ROBOT SYSTEM, PROCESSING METHOD, AND PROGRAM

Abstract

This robot system comprises: a movement means for moving an object; and a specifying means for specifying the timing at which to release the object, such specification being on the basis of a physical quantity generated by the object and measured at the destination of the object.

Description

ROBOT SYSTEM, PROCESSING METHOD, AND RECORDING MEDIUM

[0001] The present disclosure relates to a robot system, a processing method, and a recording medium.

[0002] Robots are used in a variety of fields, including logistics. Patent Document 1 discloses a related technique in which a force detection device is used to detect the contact state between parts, and the position and posture of a movable part are controlled in accordance with the contact state.

[0003] Japanese Patent Application Publication No. 11-188680

[0004] However, when a robot grasps an object, moves it to a destination, and then releases it, depending on the timing of releasing the object, an impact may be applied to the object, potentially damaging it. Therefore, there is a need for a technology in robot systems that can identify the timing at which the impact applied to an object when the robot releases it can be alleviated.

[0005] One of the objectives of each aspect of the present disclosure is to provide a robot system, a processing method, and a recording medium that can solve the above-mentioned problems.

[0006] According to one aspect of the present disclosure, a robot system includes a moving means for moving an object, and an identifying means for identifying the timing to release the object based on a physical quantity generated by the object measured at a destination of the object.

[0007] According to another aspect of the present disclosure, a processing method is a processing method executed by a robot system having a moving means for moving an object, and determines the timing to release the object based on a physical quantity generated by the object measured at a destination of the object.

[0008] According to another aspect of the present disclosure, a recording medium stores a program that causes a computer of a robot system having a moving means for moving an object to determine the timing to release the object based on a physical quantity generated by the object that is measured at a destination of the object.

[0009] According to each aspect of the present disclosure, in a robot system, it is possible to identify the timing at which an impact on an object can be alleviated when the robot releases the object.

[0010] FIG. 1 is a diagram illustrating an example of a configuration of a robot system according to an embodiment of the present disclosure. FIG. 2 is a diagram illustrating an example of a configuration of a transport system according to an embodiment of the present disclosure. FIG. 3 is a diagram illustrating an example of a configuration of a host device according to an embodiment of the present disclosure. FIG. 4 is a diagram illustrating an example of an operation status managed by a management unit according to an embodiment of the present disclosure. FIG. 5 is a diagram illustrating an example of a database according to an embodiment of the present disclosure. FIG. 6 is a diagram illustrating an example of a configuration of a processing device according to an embodiment of the present disclosure. FIG. 7 is a diagram illustrating an example of a processing flow of a robot system according to a first embodiment of the present disclosure. FIG. 8 is a diagram illustrating a robot system with a minimum configuration according to an embodiment of the present disclosure. FIG. 9 is a schematic block diagram illustrating the configuration of a computer according to at least one embodiment.

[0011] Hereinafter, embodiments will be described in detail with reference to the drawings. <Embodiment> A robot system 1 according to an embodiment of the present disclosure moves an object to a destination and identifies a timing at which an impact on the object can be alleviated when the robot releases the grasped object at the destination. Examples of objects include merchandise. Note that in this disclosure, grasping includes not only holding the object at the position of the robot arm by clamping the object, but also holding the object at the position of the robot arm by suction. The robot system 1 is used, for example, for inspecting objects in a warehouse.

[0012] 1 is a diagram illustrating an example of a configuration of a robot system 1 according to an embodiment of the present disclosure. As shown in FIG. 1, the robot system 1 includes a conveyance system 10, a robot 20, an imaging device 30, a weighing scale 40 (an example of a measuring means), and a processing device 50.

[0013] 2 is a diagram illustrating an example of the configuration of a conveyance system 10 according to an embodiment of the present disclosure. As shown in FIG. 2, the conveyance system 10 includes a conveyance mechanism 101, a host device 102, and a database DB. An example of the conveyance system 10 is a WMS (warehouse management system).

[0014] The transport mechanism 101 moves an object (e.g., a product placed in a cardboard box C) to an area where the robot 20 can operate, based on the database DB. Examples of the transport mechanism 101 include an automatic guided vehicle (AGV), a belt conveyor, and a crawler.

[0015] 3 is a diagram illustrating an example of the configuration of the host device 102 according to an embodiment of the present disclosure. As shown in FIG. 3, the host device 102 includes a management unit 1021, a specification unit 1022, and an instruction unit 1023.

[0016] The management unit 1021 manages the operation status of the robot 20. Examples of the operation of the robot 20 include grasping an object, moving an object, and releasing an object. The operation status of the robot 20 is information indicating which operation the robot 20 is performing.

[0017] FIG. 4 is a diagram illustrating an example of the status of actions managed by the management unit 1021 according to an embodiment of the present disclosure. In the example illustrated in FIG. 4, the robot 20 is scheduled to perform action 1 (e.g., an action to grasp an object) in period T1 (time t1 to t2), action 2 (e.g., an action to move an object) in period T2 (time t2 to t3), and action 3 (e.g., an action to release an object) in period T3 (time t3 to t4). In FIG. 4, status 0 indicates that the action has been processed. Status 1 indicates that the action is being processed. A blank status indicates that the action has not been processed. Therefore, the example of the status illustrated in FIG. 4 indicates that the robot 20 is moving an object while grasping it.

[0018] The identification unit 1022 identifies the shape of each object from the image captured by the image capture device 30. The image captured by the image capture device 30 includes information captured by a two-dimensional camera and information in the depth direction. This enables the identification unit 1022 to identify the shape of each object.

[0019] The instruction unit 1023 outputs an instruction for the planned operation of the robot 20 based on the status to the processing device 50. Specifically, the instruction unit 1023 outputs an instruction to the processing device 50 to execute the operation associated with status 1 during the period T associated with status 1.

[0020] The database DB stores information indicating the type, quantity, and weight of each object (e.g., product) for each cardboard box C. The information indicating the type, quantity, and weight of each object is identified, for example, when the product arrives by using a barcode reader to read the barcode attached to the cardboard box C in which the product is placed. The barcode reader then associates the information indicating the type, quantity, and weight of each object with each cardboard box C and records it in the database DB.

[0021] Fig. 5 is a diagram showing an example of a database DB according to an embodiment of the present disclosure. The example database DB shown in Fig. 5 shows that cardboard boxes C1, C2, and C3 exist, and that cardboard box C1 contains 10 items A, cardboard box C2 contains 20 items B, and cardboard box C3 contains 30 items C. The example database DB shown in Fig. 5 also shows that the weight of each item A is weight 1, the weight of each item B is weight 2, and the weight of each item C is weight 3.

[0022] 1, the robot 20 includes a robot body 201, a robot arm 202 (an example of a moving means), and a drive mechanism 203. The robot arm 202 is connected to the robot body 201. In response to the operation of the drive mechanism 203, the robot arm 202 grasps an object contained in a cardboard box C and moves the object to a destination (for example, a tray T). The robot arm 202 then releases the object at the destination.

[0023] The driving mechanism 203 operates the robot arm 202. For example, in response to a control signal from the processing device 50, the driving mechanism 203 causes the robot arm 202 to grasp an object, move the object to a destination (e.g., tray T), and release the object.

[0024] The imaging device 30 can capture images of objects (e.g., products) in an area where the robot 20 can operate. The imaging device 30 outputs the captured images of the objects to the transport system 10. The imaging device 30 is, for example, a depth camera.

[0025] Weighing scale 40 measures the force generated by the object at its destination (the force applied to weighing scale 40 by the object at its destination). For example, if the destination is a tray T, weighing scale 40 is provided below tray T. Note that when an object is inspected in a warehouse, the inspection often includes checking whether the object is at a specified weight. For this reason, a warehouse that has an inspection system is likely to have weighing scale 40 prepared in advance.

[0026] 6 is a diagram illustrating an example of the configuration of a processing device 50 according to an embodiment of the present disclosure. As shown in FIG. 6, the processing device 50 includes a control unit 501 (an example of a control means) and an identification unit 502 (an example of an identification means).

[0027] The control unit 501 controls the operation of the robot arm 202 in response to instructions from the instruction unit 1023. For example, in response to instructions from the instruction unit 1023, the control unit 501 causes the robot arm 202 to grasp an object, move the object to a destination, and release the object at a timing identified at the destination by the identification unit 502. Note that the control unit 501 causes the robot arm 202 to grasp the object until it releases the object at the destination. In other words, the control unit 501 controls the robot arm 202 to approach the destination from above the destination while grasping the object.

[0028] The identification unit 502 identifies the timing to release the object based on the force generated by the object at the destination of the object, which is measured by the weighing scale 40. For example, if the action associated with status 1 is an action to release the object, the identification unit 502 identifies the timing to release the object within the period T associated with status 1.

[0029] Specifically, the identification unit 502 acquires the measurement results of the weighing scale 40 at predetermined time intervals from the start time of the period T. The predetermined time intervals are sufficiently shorter than the period T. The measurement results herein refer to the readings of the weighing scale 40 at each timing corresponding to the predetermined time intervals. Examples of the measurement results include the force pushing the weighing scale 40 from an object grasped by the robot arm 202, the force applied to the weighing scale 40 due to the weight of the object after the robot arm 202 releases the object, and the force pushing the weighing scale 40 from an object grasped by the robot arm 202 in the presence of a previously released object. When the aforementioned forces are applied to the weighing scale 40, acceleration may be applied to the moving parts of the weighing scale 40 due to vibrations or noise around the weighing scale 40, or the force applied when the object is released, which may cause vibrations in the weighing scale 40. As a result, there may be a period during which the readings of the weighing scale 40 fluctuate (a period of free vibration). In such a case, the measurement result may be the reading of the weigh scale 40 when the reading of the weigh scale 40 has converged to a predetermined magnitude of fluctuation. That is, the measurement result is the reading of the weigh scale 40 that measures the force applied to the weigh scale 40 from objects, including past objects, at each timing as the weight of the object. Note that, if the measurement result is fluctuating, the robot arm 202 may wait until the fluctuation in the measurement result subsides, then push the weigh scale 40 away from the object it is holding, and release the object when the predetermined measurement result is achieved. Note that force is expressed as the product of mass (i.e., weight in the embodiment of the present disclosure) and acceleration. Therefore, the measurement result is not limited to the reading of the weigh scale 40 that measures the force applied to the weigh scale 40 from objects, including past objects, at each timing as the weight of the object. For example, the measurement result may also be the reading of the weigh scale 40 that measures the weight or acceleration applied to the weigh scale 40 from objects, including past objects, at each timing as the weight of the object. Note that force, weight, and acceleration are each an example of a physical quantity. The determination unit 502 calculates the acceleration by time-differentiating the acquired measurement result of the weighing scale 40 .The identifying unit 502 then identifies the timing at which the calculated acceleration exceeds the threshold value as the timing to release the object. Note that the identifying unit 502 stops acquiring the measurement results of the weighing scale 40 once it has identified the timing to release. If the identifying unit 502 has not been able to identify the timing to release by the end of the period T, it ends the process.

[0030] Specifically, the identification unit 502 acquires the measurement results of the weighing scale 40 at predetermined time intervals from the start time of the period T. This predetermined time interval is sufficiently shorter than the period T. The identification unit 502 calculates statistical values ​​for the acquired measurement results of the weighing scale 40 over a predetermined period going back (a fixed time). Examples of statistical values ​​include the mean, median, average of the maximum and minimum values, and mode. The identification unit 502 then identifies the timing at which the calculated statistical value exceeds a threshold as the timing to release the object. The identification unit 502 stops acquiring the measurement results of the weighing scale 40 once it has identified the timing to release the object. If the identification unit 502 has not been able to identify the timing to release the object by the end time of the period T, it terminates the process.

[0031] (Processing Performed by Robot System) FIG. 7 is a diagram showing an example of a processing flow of the robot system 1 according to the first embodiment of the present disclosure. Next, the processing performed by the robot system 1 will be described with reference to FIG. 7. Note that, here, for example, it is assumed that the operation of the robot 20 is planned so as to move an object from the cardboard box C shown in FIG. 1 to the tray T by the period T and operation shown in FIG. 4. It is also assumed that the instruction unit 1023 outputs instructions for the planned operation of the robot 20 to the processing device 50 based on the status.

[0032] The control unit 501 controls the operation of the robot arm 202 in response to instructions from the instruction unit 1023. A specific example will be shown below.

[0033] First, in response to an instruction from the instruction unit 1023 to grip an object, the control unit 501 causes the robot arm 202 to grip an object contained in the cardboard box C during a period T1 (step S1).

[0034] In response to an instruction to move the object from the instruction unit 1023, the control unit 501 causes the robot arm 202 to move the object from the cardboard box C to above the tray T during the period T2 (step S2).

[0035] Control unit 501 causes robot arm 202 to release the object within period T3 in response to an instruction to release the object from instruction unit 1023. Specifically, control unit 501 controls robot arm 202 to grasp the object and move the object closer to the destination from above the destination. Identification unit 502 identifies the timing to release the object based on the force generated by the object measured by weigh scale 40 at the destination of the object (step S3).

[0036] Specifically, the identification unit 502 acquires the measurement results of weighing scale 40 at predetermined time intervals from the start time of period T. This predetermined time interval is sufficiently shorter than period T. The identification unit 502 calculates the acceleration by time-differentiating the acquired measurement results of weighing scale 40. The identification unit 502 then identifies the timing at which the calculated acceleration exceeds a threshold as the timing to release the object. Note that the identification unit 502 stops acquiring the measurement results of weighing scale 40 once it has identified the timing to release. If the identification unit 502 has not been able to identify the timing to release by the end time of period T, it terminates the process.

[0037] Specifically, the identification unit 502 acquires the measurement results of weighing scale 40 at predetermined time intervals from the start time of period T. This predetermined time interval is sufficiently shorter than period T. The identification unit 502 calculates statistical values ​​for the acquired measurement results of weighing scale 40 over a predetermined period going back (a fixed time). The identification unit 502 then identifies the timing at which the calculated statistical value exceeds a threshold as the timing to release the object. Note that the identification unit 502 stops acquiring the measurement results of weighing scale 40 once it has identified the timing to release. If the identification unit 502 has not been able to identify the timing to release by the end time of period T, it terminates the process.

[0038] Then, the control unit 501 releases the object at the timing specified by the specifying unit 502 (step S4).

[0039] The robot arm 202 may change the moving speed of the object at the destination according to the type of object under the control of the control unit 501. If the type of object is classified according to the degree of susceptibility to damage when dropped, the robot arm 202 may change the moving speed of the object at the destination to slow down as the degree of susceptibility increases. In this case, the identification unit 502 may identify the timing to release the object based on the force generated by the object according to the moving speed changed by the robot arm 202.

[0040] (Advantages) The robot system 1 according to an embodiment of the present disclosure has been described above. In the robot system 1, the robot arm 202 (an example of a moving means) moves an object. The identification unit 502 (an example of an identifying means) identifies the timing to release the object based on a force generated by the object measured at a destination of the object.

[0041] The robot system 1 can identify the timing at which the impact on an object can be alleviated when the robot releases the object.

[0042] A robot system 1 having a minimum configuration according to an embodiment of the present disclosure will be described. Fig. 8 is a diagram showing the robot system 1 having a minimum configuration according to an embodiment of the present disclosure. The robot system 1 having a minimum configuration according to an embodiment of the present disclosure includes a robot arm 202 (an example of a moving means) and an identifying unit 502 (an example of an identifying means).

[0043] The robot arm 202 moves an object. The robot arm 202 can be realized, for example, using the functions of the robot arm 202 illustrated in FIG. 1. The determination unit 502 determines the timing to release the object based on the force generated by the object measured at the destination of the object. The determination unit 502 can be realized, for example, using the functions of the determination unit 502 illustrated in FIG. 6.

[0044] Next, a description will be given of the processing of the robot system 1 with the minimum configuration. Fig. 9 is a diagram showing an example of a processing flow of the robot system 1 with the minimum configuration. Here, the processing of the robot system 1 with the minimum configuration will be described with reference to Fig. 9.

[0045] The robot arm 202 moves the object (step S101). The identification unit 502 identifies the timing to release the object based on the force generated by the object measured at the destination of the object (step S102). In this way, the robot system 1 can identify the timing at which the impact on the object can be alleviated when the robot releases the object.

[0046] The order of the processes in the embodiments of the present disclosure may be changed as long as the processes are performed appropriately.

[0047] Although the embodiments of the present disclosure have been described, the robot system 1, the transport system 10, the robot 20, the processing device 50, and other control devices may have a computer device inside. The above-described processing steps are stored in the form of a program on a computer-readable recording medium, and the computer reads and executes this program to perform the above processing. Specific examples of computers are shown below.

[0048] 10 is a schematic block diagram showing the configuration of a computer according to at least one embodiment. As shown in FIG. 10 , the computer 5 includes a CPU (Central Processing Unit) 6, a main memory 7, a storage 8, and an interface 9. For example, the robot system 1, the transport system 10, the robot 20, the processing device 50, and other control devices described above are each implemented in the computer 5. The operations of each of the processing units described above are stored in the storage 8 in the form of a program. The CPU 6 reads the program from the storage 8, loads it into the main memory 7, and executes the above-described processing in accordance with the program. The CPU 6 also allocates storage areas in the main memory 7 corresponding to each of the storage units described above in accordance with the program.

[0049] Examples of storage 8 include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, a magneto-optical disk, a compact disc read-only memory (CD-ROM), a digital versatile disc read-only memory (DVD-ROM), and a semiconductor memory. Storage 8 may be an internal medium directly connected to the bus of computer 5, or an external medium connected to computer 5 via interface 9 or a communication line. Furthermore, if the program is distributed to computer 5 via a communication line, computer 5 that receives the program may load the program into main memory 7 and execute the above-described processing. In at least one embodiment, storage 8 is a non-transitory tangible storage medium.

[0050] The program may also implement some of the functions described above. Furthermore, the program may be a file that can implement the functions described above in combination with a program already stored in the computer device, a so-called differential file (differential program).

[0051] Although several embodiments of the present disclosure have been described, these embodiments are merely examples and do not limit the scope of the disclosure. Various additions, omissions, substitutions, and modifications may be made to these embodiments without departing from the spirit of the disclosure.

[0052] Note that part or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes.

[0053] (Supplementary Note 1) A robot system comprising: a moving means for moving an object; and a determination means for determining a timing for releasing the object based on a weight of a physical quantity generated by the object measured at the destination of the object.

[0054] (Supplementary Note 2) The robot system according to Supplementary Note 1, further comprising: a measuring means for measuring the physical quantity.

[0055] (Supplementary Note 3) The robot system according to Supplementary Note 2, wherein the measuring means is a weight scale included in a system for inspecting the object.

[0056] (Supplementary Note 4) The robot system according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the specifying means specifies the timing to release the object based on an acceleration obtained by time-differentiating the measurement result of the physical quantity.

[0057] (Supplementary Note 5) The robot system according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the identification means identifies the timing at which a statistical value of the measurement results of the physical quantity over a period going back a predetermined time exceeds a threshold as the timing to release the target object.

[0058] (Supplementary Note 6) The robot system according to any one of Supplementary Note 1 to Supplementary Note 5, wherein the specifying unit specifies the timing within a period indicating a status for releasing the object.

[0059] (Supplementary Note 7) The robot system described in any one of Supplementary Note 1 to Supplementary Note 6, wherein the moving means changes the moving speed of the object at the destination depending on the type of the object, and the specifying means specifies the timing to release the object based on the physical quantity depending on the moving speed changed by the moving means.

[0060] (Appendix 8) The robot system described in Appendix 7, wherein the type of the object is a classification according to the degree of susceptibility to damage when dropped, and the moving means changes the moving speed of the object at the destination so that it slows down as the degree increases.

[0061] (Supplementary Note 9) The robot system according to any one of Supplementary Note 1 to Supplementary Note 8, further comprising: a control unit configured to release the object at the release timing identified by the identification unit.

[0062] (Supplementary Note 10) The robot system according to any one of Supplementary Note 1 to Supplementary Note 9, wherein the physical quantity is a force, a weight, or an acceleration generated by the object.

[0063] (Supplementary Note 11) A processing method executed by a robot system having a moving means for moving an object, the processing method comprising: determining timing to release the object based on a physical quantity generated by the object measured at the destination of the object.

[0064] (Supplementary Note 12) A recording medium storing a program that causes a computer of a robot system having a moving means for moving an object to determine the timing to release the object based on a physical quantity generated by the object measured at the destination of the movement.

[0065] According to each aspect of the present disclosure, in a robot system, it is possible to identify the timing at which an impact on an object can be alleviated when the robot releases the object.

[0066] REFERENCE SIGNS LIST 1 robot system 5 computer 6 CPU 7 main memory 8 storage 9 interface 10 transport system 20 robot 30 imaging device 40 weighing scale 50 processing device 101 transport mechanism 102 host device 201 robot body 202 robot arm 1021 management unit 1022 identification unit 1023 instruction unit C cardboard DB database T tray

Claims

1. A moving means for moving the object; a determination unit that determines a timing to release the object based on a physical quantity generated by the object and measured at a destination of the object; A robot system comprising:

2. A measuring means for measuring the physical quantity; The robot system of claim 1 .

3. The measuring means is A weight scale included in the system for inspecting the object. The robot system according to claim 2 .

4. The identification means is determining a timing to release the object based on an acceleration obtained by time-differentiating the measurement result of the physical quantity; The robot system according to any one of claims 1 to 3.

5. The identification means is identifying a timing at which a statistical value of the measurement results of the physical quantity in a period going back a predetermined time exceeds a threshold as the timing to release the target object; The robot system according to any one of claims 1 to 3.

6. The identification means is Identifying the timing within a period indicating a status of releasing the object. The robot system according to any one of claims 1 to 5.

7. The moving means is changing a moving speed of the object at the destination in accordance with a type of the object; The identification means is determining a timing to release the target object based on the physical amount corresponding to the moving speed changed by the moving means; The robot system according to any one of claims 1 to 6.

8. The type of the object is: This is a classification according to the degree of susceptibility to damage due to dropping. The moving means is The moving speed of the object at the destination is changed so as to become slower as the degree increases. The robot system according to claim 7.

9. A processing method executed by a robot system having a moving means for moving an object, comprising: determining a timing to release the object based on a physical quantity generated by the object and measured at a destination of the object; Processing methods.

10. A computer of a robot system having a moving means for moving an object, determining a timing to release the object based on a physical quantity generated by the object and measured at a destination of the object; A program that executes the following.