Control device, control system, control method, and control program

Abstract

To suppress reduction in processing speed of a picking robot, and to prevent deterioration of inspection accuracy by an inspection system.SOLUTION: A control device according to an embodiment includes a communication interface configured to receive a second picking instruction based on an order list after a picking robot arranges a first article on a conveyor of an inspection unit based on a first picking instruction based on the order list, and receive an in-inspection notification indicating that the first article is being inspected, and a processor configured to control the picking robot to pick a second article to be picked based on the second picking instruction, and control vibration due to a picking operation of the picking robot to be reduced as compared with a normal time based on the in-inspection notification.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a control device, a control system, a control method, and a control program. [Background technology]

[0002] In recent years, digital transformation (DX) has been progressing in logistics warehouses and other facilities. As a result, various robots are working together to automate tasks in logistics as well. For example, a picking robot picks items from an inventory case and passes them on to a later stage. However, when picking by a picking robot, there are problems that are difficult for the picking robot to detect, such as damaged items or picking multiple items. If a problem occurs with the picked items, a discrepancy will occur between the number of items indicated in the inventory information held by the warehouse system and the actual number of items.

[0003] For example, Patent Document 1 discloses a technique for improving the work efficiency of a picking robot by utilizing operation history information of the picking robot.

[0004] In addition, there is a method of integrating the picking robot with an inspection system to determine whether the picking robot has picked the correct items in the correct number. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-040159 Summary of the Invention [Problem to be solved by the invention]

[0006] When a picking robot and an inspection system are integrated, there is a problem that the vibrations generated by the movement of the picking robot may cause the inspection system to lose its accuracy. Also, if the movement speed or acceleration of the picking robot is reduced to suppress the vibrations generated in the inspection system, the picking processing speed will drop significantly, resulting in a decrease in the throughput of the entire system.

[0007] This invention has been made in light of the above circumstances, and aims to provide a technology that can suppress a decrease in the processing speed of a picking robot and prevent a deterioration in the inspection accuracy of an inspection system. [Means for solving the problem]

[0008] The control device according to the embodiment includes a communication interface that receives a second picking instruction based on the order list after a picking robot places a first item on the conveyor of an inspection unit based on a first picking instruction based on the order list and receives an inspection in progress notification indicating that the first item is being inspected, and a processor that controls the picking robot to pick the second item to be picked based on the second picking instruction and controls the picking robot to reduce vibrations caused by the picking operation of the picking robot compared to normal times based on the inspection in progress notification. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a conceptual diagram showing an example of the arrangement of devices in an article inspection system according to the first embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of the configuration of the WCS according to the first embodiment. [Figure 3] FIG. 3 is a block diagram illustrating an example of the configuration of the control device according to the first embodiment. [Figure 4] FIG. 4 is a block diagram illustrating an example of the configuration of the inspection unit according to the first embodiment. [Figure 5]FIG. 5 is a diagram showing an example of the arrangement of the picking robot and the inspection unit according to the first embodiment. [Figure 6] FIG. 6 is a sequence diagram illustrating an example of an inspection operation for an item according to the first embodiment. [Figure 7] FIG. 7 is a diagram showing an example of the degree of vibration of the inspection unit in a conventional case and in a case where acceleration is reduced according to the first embodiment. [Figure 8] FIG. 8 is a block diagram showing an example of the configuration of a control device according to the second embodiment. [Figure 9] FIG. 9 is a diagram showing an example of the arrangement of the picking robot and the inspection unit according to the second embodiment. [Figure 10] FIG. 10 is a sequence diagram illustrating an example of an inspection operation for an item according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] The control device, control system, control method, and control program will be described in detail below with reference to the drawings. In the following embodiments, parts with the same numbers perform the same operations, and redundant description will be omitted. For example, when there are multiple identical or similar elements, a common symbol may be used to describe each element without distinguishing between them, or a subnumber may be used in addition to the common symbol to describe each element with distinction between them.

[0011] In the following description, the term "A" or "B" means at least one of A or B, and the term "A," "B," or "C" means at least one of A, B, or C. Furthermore, the term "A" and "B" also means at least one of A and B, and the term "A," "B," and "C" means at least one of A, B, and C.

[0012] [First embodiment] (composition) FIG. 1 is a conceptual diagram showing an example of the arrangement of devices in an article inspection system according to the first embodiment. 1, the item inspection system includes a warehouse operation system (WES) 1, a warehouse control system (WCS) 2, an item transport system 3, a picking robot system 4, and a sorter 5. Furthermore, the picking robot system 4 includes a control device 41, a picking robot 42, and an inspection unit 43.

[0013] The WES1 can be configured with one or more general-purpose computers. The WES30 includes a processor, memory, and interface. The processor is a central processing unit (CPU), a micro processing unit (MPU), a digital signal processor (DSP), or the like. The memory stores the processor's operating program, etc. The interface communicates with the WCS2, etc. via a network.

[0014] The WES1 receives item management information such as an order list from an external device such as a host server, and transmits the received item management information to the WCS2.

[0015] The WCS2 is composed of one or more computers, i.e., a processor, memory, and an interface. The processor is a CPU, MPU, DSP, or the like. The WCS2 also outputs item transport instructions to the item transport system 3 based on the order list, and controls the item transport system 3. The WCS2 also outputs picking instructions to the control device 41 of the picking robot system 4. The WCS2 also outputs inspection instructions to the inspection unit 43 for the items picked by the picking robot 42.

[0016] An order list is a list of items stored on warehouse shelves or the like, and specifies one or more items. For example, an order list may include item information, ordering information, delivery information, etc. Furthermore, an order list may include a flag indicating first-time arrival, a flag indicating unregistered image or uncompatible recognition dictionary, and an item grasping success rate. Note that the flag indicating first-time arrival, the flag indicating unregistered image or uncompatible recognition dictionary, and the item grasping success rate may be information held as an item database by the WCS 2, the control device 41, etc.

[0017] The item information includes the number of items, item names, item IDs, whether picking was successful, etc. The order information includes the order date and time and the orderer, etc. The delivery information includes the delivery destination, delivery date and time, and the recipient, etc.

[0018] The article transport system 3 is a system for transporting shelves or cases, etc., arranged in a warehouse to the picking robot system 4. For example, the article transport system 3 includes an automated guided vehicle (AGV) that transports shelves containing necessary articles to the picking robot system 4 according to an order list.

[0019] The control device 41 is composed of one or more computers, i.e., a processor, a memory, an interface, etc. For example, the control device 41 is a device that controls the picking robot 42. The processor is a CPU, an MPU, a DSP, etc. The control device 41 controls the picking robot 42. For example, under the control of the processor, the control device 41 communicates with the WCS 2 and receives a picking instruction from the WCS 2. The processor then controls the picking robot 42 in accordance with the picking instruction to have the picking robot 42 pick an item from the transported shelf or case and move it from the picking position to a destination position. Here, the destination position is, for example, a predetermined position where the inspection unit 43 is located. The picking instruction may simply be an instruction to start picking. In this case, the processor of the control device 41 controls the picking robot 42 to pick the item that arrives at the picking position or the item contained in the case, based on a detection signal of the item or case arriving at the picking position of the picking robot 42, and to move the item from the picking position to the destination position of the inspection unit 43.

[0020] The picking robot 42 is a device for picking items that is controlled by the control device 41. The picking robot 42 may be any general device that can pick items and move the picked items to a predetermined position, and therefore a detailed description thereof will be omitted here.

[0021] For example, when the picking robot 42 moves an item to a predetermined position, it is difficult for the control device 41 and the picking robot 42 to detect the following problems. (1) 0 items picked up (even though the picking robot 42 judges that it has picked up an item, it has not actually picked up an item) (2) Multiple item collection (3) Picking the wrong item (i.e., wrong item) (4) Damage to items (damaging items during picking) (5) Falling during transportation Therefore, these problems are detected using the inspection unit 43 described below.

[0022] The inspection unit 43, which is an item inspection device, is composed of one or more computers, i.e., a processor, memory, interface, etc. The processor is a CPU, MPU, DSP, etc. The inspection unit 43 transports inspected items to the sorter 5, which is the subsequent processing stage. The inspection unit 43 recognizes the items placed on the inspection unit 43 using a sensor, camera, etc., to grasp the condition of the items picked by the picking robot 42. The inspection unit 43 transmits the grasped condition of the items to the WCS 2.

[0023] For example, the inspection unit 43 receives information about an item to be inspected from the WCS 2. Then, the inspection unit 43 determines whether or not there is a problem with the item picked by the picking robot 42. Details of the method for determining whether or not there is a problem will be described later.

[0024] The sorter 5 is a sorting device that sorts the items transported by the inspection unit 43 to a sorting destination called a sorting surface. The sorter 5 sends the items that have passed through the picking robot system 4 to the sorting destination (sorting destination) in accordance with the sorting instructions received from the WCS 2.

[0025] FIG. 2 is a block diagram showing an example of the configuration of the WCS 2 according to the first embodiment. As shown in FIG. 2, the WCS 2 includes a processor 201, a ROM 202, a RAM 203, an auxiliary storage device 204, a communication interface 205, and the like.

[0026] The processor 201 is a CPU, an MPU, a DSP, or the like. The processor 201 operates based on a program stored in a ROM 202, or the like. The processor 201 acquires an order list, generates a picking instruction based on the order list, and outputs the generated picking instruction to the control device 41. Furthermore, the processor 201 acquires picking result information from the control device 41, which includes the results of picking items according to the picking instruction. The processor 201 then generates picking information based on the picking result information. Furthermore, the processor 201 generates an inspection instruction for the items picked by the picking robot 42, and outputs the picking information and the inspection instruction to the inspection unit 43.

[0027] The ROM 202 is a non-transitory computer-readable storage medium that stores the above-mentioned programs. The ROM 202 also stores data or various setting values ​​used by the processor 201 when performing various processes. For example, the ROM stores inventory information. The inventory information includes information such as the item IDs, number of items, item names, and item weights of items contained on shelves or cases in the warehouse.

[0028] The RAM 203 is a memory used for reading and writing data, and is used as a so-called work area for storing data that is temporarily used when the processor 201 performs various processes.

[0029] The auxiliary storage device 204 is a non-transitory computer-readable storage medium and may store the above programs. The auxiliary storage device 204 also stores data used by the processor 201 when performing various processes, data generated by the processes of the processor 201, various setting values, and the like.

[0030] The communication interface 205 is an interface for transmitting and receiving data to and from various devices. The communication interface 205 is connected to the article conveyance system 3, the picking robot system 4, the sorter 5, etc. The communication interface 205 also acquires order lists and the like from external systems, etc. For example, the communication interface 205 supports LAN (local area network) connections, etc. The communication interface 205 may also be configured to include separate interfaces for transmitting and receiving data to and from various devices.

[0031] FIG. 3 is a block diagram showing an example of the configuration of the control device 41 according to the first embodiment. As shown in FIG. 3, the control device 41 includes a processor 411, a ROM 412, a RAM 413, an auxiliary storage device 414, a communication interface 415, and the like.

[0032] The processor 411 is a CPU, an MPU, a DSP, or the like. The processor 411 operates based on a program stored in a ROM 412, or the like. The processor 411 receives a picking instruction. Then, the processor 411 outputs a control signal to the picking robot 42, controlling the picking robot 42 to pick an item. The processor 411 also controls the picking robot 42 to move the picked item to a predetermined position in the inspection unit 43, which will be described later. The processor 411 may generate a picking result including information about the item picked by the picking robot 42, and transmit the result to the WCS 2.

[0033] The ROM 412 is a non-transitory computer-readable storage medium that stores the above-mentioned programs. The ROM 412 also stores data and various setting values ​​used by the processor 411 when performing various processes.

[0034] The RAM 413 is a memory used for reading and writing data, and is used as a so-called work area for storing data that is temporarily used when the processor 411 performs various processes.

[0035] The auxiliary storage device 414 is a non-transitory computer-readable storage medium and may store the above programs. The auxiliary storage device 414 also stores data used by the processor 411 when performing various processes, data generated by the processes of the processor 411, various setting values, and the like.

[0036] The communication interface 415 is an interface for transmitting and receiving data to and from various devices. The communication interface 415 is connected to the WCS 2, the picking robot 42, the inspection unit 43, etc. For example, the communication interface 415 supports LAN connection, etc. The communication interface 415 may also be configured to include individual interfaces for transmitting and receiving data to and from various devices.

[0037] Furthermore, the communication interface 415 supports transmission and reception of various signals to and from the inspection unit 43 via digital signal lines (for example, a digital I / O module). That is, the control device 41 and the inspection unit 43 are connected by wire via digital signal lines without going through the WCS 2. This reduces delays in the transmission and reception of signals between the control device 41 and the inspection unit 43 compared to the transmission and reception of signals going through the WCS 2.

[0038] FIG. 4 is a block diagram showing an example of the configuration of the inspection unit 43 according to the first embodiment. As shown in FIG. 4, the inspection unit 43 includes a processor 431, a ROM 432, a RAM 433, an auxiliary storage device 434, a communication interface 435, a conveyor 436, a flipper 437, a sensor 438, and the like.

[0039] The processor 431 is a CPU, an MPU, a DSP, or the like. The processor 431 operates based on a program stored in a ROM 432, or the like. When the processor 431 receives an inspection instruction, it inspects the items picked by the picking robot 42 to determine whether or not there is a problem with the items. Furthermore, if the processor 431 determines that a problem has occurred as a result of the inspection, it generates an inspection result and outputs the generated inspection result to the WCS2.

[0040] The ROM 432 is a non-transitory computer-readable storage medium that stores the above-mentioned programs. The ROM 432 also stores data and various setting values ​​used by the processor 431 when performing various processes.

[0041] The RAM 433 is a memory used for reading and writing data, and is used as a so-called work area for storing data that is temporarily used when the processor 431 performs various processes.

[0042] The auxiliary storage device 434 is a non-transitory computer-readable storage medium and may store the above programs. The auxiliary storage device 434 also stores data used by the processor 431 when performing various processes, data generated by the processes of the processor 431, various setting values, and the like.

[0043] The communication interface 435 is an interface for transmitting and receiving data to and from various devices. The communication interface 435 is connected to the WCS2 and the like. The communication interface 435 also acquires inspection instructions and the like from the WCS2. For example, the communication interface 435 supports LAN connection and the like. The communication interface 435 may also be configured to include individual interfaces for transmitting and receiving data to and from various devices. Furthermore, the communication interface 435 supports transmitting and receiving various signals to and from the control device 41 via digital signal lines (for example, a digital I / O module).

[0044] The conveyor 436 is a place where the picking robot 42 places the item, and is a device that performs an inspection process on the item while it is flowing on the conveyor 436. If the inspection process shows that there is no problem with the item, the conveyor 436 moves the item to the sorter 5, which is a subsequent device.

[0045] The flipper 437 is a sorter that, if an item is found to have a problem as a result of the inspection process, sends the item into a reject box instead of sending it to the sorter 5. Note that the flipper 437 is not necessarily an essential component. For example, if the sorter 5 is equipped with a sorter for sending items to the reject box, the flipper 437 may be omitted.

[0046] The sensor 438 includes a weight sensor 4381, a photoelectric sensor 4382, and the like.

[0047] The weight sensor 4381 is a sensor for measuring the weight of the items flowing on the conveyor 436. For example, the measured weight of the items is used to determine whether or not there is a problem with the items, such as zero items being taken, multiple items being taken, the wrong item being taken, the item being damaged, or the item being dropped.

[0048] The photoelectric sensor 4382 is a sensor for determining whether an article is flowing on the conveyor 436. The photoelectric sensor 4382 is composed of, for example, multiple sensors. For example, when a first photoelectric sensor detects an article, the processor 431 determines that the weight sensor 4381 should measure the weight of the article. Furthermore, when a second photoelectric sensor arranged closer to the sorter 5 than the first photoelectric sensor detects an article, the processor 431 determines that measurement of the weight of the article by the weight sensor 4381 should be terminated. The photoelectric sensor 4382 may also be used to determine at which position on the conveyor 436 an article is flowing.

[0049] The photoelectric sensor 4382 is not an essential component as long as the processor 431 can determine the start and end of measuring the weight of an item by the weight sensor 4381. For example, instead of the photoelectric sensor 4382, a pressure sensor may be placed on the conveyor 436, or a camera or the like capable of detecting items moving on the conveyor 436 may be placed.

[0050] FIG. 5 is a diagram showing an example of the arrangement of the picking robot 42 and the inspection unit 43 according to the first embodiment. The picking robot 42 picks an item from a case 44 transported by the item transport system 3. The picking robot 42 then places the item on a conveyor 436 (for example, the conveyor 436 at the farthest back as viewed from the page) on the inspection unit 43. The inspection unit 43 inspects the item while moving the item placed on the conveyor. If there is no problem, the inspection unit 43 moves the item to a case 45 leading to the sorter 5. On the other hand, if there is a problem, the inspection unit 43 uses a flipper 437 to move the defective item to a reject box 46. Note that while the example in FIG. 5 shows an example in which the item is moved to the case 45, the conveyor 436 may be directly connected to the sorter 5.

[0051] 5, the picking robot 42 and the inspection unit 43 are disposed adjacent to each other, i.e., as a single unit. Because they are disposed as a single unit, vibrations generated by the picking robot 42 are transmitted to the inspection unit 43. These vibrations may cause a deterioration in inspection accuracy during weighing by the inspection unit 43.

[0052] Therefore, in the first embodiment, the inspection unit 43 notifies the picking robot 42 (controller 41) of the start and end of the inspection via a digital signal line (i.e., directly). Then, the controller 41, which has received the notification, controls the picking robot 42 to suppress vibrations while the inspection unit 43 is weighing.

[0053] (operation) Next, the inspection operation according to the first embodiment will be described. FIG. 6 is a sequence diagram illustrating an example of an inspection operation for an item according to the first embodiment. This sequence is realized by the processor 201 of the WCS 2, the processor 411 of the control device 41, and the processor 431 of the inspection unit 43 reading and executing programs stored in the ROM 202, ROM 412, and ROM 432, respectively.

[0054] First, the operation of this sequence begins when the item transport system 3 sends information to the WCS 2 indicating that a shelf or case containing an item to be picked by the picking robot 42 has been transported.

[0055] In step ST101, the processor 201 of the WCS2 sends a picking instruction. The processor 201 creates a picking instruction (first picking instruction) that indicates the items to be picked based on the order list. Then, the processor 201 sends the created picking instruction to the control device 41 via the communication interface 205.

[0056] In step ST102, the processor 411 of the control device 41 controls the picking robot 42 to perform a picking operation. For example, upon receiving a picking instruction, the processor 411 controls the picking robot 42 to pick an item (first item) in accordance with the picking instruction. Then, the processor 411 controls the picking robot 42 to move the picked item to a predetermined destination position on the conveyor 436 of the inspection unit 43.

[0057] In step ST103, the processor 411 controls the picking robot 42 to place the picked item at a predetermined location at the destination position. The processor 411 controls the picking robot 42 to place the item moved to the destination position at a predetermined location in the inspection unit 43 (for example, a predetermined position on the conveyor 436).

[0058] In step ST104, the processor 411 transmits a placement completion notification. After the picking robot 42 places the item in a predetermined location, the processor 411 generates a placement completion notification indicating that the placement of the item has been completed. Then, the processor 411 transmits the placement completion notification to the WCS2 via the communication interface 415. The placement completion notification may include a picking result including an item ID for the picked item, etc.

[0059] In step ST105, the processor 201 transmits an inspection start notification. When the processor 201 receives the placement completion notification, it generates an inspection start notification, which is an inspection instruction. The inspection start notification includes information such as the shape and weight of the item to be inspected. Then, the processor 201 transmits the inspection start notification to the inspection unit 43 via the communication interface 205.

[0060] In step ST106, the processor 201 transmits a picking instruction. Based on the order list, the processor 201 creates a picking instruction that indicates the item to be picked after the item picked in step ST102. Then, the processor 201 transmits the created picking instruction to the control device 41 via the communication interface 205. Note that steps ST105 and ST106 may be processed simultaneously, or their order may be reversed.

[0061] In step ST107, processor 431 weighs the item. Having received the inspection start notification, processor 431 operates conveyor 436 to move the item to a location where photoelectric sensor 4382 (first photoelectric sensor) detects the item, i.e., where weight sensor 4381 can measure the weight of the item. Processor 411 then starts weighing the item using weight sensor 4381, i.e., starts inspecting the item.

[0062] For example, processor 431 acquires the weight of an item measured by weight sensor 4381. Then, processor 431 compares the obtained weight of the item with the weight of the item included in the inspection start notice to determine whether the weight of the item is correct. If the weights differ, such as if the weight of the item is approximately two or more times the weight of the item included in the inspection instruction, processor 431 determines that a problem with multiple item picking has occurred. If the weighing result is approximately zero, processor 431 determines that a problem with zero picking or an item falling has occurred. Alternatively, if the bottom of the item is missing and the weight of the weighing result differs from the weight of the item included in the inspection start notice, processor 431 determines that a damaged or incorrect item has occurred. In these cases, processor 431 uses flipper 437 to send the item to reject box 46. On the other hand, if processor 431 determines that the weight of the item is correct, processor 431 controls conveyor 436 to move the item to case 45.

[0063] In step ST108, the processor 431 transmits an inspection in progress notification. When the processor 431 starts weighing the items, i.e., inspecting the items, it transmits an inspection in progress notification (weighing in progress notification) including weight sensor information indicating that inspection of the items is being carried out to the control device 41 via the communication interface 435. For example, the processor 431 controls the output of a digital signal on a digital signal line connected to the control device 41 to be set to a High level. As described above, the control device 41 and the inspection unit 43 are directly connected using a digital I / O module or the like, and there is less delay than when sending and receiving signals via the WCS2. This solves the problem that the processor 411 of the control device 41 is unable to control the picking robot 42 in time for weighing by the inspection unit 43.

[0064] In step ST109, the processor 411 controls the picking robot 42 to perform a picking operation. When the digital signal from the inspection unit 43 is High, the processor 411 controls the picking robot 42 to suppress vibrations when performing a picking operation. For example, based on the in-inspection notification, the processor 411 controls the acceleration of the picking robot 42 during the picking operation to be smaller than normal. Furthermore, the processor 411 may determine how much vibration (e.g., acceleration) to reduce based on weight sensor information, i.e., based on the inspection details performed by the inspection unit 43. Furthermore, the value by which the processor 411 controls the picking robot 42 to suppress vibrations may be the speed, jerk (jerk), or maximum power of the picking robot 42 during the picking operation, rather than the acceleration.

[0065] Here, vibrations of the picking robot 42 occur most frequently when the picking robot 42 accelerates or decelerates. Therefore, the processor 411 controls the operation of the picking robot 42 so that the acceleration of the picking robot 42 related to the picking operation is reduced compared to normal times. By controlling in this manner, vibrations to the inspection unit 43 integrated with the picking robot 42 can be suppressed.

[0066] FIG. 7 is a diagram showing an example of the degree of vibration of the inspection unit 43 in a conventional case and in a case where the acceleration is reduced according to the first embodiment. FIG. 7(a) is a diagram showing the degree of vibration of the inspection unit 43 when the acceleration of the picking operation is not reduced, i.e., a conventional inspection unit, and FIG. 7(b) is a diagram showing the degree of vibration of the inspection unit 43 according to the first embodiment. In the example of FIG. 7, the degree of vibration is represented by the maximum acceleration. FIGS. 7(a) and 7(b) show that the degree of vibration of the inspection unit 43 according to the first embodiment is reduced compared to the degree of vibration of the conventional inspection unit 43. In this way, by reducing the acceleration of the picking robot 42 during inspection (weighing) by the inspection unit 43 compared to normal times, the degree of vibration in the inspection unit 43 can be reduced. This allows the inspection unit 43 to prevent a deterioration in inspection accuracy due to vibration.

[0067] If a picking instruction has been received but an inspection-in-progress notification has not been received, the processor 411 controls the picking robot 42 to perform a picking operation at normal acceleration (i.e., normal vibrations are generated). After that, if an inspection-in-progress notification is received, the processor 411 quickly controls the operation of the picking robot 42 to reduce the vibrations of the picking robot 42 related to the picking operation compared to normal times.

[0068] In step ST110, the processor 431 transmits an inspection completion notification. When the photoelectric sensor 4382 (second photoelectric sensor) detects an item, the processor 411 determines that weighing of the item has been completed. Then, the processor 411 transmits an inspection completion notification indicating that weighing of the item has been completed to the control device 41 via the communication interface 435. For example, the processor 431 notifies the control device 41 that inspection of the item has been completed by setting the output of a digital signal on a digital signal line connected to the control device 41 to a LOW level.

[0069] In step ST111, the processor 431 transmits an inspection completion notification. The processor 431 generates an inspection completion notification and transmits the generated inspection completion notification to the WCS2 via the communication interface 435. Note that the inspection completion notification transmitted to the WCS2 may include inspection results such as the weight of the item measured by the weight sensor 4381.

[0070] Furthermore, the processes of step ST110 and step ST111 may be performed in parallel, or may be performed in reverse order.

[0071] In step ST112, the processor 431 controls the picking robot 42 to perform the picking operation at normal acceleration (i.e., normal vibration occurs). Having detected the inspection completion notification, the processor 431 controls the picking robot 42 to perform the picking operation at the acceleration of the picking operation that should be performed under normal circumstances. Note that if the picking operation has finished before receiving the inspection completion notification, the processing of step ST112 may be skipped.

[0072] Here, the processing of step ST110 may be skipped. In this case, in step ST112, the processor 431 controls the picking robot 42 so that the picking operation is performed at normal acceleration after a predetermined time has elapsed since the processor 431 received the inspection-in-progress notification. The predetermined time may be set to, for example, the maximum time it takes for the inspection unit 43 to inspect an item.

[0073] In step ST113, the processor 411 controls the picking robot 42 to place the picked item at a predetermined location in the destination position. The processor 411 controls the picking robot 42 to place the item moved to the destination position at a predetermined location in the inspection unit 43 (for example, a predetermined position on the conveyor 436).

[0074] The process repeats steps ST106 to ST113 until the picking operation based on the order list is completed.

[0075] (Operation and effect of the first embodiment) According to the first embodiment described above, while the inspection unit 43 is weighing an item, the control device 41 controls the picking robot 42 to reduce vibrations caused by the picking robot 42 compared to normal times. This reduces the degree of vibration to the inspection unit 43, making it possible to prevent a deterioration in inspection accuracy caused by vibrations of the picking robot 42.

[0076] Furthermore, the control device 41 and the inspection unit 43 are connected by a digital signal line using a digital I / O module or the like. This makes it possible to reduce the communication delay between the control device 41 and the inspection unit 43 compared to the signal delay via the WCS 2. This solves the problem that the processor 411 is unable to keep up with the vibration suppression control of the picking robot 42.

[0077] [Second embodiment] In the second embodiment, an example will be described in which inspection is performed using a camera instead of measuring the weight of an item using a weight sensor 4381.

[0078] (composition) The configuration of the inspection system and the configuration of the WCS2 in the second embodiment are the same as those in the first embodiment, so a duplicated description will be omitted here.

[0079] FIG. 8 is a block diagram showing an example of the configuration of a control device 41 according to the second embodiment.

[0080] The control device 41 differs from the first embodiment in that the sensor 438 includes a camera 4383 .

[0081] The camera 4383 photographs the conveyor 436 and acquires a photographed image. The camera 4383 may be a general camera 4383. The photographed image taken by the camera 4383 is used by the processor 431 to determine whether or not a problem has occurred with the article, such as multiple items being taken, damage to the article, or a dropped article.

[0082] FIG. 9 is a diagram showing an example of the arrangement of the picking robot 42 and the inspection unit 43 according to the second embodiment. As shown in FIG. 9, the picking robot 42 and the inspection unit 43 are installed adjacent to each other, similar to FIG.

[0083] The camera 4383 is disposed above the picking robot 42 in order to photograph the top of the conveyor 436. Therefore, the camera 4383 is significantly affected by vibrations caused by the picking robot 42. In the second embodiment, during the inspection operation by the camera 4383, the control device 41 controls the picking robot 42 to suppress vibrations.

[0084] (operation) Next, the inspection operation according to the second embodiment will be described. FIG. 10 is a sequence diagram illustrating an example of an inspection operation for an item according to the second embodiment. This sequence is realized by the processor 201 of the WCS 2, the processor 411 of the control device 41, and the processor 431 of the inspection unit 43 reading and executing programs stored in the ROM 202, ROM 412, and ROM 432, respectively.

[0085] First, the operation of this sequence is started when the article transport system 3 sends information to the WCS 2 indicating that a shelf containing an article to be picked by the picking robot 42 has been transported.

[0086] The operations in steps ST201 to ST206 are the same as the operations in steps ST101 to ST106 described with reference to Fig. 6. Therefore, a duplicated description will be omitted here.

[0087] In step ST207, the processor 431 inspects the item. Upon receiving the inspection start notification, the processor 431 operates the conveyor 436 and moves the item to a location where the photoelectric sensor 4382 (first photoelectric sensor) detects the item, that is, a location where the camera 4383 can photograph the item or can photograph it optimally. Note that the processor 431 does not necessarily have to move the item to a location where the photoelectric sensor 4382 (first photoelectric sensor) can detect the item. The camera 4383 may also detect the item. Then, the processor 411 inspects the item based on the image captured by the camera 4383.

[0088] For example, processor 431 detects whether multiple items are detected, whether an item is not detected, whether an item is damaged, etc. based on the image captured by camera 4383. If any of these problems are detected, processor 431 uses flipper 437 to send the item to reject box 46. On the other hand, if processor 431 determines that no such problems are detected, that is, that the item has been picked correctly, processor 431 controls conveyor 436 so that the item proceeds to case 45.

[0089] In step ST208, the processor 431 transmits an inspection in progress notification. When the processor 431 starts inspection of the item using the camera 4383, the processor 431 transmits an inspection in progress notification including camera information indicating that inspection of the item is being carried out to the control device 41 via the communication interface 435. For example, the processor 431 controls the output of the digital signal on the digital signal line connected to the control device 41 to be set to a high level.

[0090] In step ST209, the processor 411 controls the picking robot 42 to perform a picking operation. When the digital signal from the inspection unit 43 is High, the processor 411 controls the picking robot 42 to suppress vibrations when performing a picking operation. For example, based on the in-inspection notification, the processor 411 controls the acceleration of the picking robot 42 during the picking operation to be smaller than normal. Furthermore, the processor 411 may determine how much to reduce the vibrations (e.g., acceleration) based on camera information, i.e., based on the inspection content performed by the inspection unit 43.

[0091] As in step ST109, if a picking instruction has been received but an inspection-in-progress notification has not been received, the processor 411 controls the picking robot 42 to perform a picking operation at normal acceleration (i.e., normal vibrations are generated). After that, if an inspection-in-progress notification is received, the processor 411 quickly controls the operation of the picking robot 42 to reduce vibrations caused by the picking robot 42 during the picking operation compared to normal times.

[0092] The operations in steps ST210 to ST213 are the same as the operations in steps ST110 to ST113 described with reference to Fig. 6. Therefore, a duplicated description will be omitted here.

[0093] (Effects of the second embodiment) According to the second embodiment described above, while the inspection unit 43 inspects the items using the images captured by the camera 4383, the control device 41 controls the picking robot 42 to reduce vibrations caused by the picking robot 42 compared to normal times. This reduces the degree of vibration to the camera 4383, and makes it possible to prevent deterioration of inspection accuracy caused by vibrations of the picking robot 42.

[0094] Furthermore, the control device 41 and the inspection unit 43 are connected by a digital signal line using a digital I / O module or the like. This makes it possible to reduce the communication delay between the control device 41 and the inspection unit 43 compared to the signal delay via the WCS 2. This solves the problem of the picking robot 42 not being able to suppress vibrations in time.

[0095] [Other embodiments] The first and second embodiments can also be implemented in combination. For example, in addition to measurement by the weight sensor 4381, inspection can be performed by the camera 4383. By performing inspection of items using multiple sensors in this manner, the probability of an inspection error occurring can be further reduced. In this case, the processor 431 transmits an inspection in progress notification to the control device 41, which notification includes inspection execution information indicating that inspection is being performed by the weight sensor 4381 and the camera 4383. Then, based on the inspection execution information, the processor 411 controls the picking robot 42 to reduce vibrations so as to reduce the effects of vibrations from both the weight sensor 4381 and the camera 4383.

[0096] The program according to this embodiment may be transferred in a state where it is stored in an electronic device (computer) such as the WCS2, the control device 41, or the inspection unit 43, or may be transferred in a state where it is not stored in an electronic device. In the latter case, the program may be transferred via a network or in a state where it is stored in a storage medium. The storage medium is a non-transitory, tangible medium. The storage medium is a medium that can be read by a computer such as the WCS2, the control device 41, or the inspection unit 43 (computer-readable medium). The storage medium may be in any form, such as an optical disk (e.g., a CD-ROM), a magnetic disk, or a semiconductor memory (e.g., a memory card), as long as it is capable of storing a program and is readable by a computer.

[0097] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0098] 1…WES 2...WCS 201...Processor 202...ROM 203...RAM 204...Auxiliary storage device 205...Communication interface 3. Goods transport system 4. Picking robot system 41...Control device 411...Processor 412...ROM 413...RAM 414...Auxiliary storage device 415...Communication interface 42...Picking robot 43...Inspection unit 431...Processor 432...ROM 433...RAM 434...Auxiliary storage device 435...Communication interface 436...Conveyor 437...Flipper 438...Sensor 4381...Weight sensor 4382...Photoelectric sensor 4383...Camera 44…Case 45…Case 46...Reject box 5...Sorter

Claims

1. a communication interface that receives a second picking instruction based on the order list after a picking robot places a first item on a conveyor of an inspection unit based on a first picking instruction based on the order list, and receives an inspection-in-progress notification indicating that the first item is being inspected; a processor that controls the picking robot to pick the second item to be picked based on the second picking instruction, and controls the picking robot to reduce vibrations caused by the picking operation of the picking robot compared to normal times based on the inspection-in-progress notification; A control device comprising:

2. the processor controls the picking robot to reduce the acceleration of the picking operation compared to normal times in order to reduce the vibration compared to normal times; The control device according to claim 1 .

3. the communication interface receives an inspection completion notification indicating that inspection of the second item has been completed; The processor controls the picking robot to return the picking operation to normal. The control device according to claim 1 .

4. the processor controls the picking robot to return to normal picking operation after a predetermined time has elapsed since receiving the inspection-in-progress notification; The control device according to claim 1 .

5. The control device is connected to the inspection unit that transmits the inspection notification by a digital signal line. The control device according to claim 1 .

6. the picking robot and the inspection unit that sends the inspection notification are disposed as an integral unit; the processor controls the picking robot to reduce vibrations caused by the picking operation compared to normal times, thereby reducing the degree of vibration of the inspection unit; The control device according to claim 1 .

7. the inspection in progress notification includes weight sensor information indicating that the inspection unit is inspecting the second item using a weight sensor; and the processor controls the picking robot to reduce vibrations caused by the picking operation based on weight sensor information. The control device according to claim 1 .

8. the inspection in progress notification includes camera information indicating that the inspection unit is inspecting the second item using a camera; and the processor controls the picking robot to reduce vibrations caused by the picking operation based on the camera information. The control device according to claim 1 .

9. the inspection in progress notification includes inspection execution information indicating that the inspection unit is inspecting the second item using a weight sensor and a camera; The processor controls the picking robot to reduce vibrations caused by the picking operation based on the inspection execution information. The control device according to claim 1 .

10. a control device; an inspection unit connected to the control device by wire; The control device comprises: a communication interface that receives a second picking instruction based on the order list after a picking robot places a first item on the conveyor of the inspection unit based on a first picking instruction based on the order list, and receives an inspection-in-progress notification indicating that the first item is being inspected; a processor that controls the picking robot to pick the second item to be picked based on the second picking instruction, and controls the picking robot to reduce vibrations caused by the picking operation of the picking robot compared to normal times based on the inspection-in-progress notification; The inspection unit comprises: a processor that generates the inspection notification when the item moves to a predetermined position on the conveyor; a communication interface for transmitting the inspection notification; A control system comprising:

11. A control method executed by a processor of a control device, receiving a second picking instruction based on the order list after the picking robot places a first item on a conveyor of the inspection unit based on a first picking instruction based on the order list; receiving an in-inspection notification indicating that the first item is under inspection; Controlling the picking robot to pick a second item based on the second picking instruction; controlling the picking robot to reduce vibrations caused by the picking operation based on the inspection in progress notification compared to normal times; A control method comprising:

12. A control program comprising instructions for execution by a processor of a control device, the instructions comprising: receiving a second picking instruction based on the order list after the picking robot places a first item on a conveyor of the inspection unit based on a first picking instruction based on the order list; receiving an in-inspection notification indicating that the first item is under inspection; Controlling the picking robot to pick a second item based on the second picking instruction; controlling the picking robot to reduce vibrations caused by the picking operation based on the inspection in progress notification compared to normal times; A control program comprising:

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