Control device, control program, and weighing system

Abstract

To provide a weighing system that inhibits articles from falling from gripping means, thereby reducing the weighing accuracy.SOLUTION: In a weighing system 100, a control unit 70 returns an article A grasped by a gripper 30 to an article group containment container 52 without discharging the article A into a discharge chute if at least one of the operating state of the gripper 30 and the weighing results of a weighing unit 40 meets any of the following three conditions. The conditions are as follows. (1) The weight value of the article A weighed by the weighing unit 40 is not a pre-set target weight value. (2) The amount of movement of a gripping member 32 to hold the article A is greater than a predetermined range. (3) The amount of movement of the gripping member 32 to hold the article A is less than the predetermined range. As a result, it is avoided that the gripper 30 operates with an "article whose weight value is not the target weight value".SELECTED DRAWING: Figure 7A

Description

Technical Field

[0001] The present invention relates to a control device, a control program, and a weighing system.

Background Art

[0002] As an apparatus for weighing and distributing, for example, Patent Document 1 (Japanese Patent Application Laid-Open No. 6-3182) discloses an apparatus having a plurality of collection units each provided with gripping means for gripping and removing a part of a product and weighing means for recording the weight of a part of the product.

[0003] The apparatus further includes dispensing means and a computer programmed in advance for a predetermined total weight, measures the weight of an article gripped by the gripping means by the weighing means, and performs combination weighing based on the measured weight value.

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above apparatus, when the article is something like food that is likely to spill, there is a risk that the food will fall from the gripping means that does not participate in the combination, and in such a case, the fallen food will mix with the food after combination weighing, reducing the weighing accuracy.

[0005] An object of the present invention is to provide a weighing system that suppresses the article from falling from the gripping means and reducing the weighing accuracy.

Means for Solving the Problems

[0006] The control device according to the first aspect of the present invention is a control device that controls a weighing system which grips some articles from a group of articles stored in a container with a plurality of gripping parts, weighs the weight values of the articles gripped by the plurality of gripping parts respectively with a weighing part, and discharges them to a predetermined discharge destination. When it is determined that at least one of the operating states of any of the gripping parts and the weighing result corresponding to the gripping part meets a predetermined condition, the control device returns the gripped article to the container without discharging it to the discharge destination for the gripping part that meets the predetermined condition.

[0007] The control program according to the second aspect of the present invention is a control program for causing the CPU of a control device that controls a weighing system which grips some articles from a group of articles stored in a container with a plurality of gripping parts, weighs the weight values of the articles gripped by the plurality of gripping parts respectively with a weighing part, and discharges them to a predetermined discharge destination to execute. When it is determined that at least one of the operating states of any of the gripping parts and the weighing result corresponding to the gripping part meets a predetermined condition, this control program is a program that returns the gripped article to the container without discharging it to the discharge destination for the gripping part that meets the predetermined condition.

[0008] The weighing system according to the third aspect of the present invention is a weighing system including a weighing device that weighs the weight values of some articles gripped by a plurality of gripping parts from a group of articles stored in a container respectively, and a control device that controls the gripping parts and discharges the articles to a predetermined discharge destination. In this weighing system, when the control device determines that at least one of the operating states of any of the gripping parts and the weighing result corresponding to the gripping part meets a predetermined condition, the control device returns the gripped article to the container without discharging it to the discharge destination for the gripping part that meets the predetermined condition.

Advantages of the Invention

[0009] In the present invention, by performing the control of "when it is determined that it meets a predetermined condition, returning the article gripped by the gripping part to the container without discharging it to the target discharge destination", it is avoided that the gripping part operates while holding an "article that should not be discharged". As a result, it is suppressed that the article falls from the gripping part and the weighing accuracy is reduced.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 5C

Figure 5D

Figure 5E

Figure 5F

Figure 5G

Figure 6A

Figure 6B

Figure 6C

Figure 6D

Figure 6E

Figure 6F

Figure 6G

Figure 6H

Figure 6I

Figure 7A

Figure 7B

Figure 8A

Figure 8B

Mode for Carrying Out the Invention

[0011] Embodiments of the present invention will be described with reference to the drawings. The embodiments described below are one of the specific examples of the present invention and do not limit the technical scope of the present invention.

[0012] <First Embodiment> (1) Configuration of the weighing device 100 FIG. 1 is a schematic diagram of the weighing device 100. Further, FIG. 2 is a block diagram of the weighing device 100. In FIGS. 1 and 2, the weighing device 100 is a device that takes out and discharges some articles A from an article group A1 which is a collection of articles A.

[0013] Specifically, the weighing device 100 takes out and discharges some articles A from the article group A1 so that the weight falls within the target weight range. The articles A discharged by the weighing device 100 are, for example, packaged in bags or contained in containers in the subsequent process of the weighing device 100 and shipped as products.

[0014] The weighing device 100 includes a robot arm 10, a movable member 20, a gripper 30, a weighing unit 40, a placing unit 50, a placing unit drive unit 54, a discharge chute 60, and a control unit 70. The control unit 70 performs various calculations and controls the operations of each part of the weighing device 100.

[0015] The article group A1 is placed on the placing unit 50. The article A is, for example, food. Further, the article A is a highly sticky food such as noodles like spaghetti or food containing a lot of sugars.

[0016] The placing unit 50 is moved by the placing unit drive unit 54 between a first position where the gripper 30 grips an article A of the article group A1 placed on the placing unit 50 and a second position where the gripper 30 does not grip an article A from the article group A1 placed on the placing unit 50.

[0017] Each gripper 30 has a gripping member 32 that grips the article A. The gripper 30 is attached to the movable member 20. In the present embodiment, a plurality of grippers 30 are attached to the movable member 20.

[0018] The robot arm 10 moves the movable member 20 to which the gripper 30 is attached. The weighing unit 40 weighs the weight value of the article A gripped by each gripper 30. The discharge chute 60 receives and discharges the article A released from the grip of the gripper 30.

[0019] The control unit 70 controls the operations of various components of the weighing device 100 including the placement unit drive unit 54, the gripping member drive mechanism 34, and the robot arm 10, and performs combined calculations using the weight value of the article A measured by the weighing unit 40.

[0020] The control unit 70 controls the operation of the robot arm 10 to move the movable member 20, and brings the gripper 30 closer to the placement unit 50 placed at the first position where the article group A1 is placed. The control unit 70 controls each gripping member drive mechanism 34 of each gripper 30 to cause the gripping member 32 of each gripper 30 to grip a part of the article A of the article group A1 placed on the placement unit 50.

[0021] Each weighing unit 40 weighs the weight value of the article A gripped by the gripper 30 corresponding to that weighing unit 40. The control unit 70 performs a combined calculation based on the weight value of the article A gripped by the gripper 30 measured by each weighing unit 40.

[0022] The combined calculation is a process of finding a combination of weight values such that the sum of the weight values of the articles A gripped by each gripper 30 results in a total value within the target weight range. Based on the result of the combined calculation, the control unit 70 causes the gripping member 32 of the gripper 30 corresponding to the combination of weight values within the target weight range to release the grip of the article A above the discharge chute 60, and discharges the article A within the target weight range from the discharge chute 60.

[0023] (2) Detailed Configuration FIG. 3 is a schematic perspective view of the robot arm 10, the movable member 20, the measuring unit 40, and the gripper 30. Further, FIG. 4 is a schematic perspective view of the movable member 20, the measuring unit 40, and the gripper 30. Furthermore, FIG. 5A is a bottom view of the movable member 20 to which the gripper 30 is attached, as viewed from the side of the gripping member 32 (lower side) of the gripper 30. FIGS. 5B and 5C are bottom views of one of the grippers 30 in FIG. 5A, as viewed from below the gripping member 32 of the gripper 30.

[0024] (2-1) Movable member 20 The movable member 20 is a member to which the gripper 30 is attached. In the present embodiment, a plurality of grippers 30 are attached to the movable member 20. The movable member 20 is a frame that supports the gripper 30. The movable member 20 is a member that is moved by the robot arm 10.

[0025] Note that the description "the gripper 30 is attached to the movable member 20" does not represent only the mode in which the gripper 30 is directly attached to the movable member 20, but also includes the mode in which the gripper 30 is attached to the movable member 20 via another member. In the present embodiment, as shown in FIG. 4, the gripper 30 is attached to the movable member 20 via the sensor unit 42 of the measuring unit 40.

[0026] (2-2) Robot arm 10 The robot arm 10 is a device that supports the movable member 20 and moves the movable member 20. In the present embodiment, the robot arm 10 moves the movable member 20 along a single axis. Specifically, the robot arm 10 moves the movable member 20 up and down along a single axis extending in the vertical direction.

[0027] In the present embodiment, the robot arm 10 is an articulated robot as shown in FIG. 1. However, the type of the robot arm 10 is not limited to an articulated robot. The robot arm 10 may be any device that can move the movable member 20 in a predetermined direction.

[0028] Further, instead of the robot arm 10, the metering device 100 may have a cylinder capable of moving the movable member 20 in a predetermined direction. For example, instead of the robot arm 10, the metering device 100 may have a cylinder capable of moving the movable member 20 along a single axis.

[0029] (2-3) Gripper 30 The gripper 30 is a device for gripping the article A. Each gripper 30 includes a gripping member 32 and a gripping member driving mechanism 34 as a driving mechanism for driving the gripping member 32. The gripping member driving mechanism 34 drives the gripping member 32 using, for example, a motor or fluid pressure as a driving source.

[0030] In the present embodiment, as shown in FIG. 4, the gripping member 32 is a rod-shaped or finger-shaped member. Each gripper 30 has a plurality (for example, three) of gripping members 32. Note that the number and shape of the gripping members 32 depicted in FIG. 4 and the like are merely examples and can be changed as appropriate.

[0031] In the present embodiment, as shown in FIG. 5A, when each gripper 30 is viewed from the side of the gripping member 32, the plurality of gripping members 32 are arranged side by side in the circumferential direction. Further, when viewed from the side of the gripping member 32 of each gripper 30, the plurality of gripping members 32 are arranged at substantially equal intervals in the circumferential direction. Furthermore, when each gripper 30 is viewed from the side of the gripping member 32, the gripping member 32 is movable in the radial direction.

[0032] Also, as shown in FIGS. 5B and 5C, the gripper 30 sandwiches the article A between the plurality of gripping members 32 and grips the article A by moving the gripping members 32, which are in a separated state from each other, radially inward by the gripping member driving mechanism 34 to bring them closer to each other.

[0033] Furthermore, the gripper 30 releases the grip on the article A by moving the gripping members 32, which are in a state of being close to each other, radially outward by the gripping member driving mechanism 34 to separate them from each other.

[0034] As shown in FIGS. 3, 4, and 5A, a plurality of grippers 30 are attached to the movable member 20. Each gripper 30 is attached to the movable member 20 via the sensor unit 42 of the weighing unit 40. The sensor unit 42 of the weighing unit 40 is disposed between the gripper 30 and the movable member 20 that supports it.

[0035] In the example shown in FIGS. 3, 4, and 5A, 11 grippers 30 are attached to the movable member 20, which is just an example and does not limit the number of grippers 30. The plurality of grippers 30 attached to the movable member 20 move up and down integrally when the robot arm 10 moves the movable member 20 up and down.

[0036] As shown in FIG. 5A, each gripper 30 has a substantially circular shape when viewed from the gripper member 32 side of the gripper 30 attached to the movable member 20. In the present embodiment, the grippers 30 are generally arranged in a staggered pattern when viewed from the gripper member 32 side of the grippers 30 attached to the movable member 20. However, the arrangement is just an example and is not limited to the staggered arrangement.

[0037] (2-4) Weighing unit 40 In the weighing device 100, one weighing unit 40 is provided for each gripper 30. The weighing unit 40 weighs the weight value of the article A held by the gripper member 32 of the corresponding gripper 30.

[0038] Each weighing unit 40 includes a sensor unit 42 and a control unit (not shown). As shown in FIG. 4, each gripper 30 is attached to the movable member 20 via the sensor unit 42. The sensor unit 42 includes a force sensor and an acceleration sensor. As the force sensor, for example, a strain gauge type load cell is adopted. As the acceleration sensor, for example, a strain gauge type load cell or a MEMS type small acceleration sensor is adopted.

[0039] When the gripper 30 holding the article A is moved as the movable member 20 moves, the control unit of the measuring unit 40 measures the mass of the article A held by the gripper 30 based on the force and acceleration measured by the sensor unit 42. Specifically, the control unit of the measuring unit 40 measures the mass of the article A held by the gripper 30 by dividing the force measured by the force sensor by the acceleration measured by the acceleration sensor.

[0040] However, the measuring unit 40 is not limited to the method of measuring the mass of the article A based on the force and acceleration measured during the movement of the gripper 30. The measuring unit 40 may use a load cell or the like to measure the weight of the article A held by the gripper 30 in a stationary state.

[0041] (2-5) Mounting portion 50 and mounting portion drive unit 54 The article group A1 is placed on the mounting portion 50. Specifically, the mounting portion 50 includes an article group storage container 52 in which the article A (article group A1) is stored. In the mounting portion 50, the article group A1 is placed on the mounting surface 52a (here, the bottom surface of the article group storage container 52).

[0042] The gripper 30 grips a part of the article A from the article group A1 stored in the article group storage container 52. In the present embodiment, the article group storage container 52 is a rectangular parallelepiped container with an open top. When the amount of the article A stored inside the article group storage container 52 decreases, the mounting portion 50 is configured such that a person or a machine can replace the article group storage container 52 with a reduced amount of the article A inside with a new article group storage container 52 (in which a large amount of the article A is stored).

[0043] Note that instead of being configured such that the article group storage container 52 is replaceable, the mounting portion 50 may have an article supply mechanism for supplying the article A to the article group storage container 52.

[0044] The placement unit 50 is moved between a first position and a second position by the placement unit drive unit 54. The placement unit drive unit 54 moves the placement unit 50 using, for example, a motor or fluid pressure as a drive source. The first position is a position where the gripper 30 grips the article A of the article group A1 placed on the placement unit 50. The second position is a position where the gripper 30 does not grip the article A from the article group A1 placed on the placement unit 50.

[0045] The placement unit drive unit 54 moves the placement unit 50 in a direction intersecting the moving direction of the movable member 20 between the first position and the second position. In the present embodiment, the placement unit drive unit 54 moves the placement unit 50 horizontally between the first position and the second position.

[0046] Specifically, the first position of the placement unit 50 is a position directly below the gripper 30. When the placement unit 50 is in the first position, if the movable member 20 is moved by the robot arm 10 and the gripper 30 is brought close to a predetermined position with respect to the placement unit 50, the gripper 30 can grip the article A placed on the placement unit 50. Further, the first position of the placement unit 50 is a position directly above the discharge chute 60.

[0047] On the other hand, the second position of the placement unit 50 is a position deviated from directly below the gripper 30. In the present embodiment, since the movable member 20 to which the gripper 30 is attached moves only in the vertical direction, when the placement unit 50 is in the second position, the gripper 30 cannot grip the article A placed on the placement unit 50. Further, the second position of the placement unit 50 is a position deviated from directly above the discharge chute 60.

[0048] (2-6) Discharge chute 60 The discharge chute 60 is a funnel-shaped member. The discharge chute 60 is disposed directly below the gripper 30. Further, the discharge chute 60 is disposed directly below the placement unit 50 when the placement unit 50 is in the first position. In other words, the placement unit 50 located in the first position is disposed between the gripper 30 and the discharge chute 60.

[0049] On the other hand, when the wearing part 50 is in the second position, there is no wearing part 50 between the gripper 30 and the discharge chute 60.

[0050] The discharge chute 60 discharges the article A supplied from the gripper 30 outside the weighing device 100 when the gripper 30 releases the grip. Specifically, the discharge chute 60 receives the article A that the gripper 30 releases and drops when the wearing part 50 is in the second position, and discharges it outside the weighing device 100.

[0051] (2-7) Control unit 70 The control unit 70 has a CPU (not shown), and memories such as a ROM and a RAM. As shown in FIG. 2, the control unit 70 is electrically connected to the robot arm 10, the gripper member drive mechanism 34, the weighing unit 40, and the wearing part drive unit 54.

[0052] The control unit 70 controls the operations of various components of the weighing device 100 such as the robot arm 10, the gripper member drive mechanism 34, and the wearing part drive unit 54, and performs combined calculations using the weight value of the article A weighed by the weighing unit 40 by executing programs stored in the memory by the CPU.

[0053] Note that the various functions of the control unit 70 do not have to be realized by software, and may be realized by hardware, or may be realized by the cooperation of hardware and software.

[0054] (2-7-1) Control of the operation of the gripper member drive mechanism 34 The control unit 70 has a first control mode and a second control mode different from the first control mode as control modes of the gripper member drive mechanism 34.

[0055] In the first control mode, the control unit 70 controls the gripper member drive mechanism 34 to cause the gripper member 32 to execute a first operation.

[0056] The first operation is an operation in which the gripping member 32 grips the article A and then releases the grip on the article A. Here, in the first operation, a plurality of gripping members 32 at positions separated from each other as shown in FIG. 5B move radially inward, move to positions approaching each other as shown in FIG. 5C, and then return to positions separated from each other as shown in FIG. 5B again, which is a series of operations.

[0057] In the second control mode, the control unit 70 controls the gripping member drive mechanism 34 to cause the gripping member 32 to perform a second operation. The second operation is an operation in which the gripping member 32 removes an attachment adhering to the gripping member 32.

[0058] The attachment is, for example, the article A itself or an adhesive substance contained in the article A. For example, when the article A is spaghetti, the attachment is noodles or ingredients, the spaghetti sauce, or the like.

[0059] By the control unit 70 having the second control mode as the control mode of the gripping member drive mechanism 34, the following effects can be obtained.

[0060] The weighing unit 40 corresponding to the gripper 30 weighs not only the weight of the article A gripped by the gripping member 32 but also the weight of the attachment adhering to the gripping member 32 as the weight of the article A.

[0061] However, since the attachment is not the article A gripped by the gripping member 32, there is a possibility that the attachment may not fall from the gripping member 32 even when the gripping member 32 releases the grip on the article A.

[0062] Therefore, when the weight of the attachment adhering to the gripping member 32 increases, there is a possibility that the weight of the article A discharged by the gripper 30 and the weight of the article A measured by the weighing unit 40 corresponding to the gripper 30 may deviate.

[0063] Conversely, there is a possibility that the attachment that did not fall may suddenly fall into the discharge chute 60, impairing the weighing accuracy.

[0064] Furthermore, a state where the adherents remain attached to the gripping member 32 for a long time is not hygienically preferable. In the present embodiment, the control unit 70 has a second control mode as a control mode of the gripping member drive mechanism 34, and the gripping member 32 performs a second operation of removing the adherents attached to the gripping member 32, thereby reducing such a problem.

[0065] The second operation of the gripping member 32 is an operation different from the first operation. Note that the fact that the first operation and the second operation are different includes the case where the mode of movement of the gripping member 32 in the first operation and the mode of movement of the gripping member 32 in the second operation are different.

[0066] Also, the fact that the first operation and the second operation are different includes the case where the mode of movement of the gripping member 32 is the same, and either the operation speed or the number of executions of the operation of the gripping member 32 is different between the first operation and the second operation.

[0067] A specific example of the second operation of the gripping member 32 will be described. Note that the mode of the second operation of the gripping member 32 in one example described below may be appropriately combined with the mode of the second operation according to other examples within a range where there is no contradiction.

[0068] (a) First example of the second operation of the gripping member 32 For convenience of explanation, the positions of the plurality of gripping members 32 drawn in FIG. 5B are referred to as remote positions, and the positions of the plurality of gripping members 32 drawn in FIG. 5C are referred to as proximity positions.

[0069] The second operation of the gripping member 32 in the first example is, like the first operation, a series of operations in which a plurality of gripping members 32 arranged remotely apart from each other as shown in FIG. 5B move radially inward to a proximity position as shown in FIG. 5C and then return to the remote position again.

[0070] However, during the second operation, the average operating speed at which the gripping member 32 moves from the remote position to the proximity position (hereinafter referred to as the approaching speed) is faster than the approaching speed during the first operation. In addition to this, or instead of this, during the second operation, the average operating speed at which the gripping member 32 moves from the proximity position to the remote position (hereinafter referred to as the separating speed) is faster than the separating speed during the first operation.

[0071] In other words, during the second operation, the movement of the gripping member 32 from the remote position to the proximity position and / or the movement of the gripping member 32 from the proximity position to the remote position are performed in a shorter time compared to the first operation.

[0072] In particular, in this embodiment, the approaching speed and the separating speed during the second operation are faster than the approaching speed and the separating speed during the first operation, respectively. For example, the approaching speed and the separating speed of the gripping member 32 during the second operation are two times or more (more preferably, five times or more) faster than the approaching speed and the separating speed during the first operation.

[0073] Also, during the second operation, the maximum acceleration of the gripping member 32 (hereinafter referred to as the approaching acceleration) when moving the gripping member 32 from the remote position to the proximity position is greater than the approaching acceleration during the first operation.

[0074] In addition to this, or instead of this, during the second operation, the maximum deceleration of the gripping member 32 (the absolute value of the negative acceleration during deceleration, hereinafter referred to as the approaching deceleration) when moving the gripping member 32 from the remote position to the proximity position is greater than the approaching deceleration during the first operation.

[0075] In addition to this, or instead of this, during the second operation, the maximum acceleration of the gripping member 32 (hereinafter referred to as the separating acceleration) when moving the gripping member 32 from the proximity position to the remote position is greater than the separating acceleration during the first operation. Also, in addition to this, or instead of this, during the second operation, the maximum deceleration of the gripping member 32 (the absolute value of the negative acceleration during deceleration, hereinafter referred to as the approaching deceleration) when moving the gripping member 32 from the proximity position to the remote position is greater than the separating acceleration during the first operation.

[0076] For example, the approach acceleration and separation acceleration of the gripping member 32 during the second operation are more than twice (more preferably, more than five times) the approach acceleration and separation acceleration during the first operation. Further, the approach deceleration and separation deceleration of the gripping member 32 during the second operation are more than twice (more preferably, more than five times) the approach deceleration and separation deceleration during the first operation.

[0077] (b) Second example of the second operation of the gripping member 32 Similar to the first operation, the second operation of the gripping member 32 in the first example is a series of operations in which a plurality of gripping members 32 arranged at remote positions away from each other as shown in FIG. 5B move radially inward to a proximity position as shown in FIG. 5C and then return to the remote position again.

[0078] However, during the second operation, the number of times the gripping member 32 is moved from the remote position to the proximity position or from the proximity position to the remote position is more than that during the first operation. For example, during the first operation, a series of operations in which the gripping member 32 moves from the remote position to the proximity position and then returns to the remote position again is executed once. In contrast, during the second operation, a series of operations in which the gripping member moves from the remote position to the proximity position and then returns to the remote position again is executed a plurality of times. For example, during the second operation, the gripping member 32 executes a series of operations two or more times (more preferably, four or more times).

[0079] (c) Third example of the second operation of the gripping member 32 During the second operation, the gripping member 32 does not necessarily move within the range between the remote position and the proximity position as in the first operation. For example, during the second operation, the gripping member 32 may move within a narrower range than in the first operation. For example, the movement amount of the gripping member 32 during the second operation is set to 3 / 4 or less (more preferably, 1 / 2 or less) of the movement amount of the gripping member 32 during the first operation. Further, although not limited, for example, the movement amount of the gripping member 32 during the second operation is set to 1 / 8 or more of the movement amount of the gripping member 32 during the first operation.

[0080] For example, in the second control mode, the control unit 70 combines the aspects of the above first to third examples to control the gripper member drive mechanism 34 so that the gripper member 32 reciprocates a plurality of times at high speed in a narrow section. By such control of the control unit 70, the gripper member 32 will vibrate at high speed. When the gripper member 32 performs such an operation, it becomes easier to promote the removal of the deposits adhering to the gripper member 32.

[0081] Note that the aspects of the first to third examples of the above second operation do not all need to be combined simultaneously, and they may be combined as appropriate. For example, in other forms, in the second control mode, the control unit 70 may control the gripper member drive mechanism 34 so that the gripper member 32 performs the same movement as the first operation (the movement from the remote position to the proximity position and then back to the remote position) only once at high speed.

[0082] (3) Operation of the metering device 1 The operation of the metering device 100 controlled by the control unit 70 will be described with reference to FIGS. 6A to 6I and FIG. 7A. Here, although the metering device 1 having a plurality of grippers 30 is taken as an example for description, it can be applied to a metering device having a single gripper 30.

[0083] FIGS. 6A to 6I are schematic side views of the metering device 100 for explaining the operation of the metering device 100 of FIG. 1.

[0084] In FIGS. 6A to 6I, the drawing of the robot arm 10 that moves the movable member 20 is omitted. FIG. 7A is a flowchart for explaining the operation of the metering device 100 according to the first embodiment.

[0085] FIG. 6A depicts the initial state before the gripper 30 grips the article A. In FIG. 6A, the movable member 20 is disposed at a predetermined position such that the gripper member 32 of the gripper 30 is disposed outside the article group storage container 52 of the placement portion 50. The placement portion 50 is disposed at the first position directly below the gripper 30. The gripper members 32 of each gripper 30 are disposed at the remote position as shown in FIG. 5B.

[0086] (Step S1) During the operation of the weighing device 100, the control unit 70 controls the robot arm 10 to move the movable member 20 vertically downward from the initial state and bring the plurality of grippers 30 closer to the placement portion 50.

[0087] Specifically, the control unit 70 controls the operation of the robot arm 10 so that the gripping member 32 of the gripper 30 is disposed at a predetermined position where it can grip the article A in the article group storage container 52, and moves the movable member 20 vertically downward (see FIG. 6B).

[0088] More specifically, the control unit 70 controls the operation of the robot arm 10 so that at least a part of the gripping member 32 is inserted into the article group A1, and moves the movable member 20 vertically downward.

[0089] (Step S2) Next, in step S2, the control unit 70 controls the gripping member driving mechanism 34 of each gripper 30 to cause the gripping member 32 to grip the article A. Preferably, the control unit 70 causes the plurality of grippers 30 to grip the article A simultaneously. However, the present invention is not limited thereto, and the control unit 70 may cause the plurality of grippers 30 to grip the article A at different timings.

[0090] (Step S3) Next, with the plurality of grippers 30 gripping the article A, the control unit 70 controls the robot arm 10 to move the movable member 20 vertically upward so that the gripping member 32 of the gripper 30 is disposed outside the article group storage container 52 of the placement portion 50 (see FIG. 6C). When the robot arm 10 moves the movable member 20 vertically upward, each weighing unit 40 weighs the article A gripped by the corresponding gripper 30.

[0091] (Step S4) Next, the control unit 70 determines whether at least one of the operating state of each gripper 30 and the weighing result of the weighing unit 40 meets a predetermined condition for returning the article A gripped by the gripper 30 to the article group storage container 52 without discharging it to the discharge chute 60.

[0092] Here, predetermined conditions will be described. The main purpose of this determination is to prevent accidentally discharging the article A into the discharge chute 60 by returning it to the article group storage container 52 before moving the article group storage container 52 when the weight value of the article A measured by the weighing unit 40 is not the preset target weight value or is estimated not to be the target weight value.

[0093] Therefore, "meeting the predetermined conditions" means (1) The weight value of the article A measured by the weighing unit 40 is not the preset target weight value. (2) The amount of operation of the operation of holding the article A by the holding member 32 is greater than a predetermined range. (3) The amount of operation of the operation of holding the article A by the holding member 32 is less than a predetermined range. It means corresponding to at least one of the above.

[0094] In particular, in the case of condition (2), the fact that the amount of operation of the operation of holding the article A by the holding member 32 is greater than a predetermined range means that the weight value of the article A is greater than the target weight value.

[0095] FIG. 5D is a plan view when viewing three holding members 32 sandwiching a virtual article that coincides with the lower limit value of the target weight value from the tip side of the holding member 32. In FIG. 5D, the circle C1 is the minimum inscribed circle for the three holding members 32.

[0096] FIG. 5E is a plan view when viewing three holding members 32 sandwiching a virtual article that coincides with the upper limit value of the target weight value from the tip side of the holding member 32. In FIG. 5E, the circle C2 is the minimum inscribed circle for the three holding members 32. And the range surrounded by the circle C1 and the circle C2 is the predetermined range R that satisfies the target weight value.

[0097] FIG. 5F is a plan view when viewing three gripping members 32 that grip a virtual article exceeding the upper limit value of the target weight value from the tip side of the gripping members 32. In FIG. 5F, the circle Ca is located outside a predetermined range R when viewed from the center of the circle. That is, it means that the reaching positions (coordinates) of the respective gripping members 32 are outside the reaching positions (coordinates) of the gripping members that grip a virtual article whose reaching position (coordinate) coincides with the upper limit value of the target weight value.

[0098] In such a case, it is determined that "the operation amount of the operation of holding the article by the holding member 32 is larger than a predetermined range."

[0099] Also, in the case of condition (3), the fact that the operation amount of the operation of holding article A by the holding member 32 is smaller than a predetermined range means that the weight value of that article is smaller than the target weight value.

[0100] FIG. 5G is a plan view when viewing three gripping members 32 that grip a virtual article less than the lower limit value of the target weight value from the tip side of the gripping members 32. In FIG. 5G, the circle Cb is located inside a predetermined range R when viewed from the center of the circle. That is, it means that the reaching positions (coordinates) of the respective gripping members 32 are inside the reaching positions (coordinates) of the gripping members 32 that grip a virtual article whose reaching position (coordinate) coincides with the lower limit value of the target weight value.

[0101] In such a case, it is determined that "the operation amount of the operation of holding article A by the holding member 32 is smaller than a predetermined range."

[0102] Note that since the determination as to whether or not it corresponds to any of the above predetermined conditions (2) and (3) can be made when step S2 is completed, as shown in FIG. 7B, between step S2 and step S3, a step for determining whether or not it corresponds to the above predetermined conditions (2) and (3) may be provided. Details will be described in [(5) Modification Example of the First Embodiment] in the subsequent stage.

[0103] When the control unit 70 determines that at least one of the operation states of the respective grippers 30 and the measurement result of the measurement unit 40 corresponds to a predetermined condition, it proceeds to step S5, and when it determines that it does not correspond, it proceeds to step S6.

[0104] (Step S5) Next, the control unit 70 controls the gripper member drive mechanism 34 of the gripper 30 that meets at least one of the above predetermined conditions (1), (2), and (3) to release the gripping of the article A by the gripper 30 (see FIG. 6D).

[0105] In other words, if there is a gripper 30 that is gripping an article A whose weight value is not the target weight value, the control unit 70 controls the gripper member drive mechanism 34 of the gripper 30 to release the gripping of the article A by the gripper 30.

[0106] The article A held by the gripper 30 falls into the article group storage container 52 of the placing part 50 arranged at the first position and is reused as the article A of the article group A1. At this point, the gripper member 32 of the gripper 30 that meets the above predetermined conditions completes the first operation.

[0107] Further, immediately after the gripper member 32 of the gripper 30 releases the gripping of the article A by the first operation, the control unit 70 controls the gripper member drive mechanism 34 of the gripper 30 to cause the gripper member 32 to execute a second operation. Note that when the article A is an article that is difficult to adhere to the gripper member 32, it is not always necessary to execute the second operation.

[0108] By returning the article A of the gripper 30 that meets at least one of the conditions (1), (2), and (3) to the article group storage container 52, it is avoided to operate while having the "article A whose weight value is not the target weight value". As a result, it is suppressed that the article falls from the gripper 30 and the weighing accuracy is reduced. Furthermore, unnecessary operations are eliminated, and the production efficiency can be improved.

[0109] (Step S6) Next, the control unit 70 controls the placing part drive unit 54 to move the placing part 50 from the first position to the second position (see FIG. 6E). When the placing part 50 moves to the second position, the placing part 50 is not arranged between the gripper 30 and the discharge chute 60.

[0110] (Step S7) Next, the control unit 70 controls the robot arm 10 to move the movable member 20 vertically downward and bring the plurality of grippers 30 closer to the discharge chute 60 (see FIG. 6F).

[0111] Note that depending on the article, there may be some articles for which it is not necessary to execute this "bringing closer operation". In such a case, the article may be dropped without moving the movable member 20 vertically downward.

[0112] (Step S8) Next, the control unit 70 causes the gripper 30 that did not meet any of the predetermined conditions (1), (2), and (3) in step 5 to release the grip on the article A and discharges the article A from the discharge chute 60 (see FIG. 6G). The gripping members 32 of these grippers 30 complete the first operation at this point.

[0113] Also, immediately after the gripping member 32 of the gripper 30 releases the grip on the article A by the first operation, the control unit 70 controls the gripping member drive mechanism 34 of the gripper 30 to execute a second operation on the gripping member 32. Note that when the article A is an article that does not easily adhere to the gripping member 32, it is not always necessary to execute the second operation.

[0114] (Step S9) When the discharge of the article A is completed, the control unit 70 controls the robot arm 10 to return the movable member 20 to its original position (see FIG. 6H).

[0115] (Step S10) Next, the control unit 70 controls the placement unit drive unit 54 to return the placement unit 50 from the second position to the first position directly below the gripper 30 (see FIG. 6I).

[0116] (Step S11) Then, the control unit 70 determines whether there is an operation stop command. When the control unit 70 determines that there is an operation stop command, it stops the control. When it determines that there is no operation stop command, it returns to step S1.

[0117] The operation of the weighing device 100 described here is merely an example and can be appropriately changed within a non - conflicting range.

[0118] Also, for example, when the control unit 70 controls the robot arm 10 with the plurality of grippers 30 gripping the article A and moves the movable member 20 upward from the position depicted in FIG. 6B to the position depicted in FIG. 6C, the control unit 70 may control the robot arm 10 to move the movable member 20 downward one or more times.

[0119] Also, when the gripper 30 releases the grip, the up - and - down movement of the movable member 20 as described above can shake off the article adhering to the gripping member 32. The article adhering to the gripping member 32 is an article that is not gripped by the gripping member 32 and may fall regardless of the operation of the gripping member 32. By moving the movable member 20 downward in advance to shake off the article adhering to the gripping member 32, the weight of the article A measured by the weighing unit 40 can be made closer to the weight of the article A gripped by the gripping member 32, thereby improving the weighing accuracy.

[0120] (4) Features of the First Embodiment (4 - 1) In the weighing device 100, when at least one of the operating state of the gripper 30 and the weighing result of the weighing unit 40 meets any of the following conditions: (1) the weight value of the article A weighed by the weighing unit 40 is not the preset target weight value; (2) the amount of operation of the operation of holding the article A by the gripping member 32 is greater than a predetermined range; (3) the amount of operation of the operation of holding the article A by the gripping member 32 is less than a predetermined range, the control unit 70 returns the article A gripped by the gripper 30 to the article group storage container 52 without discharging it to the discharge chute 60.

[0121] The fact that the amount of operation of the operation of holding the article A by the gripper 30 is greater than a predetermined range means that the weight value of that article is greater than the target weight value.

[0122] For example, when holding the article A by sandwiching it with three gripping members 32, the range surrounded by the minimum inscribed circle for each gripping member 32 when sandwiching an article that coincides with the lower limit value of the target weight value and the minimum inscribed circle for each gripping member 32 when sandwiching the article A that coincides with the upper limit value of the target weight value is a predetermined range R that satisfies the target weight value.

[0123] Therefore, the minimum inscribed circle for each gripping member 32 when sandwiching an article A that exceeds the upper limit value of the target weight value is located outside the predetermined range R when viewed from the center of the circle. That is, it means that the reaching position (coordinates) of each gripping member is outside the reaching position (coordinates) of the gripping member 32 that sandwiches the article A whose weight value coincides with the upper limit value of the target weight value.

[0124] In such a case, it is determined that "the operation amount of the operation of holding the article A by the gripping member 32 is larger than the predetermined range R". Therefore, it is avoided that the gripper 30 operates while holding an "article whose weight value is not the target weight value".

[0125] Also, the fact that the operation amount of the operation of holding the article A by the gripper 30 is smaller than the predetermined range means that the weight value of the article is smaller than the target weight value.

[0126] For example, the minimum inscribed circle for each gripping member 32 when sandwiching an article A that is less than the lower limit value of the target weight value is located inside the predetermined range R when viewed from the center of the circle. That is, it means that the reaching position (coordinates) of each gripping member 32 is inside the reaching position (coordinates) of the gripping member 32 that sandwiches the article A whose weight value coincides with the lower limit value of the target weight value.

[0127] In such a case, it is determined that "the operation amount of the operation of holding the article A by the gripping member 32 is smaller than the predetermined range R".

[0128] Therefore, it is avoided that the gripper 30 operates while holding an "article whose weight value is not the target weight value". As a result, it is suppressed that the article A falls from the gripper 30 and the weighing accuracy is reduced. Also, unnecessary operations are eliminated, and the production efficiency can be improved.

[0129] (4-2) In the weighing device 100, the amount of operation of the operation of holding the article A by the gripper 30 is the opening degree of the gripping member 32. That the opening degree of the gripping member 32 is larger than a predetermined range means that the weight value of the article A is larger than the target weight value. Also, that the opening degree of the gripping member 32 is smaller than a predetermined range means that the weight value of the article A is smaller than the target weight value.

[0130] (5) Modification of the first embodiment FIG. 7B is a flowchart for explaining the operation of the weighing device 100 according to a modification of the first embodiment. In FIG. 7B, the difference between this modification and FIG. 7A is that steps S2a and S2b are inserted between step S2 and step S3.

[0131] Steps S1, S2, S3 to S11 in FIG. 7B are the same as those in FIG. 7A, so the description thereof is omitted. Here, steps S2a and S2b newly inserted will be described.

[0132] (Step S2a) In step S2a, the control unit 70 determines whether or not the operating state of each gripper 30 meets a predetermined condition for returning the article A held by the gripper 30 to the article group storage container 52 without discharging it to the discharge chute 60.

[0133] Here, "meeting the predetermined condition" means excluding (1) from the predetermined conditions (1) to (3) described in step S4 of the first embodiment (2) That the amount of operation of the operation of holding the article A by the gripping member 32 is larger than a predetermined range, (3) That the amount of operation of the operation of holding the article A by the gripping member 32 is smaller than a predetermined range, and corresponding to at least one of them.

[0134] Originally, in step S2, when the control unit 70 causes the gripping member 32 to grip the article A, it is possible to determine whether the amount of operation of the operation of holding the article A by the gripping member 32 is greater than or less than a predetermined range. Therefore, as in the first embodiment, it is not necessary for the control unit 70 to wait until the movable member 20 is moved vertically upward.

[0135] When the control unit 70 determines that the operating state of each gripper 30 meets the above-mentioned predetermined condition (2) or (3), it proceeds to step S2b. When it determines that it does not meet the condition, it proceeds to step S3.

[0136] (Step S2b) Next, the control unit 70 controls the gripping member drive mechanism 34 of the gripper 30 that meets at least one of the above-mentioned predetermined conditions (2) and (3) to release the gripping of the article A by the gripper 30 (see Fig. 6D).

[0137] In other words, if there is a gripper 30 that is gripping an article A whose weight value is not the target weight value, the control unit 70 controls the gripping member drive mechanism 34 of that gripper 30 to release the gripping of the article A by that gripper 30.

[0138] The article A that was being gripped by the gripper 30 falls into the article group storage container 52 of the placement unit 50 arranged at the first position and is reused as the article A of the article group A1. At this point, the gripping member 32 of the gripper 30 that met the above-mentioned predetermined condition completes the first operation.

[0139] Also, immediately after the gripping member 32 of the gripper 30 releases the gripping of the article A by the first operation, the control unit 70 controls the gripping member drive mechanism 34 of that gripper 30 to cause the gripping member 32 to perform a second operation. In the case of an article for which it is difficult for the article A to adhere to the gripping member 32, it is not always necessary to perform the second operation.

[0140] By returning the article A held by the gripper 30 that meets at least one of the conditions (2) and (3) to the article group storage container 52, it is avoided to operate while having the "article A whose weight value is not the target weight value". As a result, it is suppressed that the article falls from the gripper 30 and the weighing accuracy is deteriorated. Further, unnecessary operations are eliminated, and the production efficiency can be improved.

[0141] <Second Embodiment> In the first embodiment, the weighing device that quantitatively grips was described on the premise. In the second embodiment, a combination weighing device for combination weighing will be described.

[0142] Note that since the structure of the weighing device according to the second embodiment uses the structure of the weighing device according to the first embodiment as it is and only the control is made different, detailed descriptions of each part are omitted.

[0143] (1) Operation of the weighing device 100 The operation of the weighing device 100 controlled by the control unit 70 will be described with reference to FIGS. 6A to 6I and FIG. 8A.

[0144] FIG. 8A is a flowchart for explaining the operation of the weighing device 100 according to the second embodiment.

[0145] In FIG. 6A, the movable member 20 is arranged at a predetermined position so that the gripping member 32 of the gripper 30 is arranged outside the article group storage container 52 of the placement portion 50. The placement portion 50 is arranged at the first position directly below the gripper 30. The gripping members 32 of each gripper 30 are arranged at a remote position as shown in FIG. 5B.

[0146] (Step S101) During the operation of the weighing device 100, the control unit 70 controls the robot arm 10 to move the movable member 20 vertically downward from the initial state and bring the plurality of grippers 30 closer to the placement portion 50.

[0147] Specifically, the control unit 70 controls the operation of the robot arm 10 so that the gripping member 32 of the gripper 30 is disposed at a predetermined position where it can grip the article A in the article group storage container 52, and moves the movable member 20 vertically downward (see FIG. 6B).

[0148] More specifically, the control unit 70 controls the operation of the robot arm 10 so that at least a part of the gripping member 32 is inserted into the article group A1, and moves the movable member 20 vertically downward.

[0149] (Step S102) Next, the control unit 70 controls the gripping member drive mechanism 34 of each gripper 30 to cause the gripping member 32 to grip the article A. Preferably, the control unit 70 causes the plurality of grippers 30 to grip the article A simultaneously. However, it is not limited thereto, and the control unit 70 may cause the plurality of grippers 30 to grip the article A at different timings.

[0150] Note that since the determination as to whether or not it corresponds to any of the predetermined conditions (2) and (3) in the first embodiment can be made at the completion of step S102, a step for determining whether or not it corresponds to the predetermined conditions (2) and (3) may be provided between step S102 and step S103. Details will be described in [(3) Modification of the Second Embodiment] in the following section.

[0151] (Step S103) Next, with the plurality of grippers 30 gripping the article A, the control unit 70 controls the robot arm 10 to move the movable member 20 vertically upward so that the gripping member 32 of the gripper 30 is disposed outside the article group storage container 52 of the placement unit 50 (see FIG. 6C). When the robot arm 10 moves the movable member 20 vertically upward, each measuring unit 40 measures the weight of the article A gripped by the corresponding gripper 30.

[0152] (Step S104) Next, the control unit 70 performs a combined calculation using the weight values of the articles A held by the respective grippers 30 measured by the respective measuring units 40, and finds a combination of weight values whose total value falls within the target weight range.

[0153] (Step S105) Next, the control unit 70 determines whether there is a gripper 30 that has not been selected for the combination among the grippers 30.

[0154] When the control unit 70 determines that there is a gripper 30 that has not been selected for the combination, it proceeds to step S6, and when it determines that there is no gripper 30 that has not been selected for the combination, it proceeds to step S7.

[0155] (Step S106) Next, if there is a gripper 30 whose held article A has not been selected for the combination, the control unit 70 controls the gripper member drive mechanism 34 of that gripper 30, and by a first operation, releases the gripping of article A by that gripper 30 (see FIG. 6D).

[0156] The article A held by the gripper 30 falls into the article group storage container 52 of the placement unit 50 arranged at the first position, and is reused as the article A of the article group A1. At this point, the gripper member 32 of the gripper 30 that has not been selected for the combination completes the first operation.

[0157] Also, immediately after the gripper member 32 of the gripper 30 that has released the gripping of article A releases the gripping of article A by the first operation, the control unit 70 controls the gripper member drive mechanism 34 of that gripper 30 to cause the gripper member 32 to perform a second operation. Note that when article A is an article that does not easily adhere to the gripper member 32, it is not always necessary to perform the second operation.

[0158] (Step S107) Next, the control unit 70 controls the placement unit drive unit 54 to move the placement unit 50 from the first position to the second position (see FIG. 6E). When the placement unit 50 moves to the second position, the placement unit 50 is not arranged between the gripper 30 and the discharge chute 60.

[0159] (Step S108) Next, the control unit 70 controls the robot arm 10 to move the movable member 20 vertically downward and bring the plurality of grippers 30 closer to the discharge chute 60 (see FIG. 6F).

[0160] (Step S109) Next, based on the result of the combination calculation, the control unit 70 causes the gripper 30 corresponding to the combination of weight values within the target weight range above the discharge chute 60 to release the grip on the article A and discharges the article A from the discharge chute 60 (see FIG. 6G). The gripping member 32 of the gripper 30 selected for the combination completes the first operation at this point.

[0161] Also, immediately after the gripping member 32 of the gripper 30 that has released the grip on the article A releases the grip on the article A by the first operation, the control unit 70 controls the gripping member drive mechanism 34 of the gripper 30 to execute a second operation on the gripping member 32. Note that when the article A is an article that is difficult to adhere to the gripping member 32, it is not always necessary to execute the second operation.

[0162] (Step S110) When the discharge of the article A is completed for all combinations of weight values within the target weight range, the control unit 70 controls the robot arm 10 to return the movable member 20 to its original position (see FIG. 6H).

[0163] (Step S111) Next, the control unit 70 controls the placement unit drive unit 54 to return the placement unit 50 from the second position to the first position directly below the gripper 30 (see FIG. 6I).

[0164] (Step S112) Then, the control unit 70 determines whether there is an operation stop command. When the control unit 70 determines that there is an operation stop command, it stops the control, and when it determines that there is no operation stop command, it returns to step S1.

[0165] The operation of the weighing device 100 described here is only an example and can be appropriately changed within a non - conflicting range.

[0166] Also, for example, when the control unit 70 controls the robot arm 10 with the plurality of grippers 30 gripping the article A and moves the movable member 20 upward from the position depicted in FIG. 6B to the position depicted in FIG. 6C, the robot arm 10 may be controlled to move the movable member 20 downward one or more times.

[0167] Also, even when the gripper 30 releases the grip, the article adhering to the gripping member 32 can be shaken off by the vertical movement of the movable member 20 as described above. The article adhering to the gripping member 32 is an article that is not gripped by the gripping member 32 and may fall regardless of the operation of the gripping member 32. By moving the movable member 20 downward in advance to shake off the article adhering to the gripping member 32, the weight of the article A measured by the weighing unit 40 can be made closer to the weight of the article A gripped by the gripping member 32, thereby improving the weighing accuracy.

[0168] (2) Features of the Second Embodiment (2-1) In the weighing device 100, if there is a gripper 30 whose gripped article A is not selected for the combination, after returning the article A gripped by the gripper 30 not selected for the combination to the article group storage container 52, the article A gripped by the gripper 30 selected for the combination is discharged to the discharge chute 60. As a result, the article A gripped by the gripper 30 not selected for the combination does not fall off from the gripper 30 and is not discharged to the discharge chute 60, and the weighing accuracy can be improved.

[0169] (2-2) In the weighing device 100, when there is no combination that becomes the target weight value, the control unit 70 discharges the articles gripped by all the gripping parts to the article group storage container 52.

[0170] (3) Modification of the Second Embodiment Figure 8B is a flowchart for explaining the operation of the metering device 100 according to a modified example of the second embodiment. In Figure 8B, the difference between this modified example and Figure 8A is that steps S102a and S102b are inserted between step S102 and step S103.

[0171] Since steps S101, S102, S103 to S112 in Figure 8B are the same as those in Figure 8A, the description thereof will be omitted. Here, the newly inserted steps S102a and S102b will be described.

[0172] (Step S102a) In step S102a, the control unit 70 determines whether there is a gripper 30 that has not been selected for the combination among the grippers 30.

[0173] Here, "not selected for the combination among the grippers 30" means excluding (1) among the predetermined conditions (1) to (3) described in step S4 of the first embodiment (2) The operation amount of the operation of holding the article A by the holding member 32 is larger than the predetermined range, (3) The operation amount of the operation of holding the article A by the holding member 32 is smaller than the predetermined range, and corresponding to at least one of them.

[0174] Originally, in step S102, when the control unit 70 causes the holding member 32 to hold the article A, it is possible to determine whether the operation amount of the operation of holding the article A by the holding member 32 is larger or smaller than the predetermined range. Therefore, like in the first embodiment and the second embodiment, it is not necessary for the control unit 70 to wait until the movable member 20 is moved vertically upward.

[0175] When the control unit 70 determines that the operation state of each gripper 30 corresponds to the above predetermined condition (2) or (3), it proceeds to step S102b. When it determines that it does not correspond, it proceeds to step S3.

[0176] (Step S102b) Next, the control unit 70 controls the gripper member drive mechanism 34 of the gripper 30 that meets at least one of the above-described predetermined conditions (2) and (3) to release the gripping of the article A by the gripper 30 (see FIG. 6D).

[0177] In other words, if there is a gripper 30 that has not selected the weight of the gripped article A in the combination, the control unit 70 controls the gripper member drive mechanism 34 of that gripper 30 and, by the first operation, releases the gripping of the article A by that gripper 30.

[0178] The article A held by the gripper 30 falls into the article group storage container 52 of the placing portion 50 arranged at the first position and is reused as the article A of the article group A1. At this point, the gripper member 32 of the gripper 30 that meets the above-described predetermined condition completes the first operation.

[0179] Further, immediately after the gripper member 32 of the gripper 30 releases the gripping of the article A by the first operation, the control unit 70 controls the gripper member drive mechanism 34 of the gripper 30 to cause the gripper member 32 to execute a second operation. Note that when the article A is an article that is difficult to adhere to the gripper member 32, it is not always necessary to execute the second operation.

[0180] By returning the article A of the gripper 30 that meets at least one of the conditions (2) and (3) to the article group storage container 52, it is avoided to operate while having the "article A not selected in the combination". As a result, it is suppressed that an article falls from the gripper 30 and the weighing accuracy is deteriorated. Further, unnecessary operations are eliminated, and the production efficiency can be improved.

[0181] <Other configurations> (A) In the weighing device 100, when the control unit 70 returns the article A gripped by the gripper 30 to the article group storage container 52, the control unit 70 relatively moves the gripper 30 and the article group storage container 52.

[0182] In such a case, if the article A is returned to the location where it was grasped last time, it is less likely to obtain an appropriate amount when grasping the article A next time. Therefore, the gripper 30 and the article group storage container 52 are relatively moved, and the location where the article A is returned is shifted, thereby increasing the possibility of grasping an appropriate amount of the article A.

[0183] (B) In the metering device 100, the article group storage container 52 is movable in horizontal first and second directions orthogonal to each other. The control unit 70 relatively moves the gripper 30 and the article group storage container 52 in either the first direction or the second direction when returning the article A grasped by the gripper 30 to the article group storage container 52.

[0184] In such a case, since the article A is returned to the article group storage container 52 after grasping the positional relationship between the gripper 30 and the article group storage container 52 in planar coordinates, it is possible to return the articles in a manner that equalizes the distribution of the articles in the container.

[0185] (C) In the metering device 100, at least one of the gripper 30 and the article group storage container 52 is rotatable about a vertical axis. The control unit 70 rotates the gripper 30 and the article group storage container 52 by a predetermined relative angle in a plan view. Thereby, the location where the article A is returned can be shifted, and the possibility of grasping an appropriate amount of the article A can be increased.

[0186] (D) In the first embodiment, the determination of whether the operation amount of the operation of holding the article A by the holding member 32 is larger or smaller than a predetermined range is made by whether the minimum inscribed circle with respect to each holding member 32 when the article A is sandwiched is outside or inside a predetermined range R, that is, by the reaching position (coordinates) of the holding member 32.

[0187] However, when the gripper operation starts in the fully open state, when the weight value of the article to be grasped is smaller than the target weight value, the operation amount of the holding member 32 becomes larger than when grasping an article having the target weight value.

[0188] Conversely, when the weight value of the article to be gripped is greater than the target weight value, the amount of movement of the gripping member 32 becomes smaller than when gripping an article with the target weight value.

[0189] Thus, when the gripping operation of the gripping member 32 starts in the fully open state, considering the amount of movement as "displacement" based on the fully open state of the gripping member 32, "the amount of movement of the operation of holding the article by the gripping part is greater than a predetermined range" means that the weight value of the article is smaller than the target weight value. Also, "the amount of movement of the operation of holding the article by the gripping part is smaller than a predetermined range" means that the weight value of the article is greater than the target weight value.

Explanation of Signs

[0190] 30 Gripper (Gripping Part) 40 Measuring Part 52 Article Group Containing Container (Container) 60 Discharge Shoot 70 Control Part (Control Device) 100 Measuring Device A Article

Prior Art Documents

Patent Documents

[0191]

Patent Document 1

Claims

1. A control device for controlling a weighing system that grips some articles from a group of articles stored in a container with a plurality of gripping parts, weighs the weight value of the articles gripped by the gripping parts with a weighing part, and discharges them to a predetermined discharge destination, wherein the weighing part is attached to the gripping part, and when it is determined that the weighing result corresponding to the gripping part is not a preset target weight value, the gripping part is caused to return the gripped article to the container without discharging it to the discharge destination. Control device.

2. A control program to be executed by a CPU of a control device for controlling a weighing system that grips some articles from a group of articles stored in a container with a plurality of gripping parts, weighs the weight value of the articles gripped by the gripping parts with a weighing part, and discharges them to a predetermined discharge destination, wherein the weighing part is attached to the gripping part, and when it is determined that the weighing result corresponding to the gripping part is not a preset target weight value, the gripping part is caused to return the gripped article to the container without discharging it to the discharge destination. Control program.

3. A weighing device that weighs the weight value of some articles gripped by a plurality of gripping parts from a group of articles stored in a container, a control device that controls the gripping part and discharges the article to a predetermined discharge destination, A weighing system comprising: wherein the weighing device is attached to the gripping part, and when the control device determines that the weighing result corresponding to the gripping part is not a preset target weight value, the control device causes the gripping part to return the gripped article to the container without discharging it to the discharge destination. Weighing system.

Images