Picking system

Abstract

To speed up a picking operation.SOLUTION: A picking system 1 comprises a main conveyance path 10 and a plurality of branch paths 20. The main conveyance path 10 circulates and conveys cases including articles in one direction. Each branch path 20 has a main branch path 21 which branches off at a branch point 11 of the main conveyance path 10 and extends to a confluence point 12 of the main conveyance path 10, and a bypass path 22 which connects a halfway point of the main branch path 21 and the main conveyance path 10 together. The main branch path 21 has: a station 23 where one or more articles are picked from the case conveyed along the main branch path 21; and a buffer part 24 which is provided on the main branch path 21 upstream of the station 23 and temporarily holds the cases. The bypass path 22 is a path for conveying the case from the buffer part 24 to the main conveyance path 10 without passing through the station 23.SELECTED DRAWING: Figure 2

Description

Technical Field

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[0001] The present disclosure relates to a picking system for picking an article from a case containing the article.

Background Art

[0002] A picking system is known in which articles stored in cases by type are aggregated according to the types and quantities of articles ordered by the destination and stored in a shipping container (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a picking station where a plurality of picking stations are arranged on one route and a plurality of workers perform picking operations, it may occur that another worker wants to perform a picking operation on the same article at the same time. An object of the present disclosure is to appropriately allocate a case containing an article in such a case and perform the picking operation quickly.

Means for Solving the Problems

[0005] This disclosure relates to a picking system for picking articles from cases containing articles. A first aspect of the picking system comprises a main transport route and a plurality of branch routes. The main transport route transports cases in a circular manner in one direction. In the plurality of branch routes, each branch route branches off from the main transport route and merges with the main transport route. Each branch route has a main branch route that branches off from a branching point of the main transport route and merges with a merging point of the main transport route, and a bypass route that connects a part of the main branch route to the main transport route. The main branch route has a station for picking articles from cases transported along the main branch route, and a buffer section located upstream of the station on the main branch route for temporarily holding cases containing articles.

[0006] The bypass route is a route for transporting cases containing articles from the buffer section to the main transport route without passing through the station.

[0007] In the first embodiment of the picking system, since a bypass path is provided for each branch path, a buffer case that is already heading to one station can be moved to another station before picking at that station.

[0008] The second embodiment of the picking system further includes, in addition to the system of the first embodiment, a controller that controls the transport of cases on the main transport path and on branch paths. The controller assigns cases containing items to picking requests at each station. When there is a first case containing a first item in the first buffer section of the first branch path, and a picking request for the first case containing the first item occurs at a second station belonging to the second branch path, the controller determines whether to prioritize the picking request at the second station. If it determines to prioritize the picking request at the second station, the controller transports the case from the first buffer section to the main transport path via a bypass path.

[0009] In the second embodiment of the picking system, the controller makes appropriate decisions and utilizes bypass routes, allowing picking operations to be performed at other stations when items are stuck in the buffer section, thereby shortening the overall picking time.

[0010] The third embodiment of the picking system further includes, in addition to the system of the second embodiment, a buffer section case detection sensor that determines whether or not a case is present in the buffer section. The controller measures the dwell time of the first case in the first buffer section based on information from the buffer section case detection sensor. The controller may decide to prioritize the picking request at the second station if the dwell time is longer than a predetermined time.

[0011] In the third embodiment of the picking system, the controller determines whether to prioritize the second station based on the dwell time of the first case in the buffer section, so that when the first case is dwelling in the first buffer section, picking can be performed at other picking stations.

[0012] The fourth embodiment of the picking system further includes, in addition to the system of the second embodiment, a station case detection sensor that determines whether or not a case is present at the station. The controller measures the dwell time of the case at the first station based on information from the station case detection sensor. If the dwell time is longer than a predetermined time, the controller decides to prioritize the picking request at the second station.

[0013] In the fourth aspect of the picking system, the controller determines whether to prioritize the second station based on the time the cases remain at the first station, so that picking can be performed at other picking stations depending on the time spent at the first station.

[0014] In the fifth embodiment of the picking system, in addition to the system of the second embodiment, the first buffer unit is capable of holding multiple cases in order from the side closest to the first station. The first buffer unit is equipped with a case detection sensor capable of detecting cases waiting in the first buffer unit. The controller counts the number of cases between the first case and the first station based on the information from the case detection sensor and the picking information, and determines that the picking request at the second station should be prioritized if the number of cases is greater than or equal to a predetermined number.

[0015] In the fifth aspect of the picking system, the controller determines whether to prioritize the second station based on the number of cases between the first case and the first station, making the determination a simple process.

[0016] In the sixth embodiment of the picking system, in addition to the system of the second embodiment, the first buffer unit can hold multiple cases in order from the side closest to the first station. The first buffer unit may be equipped with a buffer unit case detection sensor capable of detecting cases waiting in the first buffer unit. Based on the information from the buffer unit case detection sensor and the picking information, the controller calculates the number of items to be picked for cases between the first case and the first station, and determines that the picking request at the second station should be prioritized if the total number of items to be picked is equal to or greater than a predetermined number.

[0017] In the sixth aspect of the picking system, the controller determines whether to prioritize the second station based on the total number of items to be picked in the cases between the first case and the first station, thus providing a more accurate determination than simply relying on the number of cases.

[0018] The seventh embodiment of the picking system further includes, in addition to the system of the second embodiment, a station case detection sensor that determines whether or not a case is present at the first station. Based on the information from the station case detection sensor, the controller measures the dwell time of the case at the first station, and based on the dwell time, the controller measures and stores the work time for each picking operation performed by the worker at the first station. When a picking request for the first case is made at the second station while the first case is in the first buffer unit, the controller measures the current dwell time of the case at the first station, and based on the measured dwell time and the worker's picking work time, predicts the time until the worker begins picking the first case, and if the predicted time is greater than or equal to a predetermined time, the controller decides to prioritize the picking request at the second station.

[0019] The seventh type of picking system measures the progress of the current picking operation based on past picking operation results, so it can accurately predict the time required for future picking operations and accurately predict whether or not to prioritize picking operations at the second station.

[0020] In the eighth aspect of the picking system, in addition to the system of the third aspect, when there is a first case containing a first item in the first buffer section of the first branching path, and a picking request for the first case containing the first item occurs at a second station belonging to the second branching path, the controller determines that the time required to transport the first case from the first branching path along the main transport path to the second branching path is less than or equal to a predetermined time, and therefore determines that the picking request at the second station will take priority.

[0021] In the eighth aspect of the picking system, the controller determines whether to prioritize the second station based on the time it takes to transport the first case from the first branch path along the main transport path to the second branch path, thus enabling a decision that corresponds to the length of the main transport path 10.

[0022] In the picking system according to the ninth aspect of the present disclosure, in addition to the system according to the second aspect, when there is a first case containing a first article in the first buffer section of the first branch path and a picking request for the first case containing the first article occurs at the second station belonging to the second branch path, the controller predicts, using machine learning, the total time required until the completion of the picking operation at the first station and the total time required until the completion of the picking operation at the second station, when the first station is prioritized and when the second station is prioritized, and selects which of the first station and the second station to prioritize so that the total time becomes smaller.

[0023] In the picking system according to the ninth aspect, in addition to the system according to the second aspect, the controller uses machine learning to determine whether to prioritize the second station based on the prediction of the operation time when the first station is prioritized and when the second station is prioritized, so that a more accurate determination can be made.

[0024] In the picking system according to the tenth aspect, in addition to the system according to the first aspect, the picking system further includes a controller that controls the conveyance of cases on the main conveyance path and on the branch paths. The controller assigns a case containing an article to each picking request at each station. When there is a first case containing a first article in the first buffer section of the first branch path and the assignment request for the first case on the first branch path is cancelled, the controller conveys the load from the first buffer section to the main conveyance path via the bypass path.

[0025] In the picking system of the tenth aspect, even after a case containing an article has been introduced into the split path, if the picking assignment request is changed, the case can be returned to the main conveyance path by passing through the bypass path without passing through the picking station, the case can be effectively utilized at other stations, and the total picking operation time can be reduced.

[0026] The picking system of the eleventh aspect, in addition to the system of the first aspect, the buffer unit includes a downstream buffer unit that is on the main branch path and temporarily holds the case to be conveyed to the station, and an upstream buffer unit that is on the main branch path and upstream of the downstream buffer unit and temporarily holds the case, and the upstream buffer unit is connected to the bypass path.

Effect of the Invention

[0027] Even after a case containing an article is placed in the buffer unit for picking at one picking station, when prioritizing picking at other picking stations, the case can be returned to the main conveyance path using the bypass path. By utilizing the bypass path in this way, the speed of the overall picking operation can be increased.

Brief Description of the Drawings

[0028] [Figure 1] FIG. 1 is a plan view showing the whole of the picking system 1 of the first embodiment. [Figure 2] FIG. 2 is a plan view for explaining the details of one branch path 20 of the first embodiment. [Figure 3] FIG. 3 is an enlarged view of the first branch path 20i and the second branch path 20j in FIG. 1. [Figure 4] FIG. 4 is a configuration block diagram showing the outline of the control of the first embodiment. [Figure 5] FIG. 5 is a flowchart showing the control of the conveyance of the case of the picking system 1 of the first embodiment. [Modes for carrying out the invention]

[0029] 1. First Embodiment (1) Configuration of picking system 1 The picking system 1 of this embodiment is a system that takes items from cases containing goods and places them into shipping containers according to the type and quantity of goods for each shipping destination before shipping. As shown in Figure 1, the picking system 1 comprises a main transport route 10, multiple branch routes 20a to 20l, and a controller 40. Each branch route 20, 20a to 20l includes a picking station 23, 23a to 23l. Cases containing goods are transported along the main transport route 10 and carried to the picking station 23 of each branch route 20. At the picking station 23, goods are picked from the cases and placed into shipping containers. The shipping containers usually contain a predetermined number of multiple types of goods according to the order of the shipping destination. The shipping containers are further packaged, collected in a cart 6, and shipped out of the picking system 1 by the cart 6.

[0030] The main transport route 10 transports cases containing goods in a circular path in one direction. Each case contains one or more, usually many, items of the same type. A single case may contain many items of multiple types. The cases are dispatched from the automated warehouse 2. The dispatched cases are transported along the main transport route 10. Multiple cases containing the same items may be transported along the main transport route 10. In addition, the number of cases transported along the main transport route 10 may exceed the total number of items picked at each picking station.

[0031] Cases that have traveled along the main transport route 10 enter each branch route 20, are picked at the picking station 23 in each branch route 20, and are returned to the main transport route 10. Depending on the case, picking operations may be performed at multiple picking stations from a single case. Once all picking operations are complete, the case is returned to the automated warehouse 2 from the main transport route 10. The main transport route 10 has a branching point 11, a first merging point 12, and a second merging point 13 for each branch route 20. Cases transported along the main transport route 10 enter each branch route 20 at each branching point 11, are picked, or not picked, and return to the main transport route 10 at the first merging point 12 or the second merging point 13, and are transported along the main transport route 10 again.

[0032] As shown in Figure 2, the branching route 20 comprises a main branching route 21 and a bypass route 22. The main branching route 21 branches off from the branching point 11 of the main transport route 10 and merges with the first merging point 12 of the main transport route 10. Cases containing goods are transported in one direction along the main transport route 10 from the branching point 11 towards the first merging point. The bypass route 22 connects the buffer section 24 of the main branching route 21 and the second merging point 13 of the main transport route 10. Cases containing goods are transported in one direction along the bypass route 22 from the buffer section 24 towards the second merging point 13. The second merging point 13 is downstream of the branching point 11 and upstream of the first merging point 12 in the main transport route 10.

[0033] The main branching path 21 has a buffer section 24 and a picking station 23, arranged in order from the upstream side. Cases branched off from the main transport path 10 at branching point 11 proceed along the main branching path 21 and enter the buffer section 24. Cases destined for the picking station 23 are temporarily held in the buffer section 24. When the previous picking operation is completed and the picking station 23 is empty, the cases in the buffer section 24 are transported to the picking station 23.

[0034] At the picking station 23, picking is performed by an operator. The picking station 23 is equipped with a case detection sensor 23s that detects whether or not a case is present at the picking station 23. The case detection sensor 23s is an optical sensor. The case detection sensor 23s may also detect the presence of a case by another method. After the picking operation is completed, the case is sent from the picking station 23 along the main branch path 21 toward the main transport path 10, and merges with the main transport path 10 at the first merging point 12.

[0035] As already mentioned, the bypass route 22 connects the buffer section 24 to the second junction point 13 of the main transport route 10. Even if a case has been transported from the branching point 11 of the main transport route 10 to the branch route 20, if it needs to be returned to the main transport route 10 before reaching the picking station 23, it is possible to return the case to the main transport route 10 via the bypass route 22 from the buffer section 24.

[0036] In this specification, the term "bypass route" is used not only to refer to a physical path, but also to include the spatial route and control route of goods.

[0037] In this embodiment, the buffer section 24 is composed of a first position 241, a second position 242, and a third position 243, in order from the upstream side to the downstream side of the case flow. One case can be placed in each position 241 to 243. Therefore, the buffer section 24 can hold up to three cases at a time. The buffer section 24 may also be configured to hold only one or two cases, or four or more cases. The first position 241 is equipped with a switch 241c that changes the direction in which the cases are transported, and a case detection sensor 241s that detects whether or not a case is present at the first position 241. The case detection sensor 241s is an optical sensor. The case detection sensor 241s may detect the presence of a case by another method. Similarly, the second position 242 is equipped with a switch 242c and a case detection sensor 242s. Similarly, the third position 243 is equipped with a switch 243c and a case detection sensor 243s. Cases branching off from the branching point 11 of the main transport path 10 first enter and are held at the first position 241. If the second position 242 is empty, the case at the first position 241 is redirected by the switch 241c and transported to the second position 242. Similarly, if the third position 243 is empty, the case at the second position 242 is redirected by the switch 242c and transported to the third position 243. Similarly, if the picking station 23 is empty, the case at the third position 243 is redirected by the switch 243c and transported to the picking station 23.

[0038] In this embodiment, the bypass path 22 is connected to the second position 242 of the buffer section 24. Therefore, it is possible to immediately transport a case located at the second position 242 from the bypass path 22 to the main transport path 10. A case located at the first position 241 can be transported to the second position 242 and then pass through the bypass path 22. If the second position 242 is empty, it is also possible to return a case that has already moved to the third position 243 to the second position 242 before transporting it to the bypass path 22. The system may be configured so that a case cannot be returned from the third position 243 to the second position 242. Even if it is possible to return a case from the third position 243 to the second position 242, such reverse movement may be prevented during normal operation of the picking system 1. The connection position of the bypass path 22 may be the first position 241 or the third position 243. Generally speaking, the connection position of the bypass path 22 may be on the upstream side, downstream side, or in the middle reaches of the buffer section 24.

[0039] The controller 40 includes a computer. The controller 40 may consist of multiple computers. The multiple computers may be arranged in a hierarchical structure. For example, the main transport path 10 consists of multiple conveyors, and the computer that controls the transport of the picking system 1 may control the computers that control the drive of each conveyor. Furthermore, the computer that controls the transport may be configured to receive commands from higher-level computers that control the picking of each picking station 23. The higher-level computers may be located in the cloud.

[0040] As shown in Figure 4, the controller 40 is connected to the cargo transport means of each branch route 20, such as the first position switch 241c, the second position switch 242c, and the third position switch 243c of the buffer section of each branch route 20. The controller 40 controls these cargo transport means to control the transport of cargo in each branch route 20.

[0041] The controller 40 stores information such as the type and quantity of goods stored in the automated warehouse 2, and the type and quantity of goods contained in each case. Alternatively, it can access this information.

[0042] Meanwhile, the controller 40 receives the customer's order for goods (including the type and quantity of goods) from the computer that received the customer's order. Based on the storage information of the goods in the automated warehouse 2 and the customer's order information, the controller 40 creates an item dispatch plan. Alternatively, it may receive an item dispatch plan from another computer. The item dispatch plan includes details such as which types and quantities of goods in each case should be dispatched from the automated warehouse 2 and transported along the main transport route 10, and how to assign picking requests to each station 23.

[0043] The controller 40 controls the transport of cases along the main transport route and branch routes based on the outbound transport plan. Specifically, for example, it drives a conveyor to transport the cases.

[0044] The controller 40 receives information related to the transport of cases from various sensors. For example, as shown in Figure 4, the controller 40 is connected to station case detection sensors 23s, buffer section case detection sensors 241s to 243s, and other case detection sensors located on the main transport path 10 and branch path 20, and receives case position information from each sensor. From the information from these case detection sensors, the controller 40 calculates the time that a case has stayed, for example, at the picking station 23 or the buffer section 24.

[0045] (2) When using bypass route 22 In the picking system 1 of this disclosure, the bypass route 22 is used when a case that has entered the branch route 20 from the main transport route 10 is returned to the main transport route 10 without passing through the picking station 23, in order to transport the case to the picking station 23. In other words, it is used when there is some change in the picking operation.

[0046] The simplest case is when a case scheduled for picking at the picking station 23 is waiting in the buffer unit 24, and the picking of that case is canceled. In this case, the case is returned to the main transport path 10 via the bypass path 22 from the buffer unit 24. This eliminates the waste of passing cases that are not to be picked through the picking station 23.

[0047] Another case in which the bypass route 22 may be used is when an urgent picking request for a case arises at another picking station while the case is waiting in the buffer unit 24. This case will be explained next.

[0048] (3) Method for controlling the transport of a case containing articles using the bypass route 22 In this embodiment, a method for controlling the transport of cases containing items using a bypass route 22 will be described. Figure 5 is a flowchart showing an example of a method for controlling the transport of cases containing items using a bypass route 22.

[0049] First, it is assumed that picking operations are already underway in the picking system 1, which is equipped with multiple stations 23. Then, in response to a picking request from the first station 23i, a first case containing the first item is waiting in the first buffer unit 24i (S101).

[0050] In this state, let's assume that a picking request for the first case is generated at the second station 23j (S102).

[0051] In step S103, a decision is made as to whether to prioritize the picking request from the second station 23j over the picking request from the first station 23i. If the picking request from the first station 23i is prioritized, the process proceeds to step S111. In this case, the first case is transported directly to the first station 23i after waiting for it to become available. The first bypass route 22i is not used. The second station 23j receives either the first case after picking has been completed at the first station 23i or another first case.

[0052] If the picking request from the second station 23j is prioritized in step S103, the process proceeds to step S104. The first case is returned to the main transport path 10 via the first buffer section 24i and the first bypass path 22i. The first case, returned to the main transport path 10, is transported to the second branch path 20j and picked at the second station 23j.

[0053] By utilizing the bypass route 22 in this way, for example, if there is a delay in the picking operation at the first station, it contributes to reducing the overall picking time.

[0054] (Example 1) Here, a method for controlling the transport of cases containing articles using a bypass route will be explained with a more specific example.

[0055] In the picking system 1, as shown in Figure 1, case A containing item a, case B containing item b, case C containing item c, case D containing item d, case E containing item e, and case F containing item f circulate along the main transport path 10. The first branch path 20i, to which the first station 23i belongs, is located upstream in the transport of cases on the second branch path 20j, to which the second station 23j belongs.

[0056] At station 1, 23i, worker 1 is picking 10 units of item a, 5 units of item b, and 3 units of item c. Meanwhile, at station 2, 23j, worker 2 is picking 2 units of item a, 8 units of item b, and 5 units of item e.

[0057] The second worker has finished picking items a and e, and only item b remains to be picked. As shown in Figure 3, there are no cases at the second station 23j and the second buffer section 24j of the second branch route 20j. Meanwhile, the first worker is currently picking item a, but this task is taking a lot of time. Case C containing item c and case B containing item b are waiting at the first buffer section 24i of the first branch route 20i.

[0058] In this case, in this embodiment, case B is transported via the first bypass path 22i. Case B reaches the second station 23j via the first bypass path 22i, the main transport path 10, and the second buffer section 24j. The second worker can pick item b from case B and complete this picking operation. The first worker can complete the picking operation by being assigned either another case B (in Figure 1, case B is located on the main transport path 10) or a case B that has been picked by the second worker.

[0059] In this embodiment, by transporting cases using the bypass route 22i, the picking time of the second worker can be significantly reduced compared to the case where the bypass route 22i is not used (where the first worker picks case B, and then the second worker picks case B). On the other hand, the picking time of the first worker is likely to remain unchanged or only increase slightly. Overall, this leads to a reduction in picking time.

[0060] (4) Method for determining whether to prioritize other picking stations for cases in the buffer section. When there is a first case in the buffer section 24i of the first station 23i (S101), and a picking request for the first case arises for the other second station 23j (S102), the question becomes which picking operation, the first station 23i or the second station 23j, should be prioritized (S103). In the case shown in Embodiment 1 above, prioritizing the second station 23j is the case in which the total time required for the picking operation can be minimized.

[0061] The biggest question is how much longer it will take for the first worker to begin picking the first case. In other words, how long is it expected to take for the first case to arrive at station 23i?

[0062] The controller 40 receives case location information from the case detection sensor 23s of the picking station or the case detection sensors 241s to 243s of the buffer unit, and can calculate the time that the case stays at the picking station 23 or the buffer unit 24.

[0063] Furthermore, the controller 40 naturally knows how many items the first worker is picking from each case. The controller 40 may record and store the time it takes for the first worker to pick n items (where n is an integer) from one case, and calculate the average time required to pick n items from one case. Then, for the case that the first worker is currently working on, the controller 40 may calculate the time required for the remaining picking work. In this way, the average picking time of the first worker (time spent at the picking station for each case) can be calculated, and the remaining picking time can be predicted by subtracting the picking time to date (time spent at the picking station for each case).

[0064] In the first embodiment, in the first branching path 20i, the first worker must complete picking not only for case A but also for case C before the target case B reaches the picking station 23 from the buffer unit 24i. In any case, the average work time per case can be calculated from the first worker's recorded work time, and then the time spent by cases already at the picking station 23 can be subtracted to determine the time until the target case reaches the picking station.

[0065] The picking time per case at a picking station may be determined uniformly, regardless of the type of case. Alternatively, the picking time per case may be determined based on the number of items, regardless of the type of case. Or, the picking time per case may be the same regardless of the type or number of items.

[0066] Furthermore, if the estimated time required for the first case in the first buffer unit to reach the first station exceeds a predetermined time, the request for the first case from the second station may be prioritized. In this case, the first case will be transported to the first bypass route.

[0067] Furthermore, in the decision made in step S103, the number of specified items in the first case at the first station may be taken into consideration whether or not the number of items requested at the second station exceeds the number of items requested at the second station. For example, even if it is decided in step S103 to prioritize the picking request at the second station, if the number of specified items in the first case at the first station is less than the number of items requested at the second station, the process may proceed to step S111 and send the first case directly to the first picking station.

[0068] Furthermore, in the above explanation, when the first case is in the first buffer section (S101), a picking request for the first case is generated at the second station (S102), and the second station appears to be able to process the picking request faster than the first station, in step S103, it is determined to prioritize the picking request of the second station, and the first case is transported via the first bypass route (S104). However, for example, if another first case appears to be able to reach the second station faster, in step S103, No may be selected, and the process may proceed to step S111, allowing the first case to proceed to the first station. An example of a case appearing to be able to reach the second station faster is when another first case is located upstream of the second station on the main transport route.

[0069] (4-1) Modified Embodiment 1 In the modified embodiment 1, the determination method in step S103 differs from that of the first embodiment.

[0070] Based on the detection information from the buffer unit's case detection sensors 241s to 243s, the controller 40 measures the dwell time of the target first case in the first buffer unit 24i. If the dwell time is longer than a predetermined time, the controller 40 determines in step S103 to prioritize the picking request at the second station.

[0071] This method is a simple way to determine whether to prioritize Station 1 or Station 2.

[0072] (4-2) Modified Embodiment 2 In the modified embodiment 2, the determination method in step S103 differs from that of the first embodiment and the modified embodiment 1.

[0073] Based on the detection information from the case detection sensor 23s of the first station, the controller 40 measures the dwell time of the case currently in the first station 23i. If the dwell time is longer than a predetermined time, the controller 40 determines in step S103 to prioritize the picking request at the second station.

[0074] This method is a simple way to determine whether to prioritize Station 1 or Station 2.

[0075] (4-3) Modified Embodiment 3 In the modified embodiment 3, it is assumed that multiple cases can be arranged from upstream to downstream in the buffer section 24. Furthermore, the determination method in step S103 of the modified embodiment 3 differs from that of the first embodiment and modified embodiments 1 and 2.

[0076] The controller 40 counts the number of cases between the target first case and the first station 23i based on the detection information from the case detection sensors 241s to 243s in the buffer unit and the picking information from the first station 23i.

[0077] If the number of cases is greater than or equal to a predetermined number, the controller 40 determines in step S103 to prioritize the picking request at the second station.

[0078] This method is a simple way to determine whether to prioritize Station 1 or Station 2.

[0079] (4-4) Modified Embodiment 4 In modified embodiment 4, it is assumed that multiple cases can be arranged from upstream to downstream in the buffer section 24. Furthermore, the determination method in step S103 of modified embodiment 4 differs from that of the first embodiment and modified embodiments 1 to 3.

[0080] The controller 40 detects cases between the target first case and the first station 23i based on the detection information from the case detection sensors 241s to 243s in the buffer unit and the picking information from the first station 23i. The controller 40 further calculates the number of items to be picked for the cases between the first case and the first station 23i based on the detection information from the case detection sensors and the picking information.

[0081] If the total number of items to be picked is equal to or greater than a predetermined number, the controller 40 determines in step S103 to prioritize the picking request at the second station.

[0082] This method is a simple way to determine whether to prioritize Station 1 or Station 2.

[0083] (4-5) Modified Embodiment 5 In modified embodiment 5, the determination method in step S103 differs from that of the first embodiment and modified embodiments 1 to 4. In this modified embodiment, the second station is not limited to station 23j, but can be any other station 23a to 23h, 23j to 23l other than the first station 23i.

[0084] In the flowchart of Figure 5, let's assume that in step S102, the second station is not the station 23j downstream of the first branch route 20i, but rather a station belonging to the branch route 20h upstream of the first branch route 20i. Branch route 20h is adjacent to the upstream side of the first branch route 20i. Transporting the case from the first branch route 20i to branch route 20h along the main transport route 10, which is a circular route, takes a lot of time. Therefore, in step S103, instead of prioritizing the picking request at the second station, we may proceed to step S111 and prioritize the work at the first station 23i on the first case.

[0085] In this modified embodiment, the criterion for deciding whether to prioritize the first station or the second station in S103 is whether the second station is downstream of the first station. If the second station is downstream of the first station, it may be decided to prioritize the second station.

[0086] Since the main transport path 10 in this embodiment is a circular path, it is not simple to determine whether the second station is downstream of the first station 23i. The determination may be made as follows: The station that comes first in the sequence from the downstream side when counting from either the upstream side or the downstream side from the first station 23i may be counted as the downstream side. In the case of Figure 1, stations 23j, 23k, 23l, 23a, and 23b may be considered stations located downstream of the first station 23i. Alternatively, a station may be determined to be downstream of the first station if the time it takes to transport a case along the main transport path 10 from the first branch path 20i to the branch path 20 to which the second station belongs is within a predetermined time.

[0087] The above explains whether the two stations 23 are upstream or downstream, but the exact same explanation can be given if station 23 is replaced with branch route 20.

[0088] This method is a simple way to determine whether to prioritize Station 1 or Station 2.

[0089] Furthermore, the method of this modified embodiment may be combined with the methods of the first embodiment or modified embodiments 1 to 4 to perform the determination in step S103. For example, when combined with modified embodiment 2, it may be done as follows.

[0090] First, the controller 40 determines whether the second station is a downstream station of the first station 23i. If it determines that the second station is not a downstream station of the first station 23i, the process proceeds to step S111.

[0091] If the controller determines that the second station is downstream of the first station 23i, it proceeds to the next step. Next, if the controller determines that the time the case has been at the first station 23i is longer than a predetermined time, it decides to prioritize the picking request at the second station and proceeds to step S104. If the time the case has been at the first station is less than the predetermined time, it decides to prioritize the picking request at the first station and proceeds to step S111.

[0092] (4-6) Modified Embodiment 6 In modified embodiment 6, the determination method in step S103 differs from that of the first embodiment and modified embodiments 1 to 4. In this modified embodiment, the second station is not limited to station 23j, but can be any other station 23a to 23h, 23j to 23l other than the first station 23i.

[0093] In step S103, the controller calculates the time required to transport the first case from the first branch route 20i through the main transport route to the second branch route. If the controller determines that the calculated transport time is less than or equal to a predetermined time, it decides to prioritize the picking request at the second station.

[0094] (4-7) Modified Embodiment 7 In the first embodiment and modified embodiments 1 to 6, it was explained that there are various criteria for deciding whether to prioritize the first station 23i or the second station in step S103 of Figure 5. Modified embodiment 6 makes the decision in step S103 using machine learning.

[0095] Specifically, the decision in step S103 is made such that the sum of the time required to complete the picking operation, including the first case, currently being performed by the first worker at the first station 23i, and the time required to complete the picking operation, including the first case, currently being performed by the second worker at the second station, is smaller.

[0096] Machine learning is preferable for predicting the total time mentioned above.

[0097] For machine learning, the input parameters may include one or more of the following, or a combination thereof: the positional relationship between the first and second stations as described in Modified Embodiment 5; the time currently being spent by the first worker on the case being picked as described in Modified Embodiment 2; and the quantity of items and cases to be picked by the first worker before commencing picking of the first case as described in Modified Embodiment 3 or 4. The total time described above is suitable as the output parameter for machine learning.

[0098] The controller may accumulate combinations of such input parameters and the decisions and output parameters in step S103, and then perform machine learning based on these to make decisions in step S103.

[0099] By utilizing machine learning, optimal decisions can be made, leading to a higher probability of success and reduced picking time. 2. Characteristics of the Embodiment

[0100] (1) The picking system 1 of this embodiment picks items from cases containing items and places them into shipping cases. The picking system 1 includes a main transport route 10 and a plurality of branch routes 20. The main transport route 10 transports cases in a circular path in one direction. Each branch route 20, 20a to 20l branches off from the main transport route 10 and rejoins the main transport route 10.

[0101] Each branch route 20, 20a to 20l has a main branch route 21 and a bypass route 22. The main branch route 21 branches off from the branching point 11 of the main transport route 10 and merges with the main transport route 10 at the merging point 12. The bypass route 22 connects a point along the main branch route 21 to the main transport route 10.

[0102] The main branching route 21 includes a station 23 and a buffer section 24. The station 23 is located in the middle of the main branching route 21 and picks items from cases. The buffer section 24 is located upstream of the station 23 on the main branching route 21 and temporarily holds cases containing items.

[0103] The bypass route 22 is a route for transporting cases containing goods from the buffer unit 24 to the main transport route 10 without passing through the station 23.

[0104] The picking system 1 of this embodiment has a bypass route 22, so that cases containing items that have entered the branch route 20 can be returned to the main transport route 10 without passing through the picking station 23. Therefore, it becomes possible to transport cases containing items according to the progress of the picking work at each picking station, and the picking work time can be shortened.

[0105] (2) The buffer section 24 of the picking system 1 may be configured to hold multiple cases at once. The buffer section 24 of this embodiment has a first position 231, a second position 232, and a third position 233 on the main branch path 21, from the upstream side away from the picking station toward the downstream side. The first position 231, the second position 232, and the third position 233 can each hold one case.

[0106] When the buffer unit 24 has positions that hold multiple cases, a position upstream of the downstream position (third position 233 in this embodiment) (second position 232 in this embodiment) may be connected to the bypass path 22.

[0107] At the multiple case holding positions of the buffer section 24, the further upstream the position is from the picking station, the longer the time it takes to reach the picking station. Therefore, the further away from the picking station a position is, the more significantly the time it takes to return from that position to the main transport path 10 can be reduced by using the bypass path 22. Conversely, at positions close to the picking station, the time reduction effect from using the bypass path 22 to return from that position to the main transport path 10 is not very significant. For this reason, in this embodiment, the second position 232, which is upstream of the furthest downstream position, is connected to the bypass path 22.

[0108] (3) The picking system 1 further includes a controller 40. The controller 40 controls the transport of cases on the main transport path 10 and on the branch path 20. The controller 40 assigns cases containing items to each station 23 in response to picking requests.

[0109] Assume that when there is a first case containing the first item in the first buffer section 24i of the first branch route 20i (S101), a picking request for the first case containing the first item occurs at the second station 23j belonging to the second branch route 20j (S102). At this time, the controller 40 determines whether or not to prioritize the picking request at the second station 23j (S103). If it determines that the picking request at the second station 23j should be prioritized, the controller 40 transports the case from the first buffer section 24i to the main transport route 10 via the bypass route 22i (S104).

[0110] (4) The picking station 23 has a case detection sensor 23s that determines whether or not a case is present in the station 23. The buffer unit 24 has case detection sensors 241s to 243s that determine whether or not a case is present in the buffer unit 24.

[0111] The controller 40 calculates the time a case stays at station 23 based on the detection results of the station case detection sensor 23s. The controller 40 also calculates the time a case stays at buffer section 24 based on the detection results of buffer section case detection sensors 241s to 243s.

[0112] The controller 40 measures and stores the time an operator spends on each picking task based on the time a case stays at the station.

[0113] When the first case is in the first buffer unit 24i and a picking request for the first case is made at the second station 23j, the controller 40 measures the time the case is currently in the first station 23i, and based on the measured time and the stored picking time of the worker, predicts the time until the worker starts picking the first case. If the predicted time is longer than or equal to a predetermined time, the controller 40 decides to prioritize the picking request at the second station 23j.

[0114] By collecting and storing the picking time for each case by the worker in advance, and comparing it with the time spent on cases currently in progress, it is possible to accurately predict the time it will take for the worker to begin picking cases in the first buffer section.

[0115] Furthermore, the accuracy of predictions can be further improved by measuring and utilizing the picking time of workers for each item in a case.

[0116] Furthermore, the prediction accuracy can be further improved by predicting the picking time for cases located downstream of the first case before the worker reaches the first station 23i, which is before the first case is reached. The picking time prediction utilizes the picking time for each case by the worker, which has been collected and stored in advance.

[0117] (5) When there is a first case containing the first item in the first buffer section 24i of the first branch route 20i (S101), when a picking request for the first case containing the first item occurs at the second station 23j belonging to the second branch route 20j (S102), the controller 40 may make a simpler decision on whether to prioritize the picking request at the second station 23j (S103).

[0118] Specifically, the controller 40 may, based on information from buffer unit case detection sensors 241s to 243s, measure the dwell time of the first case in the first buffer unit 24i, and if the dwell time is longer than a predetermined time, it may decide to prioritize the picking request at the second station 23j.

[0119] Alternatively, the controller 40 may, based on information from the station case detection sensor 23s, measure the dwell time of the case at the first station 23i, and if the dwell time is longer than a predetermined time, decide to prioritize the picking request at the second station 23j.

[0120] Alternatively, the controller 40 may count the number of cases between the first case and the first station 23i based on the information from the buffer unit case detection sensors 241s to 243s and the picking information, and if the number of cases is greater than or equal to a predetermined number, it may decide to prioritize the picking request at the second station.

[0121] Alternatively, the controller 40 may calculate the number of items to be picked for the cases between the first case and the first station 23i based on the detection information from the buffer unit case detection sensors 241s to 243s and the picking information, and if the total number of items to be picked is equal to or greater than a predetermined number, it may decide to prioritize the picking request at the second station 23j.

[0122] Alternatively, the controller 40 may decide to prioritize the picking request at the second station if it determines that the second station is downstream of the first station 23i.

[0123] (6) In step S103 of Figure 5, the following methods can be considered for deciding whether to prioritize the first station 23i or the second station.

[0124] Specifically, the decision in step S103 is made such that the sum of the time required to complete the picking operation, including the first case, currently being performed by the first worker at the first station 23i, and the time required to complete the picking operation, including the first case, currently being performed by the second worker at the second station, is smaller.

[0125] Machine learning can be used to predict the total time. When performing machine learning, one or more or a combination of the following may be used as input parameters: the positional relationship between the first station and the second station as described in Modified Embodiment 5, the time the first worker is currently taking to pick the case as described in Modified Embodiment 2, and the quantity of items and cases that the first worker should pick before starting to pick the first case as described in Modified Embodiment 3 or 4. The total time is suitable as the output parameter for machine learning. The controller may accumulate combinations of such input parameters and the judgment and output parameters of step S103, and perform machine learning based on this to make the judgment in step S103.

[0126] By utilizing machine learning, optimal decisions can be made, leading to a higher probability of success and reduced picking time.

[0127] 3. Other Embodiments Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention. Furthermore, the multiple embodiments and modified embodiments described herein can be combined as needed. [Industrial applicability]

[0128] This disclosure can be applied to a picking system that picks and ships items from an automated warehouse according to their destination. [Explanation of symbols]

[0129] 1. Picking System 10 Main transport route 11 Branching points 12 First confluence point 13 Second confluence point 20, 20a~20l Branch Route 20i First branch route 20j Second branch route 21 Main branch route 22 Bypass Route 22i First Bypass Route 23, 23a-23l (Picking) Station 23s Picking station case detection sensor 23i 1st (Picking) Station 23j Second (Picking) Station 24 Buffer section 24i First Buffer Section 24j Second Buffer Section 241 Buffer section first position 242 Second position of the buffer section 243 Third position of the buffer section 241c Switching mechanism for the first position of the buffer section 242c Switching mechanism for the second position of the buffer section 243c Switching mechanism for the third position of the buffer section 241s Case detection sensor at the first position of the buffer section 242s Case detection sensor at the second position of the buffer section 243s Case detection sensor at the third position of the buffer section 40 controllers

Claims

1. A picking system for picking items from cases containing items, A main transport path that transports cases in a circular motion in one direction, Multiple branching paths, each branching path branching off from the main transport path and merging back into the main transport path, Equipped with, Each of the aforementioned branching paths is, A main branching path that branches off from the branching point of the main transport path and merges with the main transport path at the merging point, A bypass route connecting the main branch route and the main transport route, It has, The main branching path includes a station for picking items from cases transported along the main branching path, and a buffer section located upstream of the station on the main branching path for temporarily holding cases containing items. The bypass route is a route for transporting cases containing articles from the buffer section to the main transport route without passing through the station. The picking system further includes a controller that controls the transport of cases along the main transport path and the branch paths. The controller assigns a case containing the items to each station in response to a picking request. When there is a first case containing a first item in the first buffer section upstream of the first station in the first branch route, and a picking request for the first case containing the first item is generated at the second station belonging to the second branch route, The controller determines whether to prioritize the picking request at the second station, and if it determines to prioritize the picking request at the second station, The controller transports the first case from the first buffer unit to the main transport path via the bypass path. Picking system.

2. The buffer section further includes a buffer section case detection sensor that determines whether or not a case is present in the buffer section. The controller measures the dwell time of the first case in the first buffer based on the information from the buffer case detection sensor. The controller determines that if the dwell time is longer than a predetermined time, it will prioritize the picking request at the second station. The picking system according to claim 1.

3. The system further includes a station case detection sensor that determines whether or not a case is present at the station. The controller measures the dwell time of the case at the first station based on the information from the station case detection sensor. The controller determines, when a picking request is received at the second station, to prioritize the picking request at the second station if the dwell time of the case is longer than a predetermined time. The picking system according to claim 1.

4. The first buffer unit is capable of waiting for multiple cases in order from the side closest to the first station, The first buffer unit is equipped with a buffer unit case detection sensor capable of detecting cases that are in standby in the first buffer unit. The controller counts the number of cases between the first case and the first station based on the information from the buffer unit case detection sensor and the picking information. The controller determines that if the number of cases is greater than or equal to a predetermined number, it will prioritize the picking request at the second station. The picking system according to claim 1.

5. The first buffer unit can hold multiple cases in order from the side closest to the first picking station. The first buffer unit is equipped with a buffer unit case detection sensor capable of detecting cases that are in standby in the first buffer unit. The controller detects cases between the first case and the first picking station based on the information from the buffer unit case detection sensor and the picking information. The controller calculates the number of items to be picked for the cases between the first case and the first station based on the detection information from the buffer unit case detection sensor and the picking information, and determines that the picking request at the second station should be prioritized if the total number of items to be picked is equal to or greater than a predetermined number. The picking system according to claim 1.

6. The system further includes a station case detection sensor that determines whether or not a case is present at the first station. The controller measures the dwell time of the case at the first station based on the information from the station case detection sensor. The controller measures and stores the work time for each picking task performed by the worker at the first station based on the dwell time. When the first case is in the first buffer unit, and a picking request for the first case is made at the second station, The controller currently measures the time spent in the case at the first station. Based on the measured dwell time and the worker's picking time, the time until the worker begins picking the first case is predicted, and if the predicted time is longer than a predetermined time, it is decided to prioritize the picking request at the second station. The picking system according to claim 1.

7. When there is a first case containing the first item in the first buffer section of the first branch route, and a picking request for the first case containing the first item is generated at the second station belonging to the second branch route, The controller determines that the time required to transport the first case from the first branch path along the main transport path to the second branch path is less than or equal to a predetermined time, and therefore decides to prioritize the picking request at the second station. The picking system according to claim 1.

8. When there is a first case containing the first item in the first buffer section of the first branch route, and a picking request for the first case containing the first item is generated at the second station belonging to the second branch route, The controller uses machine learning to predict the total time required to complete the picking operation at the first station and the total time required to complete the picking operation at the second station, under the cases of prioritizing the first station versus prioritizing the second station, and selects which station to prioritize, the first station or the second station, in order to minimize the total time. The picking system according to claim 1.

9. The system further includes a controller that controls the transport of cases along the main transport path and branch paths. The controller assigns a case containing the items to each station in response to a picking request. When there is a first case containing a first item in the first buffer section of the first branch path, and the allocation request for the first case of the first branch path is released, The controller causes the cargo to be transported from the first buffer unit to the main transport path via the bypass path. The picking system according to claim 1.

10. The buffer unit is A downstream buffer section located on the main branch path, which temporarily holds cases to be transported to the station, An upstream buffer section located upstream of the downstream buffer section on the main branch path, which temporarily holds the case, Includes, The upstream buffer section is connected to the bypass path. The picking system according to claim 1.

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