Conveying system, control device, and control method

Abstract

In a transport environment where any target location candidate can be determined (selected) as the target location from multiple candidate locations, congestion is less likely to occur, thereby preventing a decrease in transport efficiency. [Solution] For a target workpiece that is one of several workpieces, if there are multiple target position candidates corresponding to a specified task, the control device selects a target position candidate for the target workpiece according to a first selection logic based on the load of each target position candidate if the load of each of the multiple target position candidates is less than a predetermined threshold. If the load of each of the multiple target position candidates is greater than or equal to a predetermined threshold, the control device selects a target position candidate for the target workpiece according to a second selection logic based on a relational value which is the relative relationship of the loads between the target position candidates.

Description

[Technical Field]

[0001] This invention generally relates to a technology for transporting objects by the movement of a transport device. [Background technology]

[0002] In logistics centers, the process of picking items (e.g., goods) corresponding to orders from various storage facilities, sorting them into packing units, and filling order containers is a highly laborious task that involves moving items between different storage facilities. In particular, with the expansion of the e-commerce market, problems such as a shortage of workers in logistics centers are arising, making there a high need to reduce the workload.

[0003] Therefore, even when the storage locations of multiple items corresponding to an order span multiple storage facilities, there are transport systems that automate sorting work using transport devices such as AGVs (Automatic Guided Vehicles) to reduce the workload of sorting. Specifically, the transport device loads order containers (e.g., cardboard boxes) corresponding to the orders, circulates through workstations (typically workspaces where workers are positioned) in each storage facility, and collects the items corresponding to the orders into the order containers. This makes it possible to perform sorting work without workers having to move, even when the storage locations of multiple items corresponding to an order span multiple storage facilities. Furthermore, even when multiple items are stored in the same storage facility, such a transport system can be utilized if their storage locations are far apart from each other.

[0004] In such a transport system, the control device of the transport device sequentially sets the next target location each time the transport device moves. Specifically, for example, (a) to (f) below are performed. (c) and (d) are repeated as needed. (a) The control device determines the work area where the order containers will be loaded as the target position of the conveying device, and sets the determined target position to the conveying device. (b) The transport device moves to the work area (target location) and the loading of the order containers is completed. (c) The control device determines the work station of the storage facility as the target location of the conveying device and sets the determined target location to the conveying device. (d) The transport device moves and arrives at the work station (destination location), and the collection of items is completed. If collection at another work station is required, return to (c). (e) Once all items have been collected, the control device determines the packing area for packing the order containers as the target location and sets the determined target location to the conveying device. (f) The conveying device moves to the packing area (target location) and packing is performed.

[0005] In setting the target location (for example, in any of (a), (c), and (e)), it may be possible to determine (select) any target location candidate from multiple candidate locations. For example, if there are multiple work areas for loading similar order containers, it is acceptable to set any of the work areas as the target location. However, depending on the determined target location, a particular location may become congested with conveying devices, leading to congestion and a decrease in conveying efficiency. As a technology aimed at suppressing the decrease in conveying efficiency due to congestion of conveying devices, for example, there is the technology described in Patent Document 1. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2023-177468 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] According to the technology described in Patent Document 1, by selecting the work area with fewer surrounding conveying devices as the target location, it is expected that congestion will not occur around the work area.

[0008] However, in reality, congestion may not occur even if there are many conveying devices around the work area, or conversely, congestion may occur even if there are few conveying devices in the surrounding area.

[0009] A typical example of the former case is when there are no other conveyors traveling across a queue of multiple conveyors heading towards a work area. In such cases, even if many conveyors form a queue in front of the work area, they do not obstruct the movement of other conveyors, and therefore do not cause any actual congestion.

[0010] A typical example of the latter case is when other conveyors are traveling in a line that has formed from a small number of conveyors heading towards a work area. In such cases, even if there are only a few conveyors heading towards the work area, they can obstruct the movement of other conveyors, potentially causing actual congestion.

[0011] The technology described in Patent Document 1 cannot consider whether selecting the target position of a conveying device will obstruct the passage of other conveying devices. Therefore, congestion cannot be prevented in the cases described above.

[0012] In light of these circumstances, the object of the present invention is to prevent congestion from occurring in a transport environment in which any target position candidate can be determined (selected) as the target position from among a plurality of target position candidates, thereby preventing a decrease in transport efficiency. [Means for solving the problem]

[0013] For a target workpiece that is one of a plurality of workpieces, when there are a plurality of target position candidates corresponding to a specified operation as the plurality of target position candidates for the target workpiece, if the load for each of the plurality of target position candidates is less than a predetermined threshold value, the control device selects a target position candidate as the target position of the target workpiece according to a first selection logic based on the load for each target position candidate. If the load for each of the plurality of target position candidates is equal to or greater than the predetermined threshold value, the control device selects a target position candidate as the target position of the target workpiece according to a second selection logic based on a relation value that is a relative relation of the loads between the target position candidates.

Advantages of the Invention

[0014] According to the present invention, in a conveying environment where an arbitrary target position candidate can be determined (selected) as the target position from a plurality of target position candidates, congestion is unlikely to occur, and thus a decrease in conveying efficiency can be prevented. Problems, configurations, and effects other than those described above will be clarified by the description of the embodiments for carrying out the following invention.

Brief Description of the Drawings

[0015] [Figure 1] It is a diagram showing an outline of a plurality of types of areas in the first embodiment. [Figure 2] It is an explanatory diagram of the configuration of the moving area. [Figure 3A] It is a diagram showing an example of loading on a conveying device and the conveying device. [Figure 3B] It is a diagram showing another example of loading on a conveying device and the conveying device. [Figure 4A] It is a schematic diagram showing an example of the flat placement area. [Figure 4B] It is a schematic diagram showing an example of the automated warehouse area. [Figure 4C] It is a schematic diagram showing an example of the shelf conveying area. [Figure 4D] It is a schematic diagram showing an example of the flow rack area. [Figure 5] It is a schematic diagram showing an example of the packing area. [Figure 6]This figure shows some specific examples of the configuration of elements in a transport system. [Figure 7] This figure shows the remaining specific configuration examples of elements in a transport system. [Figure 8] This figure shows an example of the order table configuration. [Figure 9] This figure shows an example of the structure of an inventory table. [Figure 10] This figure shows an example of the storage area table configuration. [Figure 11] This figure shows an example of the configuration of a conveying device table. [Figure 12] This figure shows an example of the configuration of a movement area table. [Figure 13] This figure shows an example of the configuration of the shipping box table. [Figure 14] This figure shows an example of the configuration of a loading operation management table. [Figure 15] This figure shows an example of the configuration of a picking work management table. [Figure 16] This is a flowchart showing part of the order processing flow. [Figure 17] This is a flowchart showing part of the order processing flow. [Figure 18] This is a flowchart showing part of the order processing flow. [Figure 19] This is a flowchart showing part of the order processing flow. [Figure 20] This is a flowchart showing part of the order processing flow. [Figure 21] This is a flowchart showing part of the order processing flow. [Figure 22] This is a flowchart showing the process for selecting a shipping box. [Figure 23] This flowchart shows the control flow for selecting one target location candidate from multiple target location candidates and transporting the transport device to that target location. [Figure 24A] This is a schematic diagram illustrating the method for evaluating the degree of obstruction to traffic. [Figure 24B]This is a schematic diagram illustrating the method for evaluating the degree of obstruction to traffic. [Figure 25A] This is a schematic diagram illustrating a method for evaluating travel costs. [Figure 25B] This is a schematic diagram illustrating a method for evaluating travel costs. [Figure 26] This is a schematic diagram illustrating the determination of a target location while balancing the degree of obstruction to traffic and the cost of travel. [Figure 27] This is a schematic diagram of a target location determination method in which one target location candidate is selected from multiple target location candidates to be the target location of the conveying device. [Figure 28A] This figure shows examples of variations in the target location. [Figure 28B] This figure shows examples of variations in the target location. [Figure 29] This shows the sequence of events involved in the OTP-GTP synchronization logic. [Figure 30A] This is a schematic diagram illustrating an example of a deadlock. [Figure 30B] This is a schematic diagram illustrating an example of a deadlock. [Figure 30C] This is a schematic diagram illustrating an example of a deadlock. [Figure 31A] This is a schematic diagram illustrating an example of a deadlock. [Figure 31B] This is a schematic diagram illustrating an example of recovery from a deadlock. [Modes for carrying out the invention]

[0016] In the following explanation, "interface device" may refer to one or more interface devices. These one or more interface devices may be at least one of the following: • One or more I / O (Input / Output) interface devices. An I / O (Input / Output) interface device is an interface device to at least one of the following: an I / O device and a remote display computer. The I / O interface device to the display computer may be a communication interface device. The at least one I / O device may be either a user interface device, such as an input device like a keyboard and a pointing device, or an output device like a display device. • One or more communication interface devices. One or more communication interface devices may be one or more identical communication interface devices (e.g., one or more NICs (Network Interface Cards)) or two or more different communication interface devices (e.g., a NIC and an HBA (Host Bus Adapter)).

[0017] Furthermore, in the following explanation, "memory" refers to one or more memory devices, which are examples of one or more storage devices, and may typically be main memory devices. At least one memory device in memory may be a volatile memory device or a non-volatile memory device.

[0018] Furthermore, in the following explanation, "persistent storage device" may refer to one or more persistent storage devices, which are examples of one or more storage devices. Persistent storage devices are typically non-volatile storage devices (e.g., auxiliary storage devices), and specifically may be, for example, HDDs (Hard Disk Drives), SSDs (Solid State Drives), NVME (Non-Volatile Memory Express) drives, or SCMs (Storage Class Memory).

[0019] Furthermore, in the following explanation, "storage device" may also be "memory" and / or "persistent storage device".

[0020] Furthermore, in the following explanation, "processor" may refer to one or more processor devices. At least one processor device may typically be a microprocessor device such as a CPU (Central Processing Unit), but may also be other types of processor devices such as a GPU (Graphics Processing Unit). At least one processor device may be single-core or multi-core. At least one processor device may be a processor core. At least one processor device may be a broad-sense processor device such as a circuit that is a collection of gate arrays according to a hardware description language that performs some or all of the processing (e.g., FPGA (Field-Programmable Gate Array), CPLD (Complex Programmable Logic Device), or ASIC (Application Specific Integrated Circuit)).

[0021] Furthermore, in the following explanation, the term "xxx table" may be used to describe information from which an output is obtained for a given input. This information can be data of any structure (for example, structured or unstructured data), or it can be a neural network that generates an output for a given input, or a learning model such as a genetic algorithm or random forest. Therefore, "xxx table" can be referred to as "xxx information." Also, in the following explanation, the structure of each table is just an example; one table may be divided into two or more tables, or all or part of two or more tables may be a single table.

[0022] Furthermore, in the following explanation, the subject of the process may be "program," but since a program is executed by a processor and performs defined processes using memory and / or interface devices as appropriate, the subject of the process may also be the processor (or the computer, device, or system having that processor). A program may be installed from a program source into a device such as a computer. The program source may be, for example, a program distribution server or a recording medium readable by a computer (e.g., a non-temporary recording medium). Also, in the following explanation, two or more programs may be implemented as a single program, or one program may be implemented as two or more programs.

[0023] Furthermore, any information (for example, at least one of "ID," "name," and "number") may be used as information to identify an element (identification information, identifier).

[0024] Furthermore, in the following explanation, when describing similar elements without distinction, the common reference code will be used, and when describing similar elements with distinction, the reference code will be used.

[0025] Furthermore, in the following explanation, the unit of "date and time" can be either a coarser or finer unit than year, month, day, hour, and minute.

[0026] Several embodiments of the present invention will be described below. <First Embodiment>

[0027] The transport system in the first embodiment of the present invention will be described with reference to Figures 1 to 26.

[0028] Figure 1 is a diagram illustrating the schematic of multiple types of areas in the first embodiment. The multiple types of areas shown in Figure 1 may be, for example, parts of a logistics facility (e.g., a warehouse or a distribution center). A logistics facility is, for example, a storage facility used by a mail-order company or a machinery manufacturer to store goods. The goods stored in the logistics facility may be, for example, products or parts.

[0029] The transport system comprises multiple transport devices 3 that travel within a mobile area 150, and a control device 4 that remotely controls the movement of each transport device 3. Shipping boxes 87 (see Figures 3A and 3B) are loaded onto the transport devices 3, and goods (e.g., products or parts) are placed into the shipping boxes 87. A "shipping box 87" is a container (e.g., a box) into which goods that will be packed into the same box (e.g., a cardboard box) as a shipping unit (packaging unit) are placed, and may also be called an "order container." Goods that will be packed into different boxes as shipping units are not placed in the same shipping box 87, but are placed in the corresponding shipping boxes 87 for each shipping unit. Once all the goods are in the shipping boxes 87, the goods in the shipping boxes 87 are inspected, packed, and then shipped. The goods in the shipping boxes 87 may be transferred to the shipping box (e.g., a cardboard box) by a worker or a robot, packed, and shipped. Alternatively, the shipping box 87 may be the shipping box itself.

[0030] The moving area 150 includes an inspection area 103, a charging area 104, a waiting area 105, and an abnormality response area 106. The inspection area 103 is the area where the goods in the shipping boxes 87 loaded on the conveying device 3 are inspected. The charging area 104 is the area where the conveying device 3 is charged. The waiting area 105 is the area where the conveying device 3 is on standby. The abnormality response area 106 is the area where any abnormalities in the conveying device 3 are addressed. At least one of areas 103 to 106 may be located outside the moving area 150. In addition, other areas may be provided inside or outside the moving area 150 in place of or in addition to at least one of areas 103 to 106. Furthermore, in this embodiment, inspection is performed when the conveying device 3 passes through the inspection area 103 within the moving area 150, but alternatively, it may be performed after the goods have been handed over to the packing area 102 (in this case, there may be no inspection area 103 in the moving area 150, and the packing area 102 may also serve as the inspection area).

[0031] Outside the moving area 150, there is a shipping box supply area 100, multiple storage areas 101, and a packing area 102. The shipping box supply area 100 is the area where shipping boxes 87 are supplied, and the shipping boxes 87 are loaded onto the conveying device 3. In this embodiment, it is assumed that empty shipping boxes 87 are supplied in the shipping box supply area 100, but shipping boxes 87 may be supplied with some items already inside, such as items acquired outside the conveying system, to be packed into the same box as a shipping unit. The storage area 101 is the area where items are stored (arranged). The packing area 102 is the area where shipping boxes 87 containing items are packed.

[0032] Multiple storage areas 101 differ in at least one of the following: storage method, retrieval method, or picking method. Examples of multiple storage areas 101 include the flat storage area 101A, the automated warehouse area 101B, the shelf transport area 101C, and the flow rack area 101D. Storage areas 101A to 101D will be described later.

[0033] Figure 2 is an explanatory diagram of the configuration of the movement area 150. For convenience, the two-dimensional directions are defined as the x-direction and the y-direction perpendicular to the x-direction.

[0034] The movement area 150 may be divided and managed into multiple rectangular sections 201 of a predetermined size. The sections 201 can be represented as sections (α, β). α is the x-coordinate (section position along the x-direction), and β is the y-coordinate (section position along the y-direction).

[0035] Furthermore, if the moving area 150 includes areas on multiple floors or areas above and below a mezzanine, the height position of each area can be represented by using the z-coordinate. In this case, the section 201 may be in a coordinate format such as section(α, β, γ). α is the x-coordinate (section position along the x-direction), β is the y-coordinate (section position along the y-direction), and γ is the z-coordinate (area position in the height direction). When the moving area 150 extends to multiple floors, transportation between floors, or transportation between the upper and lower parts of a mezzanine, if one is provided, may be performed by, for example, a vertical conveyor. In this case, the vertical conveyor may transport only the shipping boxes, or it may transport the conveying device 3 loaded with shipping boxes.

[0036] Each section 201 may have a marker (not shown) indicating its location. The marker only needs to contain information to identify the location of the section, which may be, for example, the location information of the section, or information associated with the location information of the section (for example, identification information for section 201). The marker is information that can be read by the sensor 14 (see Figure 6) of the transport device 3, and may be, for example, a one-dimensional code, a two-dimensional code such as a QR code (registered trademark), or information such as an RFID (Radio Frequency Identifier) ​​tag. For example, when the transport device 3 passes through each section 201, it reads the marker in that section 201. Each transport device 3 transmits the information of the read marker, along with the identification information of the transport device 3, to the control device 4. The control device 4 identifies the location of each transport device 3 based on the identification information of the transport device 3 and the marker information received from each transport device 3. Plate-like members are present throughout section 201, allowing movement from section 201 to another adjacent section 201, and the conveying device 3 may rotate within section 201.

[0037] The conveying device 3 and the shipping boxes 87 may be smaller than, for example, one of the compartments 201. There may be various variations in how the compartments are configured. Furthermore, there may be compartments that the conveying device 3 is not allowed to enter (for example, compartment (3,1)).

[0038] For each section 201 of the moving area 150, as illustrated by the arrows in Figure 2, the direction in which the transport device 3 can move within that section 201 is not restricted (for example, the transport device 3 can move in any of the +x, -x, +y, and -y directions). Furthermore, movement between sections 201 may be set to be bidirectional or unidirectional. For example, by setting some sections 201 to be unidirectional, it is expected that congestion of the transport device 3 can be suppressed or reduced, and the overall movement efficiency can be improved. Also, if there are many sections 201 that can only be moved in one direction, the movement path of the transport device 3 may become longer. Therefore, the direction in which the transport device 3 can move may be predetermined based on the number of transport devices 3 in the moving area 150, or the position of each section 201 or section setting 1202, etc., or such directions may be dynamically set or changed by the control device 4.

[0039] Refer to Figure 1 again. The conveying device 3 is a device that moves according to movement instructions from the control device 4, and is typically an AGV (Automatic Guided Vehicle). For example, the conveying device 3, in accordance with one or more movement instructions from the control device 4, starts moving from the shipping box supply area 100 with empty shipping boxes 87 loaded on it, moves to two or more (or one) storage areas 101, and arrives at the packing area 102 via the inspection area 103 with the items placed in the shipping boxes 87 from each of the two or more (or one) storage areas 101. Specifically, for example, the movement sequence of the conveying device 3A is as shown in the figure: shipping box supply area 100 → flat storage area 101A → automated warehouse area 101B → shelf conveying area 101C → inspection area 103 → packing area 102. Furthermore, the movement sequence of the conveying device 3B is as shown in the diagram: shipping box supply area 100 → flow rack area 101D → shelf conveying area 101C → flat storage area 101A → inspection area 103 → packaging area 102.

[0040] There are orders that specify multiple different items, and for each order, the control device 4 assigns one or more shipping boxes 87 to the order, and these one or more shipping boxes 87 are loaded onto one or more transport devices 3. For example, if all the items corresponding to a certain order are packed in the same box as a shipping unit, the order (all the items corresponding to the order) may be assigned to one shipping box 87, but if they do not all fit in the same shipping box 87, they may be assigned to multiple shipping boxes 87. The control device 4 prevents a single shipping box 87 from being assigned to multiple orders with different delivery destinations. The order of movement from the shipping box supply area 100 to the packing area 102 may be specified in a single movement instruction, or it may be determined by a combination of multiple movement instructions. The "movement instruction" transmitted to the transport device 3 is associated with information representing the movement task assigned to the transport device 3. In this embodiment, "movement" of the transport device 3 refers to the movement of the transport device 3 in general, regardless of whether or not there are transported items (shipping boxes 87 or the items inside the shipping boxes 87). The "movement" of the conveying device 3 may be rephrased as the "travel" of the conveying device 3. The "movement" of the conveying device 3 while it is carrying an object is sometimes specifically referred to as "conveying." A movement task is a task to move the conveying device 3 to the area specified in the movement task (movement instruction), and may include a task to have the conveying device 3 transport the shipping box 87 to the specified area. Information representing a movement task may include, for example, the movement path, which is the path the conveying device 3 travels, and the direction of movement of the conveying device 3.

[0041] As shown in Figure 3A, the conveying device 3 has a platform 85 on which the shipping boxes 87 are loaded. One conveying device 3 may have one shipping box 87 loaded on it, as shown in Figure 3A, or it may have multiple (two or more) shipping boxes 87 loaded on it, as shown in Figure 3B.

[0042] The transport device 3 is configured to automatically move to the charging area 104 and charge the battery (not shown) if its remaining charge falls below a predetermined value. For example, if the remaining charge of the transport device 3's battery falls below a predetermined value, the transport device 3 may request charging from the control device 4, and the control device 4 may respond to the charging request by instructing the transport device 3 to move to the charging area 104 and charge.

[0043] The following describes the multiple storage areas 101A to 101D. In this description, the "parking area" for each storage area 101 may be an area within the movement area 150 (for example, an area adjacent to storage area 101 and composed of one or more sections 201 of the movement area 150) or an area outside the movement area 150 (for example, an area inside storage area 101).

[0044] Figure 4A is a schematic diagram showing an example of a flat parking area 101A.

[0045] Area 101A is an example of an area where PTG (Person to Goods) is applied. According to PTG, a worker (Person) walks to storage location 2 for the goods (Goods) and picks them.

[0046] The flat storage area 101A includes an item area 400 and one or more work areas 163A, with each work area 163A having a parking area 164A adjacent to it. The item area 400 is an area equipped with storage locations 2 where items are laid flat. The item area 400 may have shelves as storage locations 2, and items may be placed on the shelves. The parking area 164A is an area where the conveying device 3 stops. In the work area 163A, according to work instructions from the control device 4, items picked from the storage locations 2 are placed (loaded) by workers into the shipping boxes 87 of the conveying device 3 parked in the parking area 164A adjacent to the work area 163A.

[0047] Figure 4B is a schematic diagram showing an example of automated warehouse area 101B.

[0048] Automated warehouse area 101B is an example of an area where GTP (Goods To Person) is applied. According to GTP, goods are transported by robots (or other devices) to the location of the picking worker.

[0049] The automated warehouse area 101B includes the automated warehouse 161B, one or more conveyors 162, and one or more work areas 163B, with each work area 163B having a parking area 164B adjacent to it. The automated warehouse 161B releases (deploys) goods to one of the conveyors 162 according to the dispatch instructions from the control device 4. The conveyors 162 transport the goods that have come out of the automated warehouse 161B to the work area 163B (destination WS and / or dispatch destination WS). Alternatively, a transport vehicle (not shown) may be used instead of or in addition to the conveyor to transport the dispatched goods to the work area 163B. The work area 163B is the area where workers pick the goods being transported by the conveyor 162. The parking area 164B is the area where the transport device 3 stops. In the work area 163B, the picked items are placed by the worker into the shipping box 87 of the conveying device 3, which is parked in the parking area 164B adjacent to the work area 163B.

[0050] The moving area 150 may or may not have a temporary waiting area 165 corresponding to each storage area 101. The temporary waiting area 165 corresponding to each storage area 101 may include a temporary waiting area 165 corresponding to each work area 163, a temporary waiting area 165 corresponding to each parking area 164, or multiple temporary waiting areas 165 corresponding to work areas 163 or parking areas 164. In this embodiment, a temporary waiting area 165 corresponding to the automated warehouse area 101B may be provided. The temporary waiting area 165 is an area where the conveying device 3 temporarily waits when moving to the parking area 164B. The temporary waiting area 165 may be provided near the parking area 164B. For example, if the conveying device 3 has already parked in all parking areas 164B, the conveying device 3 temporarily waits in the temporary waiting area 165. The temporary waiting area 165 may be provided in place of or in addition to the moving area 150, as well as in the automated warehouse area 101B and other storage areas 101. Furthermore, the temporary waiting area 165 may be located inside or outside the storage area 101. For example, the temporary waiting area 165 may be included within the waiting area 105.

[0051] Figure 4C is a schematic diagram showing an example of a shelf transport area 101C.

[0052] The shelf transport area 101C is an example of an area to which GTP is applied. The shelf transport area 101C has multiple shelves 5, and multiple items are placed on multiple shelves 5. In the shelf transport area 101C, the transport device 161C transports the shelves 5 according to the outbound instruction (movement instruction) from the control device 4. The shelf transport area 101C includes one or more work areas 163C, and each work area 163C has a parking area 164C adjacent to the work area 163C. The work area 163C is the area where items are picked by workers from the shelves 5 transported by the transport device 161C. The parking area 164C is the area where the transport device 3 stops. In the work area 163C, the picked items are placed by workers into the shipping boxes 87 of the transport device 3 which is parked in the parking area 164C adjacent to the work area 163C.

[0053] Figure 4D is a schematic diagram showing an example of a flow rack area 101D.

[0054] The flow rack area 101D includes a flow rack 450 and one or more work areas 163D, with each work area 163D having a parking area 164D adjacent to it. The flow rack 450 has trays arranged vertically, with goods placed in each tray. In the work area 163D, according to work instructions from the control device 4, a worker picks goods from the flow rack 450 and places the picked goods into a shipping box 87 of the conveying device 3 parked in the parking area 164D adjacent to the work area 163D.

[0055] Thus, the multiple storage areas 101A to 101D differ in at least one of the following: storage method, retrieval method, or picking method.

[0056] Figure 5 is a schematic diagram showing an example of a packing area 102.

[0057] The packing area 102 includes one or more conveyors 171, and each conveyor 171 includes a packing machine 172 and a work area 173. There is also a stopping area 174 for each conveyor 171. For example, separate stopping areas 174 may be provided for each shipping box size, such as large, medium, and small. Furthermore, the number of stopping areas 174 for each shipping box size does not necessarily have to be one; there may be multiple. For example, if the number of large shipping boxes is greater than the number of medium and small boxes, two stopping areas 174 for large boxes may be provided, as shown in the figure.

[0058] For each conveyor 171, the stopping area 174 is located near (e.g., adjacent to) the work area 173. In the work area 173, a worker transfers a shipping box 87 from the transport device 3 parked in the stopping area 174 to the conveyor 171. If the shipping box 87 is the box to be shipped (e.g., a cardboard box), the shipping box 87 being transported by the conveyor 171 is packed by the packaging machine 172, the packed shipping box 87 is transported by the conveyor 171, and eventually shipped (delivered). Alternatively, the goods placed in the shipping box 87 may be transferred by a worker to the box to be shipped (e.g., a cardboard box), the box to be shipped may be transported by the conveyor 171, packed by the packaging machine 172, the packed box may be transported by the conveyor 171, and eventually shipped (delivered).

[0059] The stopping area 174 may be an area within the moving area 150 (for example, an area adjacent to the packing area 102 and composed of one or more sections 201 of the moving area 150), or it may be an area outside the moving area 150 (for example, inside the packing area 102).

[0060] Figures 6 and 7 show specific configuration examples of the elements of the transport system in this embodiment.

[0061] The transport system comprises a control device 4, a transport device 3, material handling equipment 161, a station terminal 710, and a network 551 (for example, a wireless communication line such as a wireless LAN (Local Area Network)). Each component of the transport system may be one or more. The transport device 3, control device 4, material handling equipment 161, and station terminal 710 are each capable of communication via the network 551. The transport system may also be called a "logistics system."

[0062] The transport device 3 comprises a drive unit 11, a storage device 12, an interface device 13, multiple types of sensors 14, a battery, and a controller 10 connected thereto.

[0063] The controller 10 is responsible for controlling the operation of the transport device 3 according to movement instructions from the control device 4 and the charge status of the built-in battery. The drive device 11 includes drive wheels 20, auxiliary wheels 21, and actuators (not shown) such as motors for rotating the drive wheels 20.

[0064] The interface device 13 is a device for communicating with the control device 4 using a predetermined wireless communication method, and may consist of, for example, a wireless LAN card.

[0065] Sensor 14 is a device for collecting information about the floor surface on which the transport device 3 travels and various information about the transport device 3. For example, sensor 14 can read information about markers on the floor section 201. The transport device 3 may be equipped with multiple types of sensors 14, such as a camera for imaging the state of the section 201, a vibration sensor for detecting vibrations experienced by the transport device 3 while it is moving, a speed sensor for measuring the speed of the transport device 3, an acceleration sensor for measuring the acceleration of the transport device 3, a weight sensor for measuring the weight of the load (transported object), and a gyro sensor for measuring the orientation of the transport device 3.

[0066] The storage device 12 stores, for example, a route table 23, a device table 24, a map table 25, a measurement table 27, and a performance table 28. The controller 10 stores a communication program 29, a movement control program 30, a measurement program 31, and a position estimation program 32. The communication unit, the driving control unit, the measurement unit, and the position estimation unit are realized when the communication program 29, the movement control program 30, the measurement program 31, and the position estimation program 32 are executed by the controller 10.

[0067] The route table 23 is a table that stores the aforementioned movement instructions received from the control device 4 and information representing the movement route specified by the movement instructions (the information representing the movement route may include information about the sections of the movement route, etc.). The device table 24 is a table that stores the ID of the transport device 3, its current location (section), and its status (e.g., "standby", "moving", or "transporting"). The map table 25 is a table that stores information representing the location and attributes of each section (e.g., which area it belongs to). Note that the map table 25 may include information as illustrated in Figure 2. The measurement table 27 is a table that stores values ​​measured by multiple types of sensors 14 (e.g., speed, acceleration, rotation, weight, position (value read from marker), captured images of the section, etc.). The performance table 28 is a table that stores information representing the movement performance, including the route and date and time traveled by the transport device 3.

[0068] The communication program 29 is a program that has the function of exchanging commands and information with the control device 4 via the interface device 13. For example, the communication program 29 transmits information from at least some of tables 23-25, 27, and 28 to the control device 4 in response to a request from the control device 4 (or without a request). The communication program 29 of each transport device 3 may transmit each of these pieces of information to the control device 4 at regular or irregular intervals.

[0069] The movement control program 30 is a program that controls the movement of the transport device 3 in response to movement instructions received from the control device 4 via the communication program 29. For example, the movement control program 30 controls the drive device 11 to move along a specified movement path in accordance with the movement instructions from the control device 4.

[0070] The measurement program 31 registers the output (measurement result) of each sensor 14 in the measurement table 27. The position estimation program 32 estimates the position of the transport device 3 based on the markers (markers in section 201 of the movement area 150) detected through the sensors 14 of the transport device 3.

[0071] The control device 4 may be one or more physical computers having hardware such as a processor 40, memory 41, storage device 42, input device 43, output device 44, and interface device 45, or it may be a system implemented on one or more physical computers (e.g., a cloud infrastructure) (e.g., a cloud computing system). Furthermore, each device of the control device 4 may be located on a single physical computer, or it may be distributed across multiple physical computers. Each program and piece of information in the storage device 42 may be stored in a single storage device, or it may be divided and stored across multiple storage devices. Instead of the input device 43 and output device 44, information input and output may be possible via a client system that can communicate through the interface device 45.

[0072] The processor 40 is a device that controls the operation of the entire control unit 4. The memory 41 is used as the work memory of the processor 40. The storage device 42 stores programs and tables. The input device 43 consists of, for example, a mouse or keyboard, and is used by the operator to input necessary information and instructions to the control unit 4. The output device 44 may be a display device such as a liquid crystal display or an organic EL (Electro Luminescence) display. The interface device 45 is a device for communicating with the transport device 3, material handling equipment 161, and station terminal 710 using a predetermined wireless communication method, and may consist of, for example, a wireless LAN card.

[0073] The storage device 42 stores, for example, a transport device table 53, an inventory table 54, an order table 55, a map table 56, a storage area table 57, a work management table 58 (a picking work management table 581 and a loading work management table 582), a shipping box table 59, and a moving area table 60. The map table 56 is information representing a map of the moving area 150 (and each stopping area) (for example, a table storing the location (coordinates) and attributes of each section) (this table 56 may be distributed to each transport device 3 and stored as a map table 25 in each transport device 3). The map table 56 may include information as illustrated in Figure 2.

[0074] The storage device 42 stores an integrated WCS program 51 and multiple WCS programs 50. The integrated WCS and WCS are realized when the integrated WCS program 51 and WCS programs 50 are executed by the processor 40. WCS stands for Warehouse Control System. The integrated WCS program 51 comprehensively controls the conveying device 3 and the material handling equipment 161. The WCS programs 50 control the material handling equipment 161 or the conveying device 3. For example, the first WCS program 50 controls the material handling equipment 161 in the automated warehouse area 101B (specifically, the automated warehouse 161B). The second WCS program 50 controls the shelf conveying area (specifically, the conveying device 161C). The third WCS program 50 controls the conveying device 3.

[0075] The material handling equipment 161 is located in the storage area 101 (typically a storage area to which GTP is applied) and is used for receiving, storing, or shipping materials from the storage area 101. The material handling equipment 161 is, for example, an automated warehouse 161B in the automated warehouse area 101B, or a conveying device 161C in the shelf conveying area 101C. The material handling equipment 161 includes, for example, an interface device 711, a storage device 713, a drive device 714, a sensor 715, and a processor 712 connected thereto.

[0076] The interface device 711 is a device for communicating with the control device 4 using a predetermined wireless communication method, and may consist of, for example, a wireless LAN card. The drive device 714 is a device for driving the material handling equipment 161. The sensor 715 may be a sensor for detecting the position of the material handling equipment 161, etc.

[0077] The storage device 713 stores an inventory table 760 and a goods receipt / issue table 761. The inventory table 760 may be a table containing at least some of the same information as the inventory table 54 held by the control device 4. The goods receipt / issue table 761 may be a table containing information regarding the receipt or issuance of goods. The processor 712 controls the operation of the entire material handling equipment 161 by executing a program in the storage device 713, for example, based on the inventory table 760 and the goods receipt / issue table 761.

[0078] The station terminal 710 is installed in the WS (work station (i.e., work area 163)) and is an information processing terminal that displays a work management table 770, which is an example of information related to a worker's work (e.g., picking work or loading work), and accepts input from the worker when the work is completed. Upon input of work completion, the work status of the target work is updated. The station terminal 710 has an interface device 731, a storage device 732, and a processor 733 connected thereto. The WS may also be called a Work Station or Working Station.

[0079] The interface device 731 is a device for communicating with the control device 4 using a predetermined wireless communication method, and may consist of, for example, a wireless LAN card. The storage device 732 stores the work management table 770. The work management table 770 may be a table from the work management tables 58 of the control device 4 that contains information corresponding to the work management table (WS). The processor 733 controls the operation of the entire station terminal 710 by executing a program in the storage device 732, for example, based on the work management table 770. The station terminal 710 may be equipped with an input device and an output device. The input device may receive input from the worker regarding work, such as the completion of work. The output device may output instructions to the worker regarding work.

[0080] Figure 8 shows an example of the configuration of the order table 55.

[0081] The order table 55 is a table that stores various information about customer orders. The order table 55 has a record for each item. Each record holds information such as status 601, invoice number 602, shipping box ID 603, store ID 604, item name 605, item ID 606, quantity 607, delivery date 608, received date and time 609, work date and time 610, and priority flag 611. Let's take one item as an example (referred to as the "item of interest" in the explanation of Figure 8). As shown in the example in Figure 8, if the invoice number 602 is the same, even if the type of item (for example, item name 605 and item ID 606) is different, it may be treated as one order.

[0082] Status 601 represents the work status for the item of interest. Document number 602 represents the order number (document number) in which the item of interest is specified.

[0083] Shipping box ID 603 represents the ID of shipping box 87 assigned to the item of interest. Store ID 604 represents the ID of the store that sells or manufactures the item.

[0084] Item Name 605 represents the name of the item of interest, Item ID 606 represents the ID of the item of interest, and Quantity 607 represents the number of items of interest (the number ordered).

[0085] The delivery date 608 represents the deadline by which the item in question will be delivered to the destination (typically the customer). The receipt date and time 609 represents the date and time when the order for the item in question was received. The work date and time 610 represents the date and time when a specific operation related to the item in question (e.g., picking, loading, inspection, packaging, etc.) is performed. In addition to or instead of this information, there may be information on work deadlines and shipping deadlines.

[0086] Priority flag 611 is assigned to orders (invoice number or shipping box group) that should be prioritized, such as sudden orders or orders with approaching deadlines. Orders with priority flag 611 are given higher priority than orders without it. Priority flag 611 may also represent a multi-level priority, such as "high," "medium," or "low."

[0087] Priority flag 611 may be automatically assigned, for example, when there is less than a specified time remaining until the work deadline, or when the order is an express order, or it may be assigned by input from the administrator and / or worker. It may also be assigned for the purpose of improving efficiency, such as preventing delays in goods related to an order, for example, when an order is divided into multiple shipping boxes, and the status 601 of some shipping boxes is picking complete, but the status 601 of the remaining shipping boxes is picking incomplete, by assigning priority flag 611 to the remaining shipping boxes.

[0088] Figure 9 shows an example of the configuration of the inventory table 54.

[0089] The inventory table 54 is a table that stores information about items. The inventory table 54 has a record for each pair of item and storage area 101. The inventory table 54 may also have a record for each pair of item and location within storage area 101 705. Each record holds information such as item name 701, item ID 702, stock quantity 703, storage area 704, location within area 705, storage container ID 706, location within container 707, number of times issued 708, and item size and weight 709. Let's take one item as an example (referred to as the "item of interest" in the explanation of Figure 9).

[0090] Item Name 701 represents the name of the item of interest. Item ID 702 represents the ID of the item of interest. Stock Quantity 703 represents the stock quantity of the item of interest. Storage Area 704 represents the ID of storage area 101 where the item of interest is located. Location within Area 705 represents the location of the item of interest within storage area 101. Storage Container ID 706 represents the ID of the storage container located at the location indicated by Location within Area 705. Location within Container 707 represents the location of the item of interest within the storage container. Number of Issues 708 represents the number of times the item has been issued. Item Size / Weight 709 represents the size or weight of the item.

[0091] The configuration of information 705-707 differs depending on the storage area 101. For example, if storage area 101 is automated warehouse area 101B, the area location 705 consists of the ID of automated warehouse area 101B and a value representing the location within the automated warehouse (column, tier, row), the storage container ID 706 consists of a value representing the ID of the bucket, which is a storage container used in automated warehouse area 101B, and the container location 707 consists of a value representing the opening of the bucket. If storage area 101 is flat storage area 101A, the area location 705 consists of the ID of flat storage area 101A and a value representing the location within flat storage area 101A (for example, column, tier, row (or column, row)). If the storage area 101 is the shelf transport area 101C, the area position 705 consists of values ​​representing the storage compartment ID (or address) of the mobile shelf, the face of the mobile shelf, the level of the mobile shelf, and the opening of the mobile shelf; the storage container ID 706 consists of a value representing the ID of the mobile shelf; and the container position 707 consists of a value representing the position within the opening of the mobile shelf. If the storage area 101 is the flow rack area 101D, the area position 705 consists of a value representing the ID of the flow rack; and the container position 707 consists of a value representing the position within the flow rack.

[0092] Figure 10 shows an example of the configuration of the storage area table 57.

[0093] The storage area table 57 is a table that stores information about the storage area 101. The storage area table 57 has a record for each location within the area. Each record holds information such as the storage area 801, the method 802, the temporary waiting area 803, the location within the area 804, and the station ID 805. Let's take one location within the area as an example (referred to as "location of interest within the area" in the explanation of Figure 10).

[0094] Storage area 801 represents the type of storage area 101 located within the area of ​​interest. Method 802 represents the method of retrieval or picking.

[0095] The temporary waiting area 803 indicates the presence or absence of a temporary waiting area. The presence or absence of a temporary waiting area may be managed for each storage area 101, or for each WS (or WS group (two or more WS)). A temporary waiting area may be reserved for each WS, but multiple WS may share a temporary waiting area.

[0096] Area location 804 represents the location within the area of ​​interest. Station ID 805 represents the ID of the WS (available WS) corresponding to the area location.

[0097] Figure 11 shows an example of the configuration of the conveying device table 53.

[0098] The transport device table 53 is a table that stores information about each transport device 3. The transport device table 53 has a record for each transport device 3. Each record holds information such as device ID 1101, shipping box ID 1102, location 1103, battery level 1104, device status 1105, storage area 1106, destination location 1107, and expected arrival date and time 1108. Let's take one transport device 3 as an example (referred to as "Target Transport Device 3" in the explanation of Figure 11).

[0099] Device ID 1101 represents the ID of the focus transport device 3. Shipping box ID 1102 represents the ID of the shipping box 87 loaded onto the focus transport device 3. When multiple shipping boxes 87 are loaded onto the focus transport device 3, multiple IDs are recorded as the ID of the focus transport device 3. For example, in the example in Figure 11, the records with device ID 1101 "AGV04-R" and "AGV04-L" indicate that the shipping box with shipping box ID "B08" is loaded on the right side (R) of the front of the device with device ID "AGV04", and the shipping box with shipping box ID "B09" is loaded on the left side (L) of the front of the device with device ID "AGV04".

[0100] Position 1103 represents the coordinates of the section (i.e., the current section) where the focus transport device 3 is located. Battery level 1104 represents the remaining battery level of the focus transport device 3.

[0101] Device status 1105 represents the status of the focus transport device 3. "Moving" means that the focus transport device 3 is moving. "Empty" means that no shipping boxes are assigned to the focus transport device 3. "Stopped" means that the focus transport device 3 is stopped in the stopping area (or temporary waiting area).

[0102] The storage area 1106 represents the storage area to which the transport device 3 of interest will move. The target location 1107 represents the location to which the transport device 3 of interest will move, and may be a location related to the storage area 1106 or a location near the storage area 1106. For example, it may be the parking area in front of the WS (work area) of the storage area 1106, or a temporary waiting area.

[0103] The estimated arrival date and time 1108 is the estimated date and time when the transport device 3 is scheduled to arrive at its destination. The estimated arrival date and time 1108 may be, for example, a date and time calculated by the integrated WCS program 51 (or WCS program 50) based on the travel route of the transport device 3 to its destination.

[0104] Figure 12 shows an example of the configuration of the mobile area table 60.

[0105] The movement area table 60 holds information for each section within the movement area 150. The movement area table 60 has a record for each section. Each record holds information such as address 1201, section setting 1202, station ID 1203, unavailable flag 1204, rotation unavailable flag 1205, and direction 1206. Let's take one section as an example (referred to as the "section of interest" in the explanation of Figure 12).

[0106] Address 1201 represents the address (location information) of the area of ​​interest. Area setting 1202 represents how the area of ​​interest is set up. For example, “Movement Area” is the area on which the transport device 3 travels. “Stopping Area” is the area belonging to the stopping area. “Temporary Waiting Area” is the area belonging to the temporary waiting area. Station ID 1203 represents the ID of the WS corresponding to the area of ​​interest.

[0107] The unavailable flag 1204 indicates whether the area of ​​interest is unavailable (cannot be a component of the movement path). The rotation impossible flag 1205 indicates whether the area of ​​interest is unable to be rotated by the transport device 3. The direction 1206 indicates the direction in which the transport device 3 located in the area of ​​interest can move.

[0108] Furthermore, if a transport device such as an AGV travels within the storage area 101, a table similar to the movement area table 60 may be managed for that storage area 101. In this case, the WCS program 50, which primarily controls the transport device, may refer to or update this table.

[0109] Figure 13 shows an example of the configuration of the shipping box table 59.

[0110] The shipping box table 59 is a table that stores information about each shipping box. The shipping box table 59 has a record for each size category of shipping boxes. Each record holds information such as the size category 1301, loadable size 1302, loadable weight 1303, loadable quantity 1304, and shipping box ID 1305. Let's take one shipping box as an example (referred to as the "featured shipping box" in the explanation of Figure 13).

[0111] Size category 1301 represents the size category to which the featured shipping box belongs (e.g., large, medium, small). Loadable size 1302 represents the size of the items that can be loaded into the featured shipping box (e.g., width, depth, height). Loadable weight 1303 represents the weight of the items that can be loaded into the featured shipping box.

[0112] The loading capacity of 1304 represents the maximum number of shipping boxes belonging to the same size category as the featured shipping box that can be loaded onto the conveying device 3.

[0113] Shipping box ID 1305 represents the ID of the shipping box of interest. Specifically, for each size category, shipping box ID 1305 is a list of IDs of the shipping boxes of interest belonging to that size category. Note that the IDs included in shipping box ID 1305 may include all shipping boxes, or they may include only the IDs of shipping boxes that have not been assigned to a document number (i.e., empty shipping boxes) (i.e., if an ID of a shipping box to be assigned is selected from shipping box ID 1305, that ID may be deleted from shipping box ID 1305).

[0114] Furthermore, the shipping box table 59 may have a record for each shipping box, and in addition to the information 1301 to 1305 mentioned above, it may also manage the allocation status of each shipping box (unassigned or assigned status, assigned slip number, assigned transport device 3 ID, etc.).

[0115] Figure 14 shows an example of the configuration of the loading operation management table 582.

[0116] The loading operation management table 582 is a table related to loading operations. The loading operation management table 582 has a record for each loading operation. Each record holds information such as station ID 1401, slip number 1402, device ID 1403, shipping box ID 1404, item ID 1405, quantity 1406, scheduled start date and time 1407, scheduled end date and time 1408, and work status 1409. Let's take a single loading operation as an example (referred to as "Featured Loading Operation" in the explanation of Figure 14).

[0117] Station ID 1401 represents the ID of the WS where the loading operation takes place. Slip number 1402 represents the slip number of the order corresponding to the loading operation. Device ID 1403 represents the ID of the conveying device 3 that transports the shipping box 87 containing (loaded) the goods to the WS during the loading operation.

[0118] Shipping box ID 1404 represents the ID of the shipping box in which the goods will be placed (loaded) during the loading operation; item ID 1405 represents the ID of the item; and quantity 1406 represents the number of the item to be loaded during the loading operation.

[0119] The scheduled start date and time 1407 represents the scheduled start date and time of the loading operation of interest. The scheduled end date and time 1408 represents the scheduled end date and time of the loading operation of interest. The scheduled start date and time 1407 may be calculated by the integrated WCS program 51 or WCS program 50 based on the scheduled arrival date and time of the conveying device 3 along the movement path to the WS, and the estimated time required for loading operations performed before the loading operation of interest (or the scheduled end date and time). The scheduled end date and time 1408 may be calculated by the integrated WCS program 51 or WCS program 50 based on the scheduled start date and time 1407 and the estimated time required for the loading operation of interest. The estimated time required for the loading operation may be calculated by the integrated WCS program 51 or WCS program 50 based on at least one of the following: the quantity of items to be loaded, the average time required for the loading operation, and the past loading operation history of the worker performing the loading operation. Note that the loading operation may be performed by a robot in place of or in addition to the worker.

[0120] Work status 1409 represents the status of the loading operation. "Before work" means that the loading operation has not yet started. "In progress" means that the loading operation has started but has not yet been completed. "Completed" means that the loading operation has been completed. Note that changes to work status 1409 may be made based on input from the operator of the loading operation, or automatically based on values ​​automatically detected regarding the loading operation.

[0121] Furthermore, the loading operation management table 582 may manage records for each WS, for example by creating a separate table for each WS, so that the loading status of each WS can be seen. The order of the records may be the order in which the conveying devices 3 (shipping boxes 87) arrived at each WS.

[0122] Figure 15 shows an example of the configuration of the picking work management table 581.

[0123] The picking work management table 581 is a table related to picking operations. The picking work management table 581 has a record for each picking operation. Each record holds information such as station ID 1501, slip number 1502, storage container ID 1503, item ID 1504, quantity 1505, scheduled start date and time 1506, scheduled end date and time 1507, and work status 1508. Let's take a single picking operation as an example (referred to as "focus picking operation" in the explanation of Figure 15).

[0124] Station ID 1501 represents the ID of the workstation (WS) where the picking operation is performed. Slip number 1502 represents the slip number of the order corresponding to the picking operation. Storage container ID 1503 represents the ID of the storage container containing the items to be picked in the picking operation.

[0125] Item ID 1504 represents the ID of the item to be picked in the featured picking operation, and quantity 1505 represents the number of items to be picked.

[0126] The scheduled start date and time 1506 represents the scheduled start date and time of the picking operation of interest. The scheduled end date and time 1507 represents the scheduled end date and time of the picking operation of interest. The scheduled start date and time 1506 may be calculated by the integrated WCS program 51 or WCS program 50 based on the scheduled arrival date and time of the storage container at the WS and the estimated time required (or scheduled end date and time) for picking operations performed prior to the picking operation of interest. The scheduled end date and time 1507 may be calculated by the integrated WCS program 51 or WCS program 50 based on the scheduled start date and time 1506 and the estimated time required for the picking operation. The estimated time required for the picking operation may be calculated by the integrated WCS program 51 or WCS program 50 based on at least one of the following: the quantity of items to be picked, the average time required for the picking operation, and the past picking history of the worker performing the picking operation. The picking operation may be performed by a robot in place of or in addition to a worker.

[0127] Work status 1508 represents the status of the picking task in question. "Before work" means that the picking task in question has not yet started. "In progress" means that the picking task in question has started but has not yet been completed. "Completed" means that the picking task in question has been completed. Note that changes to work status 1508 may be made based on input from the worker performing the picking task in question, or it may be made automatically based on values ​​automatically detected regarding the picking task in question.

[0128] Furthermore, the picking work management table 581 may be organized in a way that allows for tracking the picking status of each workstation, for example by creating a separate table for each workstation. The records may be arranged in the order in which the items (storage containers) arrived at each workstation.

[0129] Additionally, there is a slip number 1502 that represents multiple different slip numbers (e.g., "81" and "85"), which is related to the loading operation management table 582 (e.g., the record with slip numbers 1402 "81" and "85") and indicates that items from different orders with those slip numbers are picked together in a single picking operation.

[0130] The following describes an example of the processing performed in this embodiment. In this embodiment, the control device 4 receives information (for example, information including sensor measurements) periodically or irregularly from each transport device 3, each material handling equipment 161, and each station terminal 710, and the integrated WCS program 51 or WCS program 50 updates the relevant portion of tables 53 to 60 as appropriate.

[0131] Figures 16 to 21 are flowcharts showing the order processing flow. In the following explanation, "WCS program 50X" refers to the WCS program 50 corresponding to the material handling equipment 161 in the destination storage area 101. "WCS program 50Y" refers to the WCS program 50 corresponding to the conveying device 3.

[0132] As shown in Figure 16, in S1601, the integrated WCS program 51 selects one or more records from the order table 55 where the work date and time 610 corresponds to a predetermined work date and time. Orders with a priority flag 611 set to "yes" may be given priority in at least some of the following order processing steps compared to orders without a priority flag (for example, priority in the order in which items are dispatched from the material handling equipment 161 in the storage area 101, and in the order in which the conveying device 3 arrives at the stopping area 164 and / or in the waiting order).

[0133] In S1602, the integrated WCS program 51 refers to the order table 55 to identify the document number for which the shipping box ID 603 is unassigned, and performs the shipping box selection process (Figure 22). Here, for example, if all the items corresponding to the identified document number do not fit into one shipping box, it is decided that those items will be divided into multiple shipping boxes. Also, if there are multiple sizes of shipping boxes, the size of the shipping box is identified, and it is determined whether or not multiple shipping boxes will be loaded onto a single transport device 3 (if multiple shipping boxes are to be loaded, the number of shipping boxes to be loaded is determined). As a result of this S1602, information regarding shipping boxes for each of the records identified in S1601 (for example, some or all of the information such as the shipping box group ID, shipping box size, number of shipping boxes to be loaded onto the transport device 3, combination of shipping box groups, and shipping box ID corresponding to each record) is set (determined) and recorded in the order table 55.

[0134] In S1603, the integrated WCS program 51 refers to the transport device table 53.

[0135] In S1604, the integrated WCS program 51 identifies a transport device 3 for which no shipping boxes are assigned (device status 1105 is "empty").

[0136] In S1605, the integrated WCS program 51 sends a move request to the WCS program 50Y to move the identified transport device 3 to the supply WS (WS in the shipping box supply area 100). The move request specifies the device ID of the transport device identified in S1604 and the destination area (e.g., the stopping area at the destination).

[0137] In S1606, the WCS program 50Y transmits a move instruction to the designated transport device 3 to move to the supply WS, in accordance with the move request.

[0138] In S1607, WCS program 50Y receives notification from conveyor 3 that it has arrived at the supply WS and reports to the integrated WCS that conveyor 3 has arrived at the supply WS.

[0139] In S1608, Integrated WCS Program 51 receives a report of arrival completion.

[0140] As shown in Figure 17, in S1609, the integrated WCS program 51 sends a loading request for shipping boxes to the station terminal 710 of the supply WS. The loading request includes, for example, some or all of the information about the shipping boxes identified in S1602 (e.g., some or all of the information such as the shipping box group ID, the size of the shipping boxes, the number of shipping boxes to be loaded onto the conveying device 3, the combination of shipping box groups, and the shipping box ID).

[0141] In S1610, the station terminal 710 of the supply WS displays loading instructions for the shipping boxes based on the loading request. The displayed loading instructions are information about the shipping boxes to be loaded onto the transport device 3 that has arrived at the corresponding stopping area of ​​the supply WS, and include the information included in the loading request. Loading is performed according to the displayed loading instructions. For example, at the supply WS, a worker or work robot may input the information of the shipping box IDs to be loaded into the station terminal 710 by scanning (reading) the codes (e.g., including the shipping box ID) attached to the shipping boxes to be loaded using a scanning terminal such as a code reader, for the "shipping box size" and "number of shipping boxes" specified in the loading instructions. The worker or work robot loads the scanned shipping boxes onto the transport device 3 of the WS. If there are multiple shipping box sizes, the loading instructions display will include information about the size of the shipping boxes. The worker loads the shipping boxes of that size (i.e., one or more shipping boxes are loaded onto a single conveying device 3 according to the loading instructions).

[0142] As an alternative modification, the supply WS may be separated according to the size of the shipping box. In this case, the integrated WCS program 51 may send a move request to the WCS program 50Y to move the transport device 3 to the supply WS corresponding to the size of the shipping box. As another alternative modification, if there is a transport device 3 corresponding to the device status 1105 "empty", the shipping boxes may be loaded onto the supply WS first, and then an unassigned slip number (shipping box group) may be assigned to that shipping box.

[0143] In S1611, the station terminal 710 receives input from the worker indicating that loading is complete and reports the loading completion (including, for example, information about the shipping box ID) to the integrated WCS program 51.

[0144] In S1612, the integrated WCS program 51 receives a report that loading is complete and updates the conveyor table 53 (setting the ID of the loaded shipping box as shipping box ID 1102 for the target conveyor 3).

[0145] In S1613, the integrated WCS program 51 updates the order table 55. For example, the integrated WCS program 51 assigns the loaded shipping boxes to the target document number (shipping box group). If multiple shipping boxes are loaded on the same transport device, the integrated WCS program 51 assigns the loaded shipping boxes to each shipping box group corresponding to the target combination of shipping box groups. In the order table 55, the integrated WCS program 51 sets the ID of the loaded (assigned) shipping box as the shipping box ID 603 for each item record corresponding to each shipping box group.

[0146] As a variation, if a shipping box ID is set in S1602 (Figure 22), and the loading request in S1609 and the loading instruction in S1610 include information about the shipping box ID, the worker or robot may load the shipping box with the shipping box ID specified in the loading instruction onto the conveying device 3.

[0147] As shown in Figure 18, in S1614, the integrated WCS program 51 refers to the order table 55 and the inventory table 54 to identify the storage area 101 that stores the item corresponding to the relevant document number (the item whose status 601 indicates that picking or loading is incomplete).

[0148] In S1615, the integrated WCS program 51 refers to the work management table 58 (picking work management table 581 and loading work management table 582), the storage area table 57, the movement area table 60, and the conveying device table 53 (and also, for example, the inbound / outbound table 761 of each material handling equipment 161). From the referenced tables, the integrated WCS program 51 identifies the work status of each WS (e.g., work capacity and congestion), the location and movement status of each conveying device 3 (e.g., destination and expected arrival date and time), and the items scheduled for outbound, and determines (selects) the destination storage area and target location (e.g., the WS or temporary waiting area of ​​the destination storage area 101). Based on this determination, the integrated WCS program 51 determines the patrol sequence (all or some destinations, including at least the first destination). The integrated WCS program 51 updates the conveying device table 53 (e.g., device status 1105, storage area 1106, and target location 1107).

[0149] In S1616, the integrated WCS program 51 refers to the storage area table 57 and determines whether the destination storage area 101 is a GTP area (an area to which GTP is applied). If the result of the determination in S1616 is false (S1616: NO), the process proceeds to S1632 (Figure 20).

[0150] If the result of the determination in S1616 is true (S1616: YES), in S1617, the integrated WCS program 51 sends a move request to the WCS program 50Y to move the transport device 3 to the target position.

[0151] In S1618, the WCS program 50Y transmits a move instruction to the transport device 3 to move it to the target position in accordance with the move request.

[0152] In S1619, WCS program 50Y receives a completion notification from the transport device 3 that it has arrived at the destination location, and reports the arrival completion to integrated WCS program 51.

[0153] In S1620, Integrated WCS Program 51 receives a report of arrival completion.

[0154] As shown in Figure 19, at S1621, the integrated WCS program 51 sends a dispatch request to the WCS program 50X corresponding to the material handling equipment 161 in the destination storage area 101 to dispatch the goods (the goods corresponding to the relevant document number) from the destination storage area 101.

[0155] In S1622, the WCS program 50X transmits a dispatch instruction to the corresponding material handling equipment 161 to dispatch the items corresponding to the relevant document number in accordance with the dispatch request. The dispatch instruction may include, in part or in whole, information such as the dispatch destination WS in storage area 101, and the order and timing of the items' arrival.

[0156] For example, WCS program 50X refers to inventory table 54 to identify area location 705 corresponding to item name 701 and / or item ID 702 of the item to be issued. WCS program 50X refers to storage area table 57 to identify area location 804 corresponding to area location 705, identifies station ID 805 corresponding to area location 804, and identifies (determines) the WS (shipping destination WS, transport destination WS) to which the item will be issued.

[0157] If there are multiple station IDs, the WCS program 50X may refer to the picking work management table 581 and determine the WS to which the item will be shipped, taking into account the status of the picking work tasks at each WS so that the work tasks at each WS are leveled or optimized (based on the worker's work processing speed, etc.). Furthermore, if it is more efficient to pick the item together with other picking work tasks (picking work tasks for the same or different items, such as items corresponding to other slip numbers), the WCS program 50X may determine the destination WS so that the same WS is used for shipping, and may also determine the arrival order and / or timing of the items when they arrive at the destination WS.

[0158] Another example of a case where there are multiple station IDs is that the WCS program 50X may determine the destination WS in such a way that the degree of obstruction to the passage of the transport device 3 that desires the item to be dispatched is minimized when it heads towards the WS. Alternatively, the WCS program 50X may determine the destination WS in such a way that the movement cost of the transport device 3 that desires the item to be dispatched is minimized.

[0159] "Passage obstruction degree" is an index that represents the extent to which a particular transport device 3 can obstruct the passage of other transport devices 3, such as when there are other transport devices 3 that cross a queue of transport devices 3 extending from the destination location. The specific calculation method will be described later. "Travel cost" is an index that represents the cost of traveling to the destination location, and specifically, it may be the distance traveled to the destination location or the time it takes to travel to the destination location. Both the passage obstruction degree and travel cost are indexes for the candidate destination location (destination location).

[0160] As yet another example, the WCS program 50X may determine the WS to which the item will be shipped by combining the three examples mentioned above: the example of leveling or optimizing the work tasks of each WS, the example of reducing the degree of obstruction to traffic, and the example of reducing the movement cost of the transport device 3. Specific methods of combination and further developmental methods of determination will be described later. While it is typical for all of these processes to be performed by the WCS program 50X, it is not necessarily limited to this, and all or part of the processes may be performed by the integrated WCS program 51 or the WCS program 50Y.

[0161] In S1623, WCS program 50X receives status information from material handling equipment 161 representing the status of goods being issued and transported, and reports this status information to the integrated WCS. The status information may include, for example, information representing the destination WCS in storage area 101, and the order and timing of goods' arrival.

[0162] In S1624, the integrated WCS program 51 receives a report containing status information on outbound and transport status.

[0163] In S1625, the integrated WCS program 51 sends an output request (a request to display picking and loading work instructions) to the station terminal 710 of the storage WS (WS in the destination storage area 101), or sends a move request to the WCS program 50Y. Specifically, for example, the integrated WCS program 51 sends an output request to the station terminal 710 of the storage WS based on status information (for example, information on the destination WS and the order and timing of arrival of the items), or determines a move request such that the order and timing of arrival of the conveying device 3 at the parking area 164 corresponding to the storage WS is the same as the order and timing of arrival of the items at the destination WS, and sends it to the WCS program 50Y. The work instructions include information representing the items to be picked at the destination storage area 101 and loaded onto the conveying device 3, the number of items, and the location of the items (location within the area or location within the container).

[0164] In S1626, the WCS program 50Y transmits a movement instruction to the transport device 3 to its target location (WS in the storage area 101) in accordance with the movement request. If multiple IDs are listed for station ID 1401 in the loading work management table 582, the integrated WCS program 51 may determine the target location to correspond to the WS that will be the destination for shipment, as determined by the WCS program 50X. Alternatively, as mentioned above, the WS that will be the destination for shipment may be determined by either the integrated WCS program 51 or the WCS program 50Y, in which case these programs may simultaneously determine the target location of the transport device 3. These processes may be executed by any of the integrated WCS program 51, WCS program 50X, or WCS program 50Y, and some of the processes may be shared among them.

[0165] In S1627, WCS program 50Y receives completion notification from conveyor 3 that it has arrived at the destination location, and reports the arrival completion to integrated WCS program 51.

[0166] In S1628, the storage WS station terminal 710 displays picking and / or loading work instructions based on the output request.

[0167] In S1629, station terminal 710 receives input from the worker indicating that picking and / or loading is complete, and reports the completion of the work to the integrated WCS program 51.

[0168] In S1630, Integrated WCS Program 51 receives a report of arrival completion.

[0169] In S1631, the integrated WCS program 51 receives a report of picking completion and / or loading completion and updates the status 601 in the order table 55 (updating the status 601 of the item corresponding to the relevant document number to "completed" for picking and / or loading). After the status 601 for picking and loading is set to "completed", the process proceeds to S1640 (Figure 21).

[0170] In the case of S1616:NO in Figure 18, as mentioned above, the process proceeds to S1632 in Figure 20. In S1632, the integrated WCS program 51 sends a move request to the WCS program 50Y to move the transport device 3 to the target location (storage WS) in the destination storage area 101.

[0171] In S1633, the WCS program 50Y transmits an instruction to the transport device 3 to move to the target position in accordance with the move request.

[0172] In S1634, WCS program 50Y receives completion notification from transport device 3 that it has arrived at the destination location, and reports the arrival completion to integrated WCS program 51.

[0173] In S1635, Integrated WCS Program 51 receives a report of arrival completion.

[0174] In S1636, the integrated WCS program 51 sends an output request to the storage WS station terminal 710, which is a request to display picking and loading work instructions. The work instructions include information indicating the items to be picked in the destination storage area 101 and loaded onto the conveying device 3, the number of items, and the location of the items (location within the area or location within the container).

[0175] In S1637, station terminal 710 displays picking and loading work instructions based on the output request.

[0176] In S1638, station terminal 710 receives input from the worker indicating the completion of picking and loading, and reports the completion of the work to the integrated WCS program 51.

[0177] In S1639, the integrated WCS program 51 receives a report of work completion and updates status 601 in the order table 55 (updating status 601 of the item corresponding to the relevant document number to "completed" for picking and / or loading). After the status 601 for picking and loading is set to "completed", the process proceeds to S1640 (Figure 21).

[0178] As shown in Figure 21, in S1640, the integrated WCS program 51 refers to the status 601 of each item in the order table 55 that corresponds to the relevant document number (and / or the relevant shipping box ID).

[0179] In S1641, the integrated WCS program 51 determines whether the status 601 of each item corresponding to the target document number (or target shipping box ID, or multiple shipping box IDs loaded onto the same transport device 3) is "completed" or not (i.e., whether all items corresponding to the target document number have been loaded into the shipping box). If the result of the determination in S1641 is false (S1641: NO), the process returns to S1614 in Figure 18. In other words, another destination storage area is identified, and the same process proceeds.

[0180] If the result of the determination in S1641 is true (S1641: YES), in S1642, the integrated WCS program 51 sends a move request to the WCS program 50Y to move the transport device 3 to the target position in the inspection area 103.

[0181] In S1643, the WCS program 50Y transmits a move instruction to the conveying device 3 to move it to the target location (inspection area 103) in accordance with the move request.

[0182] In S1644, WCS program 50Y receives completion notification from conveyor 3 that it has arrived at the destination location, and reports the arrival completion to integrated WCS program 51.

[0183] At S1645, the integrated WCS program 51 receives a report of arrival completion and sends an inspection instruction to the inspection equipment (not shown) in the inspection area 103.

[0184] In S1646, the integrated WCS program 51 receives a report that the inspection is complete and sends a move request to the WCS program 50Y to move the conveying device 3 to the target position in the packing area 102. As explained in Figure 5, if there are multiple stopping areas 174 corresponding to the same shipping box size, the WCS program 50Y may arbitrarily determine (select) the target position from among the candidate stopping areas 174. At this time, the target position (stopping area 174 and corresponding work area 173) may be determined considering the status of the packing work tasks of each WS so that the work tasks in the packing area 102 are leveled or optimized (based on the worker's work processing speed, etc.).

[0185] Another example of determining (selecting) the target location is that the WCS program 50Y may determine the target location in a way that minimizes obstruction to traffic. Alternatively, the WCS program 50Y may determine the target location in a way that minimizes the movement cost of the transport device 3. Yet another example is that the WCS program 50Y may determine the target location by combining the three examples mentioned above: leveling or optimizing the work tasks, minimizing obstruction to traffic, and minimizing the movement cost of the transport device 3. Specific methods for combining these methods, and further advanced methods for determining the target location, will be described later.

[0186] In S1647, the WCS program 50Y transmits a move instruction to the conveying device 3 to move it to the target location (packing area 102) in accordance with the move request.

[0187] In S1648, WCS program 50Y receives completion notification from conveyor device 3 that it has arrived at the destination location, and reports the arrival completion to integrated WCS program 51.

[0188] In S1649, the integrated WCS program 51 receives a report of arrival completion and sends a request to the station terminal 710 of the WS in the packing area 102 to output a loading instruction to transfer the shipping boxes to the packing area 102. The integrated WCS program 51 updates the device status 1105 of the transport device 3 from which the shipping boxes have been removed to "empty" and sends a move request to the WCS program 50Y to move the transport device 3 to the next destination location (for example, the waiting area 105 or the shipping box supply area 100).

[0189] Figure 22 is a flowchart showing the flow of the shipping box selection process.

[0190] In S2201, the integrated WCS program 51 calculates the total size and / or weight (sum of size and / or weight) corresponding to the target document number (document number for which no shipping box has been assigned). Specifically, for example, the integrated WCS program 51 identifies the item name 605, item ID 606, and quantity 607 corresponding to the target document number from the order table 55. For each pair of item name 605 and item ID 606, the integrated WCS program 51 identifies the corresponding item size and weight 709 from the inventory table 54 and calculates the product of the identified item size and weight 709 and the corresponding quantity 607. The integrated WCS program 51 calculates the total size and weight corresponding to the target document number by summing up all the calculated products.

[0191] In S2202, the integrated WCS program 51 determines whether the total size weight calculated in S2201 is below a predetermined threshold.

[0192] If the result of S2202 is false (S2202:NO), in S2203, the integrated WCS program 51 divides the items corresponding to the relevant invoice number into multiple subgroups so that the total size and weight are below a predetermined threshold. A "subgroup" corresponds to a shipping box unit. In other words, S2202:NO means that it has been determined that the items corresponding to the relevant invoice number cannot fit into a single shipping box, and in this case, the integrated WCS program 51 decides to divide the items into multiple shipping boxes. If at least one item exceeds the total size and weight threshold, the integrated WCS program 51 may notify the administrator of an error (or a request for manual picking).

[0193] Here, a group (unit) of multiple items assigned to a single shipping box is sometimes called a "shipping box group (order container group)." For example, if the result of the S2202 check is false (S2202:NO), and the multiple items corresponding to the relevant invoice number are divided into multiple "subgroups," each "subgroup" becomes a "shipping box group." Also, if the result of the S2202 check is true (S2202:YES), and all items corresponding to the relevant invoice number are placed in the same shipping box, all items corresponding to that invoice number become the same "shipping box group." The integrated WCS program 51 assigns a unique identification information, a shipping box group ID, to each "shipping box group."

[0194] After S2203, or if the result of S2202 is true (S2202:YES), in S2204, the integrated WCS program 51 refers to the shipping box table 59 (for example, the column for size category 1301) and determines whether there are multiple sizes of shipping boxes.

[0195] If the result of S2204 is true (S2204:YES), in S2205, the integrated WCS program 51 refers to the shipping box table 59 and the inventory table 54 and, based on the loadable size 1302 and / or loadable weight 1303 and the item size weight 709 of each item, determines the size of the shipping box that can accommodate the total size weight of the target shipping box group.

[0196] After S2205, or if the result of S2204 is false (S2204: NO), in S2206, the integrated WCS program 51 refers to the shipping box table 59 and determines whether the size of the shipping box is such that multiple shipping boxes can be loaded onto the conveying device 3. Specifically, the integrated WCS program 51 determines whether the value of the number of boxes that can be loaded 1304 corresponding to the size category 1301 of the shipping box is "2" or greater.

[0197] If the result of S2206 is true (S2206:YES), then in S2207, the integrated WCS program 51 determines whether the time remaining until the work deadline (or shipping deadline) is greater than or equal to a threshold. Note that the information on the work deadline (and / or shipping deadline) corresponding to each order may be included, for example, in the order table 55.

[0198] If the result of the judgment in S2207 is true (S2207:YES), in S2208, the integrated WCS program 51 decides to load multiple shipping boxes onto the conveying device 3 and determines the number of shipping boxes to be loaded onto the conveying device 3 (for example, the number of boxes that can be loaded corresponding to the size category 1301 of the shipping boxes, 1304).

[0199] Furthermore, when loading multiple shipping boxes onto the conveying device 3, the integrated WCS program 51 selects "other unassigned shipping box groups" to which the "target shipping box group" will be assigned to other shipping boxes loaded together on the same conveying device 3. For example, the integrated WCS program 51 also performs the shipping box selection process shown in Figure 22 for other unassigned slip numbers, identifies the size of the shipping box to be assigned to "other unassigned shipping box groups," and selects "other unassigned shipping box groups" that match the size of the other shipping box.

[0200] Furthermore, when multiple shipping boxes are loaded onto a single transport device 3, the integrated WCS program 51 selects (determines) a combination of shipping box groups to assign to the multiple shipping boxes in order to improve the efficiency of picking, loading, and / or transport. For example, the integrated WCS program 51 may refer to the order table 55 and, if there is another unassigned shipping box group with the same document number as the target shipping box group, select that other unassigned shipping box group. As the items with the same document number are gathered in each shipping box, they can be transported to the inspection area 103 and the packing area 102, thus improving the efficiency of transport, inspection, and packing.

[0201] For example, the integrated WCS program 51 may refer to the order table 55 and select "other unassigned shipping box groups" that have items with a high degree of overlap (redundancy), such as having items that are the same as or many of the same items as the items corresponding to the target shipping box group. By picking these same items together and loading them into the respective shipping boxes transported by the same conveyor 3, picking, loading, and / or transport can be made more efficient. Alternatively, for example, the integrated WCS program 51 may refer to the order table 55, inventory table 54, and storage area table 57 and select "other unassigned shipping box groups" that have items with a high degree of overlap (redundancy) in storage areas (or destination WSs) that are the same as or many of the items corresponding to the target shipping box group. This improves the movement efficiency of the conveyor 3, reduces waiting times for the conveyor 3 to arrive at destination WSs, and further reduces the accumulation of picked items at WSs, thus making picking and loading operations more efficient. In addition to or instead of the above selection criteria, the integrated WCS program 51 may refer to the order table 55, inventory table 54, storage area table 57, etc., and select "other unassigned shipping box groups" based on other selection criteria, such as ensuring that the transport time (including waiting time) of the transport device 3 is met in time for the work deadline (calculating the scheduled work completion date and time, and ensuring that the time from the scheduled work completion date and time to the work deadline is above a predetermined threshold), ensuring that the charge rate of the transport device 3 does not fall below a threshold (calculating the transport time, and ensuring that the transport time is within a predetermined range), and ensuring that the number of transport destinations in the storage area (destination WS) is below a predetermined threshold. The integrated WCS program 51 may also select "other unassigned shipping box groups" not only for the target shipping box group, but also to optimize the processing of all document numbers included in the work date and time.

[0202] The integrated WCS program 51 controls, in S1609 and S1610, to ensure that the shipping boxes assigned to the target shipping box group and the shipping boxes assigned to the selected "other unassigned shipping box group" are loaded onto the same conveyor 3 (requesting loading of shipping boxes, issuing loading instructions). The combination of the target shipping box group and the selected shipping box group is sometimes referred to as the "combination of shipping box groups".

[0203] The integrated WCS program 51 may record information about the shipping boxes (for example, shipping box group ID, shipping box size, number of shipping boxes to be loaded onto the conveying device 3, combination of shipping box groups, etc.) in the order table 55, corresponding to the target shipping box group.

[0204] If the result of the judgment in S2206 is false (S2206:NO), or if the result of the judgment in S2207 is false (S2207:NO), then in S2209, the integrated WCS program 51 decides to load one shipping box onto the conveying device 3. Specifically, for example, the integrated WCS program 51 records information about the shipping boxes (e.g., shipping box group ID, shipping box size, number of shipping boxes to be loaded onto the conveying device 3, etc.) in the order table 55, corresponding to the target shipping box group.

[0205] As an example, when setting a shipping box ID in the shipping box selection process shown in Figure 22, after S2208 and S2209, the integrated WCS program 51 may refer to the shipping box table 59 and set the IDs of the unassigned shipping boxes corresponding to the size identified in S2205, in the number identified in S2208 or S2209 (the number of shipping boxes to be loaded onto the conveying device 3), as the shipping box ID 603 corresponding to the target shipping box group, and record this in the order table 55.

[0206] In the process illustrated in Figure 22, at least S2207 may be optional. For example, when loading multiple shipping boxes corresponding to multiple invoice numbers onto a single conveyor 3, it takes time to collect goods for all of the shipping boxes. Therefore, if time takes priority in relation to deadlines, such as when the deadline for the relevant invoice number is approaching, the integrated WCS program 51 may decide to load only one shipping box. However, even if multiple shipping boxes are loaded onto the conveyor 3, the conveyor 3 may prioritize collecting goods from one of the shipping boxes and inspecting and packing that box first. After that, the conveyor 3 may sequentially move from the packing area 102 to one or more storage areas 101 to collect goods corresponding to the remaining shipping boxes that have not yet been packed.

[0207] Using Figures 23 to 26, an example of a method for determining the target position of the conveying device 3 when the target position can be arbitrarily determined (selected) from multiple target position candidates will be explained. In Figures 23 to 26, the example of selecting the target position from multiple stopping areas 184 is used, but the stopping area 184 may be stopping area 174 in the packing area 102, stopping area 164 corresponding to the WS in the storage area 101, or any other arbitrary stopping area. Also, in Figures 23 to 26, the work area 183 may be work area 173 in the packing area 102, work area 163 in the storage area 101, or any other arbitrary work area. Furthermore, the conveying device 3 that is the target of the determination (selection) of the target position will be referred to as the "target conveying device 3" from now on. In the following explanation, the processing mainly performed by the "processor 40" may be the processing performed by the integrated WCS program 51 (or WCS program 50) being executed by the processor 40.

[0208] Figure 23 is a flowchart showing the control flow for determining the target position of the transport device 3 from multiple target position candidates and transporting the transport device 3 to that target position. Note that the process shown in Figure 23 may be performed in at least one of S1605, S1615, S1621, S1625, S1632, S1642, and S1646, for example.

[0209] The processor 40 (for example, the integrated WCS program 51) performs S2301 for all target position candidates. In other words, S2301 is looped.

[0210] In S2301, the processor 40 calculates an evaluation value of the degree of obstruction to passage at a candidate target location and an evaluation value of the travel cost, and calculates an overall evaluation value of the target location.

[0211] When the loop in S2301 is completed, in S2302 the processor 40 determines (selects) the target position candidate with the smallest overall evaluation value as the target position. At this time, the processor 40 may set the position data (e.g., coordinates) of the determined candidate (target position) in the target position 1107 of the transport device table 53.

[0212] In S2303, the processor 40 controls the target transport device 3 to move to the target location. For example, the target location may be set in the move request and the move request may be sent to the WCS program 50. The WCS program 50 may set the target location set in the move request as a move instruction and send the move instruction to the target transport device 3.

[0213] As described above, the control device 4 in this embodiment determines the target location as the candidate that balances the degree of obstruction to passage and the travel cost, that is, the candidate with the smallest overall evaluation value. As previously mentioned, in order to reduce congestion in the transport device, it is important to determine the target location from one or both of the following two perspectives: reducing the degree of obstruction to passage and reducing the travel cost. It is preferable to adopt both perspectives. Since there may be a trade-off between reducing the degree of obstruction to passage and reducing the travel cost, it is important to determine the target location by balancing the two. Therefore, by determining the target location in this way, it is possible to prevent the congestion of the transport device 3 from increasing. A detailed evaluation method for the degree of obstruction to passage and the travel cost will be described later.

[0214] As previously mentioned, the target location may be determined in a way that levels or optimizes the work tasks. Furthermore, as previously mentioned, a combination of selecting the target location from the perspective of traffic obstruction and travel costs, and selecting the target location from the perspective of leveling or optimizing the work tasks, may be used.

[0215] Figures 24A and 24B are schematic diagrams illustrating the method for evaluating the degree of obstruction to traffic, respectively.

[0216] There are various methods for evaluating the degree of obstruction to traffic, but one simple example is to evaluate the degree of obstruction to traffic by the length of the waiting line formed by multiple transport devices 3 (including the target transport device 3) heading toward the candidate stopping area 184, which is the destination location, as shown in Figure 24A. The longer the waiting line, the higher the likelihood that it will cross (block) the travel path of other transport devices 3 and obstruct their movement. Therefore, the processor 40 can evaluate the length of the waiting line in the stopping area 184 (an example of a candidate destination location) as the degree of obstruction to traffic in the stopping area 184. This can be expressed mathematically as equation (1). Cobst=Nwait ···(1)

[0217] However, Cobst is an evaluation value of the degree of obstruction to traffic in the stopping area 184, and Nwait is the length of the waiting queue formed by the multiple transport devices 3 heading toward the stopping area 184.

[0218] Figure 24B is a schematic diagram illustrating a more advanced method for evaluating the degree of obstruction to traffic, taking into account the presence or absence of routes that cross the waiting line. As shown in the figure, each section around (near) the stopping area 184 is defined in which the transport device 3 can travel. Sections with multiple defined entry directions or multiple defined exit directions are considered to have branches. On the other hand, sections with only one entry direction and one exit direction are considered to have no branches. A series of sections without branches is called a "group of one-way sections."

[0219] The area surrounding stopping area 184A is composed of sections with branches. In this case, transport devices 3 other than those heading to stopping area 184A may also pass through these sections. In contrast, the area surrounding stopping area 184B is composed of a group of one-way sections. In this case, only transport devices 3 heading to stopping area 184B (or transport devices 3 departing from stopping area 184B) may pass through the group of one-way sections.

[0220] In such cases, even if the length of the queue formed by the transport device 3 heading towards stopping area 184A is the same as the length of the queue formed by the transport device 3 heading towards stopping area 184B, the transport device 3 heading towards stopping area 184A has a high degree of obstruction to traffic because it may obstruct the passage of other transport devices 3, while the transport device 3 heading towards stopping area B has a low degree of obstruction to traffic because it may not obstruct the passage of other transport devices 3. Therefore, for example, when evaluating the degree of obstruction to traffic based on the length of the queue, the processor 40 can evaluate the degree of obstruction to traffic in a way that more accurately reflects the actual situation by weighting the number of branches included in the group of sections that form the queue. This can be expressed mathematically as equation (2). Cobst = Σ(Nbr) ... (2)

[0221] However, Σ is the summation symbol for the group of partitions that form the waiting queue, and Nbr is the number of branches in each partition.

[0222] Furthermore, if there is a mix of one-way sections and sections with branches around the stopping area 184, the processor 40 may control the transport device 3 to prioritize the formation of waiting queues in the one-way sections.

[0223] To further evaluate the degree of obstruction that is more in line with reality, in equation (2), instead of weighting the number of branches (Nbr) included in the group of sections forming the waiting queue, the processor 40 may weight the evaluation value of the frequency with which each branch is used. That is, since some branches are used infrequently and others infrequently, the processor 40 does not simply weight the number of branches in the sections forming the waiting queue, but rather weights the frequency with which each branch in the sections forming the waiting queue is used. This can be expressed mathematically as equation (3). Cobst = Σ(Pbr) ... (3)

[0224] However, Σ is the summation symbol for all branches in the section that makes up the waiting queue, and Pbr is the estimated frequency of use for each branch.

[0225] There are various ways to calculate Pbr, an evaluation value for the frequency with which each branch is used. For example, for each section, the processor 40 may record the number of times that the branch in that section has actually been used so far, and this recorded value (number of times) may be used as Pbr. Alternatively, for all the stopping areas 184 that exist within the moving area 150, the processor 40 may find all combinations of two stopping areas 184 (for example, if there are stopping areas A, B and C, it may find all possible combinations such as AB, BC, and AC), find the path to move between the two stopping areas 184 that make up the combination for each combination, and calculate Pbr by counting how many paths in total use that branch.

[0226] Furthermore, in order to evaluate the degree of obstruction that is more in line with reality, the processor 40 may use a predicted value Nwait' of the future queue length instead of (or in addition to) using the queue length Nwait in equations (1) to (3). There are various ways to calculate the predicted value Nwait' of the future queue length, but for example, the processor 40 may calculate Nwait' for the stopping area 184 by adding Nmove, which is the number of transport devices 3 that are heading towards the stopping area 184 but are still in motion and not forming a queue, to the current queue length Nwait. This can be expressed mathematically as equation (4). Nwait' = Nwait + Nmove ... (4)

[0227] By performing calculations in this manner, it is possible to assess the degree of obstruction to traffic not only by considering the length of the queue at the time of evaluation, but also by anticipating a sudden increase in the queue length in the near future as a result of the transport device 3 moving.

[0228] Cobst may be calculated based on at least one of equations (1) to (4). For example, Cobst may be calculated using at least one of Nwait, Σ(Nbr), Σ(Pbr), and Nwait'. In addition, at least one element used in the calculation of Cobst (at least one of Nwait, Σ(Nbr), Σ(Pbr), and Nwait') may be multiplied by a weight coefficient, and the weight coefficient may be adjusted (determined) by the processor 40 based on data identified from at least one table stored in the memory device 42 with respect to the aspect of the element to which the weight coefficient is multiplied.

[0229] As explained above, the processor 40 evaluates the degree of obstruction to traffic for each of the multiple stopping areas 184, which are examples of multiple candidate destination locations, and determines (selects) a stopping area 184 as the destination location in a way that minimizes the degree of obstruction to traffic. This adjusts the length of the waiting line that forms at the destination location and makes it less likely to obstruct the passage of other transport devices 3. In particular, it prevents congestion of multiple transport devices 3 around the destination location.

[0230] Figures 25A and 25B are schematic diagrams illustrating methods for evaluating movement costs, respectively. While various methods can be considered for evaluating movement costs, one simple example is to evaluate the distance traveled from the target transport device 3 to each candidate target location. This can be expressed mathematically as equation (5). Cmove=L ···(5)

[0231] However, Cmove is the estimated cost of movement, and L is the distance traveled. There are various ways to calculate L.

[0232] In simple terms, as shown in Figure 25A, L may be the Manhattan distance from the current position of the transport device 3 to the candidate target position. In this example, for the transport device 3, the distance to stopping area 184A is shorter than the distance to stopping area 184B, and therefore the cost of moving to stopping area 184A is smaller than the cost of moving to stopping area 184B.

[0233] More precisely, as shown in Figure 25B, the path length of the shortest travel path may be used, taking into account the traversable directions defined within the sections of the travel area 150. In this example, for the transport device 3, the travel distance to the stopping area 184A is longer than the travel distance to the stopping area 184B. Therefore, unlike the example shown in Figure 25A, the travel cost to the stopping area 184A is greater than the travel cost to the stopping area 184B.

[0234] Furthermore, the processor 40 may also consider the positions of other transport devices 3 and determine a travel path to the target location while avoiding other transport devices 3, and use the length of that path as the distance (L) to the target location candidate for the target transport device 3. By selecting a target location with low travel cost, the travel time of the transport device 3 can be shortened, and therefore the time that each transport device 3 is in the travel area 150 can be shortened, thus suppressing the exacerbation of congestion.

[0235] Furthermore, to evaluate travel costs in a more realistic manner, travel time may be used instead of (or in addition to) travel distance. When the transport device 3 moves, it takes time to turn in place to change direction, and also takes time to decelerate or accelerate immediately before or after turning in place. Therefore, using travel time that takes this into account is expected to more accurately evaluate the amount of time the transport device 3 is in the travel area 150. This can be expressed mathematically as equation (6). Cmove=T ···(6)

[0236] However, T is the travel time. There are various ways to calculate T, but for example, one could determine the travel path to the candidate destination position in the same way as when calculating the travel distance L, and then calculate the time it takes to travel along the travel path based on the acceleration / deceleration and turning speed of the transport device 3.

[0237] As explained above, the processor 40 evaluates the travel cost for each of the multiple stopping areas 184, which are examples of multiple target location candidates, and determines (selects) the stopping area 184 as the target location in order to reduce the travel cost, thereby reducing the time that the transport device 3 is in the moving area 150. This makes it easier to reduce the frequency with which the transport device 3 obstructs the movement of other transport devices 3, and thus reduces congestion of multiple transport devices 3 throughout the moving area 150. Furthermore, by evaluating the travel cost, the following problem can be avoided, for example. That is, if there are two stopping areas 184 located far apart from each other, and the stopping area 184 with the higher travel cost from the perspective of the target transport device 3 is determined as the target location, the travel time of the target transport device 3 will increase. When the travel time of multiple transport devices 3, including the target transport device 3, increases, each transport device will be in the moving area 150 for a longer period of time, which leads to increased congestion. Such problems can be avoided.

[0238] From this perspective, it is expected that congestion can be prevented by determining (selecting) the stopping area 184 with the lower travel cost from the target transport device 3 as the target location. However, determining the target location from this perspective may create the problem of obstructing the passage of other transport devices. For this reason, it is preferable to determine the target location by balancing the degree of obstruction to passage and the travel cost.

[0239] Figure 26 is a schematic diagram illustrating the determination of a target location while balancing the degree of obstruction to traffic and the cost of travel.

[0240] In many cases, a high degree of obstruction to traffic (e.g., Cobst=Nwait) directly causes congestion of the transport device 3 compared to a high movement cost (e.g., Cmove=L), so reducing the degree of obstruction to traffic is considered particularly important for preventing congestion. However, as shown in Figure 26, even if the degree of obstruction to traffic is low, if a candidate destination location (stopping area 184A) with a significantly high movement cost is selected as the destination location, the transport device 3 in question may obstruct the passage of many other transport devices 3 on the way to the destination location, potentially causing congestion. This problem is particularly pronounced, for example, if there is a bottleneck section 2600 (a narrow section that must be passed through in order to move from one position to another in the movement area 150) along the way. In such cases, it is desirable to select a stopping area 184B, which has a relatively high degree of obstruction to traffic but a relatively low movement cost, as the destination location, rather than selecting a stopping area 184A, which has a significantly high movement cost.

[0241] As mentioned earlier, the target location can be determined while balancing minimizing the degree of obstruction to traffic and reducing travel costs. There are various ways to achieve this balance, but one typical example is to calculate an overall evaluation value by weighting the evaluation values ​​of both, and then select the target location that minimizes this value. This can be expressed mathematically as equation (7). F = αCobst + βCmove ... (7)

[0242] However, F is the overall evaluation value, and α and β are weighting coefficients. By using a weighted sum as shown in the above equation, it is possible to select a destination location where both are relatively low, rather than selecting a location where the degree of obstruction to traffic is reduced but the travel cost is extremely high (or vice versa). In cases where the travel cost is significantly high, as shown in Figure 26, or conversely, where the degree of obstruction to traffic is significantly high (not shown), congestion often increases significantly or transport efficiency decreases significantly. By using equation (7) to select a destination location that balances both, such situations can be prevented. Furthermore, by adjusting α and β, it is possible to adjust which of the degree of obstruction to traffic or the travel cost is given more importance.

[0243] Furthermore, although Figure 26 shows an extreme example, in more common cases, two candidate destination locations may have similar degrees of obstruction to traffic or similar travel costs. In such cases as well, using equation (7), if the degrees of obstruction to traffic are similar, the one with the lower travel cost can be selected, and if the travel costs are similar, the one with the lower degree of obstruction to traffic can be selected.

[0244] As described above, with the transport system of this embodiment, when the target position of the transport device 3 can be arbitrarily determined (selected) from a plurality of target position candidates, it is possible to select a target position that balances the degree of obstruction to passage and the travel cost, so that both are low to a certain extent. This prevents congestion of the transport device 3 from increasing and prevents a decrease in transport efficiency. <Second Embodiment>

[0245] Next, a transport system according to a second embodiment of the present invention will be described. In the following, the transport system in the second embodiment will be described mainly in terms of the differences from the transport system in the first embodiment.

[0246] If there is a work area 183 corresponding to the parking area 184, or if there are subsequent processes for the work performed in the parking area 184 (for example, transport on the conveyor belt 171 or packaging with the packaging machine 172), the work speed in the work area 183 and the speed at which the subsequent processes are processed (hereinafter referred to as processing speed) may be used as elements (variables) in the calculation of the degree of obstruction to traffic.

[0247] As previously mentioned, a method for calculating Nwait' (predicted length of future queues) used to evaluate the degree of obstruction to traffic was to sum Nwait (length of the queue formed by transport devices 3 heading towards the stopping area 184) and Nmove (number of transport devices 3 heading towards the stopping area 184 but still in motion and not forming a queue). However, when comparing a stopping area 184 with a fast processing speed and a stopping area 184 with a slow processing speed, even if the value of Nwait+Nmove is the same, it can be expected that the actual length of the queue that will occur in the future will be shorter in the stopping area 184 with a fast processing speed. Therefore, for example, processing speed may be weighted when calculating the predicted length of future queues. This can be expressed mathematically as, for example, equation (8). Nwait'=(Nwait+Nmove)·f(Vop) ···(8)

[0248] However, Vop is the processing speed, and f(x) is a monotonically decreasing function with respect to x as input. Various functions can be used for the function f(x), but for example, f(x) = 1 / x is acceptable. In this case, however, Vop must be a value greater than 0. By calculating in this way, the faster the processing speed of the stopping area (184), the smaller the predicted length of the future waiting line will be, resulting in a more accurate prediction. This allows for a more accurate assessment of the degree of obstruction to traffic, making it possible to select a destination location where congestion is less likely to occur.

[0249] Furthermore, various methods can be considered to determine the processing speed Vop. For example, the processing speed measured as an actual result in each work area 183 may be used to calculate Vop, or Vop may be estimated based on the type and amount of work to be performed in each work area 183.

[0250] Also, in the above description, Vop was set to a value greater than 0. However, in reality, when an operator in the work area 183 temporarily leaves his / her seat, or when a malfunction occurs in a device in the subsequent process, etc., Vop may temporarily become 0. In such a case, instead of (or in addition to) calculating Nwait’ using the formula (8), a extremely large value may be substituted into Nwait’ to select the target position, or the target parking area 184 may be explicitly excluded from the candidates for selecting the target position. Alternatively, if a function f(x) whose domain also includes 0, such as f(x)=1 / (x + 0.01), etc., is used, the traffic obstruction degree can be evaluated using the formula (8) including the case where Vop becomes 0.

[0251] As described above, according to the transport system in the present embodiment, by considering the processing speed when evaluating the traffic obstruction degree, the traffic obstruction degree can be evaluated more accurately. Therefore, it is possible to select a target position where congestion is less likely to occur, and prevent a decrease in transport efficiency. <The Third Embodiment>

[0252] Next, the transport system in the third embodiment of the present invention will be described. Hereinafter, the differences between the transport system in the third embodiment and the transport system in the first or second embodiment will be mainly described.

[0253] Using Figures 27 to 28B, an example of a method for determining the target position of the conveying device 3 when the target position can be arbitrarily determined (selected) from multiple target position candidates will be explained. In Figures 27 to 28B, the example of selecting the target position from multiple stopping areas 184 is used, but the stopping area 184 may be stopping area 174 in the packing area 102, stopping area 164 corresponding to the WS in the storage area 101, or any other arbitrary stopping area. Also, in Figures 27 to 28B, the work area 183 may be work area 173 in the packing area 102, work area 163 in the storage area 101, or any other arbitrary work area. If the stopping area 184 as a target position candidate is included in the work area 183, then the work area 183 may be the target position candidate. Furthermore, the conveying device 3 that is the target of the determination (selection) of the target position will be referred to as the "target conveying device 3" from now on. Furthermore, in the following description, the processing mainly performed by "processor 40" may be the processing performed by the integrated WCS program 51 (or WCS program 50) being executed by processor 40. The processing shown in Figures 27 to 28B may be performed in at least one of, for example, S1605, S1615, S1621, S1625, S1632, S1642, and S1646. Also, the target location candidate may be either a work area or a parking area. That is, regardless of whether the target location candidate is a work area or a parking area, the transport device 3 may arrive at and wait in a parking area adjacent to the rear of the work area (e.g., a work station) (or at the end of a waiting line extending from said parking area).

[0254] In this embodiment, the processor 40 may set a new target location each time the conveying device 3 arrives at a target location. For example, if the conveying device 3 is not loaded with shipping boxes, the processor 40 sets the stopping area (or queue) in the shipping box supply area 100 as the target location. If the queue is full (for example, if the Nwait of the queue has reached a threshold), the processor 40 sets the temporary waiting area as the target location in order to wait until a space becomes available (for example, until Nwait falls below the threshold). Next, if all picking is complete, the processor 40 sets the stopping area in the packing area 102 as the target location. In this case, the stopping area, queue, and temporary waiting area in the packing area 102 are determined as the target location by a process similar to the process used to determine the stopping area in the shipping box supply area 100 as the target location. If the timing for the stock boxes (an example of storage containers) to be released is determined, the processor 40 selects the stock box with the earliest arrival time and sets its work area as the next target location. At that time, the processor 40 may check whether it is possible to park in the work area. "Parking in" means that the conveying device 3 enters the area in front of the work area (i.e., the stopping area) which is set as the area where each operation can be performed. Parking is possible when the order in which the inventory boxes arrive in the work area matches the order in which the conveying devices 3 are lined up, and this is a condition to prevent deadlocks in picking performed in the work area. If parking is possible, the processor 40 determines the stopping area (or work area) as the target location. If parking is not possible, the processor 40 determines the temporary waiting area as the target location. The processor 40 makes the conveying device 3 wait in the temporary waiting area until parking becomes possible. When the timing of the outbound shipment has not been determined, such as when the inventory boxes are still moving inside the automated warehouse, it is not determined which stopping area (which candidate target location) the conveying device 3 should go to. In this case, the temporary waiting area may be determined as the target location by considering the positions of all candidate target locations that could be the next target location.

[0255] FIG. 27 is a schematic diagram of a target position determination method for determining one target position candidate from a plurality of target position candidates as the target position of the transfer device in the third embodiment. According to the example shown in FIG. 27, the plurality of target position candidates are a plurality of ST183A and 183B. ST is an abbreviation for a work station and is an example of a work area. Each ST183 has a standby area 184 adjacent to the ST183, and a standby queue with a length of Nwait can be formed with the transfer device 3 that has entered the standby area 184 at the head.

[0256] According to the target position determination method according to the third embodiment, "load leveling" and "collision prevention" are appropriately switched. As a result, each of the following influences can be reduced, and congestion is unlikely to occur in a transfer environment in which one ST183 is determined (selected) as the target position from a plurality of ST183A and 183B, thereby preventing a decrease in transfer efficiency. · If only "load leveling" is prioritized, the transfer device 3 heads towards a distant ST183 (the degree of freedom in selecting the target position candidate decreases), and the possibility of the transfer devices 3 crossing each other increases. · On the other hand, if only "collision prevention" is prioritized, the transfer device 3 heads towards a nearby ST183, and Nwait (the length of the standby queue formed by a plurality of transfer devices 3 heading towards the ST183) becomes long at one ST183. Therefore, the possibility of the load being biased at the ST183 increases.

[0257] The switching between "load leveling" and "collision prevention" is as follows.

[0258] Normalizing the length of the standby queue for a plurality of ST183s leads to maintaining productivity by, in addition to the perspective of preventing congestion, normalizing the amount of work at each ST183, that is, preventing the interruption of work at each ST183.

[0259] Therefore, in the present embodiment, until the length of the waiting queue of each ST183 exceeds a certain value, the equalization of the length of the waiting queue is prioritized. When a waiting queue of a certain length is ensured for each ST183, the ST183 as the target position is selected so as to prevent the interleaving of the transfer device 3. That is, when the processor 40 selects which of the plurality of ST183A and 183B is to be the target position of the target transfer device 3T, first, for each ST183, it is determined whether Nwait at that ST183 is n min or more (S2701). n min is the lower threshold value of the number of transfer devices 3 constituting the waiting queue.

[0260] If the determination result of S2701 is false (S2701: NO), that is, if Nwait is less than n min for at least one ST183, the processor 40 determines the ST183 with the shortest Nwait (ST183B in FIG. 27) among the plurality of ST183A and 183B as the target position of the target transfer device 3T (S2702). That is, the processor 40 performs load equalization.

[0261] If the determination result of S2701 is true (S2701: YES), that is, if Nwait is n min or more for any of all ST183A and 183B, the processor 40 determines whether the difference in Nwait between the ST183s exceeds the set allowable range n range (S2703). n range is set to prevent a significant load bias. n range and n min may be set in the memory 41. If the Nwait of ST183A is "Nwait1" and the Nwait of ST183B is "Nwait2", the difference in Nwait between the ST183s is the absolute value of Nwait1 - Nwait2.

[0262] If the determination result of S2703 is true (S2703: YES), that is, if the difference in Nwait between the ST183s is n rangeIf the value exceeds this limit, the processor 40, similar to S2702, determines the ST183 (ST183B in Figure 27) with the shortest Nwait time among the multiple ST183A and 183B as the target position for the transport device 3T (S2704). In other words, the processor 40 performs load leveling.

[0263] On the other hand, if the result of S2703 is false (S2703:NO), that is, if the difference in Nwait between ST183 is n range If located within the area, the processor 40 determines the ST183 closest to the target conveyor 3T (ST183A in Figure 27) from among the multiple ST183A and 183B as the target position for the target conveyor 3T (S2705). In other words, the processor 40 implements collision prevention. "ST183 closest to the target conveyor 3T" refers to the ST183 with the shortest travel path (or travel time) from the current position of the target conveyor 3T. As a result, the target conveyor 3T moves towards the ST183 closest to it, reducing the possibility of the target conveyor 3T's travel path intersecting with the travel paths of other conveyors 3. Note that for each ST183, the travel distance or travel time from the target conveyor 3T may be an example of the travel cost from the target conveyor 3T.

[0264] As described above, the Nwait of each ST183 switches between the ST selection logic that follows load leveling (S2702 or S2704) and the ST selection logic that follows collision prevention (S2705). This makes it possible to suppress the operation delay of the transport device 3. min and n range By adjusting this setting, you can adjust the degree to which Nwait leveling and intersection suppression are prioritized.

[0265] Note that the "target location candidate" is not limited to ST183 (or stopping area 184). For example, as shown in Figure 28A, two waiting lines (sections adjacent to the ends of the two waiting lines) branching off from one ST183 by a branch 2801 (for example, a section into which the transport device 3 cannot enter) may be considered target location candidates for the transport device 3T. Note that there is not limited to one branch 2801; as shown in Figure 28B, there may be multiple branches 2801, thereby forming more than two waiting lines for one ST183. Also, according to Figures 28A and 28B, two waiting lines are formed for one branch 2801, but more than two waiting lines may be formed for one branch 2801.

[0266] If there is a branch 2801, the target position determination method described with reference to Figure 27 may be applied to each branch 2801. That is, for each branch 2801, the processor 40 may perform S2701 to S2705 with respect to the multiple waiting lines formed by the branch 2801 as multiple target position candidates. min and n range The set of branches may be common to all branches 2801, or it may differ depending on the position of branch 2801.

[0267] Furthermore, Nwait is an example of an evaluation (index) that represents the load on a target position candidate (e.g., ST183). The evaluation representing the load on a target position candidate (e.g., evaluation value F) may be based on the amount of work at the target position candidate and the work time per unit time (work speed) of the worker (or work robot) responsible for the work at the target position candidate, either in addition to or instead of Nwait.

[0268] Also, n range This value may be based on the relative relationship of evaluations among target position candidates. For example, instead of the difference in Nwait among target position candidates, it may be the ratio of Nwait among target position candidates, or it may be the ratio of the maximum and minimum values ​​of Nwait among target position candidates.

[0269] Furthermore, there may be three or more target location candidates, not just two. For each task, there may be a set of multiple target location candidates corresponding to that task. min and n range At least one threshold may be common to all target location candidate sets, or it may differ depending on the target location candidate set.

[0270] Furthermore, for each target position candidate, the waiting queue may be a continuous queue, or it may include some space (for example, space for other conveying devices to pass through). For a waiting queue that includes some space, Nwait may be the number of conveying devices 3 that make up the waiting queue, regardless of whether there is space or not, or it may be the number of sections occupied by the waiting queue that includes space.

[0271] Furthermore, for each candidate target location, the waiting line may be a straight line without bends or turns, or it may be a non-straight line with meanders or turns.

[0272] Furthermore, the transport device for carrying the shipping boxes is not limited to AGVs; for example, a conveyor such as a belt conveyor may be used. In this case, the elements constituting the waiting line for each target position candidate can be shipping boxes instead of AGVs, and therefore, for example, Nwait for each target position candidate can be the number of shipping boxes constituting the waiting line.

[0273] Furthermore, potential target locations may include the picking station (ST) where shipping boxes are loaded, the picking station where shipping boxes are unloaded, or the picking station. For example, if there is a high degree of freedom in transporting the stock boxes to be shipped to multiple picking stations (for example, when AGVs transport stock boxes in a 3D automated warehouse), or if the same stock boxes are accessible from multiple picking stations and the same workers are performing the tasks, then multiple potential target locations may be multiple picking stations.

[0274] At least part of the description of the third embodiment may be applied to the first or second embodiment. For example, also in the second embodiment, the element of the waiting queue at the target position candidate may be a shipping box conveyed by a conveying device other than the AGV (for example, a conveyor) instead of the conveying device 3 as the AGV.

[0275] Similarly, at least part of the description of the first or second embodiment may be applied to the third embodiment. For example, in the third embodiment, Nwait may be the Nwait described in the first or second embodiment, or instead of Nwait, Nwait' described in the first or second embodiment may be adopted. For each target position candidate, each of Nwait and Nwait' may be an example of the load related to the target position candidate.

[0276] In any of the first to third embodiments, at least one of the following "OTP-GTP synchronization logic" and "deadlock countermeasure" may be introduced. In the following description, OTP is an abbreviation for Orders-to-Person. The conveying device 3 may typically be an AGV, and the conveying device 3 in the movement area 150 can be called an "OTP-AGV". <OTP-GTP synchronization logic>

[0277] FIG. 29 shows a sequence related to the OTP-GTP synchronization logic. According to the OTP-GTP synchronization logic, synchronization between the conveying device 3 and the GTP 101B is expected.

[0278] The processor 40 determines which of the available transport devices 3 identified from the transport device table 53 is responsible for the order to be processed from the order represented in the order table 55 (S2901). The processor 40 then sends a request to the transport device 3 to predict the time when the transport device 3 will arrive at the destination, the stopping area 164 (S2902), and may receive a response to the request (S2903). Alternatively, the processor 40 sends a request to the GTP 101B (material handling equipment 161) to predict the time when the stock boxes will arrive at ST 163B (S2904), and may receive a response to the request (S2905). Alternatively, the processor 40 may perform all of the above processes from S2902 to S2905. The processor 40 plans the time to perform the picking operation for the items included in the order to be processed based on the response from each conveyor 3 (predicted arrival time of each conveyor 3), the response from the GTP 101B (predicted arrival time of the stock box), or both (S2906). That is, the integrated WCS 51 plans the picking operation time (e.g., scheduled start date and time 1506) based on the predicted arrival time of the conveyor 3, the predicted arrival time of the stock box, or both, so that the conveyor 3, the stock box, or both can move in time. The processor 40 transmits data representing the planned picking operation time to the conveyor 3 and the GTP 101B as data representing the expected arrival time (S2911A and S2911B). The conveyor 3 and the GTP 101B then perform the shipping box transport and stock box transport, respectively, so that they can arrive in time for the expected arrival time (S2912A and S2912B). The transport device 3 and GTP101B send a picking operation request to ST163B (station terminal 710) (S2913A and S2913B), the picking operation is performed at ST163B (S2921), and the completion of the picking operation is notified to the processor 40 (S2922).

[0279] Furthermore, the prediction of the arrival times of the conveying device 3 and the inventory boxes does not necessarily have to be performed by the conveying device 3 or the GTP101B; for example, it may be performed by the processor 40. In this case, the integrated WCS program 51 (or WCS program 50) maintains a calculation model for predicting the conveying time by the conveying device 3 and the GTP101B, and the processor 40 uses these calculation models to predict the arrival times. Therefore, in this case, the requests for arrival time predictions to the conveying device 3 and the GTP101B (S2902, S2904) and their responses (S2903, S2905) may be omitted.

[0280] As described above, the processor 40 creates a picking work plan based on the movement time of the conveying device 3 and controls the conveying device 3 to adhere to it. This allows for synchronization between the GTP 101B and the conveying device 3.

[0281] The transport device 3 can predict its arrival time at the stopping area 164B by calculating the shortest path from its current position to the stopping area 164B, and by estimating the shortest time required to travel the path, taking into account the transport device 3's maximum speed and acceleration / deceleration. In planning the path for each transport device 3, the shortest path can be calculated without considering the positions of other transport devices 3. Even if a transport device 3 interferes with the travel path of another transport device 3, it does not take a detour route; instead, the interference can be resolved by applying the mutual exclusion control described later while keeping the path as is.

[0282] In multiple transport processes (transport of shipping boxes and / or transport of inventory boxes), the processor 40 may formulate a work plan to provide each transported item to the transfer worker in a timely manner and control the transport device that transports each transported item. Specifically, the processor 40 minimizes the worker's waiting time by predicting the time required for each transported item to reach its destination and determining the transfer work point and the arrival timing of the transported item. In addition, it controls each transport device while making priority decisions between transported items (or transport devices) based on their progress to prevent delays in the start time of each work according to the formulated work plan. <Deadlock prevention>

[0283] In the explanation of deadlock prevention, the transport device 3 with ID:n may be referred to as "transport device n" below. Also, in the explanation of deadlock prevention, the available compartment may be identified from the route table 23, device table 24, and map table 25 of the transport device 3, or from the sensor 14 of the transport device 3, or from the transport device table 53 and map table 56 of the control device 4.

[0284] If the travel path of one transport device 3 interferes with that of another transport device 3, the interference can be resolved by mutual exclusion control. In mutual exclusion control, the transport device 3 (or processor 40) first reserves all sections up to a predetermined number of sections ahead in its travel path. That is, at least the next section 201 is reserved. If the transport device 3 has secured the reservation for the next section 201, it enters that section 201. On the other hand, if the reservation for the next section 201 is not secured, the transport device 3 waits in the section 201 where it is currently located. Once the movement to the next section 201 is complete, the transport device 3 (or processor 40) releases the reservation for the original section 201 before the movement. As a result, each transport device 3 only enters the section 201 reserved for it (for example, the section 201 it reserved), so even if the travel paths of two transport devices 3 interfere, the transport devices 3 will not collide with each other.

[0285] However, with the above method, if the sections 201 that multiple conveying devices 3 are heading towards become a chain, a deadlock may occur where none of the conveying devices 3 can move forward.

[0286] For example, as shown in the example in Figure 30A, when transport device A enters section 201X, the destinations of transport devices A through F become a chain reaction, and a deadlock occurs as none of the transport devices can move to the next section 201.

[0287] Furthermore, as shown in another example in Figure 30B, the deadlock described above does not appear to occur because the next destination for conveyor A after section 201X, section 201Y, is currently empty. However, if section 201Y has already been reserved for conveyor B, then by the time conveyor A moves to section 201X, conveyor B will also have entered section 201Y, and a deadlock will similarly occur.

[0288] Therefore, as a measure against deadlocks, if the occurrence of a deadlock is foreseen, the reservation of section 201X is prohibited by the transport device (or processor 40). The occurrence of a deadlock can be foreseen, for example, by the following process. S301: The transport device (or processor 40) identifies the transport device that occupies or reserves the next partition it wants to go to after partition 201X. S302: The transport device (or processor 40) identified in S301 or the immediately preceding S302 identifies the transport device that occupies or reserves the section to which the transport device wishes to go next. If there is a transport device not identified in S301 or the immediately preceding S302, the process returns to S302. If the repetition of S303:S302 is complete and the last identified transport device wants to go to section 201X, a daisy-chain (loop) has occurred. If the number of sections in the daisy-chain is the same as the number of transport devices 3, a deadlock will occur.

[0289] This process is expected to avoid most deadlocks by prohibiting the reservation of section 201X when a deadlock is foreseen, but there may be deadlocks that are difficult to avoid. For example, in the example shown in Figure 30C, when conveyor A enters section 201X, a chain of conveyors A→F→E→D→A is formed, and therefore a deadlock occurs. When conveyor D enters section 201X, a chain of conveyors D→C→B→A→D is formed, and therefore a deadlock occurs. When any of these deadlocks occur, none of the conveyors forming the chain can operate. When multiple such chains occur, it is difficult to avoid them with the logic described above.

[0290] Therefore, if a deadlock occurs as shown in the example in Figure 30C, the deadlocked transport device 3 (transport device 3 in a daisy-chain configuration) will autonomously or, in accordance with instructions from the processor 40, temporarily move to an empty compartment 201. Specific examples are shown in Figures 31A and 31B. That is, if there is a transport device 3 in a deadlock whose adjacent compartment is empty, that transport device 3 will temporarily move to the adjacent empty compartment. For a transport device 3 that has temporarily moved, since the empty compartment at the temporary location is a compartment that does not constitute the transport device 3's travel path, the transport device 3 (or processor 40) calculates the travel path from the empty compartment at the temporary location to the transport device 3's destination ST. This makes it possible to resolve the deadlock.

[0291] Furthermore, if the transport devices 3 are densely packed, there may be no place for a transport device 3 to retreat to during a deadlock. In such cases, the transport devices 3 surrounding the deadlock may retreat to an adjacent empty compartment, and the transport device 3 that is in the deadlock may retreat to the empty compartment created by the retreat of such transport devices 3 (the compartment before the transport device 3 moved).

[0292] Although several embodiments have been described above, these are merely illustrative examples for explaining the present invention and are not intended to limit the scope of the present invention to these embodiments only. The present invention can be implemented in various other forms.

[0293] Furthermore, for example, the shape of the partition is not limited to a rectangle, but may be other shapes. Also, partitions of different sizes or shapes may be mixed together. In addition, the location of a partition may be identified by a method other than by markers on the partition.

[0294] Furthermore, for example, the integrated WCS program 51 and WCS program 50 may be executed by the transport device 3 instead of or in addition to the control device 4. Also, the transport device 3 may also function as the control device 4.

[0295] The above explanation can be summarized as follows, for example. The summary below may include supplementary explanations to the above explanation and descriptions of modifications of the above embodiments.

[0296] The control device (e.g., control device 4) comprises an interface device (e.g., interface device 45) and a processor (e.g., processor 40) that controls one or more transport devices (e.g., multiple transport devices 3 or transport devices as a conveyor) through the interface device. For a target object (e.g., a transport device 3 as an AGV or a shipping box) which is one of multiple workpieces (e.g., multiple transport devices 3 as multiple AGVs or multiple shipping boxes), if there are multiple target position candidates corresponding to a specified task for the target object, the processor selects a target position candidate for the target object according to a first selection logic based on the load for each of the multiple target position candidates if the load for each of the multiple target position candidates is less than a predetermined threshold. If the load for each of the multiple target position candidates is greater than or equal to a predetermined threshold, the processor selects a target position candidate for the target object according to a second selection logic based on a relation value which is the relative relationship of the loads between the target position candidates. The processor transmits a request to move the workpiece to the selected target position candidate to one or more transport devices through the interface device. For each of the multiple target location candidates, the load on that target location candidate may be based on the length of the waiting line formed for that target location candidate and consisting of one or more workpieces (e.g., Nwait or Nwait'). Furthermore, for each of the multiple target location candidates, the load on that target location candidate may also be based on at least one of the workload of the work performed for that target location candidate and the work speed, which is the workload per unit time of the work. For each of the multiple target location candidates, if the workpiece is a conveying device such as an AGV, the load on that target location candidate may also be the degree of obstruction to passage (the degree to which it can obstruct the passage of one or more other conveying devices other than the conveying device in question), or an evaluation value based on the degree of obstruction to passage. Furthermore, the above relationship value may be the difference, ratio, or proportion of loads between the target location candidates.

[0297] Depending on whether the load for each of the multiple target location candidates is below a predetermined threshold, a first selection logic based on the load for each target location candidate and a second selection logic based on a relationship value, which is the relative relationship of the loads between the target location candidates, are switched. This allows for the selection of an appropriate target location, thus reducing congestion and preventing a decrease in transport efficiency.

[0298] In this summary, the "specified work" may be any work to be performed on the target object, for example, any work determined for the target object according to a prescribed work sequence or other policy. The work could be either loading or unloading order containers such as shipping boxes 87, or charging a conveying device. Furthermore, the "work station" as an example of a target location can be any location where work is performed, for example, either the stopping area 184 or the work area 183 mentioned above, or at least one of the inspection area 103, charging area, and abnormal response area 106. The "multiple work stations corresponding to the specified work" are work stations on which the specified work is performed, and the specified work can be performed at any of these multiple work stations.

[0299] The processor determines the load for each of the multiple target location candidates by a first threshold (e.g., n) which is a predetermined threshold. min A first determination (e.g., S2701) may be made to determine whether the value is greater than or equal to ) or not. If the result of the first determination is false (e.g., S2701: NO), the processor may, according to the first selection logic, select the target location candidate with the smallest load from among the multiple target location candidates as the target location of the workpiece (e.g., S2702). By doing so, leveling the load across multiple target location candidates is expected to prevent interruptions in work for each target location candidate, that is, to maintain productivity.

[0300] If the result of the first determination is true (e.g., S2701:YES), the processor determines that the above relationship value is a second threshold (e.g., n rangeA second determination (e.g., S2703) may be made to determine whether or not the value exceeds the specified limit. If the result of the second determination is true (e.g., S2703: YES), the processor may, according to the second selection logic, select the target location candidate with the smallest movement cost from the target workpiece from among the multiple target location candidates as the target location of the workpiece (e.g., S2704). This reduces the possibility of intersection (intersection between workpieces) that may occur if only the first selection logic is implemented.

[0301] If the result of the second determination is false (e.g., S2703: NO), the processor may, according to the first selection logic, select the target location candidate with the lowest load from among multiple target location candidates as the target location of the workpiece (e.g., S2705). This reduces the possibility of load imbalance that may occur if only the second selection logic is executed after switching from the first selection logic to the second selection logic.

[0302] For each of the multiple target location candidates, the processor may calculate the degree of obstruction to passage based on (a) below. (a) The length of the queue formed by one or more workpieces waiting to enter the target location candidate.

[0303] The longer the queue, the greater the potential obstruction to the passage of other workpieces; therefore, an appropriate degree of obstruction is expected. While a "queue" is typically a straight line, the queue does not necessarily have to be straight.

[0304] For each of the multiple target location candidates, the processor may calculate the degree of obstruction to traffic based on a value derived from (b) below, in addition to (a). (b) Whether or not there is a path that crosses the waiting line for the candidate target location, and if there is such a path, the arrangement of that path.

[0305] If there are no paths crossing the queue, a predetermined degree (value) may be calculated as the degree of obstruction to passage, regardless of the length of the queue. Alternatively, if there are paths crossing the queue, the degree of obstruction to passage may be calculated according to the extent to which other work objects' paths cross the queue. In this way, a more appropriate degree of obstruction to passage can be expected.

[0306] For each of the multiple target location candidates, the processor may predict (c) below based on (a), and calculate the degree of obstruction to traffic based on (c). (c) The length of the queue in the future.

[0307] This is expected to allow for a more accurate calculation of the degree of traffic obstruction.

[0308] For each of the multiple target location candidates, the processor may calculate (c) based on (a) and the number of objects to be worked on that are the target location candidate but are not yet included in the waiting queue at that target location candidate. This allows (c) to be calculated appropriately, and a more appropriate degree of obstruction to traffic can be expected.

[0309] The movement area may consist of multiple sections. For each of the multiple sections, one or more entry directions into the section and one or more exit directions out of the section may be defined. If multiple entry directions or multiple exit directions are defined for a section, that section may be a section with a branch. For each of the multiple target location candidates, the value based on (b) when there is a crossing path may be based on the number of sections with a branch among the one or more sections in which one or more work objects constituting the waiting line exist. This improves the accuracy of the evaluation of how much the path crosses the waiting line, and thereby a more appropriate degree of obstruction to passage can be expected.

[0310] For each of the multiple target location candidates, the processor may calculate the degree of obstruction to traffic based on a value derived from (d) below, in addition to (a). (d) Whether or not there is a waiting space for the candidate target location, and if there is a waiting space, the arrangement of the waiting space.

[0311] If there is no waiting space, the degree of obstruction to traffic may be calculated based on the length of the waiting line. Conversely, if there is a waiting space, other workpieces can wait without having to detour around the waiting line, so a lower degree of obstruction to traffic may be calculated compared to the case without a waiting space. In this way, a more appropriate degree of obstruction to traffic can be expected.

[0312] For each of the multiple target location candidates, the processor may calculate the degree of obstruction to passage based on a value derived from (e) below, in addition to (a). (e) Working speed at the target location candidate.

[0313] Since the rate at which queues shorten or lengthen varies depending on the work speed, using the work speed as the basis for determining the degree of obstruction to traffic is expected to result in a more appropriate degree of obstruction.

[0314] For each of the multiple target location candidates, the processor may calculate the travel cost for the target object to reach that target location candidate and calculate an evaluation value based on both the degree of obstruction and the travel cost. If the degree of obstruction is low but the travel cost is high, the target object will stay in the travel area for a long time relative to the degree of obstruction. Similarly, if the travel cost is low but the degree of obstruction is high, the target object will stay in the travel area for a long time relative to the travel cost. In this way, the evaluation of the length of time the target object stays in the travel area is performed based on both the degree of obstruction and the travel cost, so a more appropriate evaluation value can be expected for each target location candidate that is considered in determining the target location candidate.

[0315] For each of the multiple target location candidates, the processor determines the movement path of the object to be worked on to that target location candidate, and calculates the movement cost based on at least one of the path length and the movement time, which is the time it takes to travel along the path and arrive at the target location candidate. This allows for the expectation of an appropriate movement cost, and thus an appropriate evaluation value.

[0316] For each of the multiple target location candidates, the processor may determine a first coefficient, which is a weighting coefficient for the degree of obstruction to passage, and a second coefficient, which is a weighting coefficient for the travel cost, based on the degree of obstruction to passage for that target location candidate. Based on the degree of obstruction to passage and the determined first coefficient, and the travel cost and the determined second coefficient, an evaluation value may be calculated. In this way, since the first and second coefficients are determined according to the degree of obstruction to passage for each target location candidate, a more appropriate evaluation value can be expected.

[0317] The control device may include a memory device (e.g., memory device 42), to which a processor may be connected. The memory device may store management information, which may include at least a portion of the following for each of a plurality of work objects: information representing the location of the work object (e.g., current location and target location), information regarding the movement area (e.g., for each of a plurality of sections constituting the movement area, information representing the location of the section and the entry and exit directions defined for that section), and information representing the locations of a plurality of target location candidates. Based on the management information stored in the memory device, the processor may calculate the degree of obstruction to passage (evaluation value based on the degree of obstruction to passage) and the movement cost for each of the plurality of target location candidates corresponding to the specified work. [Explanation of symbols]

[0318] 3: Conveying device, 4: Control device

Claims

1. Interface device and A processor that controls one or more transport devices through the interface device. Equipped with, If, for a target workpiece that is one of several workpieces, there are multiple target position candidates corresponding to the specified workpiece, the processor will: If the load for each of the multiple target position candidates is less than a predetermined threshold, a target position candidate is selected as the target position of the workpiece according to a first selection logic based on the load for each target position candidate. If the load for each of the aforementioned multiple target position candidates exceeds a predetermined threshold, a target position candidate is selected as the target position of the workpiece according to a second selection logic based on a relationship value which is the relative relationship of the loads between the target position candidates. A request to move the workpiece to the selected target position candidate is transmitted to one or more of the transport devices via the interface device. Control device.

2. The aforementioned processor, A first determination is made as to whether the load for each of the plurality of target position candidates is equal to or greater than a first threshold which is a predetermined threshold. If the result of the first determination is false, the target location candidate with the smallest load among the multiple target location candidates is selected as the target location of the workpiece, according to the first selection logic. The control device according to claim 1.

3. The aforementioned processor, If the result of the first determination is true, a second determination is made to determine whether the relational value exceeds a second threshold. If the result of the second determination is true, then, according to the second selection logic, the target location candidate that has the lowest movement cost from the target workpiece among the multiple target location candidates is selected as the target location of the target workpiece. The control device according to claim 2.

4. The aforementioned processor, If the result of the second determination is false, then, according to the first selection logic, the target location candidate with the smallest load among the multiple target location candidates is selected as the target location of the workpiece. The control device according to claim 3.

5. For each of the aforementioned plurality of target location candidates, the load on said target location candidate is based on the length of the waiting line formed around said target location candidate and consisting of one or more workpieces. The control device according to claim 1.

6. For each of the aforementioned multiple candidate target locations, the load on said candidate target location is further based on at least one of the amount of work performed on said candidate target location and the work speed, which is the amount of work per unit time of said work. The control device according to claim 5.

7. The aforementioned relationship value is the difference, ratio, or proportion of load between candidate target locations. The control device according to claim 1.

8. One or more conveying devices, A control device for controlling one or more of the aforementioned transport devices Equipped with, If, for a target workpiece that is one of several workpieces, there are multiple target position candidates corresponding to the specified workpiece, the control device shall: If the load for each of the multiple target position candidates is less than a predetermined threshold, a target position candidate is selected as the target position of the workpiece according to a first selection logic based on the load for each target position candidate. If the load for each of the aforementioned multiple target position candidates exceeds a predetermined threshold, a target position candidate is selected as the target position of the workpiece according to a second selection logic based on a relationship value which is the relative relationship of the loads between the target position candidates. A request to move the workpiece to the selected target position candidate is transmitted to one or more of the transport devices. Conveyor system.

9. If, for a target workpiece that is one of several workpieces, there are multiple target location candidates for that target workpiece that correspond to the specified task, If the load for each of the multiple target position candidates is less than a predetermined threshold, a target position candidate is selected as the target position of the workpiece according to a first selection logic based on the load for each target position candidate. If the load for each of the aforementioned multiple target position candidates exceeds a predetermined threshold, a target position candidate is selected as the target position of the workpiece according to a second selection logic based on a relationship value which is the relative relationship of the loads between the target position candidates. A request to move the workpiece to the selected target position candidate is transmitted to one or more of the transport devices. A control method that uses a computer to perform this action.

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