the second warehousing mode is performed by using a dummy article. For example, during a normal operation, the first warehousing mode is used in the first warehousing mode, and an interval is provided at intervals. In the case of regularly (or irregularly) using the second storage mode to check whether all shelves are normal, low-priority shelves that are not used in the normal first storage mode may be used. In the storage mode, abnormalities often occur on shelves. According to the present invention, even in the unlikely event that an article is dropped or otherwise handled improperly due to such an abnormality of the shelf, it is a dummy article. The losses are small.

[Brief description of the drawings]

FIG. 1 is a side view showing the overall configuration of an automatic warehouse according to one embodiment of the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a rear view of the same.

FIG. 4 is a block diagram showing a configuration of a control system.

FIG. 5 is a diagram illustrating a state where a first cassette is stored in a state where all shelves are empty.

FIG. 6 is a diagram showing a state in which a second cassette is stored from the state of FIG. 5;

FIG. 7 is a diagram showing a state where a third cassette is stored from the state of FIG. 6;

FIG. 8 is a diagram showing a state where the first cassette is ejected from the state of FIG. 7;

FIG. 9 is a diagram showing a state where a fourth cassette is stored from the state of FIG. 8;

[Explanation of symbols]

 1 automatic warehouse 4 shelf 5 stacker crane w cassette

Claims (3)

[Claims] 1. An automatic warehouse having a plurality of shelves each assigned a unique priority and a stacker crane capable of transferring articles to the shelves. An automatic warehouse that can freely switch modes. a) A first storage mode in which, when goods are stored, the goods are transferred to the shelf with the highest priority among the empty shelves. b) When receiving the goods, the goods were transferred to the empty highest priority shelf among the shelves having lower priorities than the shelf on which the goods were previously transferred, and the goods were transferred last time. If the shelf is the lowest priority shelf, or if all shelves with lower priorities than the shelf to which the goods were previously transferred are not empty, the shelf with the highest priority among all shelves is empty. The second warehousing mode for transferring goods. 2. A means for predicting and calculating a future work amount of the stacker crane, wherein the work amount is larger than a predetermined value, the first storage mode is set, and if the work amount is smaller than the predetermined value, the second storage mode is set. The automatic warehouse according to claim 1, wherein the automatic storage mode is automatically switched to a storage mode. 3. The automatic warehouse according to claim 1, wherein the second storage mode is performed by using a dummy article.