Metering device

Abstract

The present invention aims to provide a weighing device that suppresses the drop of articles from a holding unit, thereby reducing the measurement accuracy. In the weighing device (100), when at least one of the operating state of the gripper (30) and the measurement result of the measuring unit (40) meets any one of the following conditions: "the weight value of the article (A) measured by the measuring unit (40) is not a preset target weight value", "the amount of movement of the gripping member (32) gripping the article (A) is greater than a prescribed range", and "the amount of movement of the gripping member (32) gripping the article (A) is less than a prescribed range", the control unit (70) causes the article (A) gripped by the gripper (30) to be returned to the article group storage container (52) instead of being discharged to the discharge chute. As a result, the gripper (30) is prevented from operating in a state where it grips an article whose weight value is not the target weight value.

Description

Technical Field

[0001] The present invention relates to a metering device for metering objects in a group of objects contained in a container. Background Art

[0002] As a device for weighing and distributing, for example, Patent Document 1 (Japanese Patent Publication No. 6-3182) discloses a device having multiple collection units, each of which includes a gripping unit for gripping and taking away a portion of a product, and a weighing unit for recording the weight of a portion of the product.

[0003] The device further includes a dispensing unit and a computer pre-programmed to obtain a predetermined total weight. The weighing unit measures the weight of the articles gripped by the gripping unit, and performs combined weighing based on the measured weight value. Summary of the Invention

[0004] Technical problem to be solved by the invention

[0005] However, in the above device, if the items are easily spilled, such as food, the food may fall from the gripping unit that is not involved in the combination. In this case, the fallen food mixes with the combined measured food, reducing the measurement accuracy.

[0006] An object of the present invention is to provide a weighing device that suppresses a decrease in weighing accuracy caused by an article falling from a gripping unit.

[0007] Solutions for solving technical problems

[0008] A weighing device according to a first aspect of the present invention weighs items in a group of items contained in a container. The weighing device comprises a robotic arm, a gripping unit, a weighing unit, and a control unit. The gripping unit is mounted at the front end of the robotic arm and grips a portion of the items in the group of items in the container. The weighing unit measures the weight of the items gripped by the gripping unit. The control unit controls the operation of the gripping unit. Furthermore, if at least one of the gripping unit's operating state and the weighing unit's measurement results meet specified conditions, the control unit causes the items gripped by the gripping unit to be returned to the container rather than discharged to a desired discharge destination.

[0009] This weighing device implements control to prevent the gripping unit from operating while gripping items that should not be ejected, by returning them to the container when specified conditions are met. This prevents the gripping unit from operating while gripping items that should not be ejected. This prevents items from falling from the gripping unit and reducing weighing accuracy.

[0010] A weighing device according to a second aspect of the present invention is the weighing device according to the first aspect, further comprising a plurality of gripping units and a plurality of weighing units. When at least one of the operating state of any one of the plurality of gripping units and the weighing result of the weighing unit corresponding to the gripping unit satisfies a predetermined condition, the control unit causes the article gripped by the gripping unit that satisfies the predetermined condition to be returned to the container without being discharged to a discharge destination.

[0011] The weighing device of the third aspect of the present invention is based on the weighing device of the first aspect, and the weighing device further includes a plurality of gripping parts, a plurality of measuring parts and a discharge chute. The discharge chute receives and discharges the items discharged from the gripping parts. The control unit uses the weight values ​​of the items respectively held by the plurality of gripping parts to perform a combined calculation and selects a combination that becomes a pre-set target weight value. Furthermore, when the measurement result of the measuring part corresponding to at least any one of the plurality of gripping parts meets the specified conditions, the control unit returns the items held by the gripping part that meets the specified conditions to the container, and thereafter discharges the items held by the gripping part that does not meet the specified conditions into the discharge chute.

[0012] A weighing device according to a fourth aspect of the present invention is the weighing device according to the first or second aspect, wherein the predetermined condition includes a weight value of the article weighed by the weighing unit not being a preset target weight value.

[0013] This weighing device prevents the gripping unit from operating while gripping an item whose weight does not meet the target weight. This prevents items from falling from the gripping unit, which could reduce weighing accuracy. Furthermore, it eliminates unnecessary movement, improving production efficiency.

[0014] A weighing device according to a fifth aspect of the present invention is the weighing device according to the first or second aspect, wherein the predetermined condition includes an amount of movement of the gripping unit gripping the article being greater than a predetermined range.

[0015] Here, the phrase "the amount of movement of the gripping unit in gripping the article is greater than a predetermined range" is specifically described. For example, when the gripping unit grips and holds the article using multiple gripping members, the range enclosed by the minimum inscribed circle relative to each gripping member when gripping an article that meets the lower limit of the target weight value, and the minimum inscribed circle relative to each gripping member when gripping an article that meets the upper limit of the target weight value, falls within the predetermined range that satisfies the target weight value.

[0016] Therefore, when gripping an item exceeding the upper limit of the target weight, the minimum inscribed circle relative to each gripping member is located outside the specified range as viewed from the center of the circle. In other words, the arrival position (coordinates) of each gripping member is located outside the arrival position (coordinates) of the gripping member when gripping an item that matches the upper limit of the target weight.

[0017] In the above case, it is determined that "the movement amount of the movement of the gripping portion to grip the article is greater than a predetermined range."

[0018] On the other hand, if the gripping member is in the fully open state at the start of the gripping operation, the amount of movement of the gripping member when the weight of the gripped object is greater than the target weight is less than when gripping an object of the target weight. Therefore, when the amount of movement is considered in terms of "displacement" with the gripping member in the fully open state as a reference, "the amount of movement of the gripping member to grip the object is less than a predetermined range" means that the weight of the object is greater than the target weight.

[0019] In this weighing device, if the amount of movement of the gripping unit to grasp an item exceeds a predetermined range, it means that the weight of the item is not the target weight. Therefore, the gripping unit is prevented from operating while grasping an item whose weight is not the target weight. This prevents the item from falling from the gripping unit, which could reduce weighing accuracy. Furthermore, unnecessary movement can be eliminated, improving production efficiency.

[0020] A weighing device according to a sixth aspect of the present invention is the weighing device according to the first or second aspect, wherein the predetermined condition includes an amount of movement of the gripping unit gripping the article being less than a predetermined range.

[0021] Here, the phrase "the amount of movement of the gripping unit in gripping the article is less than a predetermined range" is specifically described. For example, when the gripping unit grips and holds the article using multiple gripping members, the range enclosed by the minimum inscribed circle relative to each gripping member when gripping an article that meets the lower limit of the target weight value, and the minimum inscribed circle relative to each gripping member when gripping an article that meets the upper limit of the target weight value, falls within the predetermined range that satisfies the target weight value.

[0022] Therefore, when gripping an item smaller than the lower limit of the target weight, the minimum inscribed circle relative to each gripping member is located inward of the specified range as viewed from the center of the circle. In other words, the arrival position (coordinates) of each gripping member is located inward of the arrival position (coordinates) of the gripping member when gripping an item that matches the lower limit of the target weight.

[0023] In the above case, it is determined that "the movement amount of the movement of the gripping portion to grip the article is smaller than a predetermined range."

[0024] On the other hand, when the gripping member is in the fully open state at the start of the gripping operation, the gripping member movement amount is greater when the weight of the gripped article is less than the target weight than when gripping an article with the target weight.

[0025] Therefore, when the movement amount is considered as "displacement" based on the fully opened state of the gripping member, "the movement amount of the gripping part gripping the article is greater than the predetermined range" means that the weight value of the article is less than the target weight value.

[0026] In this weighing device, if the amount of movement of the gripping unit to grasp an item falls below a predetermined range, it means that the weight of the item is not the target weight. Therefore, the gripping unit is prevented from operating while grasping an item that is not the target weight. This eliminates unnecessary movement and improves production efficiency.

[0027] A weighing device according to a seventh aspect of the present invention is the weighing device according to the fifth aspect or the sixth aspect, wherein the gripping portion has at least two claws for grasping the article, and the movement amount is the opening degree of the two claws.

[0028] For example, the range enclosed by the minimum inscribed circle relative to each claw when clamping an item consistent with the lower limit value of the target weight value, and the range enclosed by the minimum inscribed circle relative to each claw when clamping an item consistent with the upper limit value of the target weight value is the specified range that meets the target weight value.

[0029] Therefore, when gripping an item exceeding the upper limit of the target weight, the minimum inscribed circle of each jaw, as viewed from the center of the circle, is located outside the specified range. In other words, the reach position (coordinates) of each jaw is located outside the reach position (coordinates) of the jaw gripping an item that meets the upper limit of the target weight. In this case, it is determined that "the opening of the two jaws is greater than the specified range."

[0030] In contrast, when gripping an item smaller than the lower limit of the target weight, the minimum inscribed circle of each jaw, as viewed from the center of the circle, is located further inward than the specified range. In other words, the reach position (coordinates) of each jaw is located further inward than the reach position (coordinates) of the jaw gripping an item that meets the lower limit of the target weight. In this case, it is determined that "the opening of the two jaws is less than the specified range."

[0031] On the other hand, if the gripping action of both claws is fully open at the start, the amount of claw movement when the weight of the gripped object exceeds the target weight will be less than when gripping an object of the target weight. Therefore, when the amount of movement is considered as "displacement" with the fully open claws as the reference, "the amount of movement of the gripping action of the claws is less than the specified range" means that the weight of the object is greater than the target weight.

[0032] On the other hand, when the two claws are in a fully open state at the start of the gripping operation, the amount of movement of the claws is greater when the weight of the gripped article is less than the target weight than when gripping an article of the target weight.

[0033] Therefore, when the movement amount is considered as "displacement" based on the fully opened state of the claws, "the movement amount of the movement of the claws grasping the object is greater than the predetermined range" means that the weight value of the object is less than the target weight value.

[0034] In this weighing device, if the opening of the two jaws exceeds a specified range, the weight of the item exceeds the target weight. Conversely, if the opening of the two jaws falls below the specified range, the weight of the item falls below the target weight. This prevents the gripping unit from operating while gripping an item weighing less than the target weight. This prevents the item from falling from the gripping unit, which could reduce weighing accuracy. Furthermore, unnecessary movement can be eliminated, improving production efficiency.

[0035] A weighing device according to an eighth aspect of the present invention is the weighing device according to the third aspect, wherein the predetermined condition includes that the weighing result is not selected as a combination that becomes the target weight value.

[0036] In this measuring device, after the items gripped by the gripping parts that are not selected as the combination are returned to the container, the items gripped by the gripping parts that are selected as the combination are discharged into the discharge chute. Therefore, the items gripped by the gripping parts that are not selected as the combination will not fall from the gripping parts and will be discharged into the discharge chute, which can achieve improved measuring accuracy.

[0037] A weighing device according to a ninth aspect of the present invention is the weighing device according to the eighth aspect, wherein the control unit discharges the articles gripped by all the gripping units into the container when no combination reaches the target weight value.

[0038] A weighing device according to a tenth aspect of the present invention is the weighing device according to any one of the first to ninth aspects, wherein the control unit moves the gripping unit relative to the container when returning the article gripped by the gripping unit to the container.

[0039] In this weighing device, if the container returns to the location where the item was last picked up, the possibility of obtaining the appropriate amount of items when picking up the next item is low. Therefore, by moving the gripping part and the container relative to each other, the location where the items are returned is staggered, thereby increasing the possibility of picking up the appropriate amount of items.

[0040] A weighing device according to an eleventh aspect of the present invention is the weighing device according to any one of the first to ninth aspects, wherein the container is movable in first and second horizontal directions orthogonal to each other. When returning the article grasped by the grasping portion to the container, the control unit causes the grasping portion and the container to move relative to each other in either the first or second direction.

[0041] In this weighing device, the articles are returned to the container after the positional relationship between the gripping portion and the container is understood in plane coordinates. Therefore, a method of returning the articles so that the distribution of the articles in the container is uniform can be realized.

[0042] A measuring device according to a twelfth aspect of the present invention is the measuring device according to any one of the first to ninth aspects, wherein at least one of the gripping portion and the container is rotatable about a vertical axis. The control portion rotates the gripping portion and the container by a predetermined relative angle in a plan view.

[0043] Effects of the Invention

[0044] The weighing device of the present invention implements control to prevent the gripping unit from operating while gripping items that should not be ejected, by returning them to the container when specified conditions are met. This prevents the gripping unit from operating while gripping items that should not be ejected. This prevents items from falling from the gripping unit and causing a decrease in weighing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a schematic diagram of a measuring device according to one embodiment of the present invention.

[0046] Figure 2 yes Figure 1 Block diagram of the metering device.

[0047] Figure 3 yes Figure 1 A schematic three-dimensional diagram of the robot, movable parts, measuring unit, and gripper of the measuring device.

[0048] Figure 4 yes Figure 1 A schematic three-dimensional diagram of the movable parts, measuring part and holder of the measuring device.

[0049] Figure 5A The device is installed when viewed from the gripping part side of the gripper. Figure 1 Bottom view of the movable part of the holder of the metering device.

[0050] Figure 5B Is for Figure 5A A bottom view of a gripper of one of the grippers is shown as a bottom view of the gripper from below, depicting the gripper located at a remote position before gripping an article or after gripping of the article is released.

[0051] Figure 5C Is for Figure 5A A bottom view of a gripper of one of the grippers is shown as viewed from below, depicting the gripper in a close position when gripping an article.

[0052] Figure 5D This is a plan view of three gripping members holding a virtual object that matches the lower limit of the target weight value, as viewed from the front end side of the gripping members.

[0053] Figure 5E This is a plan view of three gripping members holding a virtual object that matches the upper limit of the target weight value, as viewed from the front end side of the gripping members.

[0054] Figure 5F This is a plan view of three gripping members holding a virtual article exceeding the upper limit of the target weight value, as viewed from the front end side of the gripping members.

[0055] Figure 5G This is a plan view of three gripping members holding a virtual article smaller than the lower limit of the target weight value, as viewed from the front end side of the gripping members.

[0056] Figure 6A Is used to illustrate Figure 1 The diagram is a schematic side view of the main parts of the weighing device, showing the operation of the weighing device, and depicting the state before the gripper grips the article (initial state).

[0057] Figure 6B Is used to illustrate Figure 1 The present invention is a schematic side view of the main parts of the weighing device, illustrating the operation of the weighing device, and depicts a state in which the gripping member of the gripper is inserted into the group of articles in order to grip the articles.

[0058] Figure 6C Is used to illustrate Figure 1 The present invention is a schematic side view of the main part of the weighing device, which shows the operation of the weighing device, and depicts a state in which the gripping member of the gripper that grips the article has moved outside the article group storage container.

[0059] Figure 6D Is used to illustrate Figure 1 The diagram is a schematic side view of the main part of the weighing device, illustrating the operation of the weighing device, and depicts a state in which a gripper corresponding to a weight value not selected as a combination drops an article into an article group storage container.

[0060] Figure 6E Is used to illustrate Figure 1 The diagram is a schematic side view of the main part of the weighing device, showing the operation of the weighing device, and depicting a state in which the placing portion has moved to the second position.

[0061] Figure 6F Is used to illustrate Figure 1 The operation of the weighing device is a schematic side view of the main part of the weighing device, which depicts a state in which the gripper moves to the vicinity of the chute in order to discharge the article.

[0062] Figure 6G Is used to illustrate Figure 1 The diagram is a schematic side view of the main parts of the weighing device, showing the operation of the weighing device, and depicting a state in which a part of the gripper drops an article into the chute.

[0063] Figure 6H Is used to illustrate Figure 1 The operation of the measuring device is a schematic side view of the main part of the measuring device, which depicts a state in which the gripper moves vertically upward.

[0064] Figure 6I Is used to illustrate Figure 1 The schematic side view of the main part of the weighing device is a diagram depicting the state in which the placing portion has moved to the first position.

[0065] Figure 7A This is a flowchart for explaining the operation of the measuring device according to the first embodiment.

[0066] Figure 7B This is a flowchart for explaining the operation of the measuring device according to the modified example of the first embodiment.

[0067] Figure 8A This is a flowchart for explaining the operation of the measuring device according to the second embodiment.

[0068] Figure 8B This is a flowchart for explaining the operation of the measuring device according to the modified example of the second embodiment. DETAILED DESCRIPTION

[0069] The embodiment of the present invention will be described with reference to the accompanying drawings. The embodiment described below is one specific example of the present invention and does not limit the technical scope of the present invention.

[0070] <First embodiment>

[0071] (1) Structure of the measuring device 100

[0072] Figure 1 is a schematic diagram of the metering device 100. In addition, Figure 2 is a block diagram of the metering device 100. Figure 1 and Figure 2 In the embodiment, the weighing device 100 is a device that takes out some articles A from an article group A1 that is a collection of articles A and discharges them.

[0073] Specifically, the weighing device 100 removes and discharges some articles A from the article group A1 so that their weight falls within the target weight range. The articles A discharged by the weighing device 100 are packaged in bags or containers in a subsequent process of the weighing device 100 and shipped as products.

[0074] The weighing device 100 includes a robot arm 10, a movable member 20, a gripper 30, a weighing unit 40, a placement unit 50, a placement unit driver 54, a discharge chute 60, and a control unit 70. The control unit 70 performs various calculations and controls the operation of each unit of the weighing device 100.

[0075] The article group A1 is placed on the placement portion 50. The article A is, for example, food. The article A is, for example, a highly sticky food such as noodles such as spaghetti, or a food containing a large amount of sugar.

[0076] The placement section 50 is moved by the placement section driving section 54 between a first position where the gripper 30 grips the articles A of the article group A1 placed on the placement section 50 and a second position where the gripper 30 does not grip the articles A from the article group A1 placed on the placement section 50 .

[0077] Each gripper 30 includes a gripping member 32 for gripping 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.

[0078] The robot arm 10 moves the movable member 20 to which the grippers 30 are attached. The weighing unit 40 measures the weight of the articles A gripped by the grippers 30. The discharge chute 60 receives and discharges the articles A released from the grippers 30.

[0079] 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 calculation of weight values ​​of the articles A measured by the weighing unit 40 .

[0080] The control unit 70 controls the operation of the robot arm 10 to move the movable member 20, causing the grippers 30 to approach the placement portion 50, which is positioned at the first position on which the article group A1 is placed. The control unit 70 controls the gripping member driving mechanism 34 of each gripper 30, causing the gripping member 32 of each gripper 30 to grip a portion of the article A of the article group A1 placed on the placement portion 50.

[0081] Each measuring unit 40 measures the weight of the article A gripped by the gripper 30 corresponding to the measuring unit 40 . The control unit 70 performs combined calculation based on the weight of the article A gripped by the gripper 30 measured by each measuring unit 40 .

[0082] The combination calculation process involves adding the weights of the articles A held by the grippers 30 to find a combination whose total weight falls within the target weight range. Based on the combination calculation results, the control unit 70 causes the gripping members 32 of the grippers 30 corresponding to the combination of weight values ​​falling within the target weight range to release their grip on the articles A above the discharge chute 60, thereby discharging the articles A within the target weight range from the discharge chute 60.

[0083] (2) Detailed structure

[0084] Figure 3 : is a schematic perspective view of the robot arm 10, the movable member 20, the measuring unit 40 and the gripper 30. Figure 4 : is a schematic perspective view of the movable member 20, the measuring unit 40 and the gripper 30. Figure 5A This is a bottom view of the movable member 20 to which the gripper 30 is attached, as seen from the gripping member 32 side (below) of the gripper 30 . Figure 5B and Figure 5C Is for Figure 5A FIG. 1 is a bottom view of one of the grippers 30 , wherein the gripping member 32 of the gripper 30 is viewed from below.

[0085] (2-1) Movable member 20

[0086] The movable member 20 is a member to which the gripper 30 is attached. In this 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.

[0087] In addition, the description "the gripper 30 is mounted on the movable member 20" not only indicates a method in which the gripper 30 is directly mounted on the movable member 20, but also includes a method in which the gripper 30 is mounted on the movable member 20 via other components. Figure 4 As shown, the gripper 30 is attached to the movable member 20 via the sensor portion 42 of the measuring portion 40 .

[0088] (2-2) Robotic Arm 10

[0089] The robot arm 10 is a device that supports and moves the movable member 20. In this 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.

[0090] In this embodiment, the robot arm 10 is Figure 1 However, the type of the robot arm 10 is not limited to a multi-joint robot. The robot arm 10 may be any device as long as it can move the movable member 20 in a predetermined direction.

[0091] The measuring device 100 may include an air cylinder capable of moving the movable member 20 in a predetermined direction instead of the robot arm 10. For example, the measuring device 100 may include an air cylinder capable of moving the movable member 20 along a single axis instead of the robot arm 10.

[0092] (2-3) Holder 30

[0093] The grippers 30 are devices 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.

[0094] In this embodiment, if Figure 4 As shown, the gripping member 32 is a rod-shaped or finger-shaped member. Each gripper 30 has a plurality of (for example, three) gripping members 32. Figure 4 The number and shape of the gripping members 32 shown in the drawings are merely examples and can be changed as appropriate.

[0095] In this embodiment, if Figure 5A As shown, when viewing each gripper 30 from the gripping member 32 side, the plurality of gripping members 32 are arranged in a circumferential direction. Furthermore, when viewing each gripper 30 from the gripping member 32 side, the plurality of gripping members 32 are arranged at substantially equal intervals in the circumferential direction. Furthermore, when viewing each gripper 30 from the gripping member 32 side, the gripping member 32 is movable in the radial direction.

[0096] In addition, if Figure 5B and Figure 5C As shown, the gripper 30 moves the gripping members 32 that are separated from each other in the radially inward direction by the gripping member driving mechanism 34 so as to bring them closer to each other, thereby sandwiching the article A between the plurality of gripping members 32 and gripping the article A.

[0097] Furthermore, the gripper 30 releases the grip of the article A by moving the gripping members 32 , which are in a state of being close to each other, in the radially outward direction so as to separate from each other via the gripping member driving mechanism 34 .

[0098] like Figure 3 、 Figure 4 and Figure 5A As shown, a plurality of grippers 30 are attached to the movable member 20. Each gripper 30 is attached to the movable member 20 via a sensor unit 42 of a measuring unit 40. The sensor unit 42 of the measuring unit 40 is arranged between the gripper 30 and the movable member 20 supporting the gripper 30.

[0099] exist Figure 3 、 Figure 4 and Figure 5A In the example shown, eleven grippers 30 are attached to the movable member 20, but this is an example and the number of grippers 30 is not limited. The plurality of grippers 30 attached to the movable member 20 move vertically as a whole when the robot arm 10 moves the movable member 20 vertically.

[0100] like Figure 5A As shown, when viewing the grippers 30 attached to the movable member 20 from the gripping member 32, each gripper 30 has a generally circular shape. In this embodiment, the grippers 30 attached to the movable member 20 are arranged in a generally staggered pattern when viewed from the gripping member 32. However, this arrangement is merely an example and is not limited to a staggered arrangement.

[0101] (2-4) Measuring unit 40

[0102] In the weighing device 100, a weighing unit 40 is provided for each gripper 30. The weighing unit 40 measures the weight of the article A gripped by the gripping member 32 of the corresponding gripper 30.

[0103] Each measuring unit 40 includes a sensor unit 42 and a control unit (not shown). Figure 4 As shown, each gripper 30 is attached to the movable member 20 via a sensor unit 42. The sensor unit 42 includes a force sensor and an acceleration sensor. For example, a strain gauge load cell is used as the force sensor. For example, a strain gauge load cell or a small MEMS acceleration sensor is used as the acceleration sensor.

[0104] When the gripper 30, while gripping the article A, moves in conjunction with the movement of the movable member 20, the control unit of the measuring unit 40 measures the mass of the article A gripped 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 gripped by the gripper 30 by dividing the force measured by the force sensor by the acceleration measured by the acceleration sensor.

[0105] However, the measuring unit 40 is not limited to measuring the mass of the article A based on the force and acceleration measured when the gripper 30 moves. The measuring unit 40 may also measure the weight of the article A gripped by the stationary gripper 30 using a load cell or the like.

[0106] (2-5) Placing Unit 50 and Placing Unit Driving Unit 54

[0107] Article group A1 is placed on placement section 50. Specifically, placement section 50 includes article group storage container 52 that stores articles A (article group A1). In placement section 50, article group A1 is placed on placement surface 52a (here, the bottom surface of article group storage container 52).

[0108] The gripper 30 grasps a portion of the articles A from the article group A1 contained in the article group container 52. In this embodiment, the article group container 52 is a rectangular container with an upper opening. The loading portion 50 is configured so that if the amount of articles A contained in the article group container 52 decreases, a person or machine can replace the article group container 52 with a new one (containing more articles A).

[0109] Alternatively, the placement section 50 may include an article supply mechanism for supplying articles A to the article group storage containers 52 , instead of configuring the article group storage containers 52 to be replaceable.

[0110] The placing section 50 is moved between a first position and a second position by a placing section drive unit 54. The placing section drive unit 54 uses, for example, a motor or fluid pressure as a driving source to move the placing section 50. The first position is a position in which the gripper 30 grips an article A from the article group A1 placed on the placing section 50. The second position is a position in which the gripper 30 does not grip an article A from the article group A1 placed on the placing section 50.

[0111] The placement unit drive unit 54 moves the placement unit 50 between the first position and the second position in a direction intersecting the moving direction of the movable member 20. In this embodiment, the placement unit drive unit 54 moves the placement unit 50 between the first position and the second position in the horizontal direction.

[0112] Specifically, the first position of the placement section 50 is directly below the gripper 30. When the placement section 50 is in the first position, if the movable member 20 is moved by the robot arm 10 and the gripper 30 approaches a predetermined position relative to the placement section 50, the gripper 30 can grip the article A placed on the placement section 50. Furthermore, the first position of the placement section 50 is directly above the discharge chute 60.

[0113] On the other hand, the second position of the placement section 50 is a position away from directly below the gripper 30. In this embodiment, the movable member 20 to which the gripper 30 is mounted moves only in the vertical direction. Therefore, when the placement section 50 is in the second position, the gripper 30 cannot grip the article A placed on the placement section 50. Furthermore, the second position of the placement section 50 is a position away from directly above the discharge chute 60.

[0114] (2-6) Discharge chute 60

[0115] The discharge chute 60 is a funnel-shaped component. It is located directly below the gripper 30. Furthermore, when the loading section 50 is in the first position, the discharge chute 60 is located directly below the loading section 50. In other words, when the loading section 50 is in the first position, it is located between the gripper 30 and the discharge chute 60.

[0116] On the other hand, when the placement portion 50 is located at the second position, the placement portion 50 does not exist between the gripper 30 and the discharge chute 60 .

[0117] The discharge chute 60 discharges the article A supplied from the gripper 30 to the outside of the weighing device 100 when the gripper 30 releases the grip. Specifically, when the placement portion 50 is in the second position, the discharge chute 60 receives the article A dropped by the gripper 30 and discharges it to the outside of the weighing device 100.

[0118] (2-7) Control Unit 70

[0119] The control unit 70 includes a CPU (not shown), and memories such as ROM and RAM. Figure 2 As shown, the control unit 70 is electrically connected to the robot arm 10 , the gripping member driving mechanism 34 , the measuring unit 40 , and the placing unit driving unit 54 .

[0120] The control unit 70 executes the program stored in the memory through the CPU to control the actions of various structures of the weighing device 100 such as the robot arm 10, the gripping part driving mechanism 34, the loading part driving unit 54, and the combined calculation of the weight value of the item A measured by the weighing unit 40.

[0121] In addition, the various functions of the control unit 70 may be implemented not by software but by hardware, or by a combination of hardware and software.

[0122] (2-7-1) Control of the Operation of the Gripping Member Driving Mechanism 34

[0123] 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 grip member driving mechanism 34 .

[0124] In the first control mode, the control unit 70 controls the gripping member driving mechanism 34 to cause the gripping member 32 to perform the first operation.

[0125] The first action refers to the action of the holding member 32 holding the article A and then releasing the grip of the article A. Here, the first action is the following series of actions: Figure 5B The plurality of holding members 32 shown in the figure, which are located at positions separated from each other, move inward in the radial direction to Figure 5C The positions shown are close to each other, and then return to Figure 5B The separated positions are shown.

[0126] In the second control mode, the control unit 70 controls the gripping member driving 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 adhering object attached to the gripping member 32.

[0127] The attached matter 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 attached matter is the noodles, toppings, spaghetti sauce, and the like.

[0128] Since the control unit 70 has the second control mode as the control mode of the gripping member driving mechanism 34 , the following effects are obtained.

[0129] The weighing unit 40 corresponding to the gripper 30 measures not only the weight of the article A gripped by the gripping member 32 but also the weight of any attachments attached to the gripping member 32 as the weight of the article A.

[0130] However, the attached object is not the article A gripped by the gripping member 32 , and therefore, even if the gripping member 32 releases the grip of the article A, the attached object may not fall from the gripping member 32 .

[0131] Therefore, if the weight of the objects attached to the gripping member 32 increases, the weight of the articles A discharged by the gripper 30 may deviate from the weight of the articles A measured by the measuring unit 40 corresponding to the gripper 30 .

[0132] Furthermore, on the contrary, there is a possibility that the attached matter that has not fallen off may suddenly fall into the discharge chute 60 and impair the measurement accuracy.

[0133] Furthermore, it is not desirable from a hygienic point of view for attached matter to remain attached to the gripping member 32 for a long period of time. In this embodiment, the control unit 70 has a second control mode as a control mode for the gripping member drive mechanism 34, and the gripping member 32 performs a second operation to remove attached matter, thereby alleviating such an undesirable situation.

[0134] The second motion of the gripping member 32 is different from the first motion. The difference between the first motion and the second motion includes the following: the movement mode of the gripping member 32 in the first motion is different from the movement mode of the gripping member 32 in the second motion.

[0135] The difference between the first and second actions includes the following: the movement method of the gripping member 32 is the same, but the first and second actions differ in any one of the movement speed and the number of executions of the gripping member 32 .

[0136] A specific example of the second operation of the gripping member 32 will be described. The second operation of the gripping member 32 in one example described below can be appropriately combined with the second operation in other examples within a range that does not conflict with each other.

[0137] (a) First Example of the Second Movement of the Holding Member 32

[0138] For ease of explanation, we will Figure 5B The positions of the plurality of holding members 32 depicted in FIG. 3 are referred to as remote positions and will be Figure 5C The positions of the plurality of gripping members 32 depicted in FIG. 3 are referred to as proximity positions.

[0139] The second action of the holding member 32 in the first example is the same as the first action, which is the following series of actions: Figure 5B The plurality of gripping members 32 that are separated from each other and arranged at distant positions are moved radially inward. Figure 5C The illustrated approach position is moved and thereafter returns again to the distanced position.

[0140] However, during the second movement, the average movement speed of the gripping member 32 from the distant position to the close position (hereinafter referred to as the close speed) is faster than the close speed during the first movement. In addition to or instead of this, during the second movement, the average movement speed of the gripping member 32 from the close position to the distant position (hereinafter referred to as the separate speed) is faster than the separate speed during the first movement.

[0141] In other words, during the second operation, the gripping member 32 moves from the distant position to the close position and / or moves from the close position to the distant position in a shorter time than during the first operation.

[0142] In particular, in this embodiment, the approaching speed and the separation speed during the second movement are faster than the approaching speed and the separation speed during the first movement. For example, the approaching speed and the separation speed during the second movement of the holding member 32 are more than twice (more preferably more than five times) the approaching speed and the separation speed during the first movement.

[0143] Furthermore, the maximum acceleration of the gripping member 32 when moving the gripping member 32 from the distant position to the close position during the second operation (hereinafter referred to as close acceleration) is greater than the close acceleration during the first operation.

[0144] In addition, on the basis of this or instead of this, the maximum deceleration of the holding part 32 when moving the holding part 32 from the distant position to the close position during the second action (the absolute value of the negative acceleration during deceleration, hereinafter referred to as the approach deceleration) is greater than the approach deceleration during the first action.

[0145] In addition to or instead of this, the maximum acceleration of the gripping member 32 when moving the gripping member 32 from the approach position to the distanced position during the second action (hereinafter referred to as the distanced acceleration) is greater than the distanced acceleration during the first action. Furthermore, in addition to or instead of this, the maximum deceleration of the gripping member 32 when moving the gripping member 32 from the approach position to the distanced position during the second action (the absolute value of the negative acceleration during deceleration, hereinafter referred to as the approach deceleration) is greater than the distanced acceleration during the first action.

[0146] For example, the approach acceleration and the departure acceleration of the second movement of the holding member 32 are more than twice (more preferably more than five times) the approach acceleration and the departure acceleration of the first movement. In addition, the approach deceleration and the departure deceleration of the second movement of the holding member 32 are more than twice (more preferably more than five times) the approach deceleration and the departure deceleration of the first movement.

[0147] (b) Second Example of the Second Movement of the Holding Member 32

[0148] The second action of the holding member 32 in the first example is the same as the first action, which is the following series of actions: Figure 5B The plurality of gripping members 32 shown as being separated from each other and arranged at distant positions are moved radially inwardly toward Figure 5C The illustrated approach position is moved and thereafter returns again to the distanced position.

[0149] However, during the second movement, the gripping member 32 is moved from the remote position to the close position, or vice versa, more times than during the first movement. For example, during the first movement, the gripping member 32 performs a series of movements from the remote position to the close position and back to the remote position once. In contrast, during the second movement, the gripping member performs a series of movements from the remote position to the close position and back to the remote position multiple times. For example, during the second movement, the gripping member 32 performs a series of movements two or more times (more preferably four or more times).

[0150] (c) Third Example of the Second Movement of the Holding Member 32

[0151] The holding member 32 may not move within the range of the distant position and the approaching position during the second action as it does during the first action. For example, the holding member 32 may move within a narrower range during the second action than during the first action. For example, the amount of movement of the holding member 32 during the second action is set to be less than 3 / 4 (more preferably less than 1 / 2) of the amount of movement of the holding member 32 during the first action. In addition, although not limited to this, for example, the amount of movement of the holding member 32 during the second action is set to be more than 1 / 8 of the amount of movement of the holding member 32 during the first action.

[0152] For example, in the second control mode, the control unit 70 controls the gripping member drive mechanism 34 by combining the methods of the first through third examples above, causing the gripping member 32 to move back and forth multiple times at high speed within a narrow range. This control by the control unit 70 causes the gripping member 32 to vibrate at high speed. This movement of the gripping member 32 facilitates the removal of debris adhering to the gripping member 32.

[0153] Furthermore, the first to third examples of the second action do not need to be combined simultaneously; they can be combined as appropriate. For example, in another embodiment, the control unit 70 can control the gripping member drive mechanism 34 in the second control mode to cause the gripping member 32 to perform a high-speed movement similar to the first action (movement from the distanced position to the approached position and then back to the distanced position).

[0154] (3) Operation of the measuring device 1

[0155] Reference Figures 6A to 6I and Figure 7A The operation of the weighing device 100 controlled by the control unit 70 will be described. In addition, although the weighing device 1 including a plurality of grippers 30 is described here as an example, the present invention can also be applied to a weighing device including a single gripper 30.

[0156] Figures 6A to 6I Is used to illustrate Figure 1 A schematic side view of the measuring device 100 illustrating the operation of the measuring device 100 .

[0157] exist Figures 6A to 6I In FIG, the robot arm 10 that moves the movable member 20 is omitted from depiction. Figure 7A This is a flowchart for explaining the operation of the measuring device 100 according to the first embodiment.

[0158] Figure 6A The initial state of the gripper 30 before gripping the article A is depicted. Figure 6A In the embodiment, 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 unit 50. The placement unit 50 is arranged at a first position directly below the gripper 30. The gripping member 32 of each gripper 30 is arranged as shown in FIG. Figure 5B Configuration shown in remote position.

[0159] (Step S1)

[0160] During the operation of the weighing device 100 , the control unit 70 controls the robot arm 10 from the initial state to move the movable member 20 vertically downward and bring the plurality of grippers 30 close to the placement unit 50 .

[0161] Specifically, the control unit 70 controls the operation of the robot arm 10 to move the movable member 20 vertically downward so that the gripping member 32 of the gripper 30 is positioned at a predetermined position capable of gripping the article A in the article group storage container 52 (see FIG. Figure 6B ).

[0162] More specifically, the control unit 70 controls the operation of the robot arm 10 to move the movable member 20 vertically downward so that at least a portion of the gripping member 32 is inserted into the article group A1 .

[0163] (Step S2)

[0164] Next, in step S2, the control unit 70 controls the gripping member driving mechanism 34 of each gripper 30 so that the gripping member 32 grips the article A. Preferably, the control unit 70 causes the plurality of grippers 30 to grip the article A simultaneously. However, this is not limiting, and the control unit 70 may also cause the plurality of grippers 30 to grip the article A at different timings.

[0165] (Step S3)

[0166] Next, the control unit 70 controls the robot arm 10 to move the movable member 20 vertically upward while the plurality of grippers 30 are gripping the articles A, so that the gripping members 32 of the grippers 30 are positioned outside the article group storage container 52 of the placement unit 50 ( Figure 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 .

[0167] (Step S4)

[0168] 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 articles A gripped by the gripper 30 to the article group storage container 52 instead of being discharged to the discharge chute 60 .

[0169] The main purpose of this determination is to prevent the accidental discharge of the article A into the discharge chute 60 by returning the article A to the article group storage container 52 before moving the article group storage container 52, if the weight value of the article A measured by the weighing unit 40 is estimated to be different from the preset target weight value or is not the target weight value.

[0170] Therefore, "meeting the prescribed conditions" means meeting

[0171] (1) The weight of the article A measured by the weighing unit 40 is not the preset target weight value;

[0172] (2) The amount of movement of the gripping member 32 to grip the article A is greater than a predetermined range,

[0173] (3) The amount of movement of the gripping member 32 to grip the article A is less than a predetermined range.

[0174] At least one of .

[0175] In particular, in the case of condition (2), the fact that the amount of movement of the gripping member 32 gripping the article A is greater than the predetermined range means that the weight value of the article A is greater than the target weight value.

[0176] Figure 5D This is a top view of the three gripping members 32 holding a virtual object that matches the lower limit of the target weight value, as viewed from the front end side of the gripping members 32. Figure 5D In FIG, the circle C1 is the minimum inscribed circle with respect to the three gripping members 32 .

[0177] Figure 5E This is a top view of three gripping members 32 holding a virtual object that matches the upper limit of the target weight value, as viewed from the front end side of the gripping members 32. Figure 5E In FIG, circle C2 is the minimum inscribed circle with respect to the three gripping members 32. Furthermore, the range enclosed by circles C1 and C2 is a predetermined range R that satisfies the target weight value.

[0178] Figure 5F This is a top view of three gripping members 32 holding an imaginary article exceeding the upper limit of the target weight value, as viewed from the front end side of the gripping members 32. Figure 5F , the circle Ca is located outside the predetermined range R when viewed from the center of the circle. That is, the reaching position (coordinates) of each gripping member 32 is located outside the reaching position (coordinates) of the gripping member holding a virtual article that matches the upper limit of the target weight value.

[0179] In the above case, it is determined that "the movement amount of the movement of the gripping member 32 to grip the article is greater than the predetermined range."

[0180] Furthermore, in the case of condition (3), the fact that the movement amount of the movement of the gripping member 32 to grip the article A is smaller than the predetermined range means that the weight value of the article is smaller than the target weight value.

[0181] Figure 5G This is a top view of three gripping members 32 holding an imaginary object smaller than the lower limit of the target weight value, as viewed from the front end side of the gripping members 32. Figure 5G, the circle Cb is located inward of the predetermined range R when viewed from the center of the circle. That is, the reaching position (coordinates) of each gripping member 32 is located inward of the reaching position (coordinates) of the gripping member 32 gripping a virtual article that matches the lower limit of the target weight value.

[0182] In the above case, it is determined that "the movement amount of the movement of the gripping member 32 to grip the article A is smaller than the predetermined range."

[0183] In addition, whether any of the above-mentioned conditions (2) and (3) are met can be determined when step S2 is completed. Figure 7B As shown, a step of determining whether the above-mentioned predetermined conditions (2) and (3) are met may be provided between step S2 and step S3. The details are described in [(5) Variation of the first embodiment] below.

[0184] The control unit 70 proceeds to step S5 when it determines that at least one of the operating state of each gripper 30 and the measurement result of the measurement unit 40 meets the predetermined condition, and proceeds to step S6 when it determines that it does not meet the predetermined condition.

[0185] (Step S5)

[0186] Next, the control unit 70 controls the gripping member driving mechanism 34 of the gripper 30 that meets at least one of the above-mentioned conditions (1), (2) and (3), so that the gripper 30 releases the grip of the article A (see Figure 6D ).

[0187] In other words, if there is a gripper 30 gripping an article A whose weight value is not the target weight value, the control unit 70 controls the gripping member driving mechanism 34 of the gripper 30 to release the gripper 30 from gripping the article A.

[0188] The article A 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 meets the above-mentioned predetermined conditions completes the first operation.

[0189] Furthermore, immediately after the gripping member 32 of the gripper 30 releases the grip of the article A through the first action, the control unit 70 controls the gripping member driving mechanism 34 of the gripper 30 to cause the gripping member 32 to perform the second action. Furthermore, if the article A is difficult to adhere to the gripping member 32, the second action is not necessarily required.

[0190] By returning the article A held by the gripper 30 that meets at least one of conditions (1), (2), and (3) to the article group container 52, the system avoids operating while holding an article A whose weight does not meet the target weight. This prevents the article from falling from the gripper 30 and causing a decrease in weighing accuracy. Furthermore, unnecessary movement can be eliminated, leading to improved production efficiency.

[0191] (Step S6)

[0192] Next, the control unit 70 controls the placement unit driving unit 54 to move the placement unit 50 from the first position to the second position (see Figure 6E When the placement portion 50 moves to the second position, the placement portion 50 is not disposed between the gripper 30 and the discharge chute 60 .

[0193] (Step S7)

[0194] Next, the control unit 70 controls the robot arm 10 to move the movable member 20 vertically downward so that the plurality of grippers 30 are close to the discharge chute 60 (see FIG. Figure 6F ).

[0195] Note that, depending on the article, this “approaching motion” may not be necessary. In such a case, the article may be dropped without moving the movable member 20 vertically downward.

[0196] (Step S8)

[0197] Next, the control unit 70 releases the gripper 30 that does not meet any of the prescribed conditions (1), (2) and (3) from gripping the article A in step 5, and discharges the article A from the discharge chute 60 (refer to Figure 6G ). The gripping parts 32 of these grippers 30 complete the first action at this moment.

[0198] Furthermore, immediately after the gripping member 32 of the gripper 30 releases the grip of the article A through the first action, the control unit 70 controls the gripping member driving mechanism 34 of the gripper 30 to cause the gripping member 32 to perform the second action. Furthermore, if the article A is difficult to adhere to the gripping member 32, the second action is not necessarily required.

[0199] (Step S9)

[0200] 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 Figure 6H ).

[0201] (Step S10)

[0202] Next, the control unit 70 controls the placing unit driving unit 54 to return the placing unit 50 from the second position to the first position directly below the gripper 30 (see FIG. Figure 6I ).

[0203] (Step S11)

[0204] Then, the control unit 70 determines whether or not there is an operation stop instruction. If the control unit 70 determines that there is an operation stop instruction, it stops control, and if it determines that there is no operation stop instruction, it returns to step S1.

[0205] The operation of the measuring device 100 described here is merely an example and can be appropriately changed within a range that does not conflict.

[0206] In addition, for example, the control unit 70 may control the robot arm 10 in a state where the plurality of grippers 30 grip the article A, and move the movable member 20 from Figure 6B The position depicted in Figure 6C When the position depicted in FIG. 1 moves upward, the robot arm 10 is controlled so that the movable member 20 moves downward one or more times.

[0207] Furthermore, when the gripper 30 releases its grip, the upward and downward movement of the movable member 20 can also be used to shake off objects attached to the gripping member 32. Objects attached to the gripping member 32 are objects that are not gripped by the gripping member 32 and may fall regardless of the movement of the gripping member 32. By moving the movable member 20 downward to pre-shake off objects attached to the gripping member 32, the weight of the object A measured by the weighing unit 40 can be made closer to the weight of the object A gripped by the gripping member 32, thereby improving measurement accuracy.

[0208] (4) Features of the first embodiment

[0209] (4-1)

[0210] In the measuring device 100, when at least one of the operating state of the gripper 30 and the measuring result of the measuring unit 40 meets any one of the following conditions: (1) the weight value of the item A measured by the measuring unit 40 is not a preset target weight value, (2) the amount of the action of the gripping part 32 gripping the item A is greater than a prescribed range, and (3) the amount of the action of the gripping part 32 gripping the item A is less than a prescribed range, the control unit 70 causes the item A gripped by the gripper 30 to be not discharged into the discharge chute 60 but returned to the item group storage container 52.

[0211] The fact that the movement amount of the gripper 30 gripping the article A is greater than the predetermined range means that the weight value of the article is greater than the target weight value.

[0212] For example, when an item A is clamped and held by three holding parts 32, the range enclosed by the minimum inscribed circle relative to each holding part 32 when clamping an item consistent with the lower limit value of the target weight value, and the range enclosed by the minimum inscribed circle relative to each holding part 32 when clamping an item A consistent with the upper limit value of the target weight value is the specified range R that satisfies the target weight value.

[0213] Therefore, when gripping an article A exceeding the upper limit of the target weight value, the minimum inscribed circle relative to each gripping member 32 is located outside the predetermined range R as viewed from the center of the circle. In other words, the arrival position (coordinates) of each gripping member is located outside the arrival position (coordinates) of the gripping member 32 when gripping an article A that matches the upper limit of the target weight value.

[0214] In this case, it is determined that the movement amount of the gripping member 32 gripping the article A exceeds the predetermined range R. Therefore, the gripper 30 is prevented from operating while gripping an article whose weight is not the target weight.

[0215] Furthermore, the fact that the movement amount of the gripper 30 gripping the article A is smaller than the predetermined range means that the weight value of the article is smaller than the target weight value.

[0216] For example, when gripping an article A smaller than the lower limit of the target weight, the minimum inscribed circle relative to each gripping member 32 is located inward of the predetermined range R as viewed from the center of the circle. In other words, the arrival position (coordinates) of each gripping member 32 is located inward of the arrival position (coordinates) of the gripping member 32 when gripping an article A that matches the lower limit of the target weight.

[0217] In the above case, it is determined that "the movement amount of the movement of the gripping member 32 to grip the article A is smaller than the predetermined range R."

[0218] This prevents the gripper 30 from operating while gripping an item whose weight does not match the target weight. This prevents the item A from falling from the gripper 30 and reducing weighing accuracy. Furthermore, unnecessary movement can be eliminated, improving production efficiency.

[0219] (4-2)

[0220] In the weighing device 100, the amount of movement of the gripper 30 in gripping the article A is the opening degree of the gripping member 32. If the opening degree of the gripping member 32 is greater than a predetermined range, the weight of the article A is greater than a target weight. If the opening degree of the gripping member 32 is less than a predetermined range, the weight of the article A is less than a target weight.

[0221] (5) Modification of the First Embodiment

[0222] Figure 7B This is a flowchart for explaining the operation of the measuring device 100 according to the modified example of the first embodiment. Figure 7B In this modification, Figure 7A The difference is that step S2a and step S2b are inserted between step S2 and step S3.

[0223] Figure 7B Steps S1, S2, S3 to S11 and Figure 7A Since they are the same, the description is omitted and the newly inserted steps S2a and S2b are described here.

[0224] (Step S2a)

[0225] In step S2 a , the control unit 70 determines whether the operating state of each gripper 30 meets a predetermined condition for returning the articles A gripped by the gripper 30 to the article group storage container 52 instead of being discharged to the discharge chute 60 .

[0226] Here, "meeting the prescribed conditions" means meeting all conditions except (1) among the prescribed conditions (1) to (3) described in step S4 of the first embodiment.

[0227] (2) The amount of movement of the gripping member 32 to grip the article A is greater than a predetermined range,

[0228] (3) The amount of movement of the gripping member 32 to grip the article A is less than a predetermined range.

[0229] At least one of .

[0230] Initially, in step S2, when the control unit 70 causes the holding part 32 to hold the article A, it is possible to determine whether the amount of movement of the holding part 32 to hold the article A is greater than or less than the specified range. Therefore, the control unit 70 does not need to wait until the movable part 20 is moved vertically upward as in the first embodiment.

[0231] The control unit 70 proceeds to step S2b when it is determined that the operating state of each gripper 30 meets the above-mentioned predetermined condition (2) or (3), and proceeds to step S3 when it is determined that the operating state of each gripper 30 does not meet the above-mentioned predetermined condition (2) or (3).

[0232] (Step S2b)

[0233] Next, the control unit 70 controls the gripping member driving mechanism 34 of the gripper 30 that meets at least one of the above-mentioned conditions (2) and (3) to release the gripping of the article A by the gripper 30 (refer to Figure 6D ).

[0234] In other words, if there is a gripper 30 gripping an article A whose weight value is not the target weight value, the control unit 70 controls the gripping member driving mechanism 34 of the gripper 30 to release the gripper 30 from gripping the article A.

[0235] The article A 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 meets the above-mentioned predetermined conditions completes the first operation.

[0236] Furthermore, immediately after the gripping member 32 of the gripper 30 releases the grip of the article A through the first action, the control unit 70 controls the gripping member driving mechanism 34 of the gripper 30 to cause the gripping member 32 to perform the second action. Furthermore, if the article A is difficult to adhere to the gripping member 32, the second action is not necessarily required.

[0237] By returning the articles A held by the grippers 30 that meet at least one of conditions (2) and (3) to the article group storage container 52, the system avoids operating while holding articles A whose weights do not meet the target weights. This prevents articles from falling from the grippers 30, which could reduce weighing accuracy. Furthermore, unnecessary movement can be eliminated, improving production efficiency.

[0238] <Second embodiment>

[0239] In the first embodiment, the description is based on a weighing device that holds a fixed amount of data. In the second embodiment, the description is based on a combined weighing device that measures a combination of data.

[0240] The configuration of the measuring device of the second embodiment directly utilizes the configuration of the measuring device of the first embodiment, with only the control being different, and therefore detailed description of each part will be omitted.

[0241] (1) Operation of the measuring device 100

[0242] Reference Figures 6A to 6I and Figure 8A , the operation of the measuring device 100 controlled by the control unit 70 will be described.

[0243] Figure 8A This is a flowchart for explaining the operation of the measuring device 100 according to the second embodiment.

[0244] exist Figure 6A In the embodiment, 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 unit 50. The placement unit 50 is arranged at a first position directly below the gripper 30. The gripping member 32 of each gripper 30 is arranged as shown in FIG. Figure 5BConfiguration shown in remote position.

[0245] (Step S101)

[0246] During the operation of the weighing device 100 , the control unit 70 controls the robot arm 10 from the initial state to move the movable member 20 vertically downward and bring the plurality of grippers 30 close to the placement unit 50 .

[0247] Specifically, the control unit 70 controls the operation of the robot arm 10 to move the movable member 20 vertically downward so that the gripping member 32 of the gripper 30 is positioned at a predetermined position capable of gripping the article A in the article group storage container 52 (see FIG. Figure 6B ).

[0248] More specifically, the control unit 70 controls the operation of the robot arm 10 to move the movable member 20 vertically downward so that at least a portion of the gripping member 32 is inserted into the article group A1 .

[0249] (Step S102)

[0250] Next, 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 to this, and the control unit 70 may cause the plurality of grippers 30 to grip the article A at different timings.

[0251] Furthermore, since it is possible to determine whether any of the conditions (2) and (3) in the first embodiment are met upon completion of step S102, a step for determining whether the conditions (2) and (3) are met may be provided between step S102 and step S103. Details are described later in [(3) Variations of the Second Embodiment].

[0252] (Step S103)

[0253] Next, the control unit 70 controls the robot arm 10 to move the movable member 20 vertically upward while the plurality of grippers 30 grip the articles A, so that the gripping members 32 of the grippers 30 are positioned outside the article group storage container 52 of the placement unit 50 (see FIG. Figure 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 .

[0254] (Step S104)

[0255] Next, the control unit 70 performs a combination calculation using the weight values ​​of the articles A gripped by the grippers 30 measured by the weighing units 40 , and finds a combination of weight values ​​whose total value falls within the target weight range.

[0256] (Step S105)

[0257] Next, the control unit 70 determines whether or not there is a gripper 30 that has not been selected as a combination among the grippers 30 .

[0258] The control unit 70 proceeds to step S6 when determining that there is a gripper 30 that has not been selected as a combination, and proceeds to step S7 when determining that there is no gripper 30 that has not been selected as a combination.

[0259] (Step S106)

[0260] Next, if the gripper 30 has a weight that is not selected as a combination of the gripper A, the control unit 70 controls the gripping member driving mechanism 34 of the gripper 30 to release the gripping of the gripper 30 from the gripping of the object A through the first action (see Figure 6D ).

[0261] The article A 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 not selected for the combination completes the first operation.

[0262] Furthermore, immediately after the gripping member 32 of the gripper 30 has released its grip on the article A through the first action, the control unit 70 controls the gripping member driving mechanism 34 of the gripper 30 to cause the gripping member 32 to perform the second action. If the article A is difficult for the gripping member 32 to adhere to, the second action is not necessarily required.

[0263] (Step S107)

[0264] Next, the control unit 70 controls the placement unit driving unit 54 to move the placement unit 50 from the first position to the second position (see Figure 6E When the placement portion 50 moves to the second position, the placement portion 50 is not disposed between the gripper 30 and the discharge chute 60 .

[0265] (Step S108)

[0266] Next, the control unit 70 controls the robot arm 10 to move the movable member 20 vertically downward so that the plurality of grippers 30 are close to the discharge chute 60 (see FIG. Figure 6F ).

[0267] (Step S109)

[0268] Next, based on the result of the combination calculation, the control unit 70 causes the gripper 30 corresponding to the combination of weight values ​​that fall within the target weight range above the discharge chute 60 to release the grip of the article A and discharge the article A from the discharge chute 60 (see Figure 6G ). The gripping member 32 of the gripper 30 selected as the combination completes the first action at this moment.

[0269] Furthermore, immediately after the gripping member 32 of the gripper 30 has released its grip on the article A through the first action, the control unit 70 controls the gripping member driving mechanism 34 of the gripper 30 to cause the gripping member 32 to perform the second action. If the article A is difficult for the gripping member 32 to adhere to, the second action is not necessarily required.

[0270] (Step S110)

[0271] When the discharge of the articles A is completed for all combinations of weight values ​​that fall 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. Figure 6H ).

[0272] (Step S111)

[0273] Next, the control unit 70 controls the placing unit driving unit 54 to return the placing unit 50 from the second position to the first position directly below the gripper 30 (see FIG. Figure 6I ).

[0274] (Step S112)

[0275] Then, the control unit 70 determines whether or not there is an operation stop instruction. If the control unit 70 determines that there is an operation stop instruction, it stops control, and if it determines that there is no operation stop instruction, it returns to step S1.

[0276] The operation of the measuring device 100 described here is merely an example and can be appropriately changed within a range that does not conflict.

[0277] In addition, for example, the control unit 70 may control the robot arm 10 in a state where the plurality of grippers 30 grip the article A, and move the movable member 20 from Figure 6B The position depicted in Figure 6C When the position depicted in FIG. 1 moves upward, the robot arm 10 is controlled so that the movable member 20 moves downward one or more times.

[0278] Furthermore, when the gripper 30 releases its grip, the upward and downward movement of the movable member 20 can also be used to shake off objects attached to the gripping member 32. Objects attached to the gripping member 32 are objects that are not gripped by the gripping member 32 and may fall regardless of the movement of the gripping member 32. By moving the movable member 20 downward to pre-shake off objects attached to the gripping member 32, the weight of the object A measured by the weighing unit 40 can be made closer to the weight of the object A gripped by the gripping member 32, thereby improving measurement accuracy.

[0279] (2) Features of the Second Embodiment

[0280] (2-1)

[0281] In the weighing device 100, if a gripper 30 having a weight holding an article A is not selected for combination, the article A held by the gripper 30 not selected for combination is returned to the article group storage container 52, and then the article A held by the gripper 30 selected for combination is discharged into the discharge chute 60. As a result, the article A held by the gripper 30 not selected for combination is discharged into the discharge chute 60 without falling from the gripper 30, thereby improving weighing accuracy.

[0282] (2-2)

[0283] In the weighing device 100 , if there is no combination that meets the target weight value, the control unit 70 discharges the articles gripped by all the gripping units into the article group storage container 52 .

[0284] (3) Modification of the Second Embodiment

[0285] Figure 8B This is a flowchart for explaining the operation of the measuring device 100 according to the modified example of the second embodiment. Figure 8B In this modification, Figure 8A The difference is that step S102a and step S102b are inserted between step S102 and step S103.

[0286] Figure 8B Steps S101, S102, S103 to S112 and Figure 8A Since they are the same, the description is omitted, and here, the newly inserted steps S102a and S102b are described.

[0287] (Step S102a)

[0288] In step S102 a , the control unit 70 determines whether or not there is a gripper 30 that has not been selected as a combination among the grippers 30 .

[0289] Here, "there is no combination that has not been selected in the gripper 30" means that the combination meets all conditions except (1) among the predetermined conditions (1) to (3) described in step S4 of the first embodiment.

[0290] (2) The amount of movement of the gripping member 32 to grip the article A is greater than a predetermined range,

[0291] (3) The amount of movement of the gripping member 32 to grip the article A is less than a predetermined range.

[0292] At least one of .

[0293] Initially, at the moment when the control unit 70 causes the holding part 32 to hold the article A in step S102, it is possible to determine whether the amount of movement of the holding part 32 to hold the article A is greater than or less than the prescribed range. Therefore, the control unit 70 does not need to wait until the movable part 20 is moved vertically upward as in the first and second embodiments.

[0294] The control unit 70 proceeds to step S102b when it is determined that the operating state of each gripper 30 meets the above-mentioned predetermined condition (2) or (3), and proceeds to step S3 when it is determined that the operating state of each gripper 30 does not meet the above-mentioned predetermined condition (2) or (3).

[0295] (Step S102b)

[0296] Next, the control unit 70 controls the gripping member driving mechanism 34 of the gripper 30 that meets at least one of the above-mentioned conditions (2) and (3) to release the gripping of the article A by the gripper 30 (refer to Figure 6D ).

[0297] In other words, if the gripper 30 has a weight that is not selected as a combination for the gripped article A, the control unit 70 controls the gripping member driving mechanism 34 of the gripper 30 to release the grip of the article A by the gripper 30 through the first operation.

[0298] The article A 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 meets the above-mentioned predetermined conditions completes the first operation.

[0299] Furthermore, immediately after the gripping member 32 of the gripper 30 releases the grip of the article A through the first action, the control unit 70 controls the gripping member driving mechanism 34 of the gripper 30 to cause the gripping member 32 to perform the second action. Furthermore, if the article A is difficult to adhere to the gripping member 32, the second action is not necessarily required.

[0300] By returning the articles A held by the grippers 30 that meet at least one of conditions (2) and (3) to the article group storage container 52, the grippers 30 are prevented from operating while holding articles A not selected for the group. This prevents articles from falling from the grippers 30 and reducing weighing accuracy. Furthermore, unnecessary movement can be eliminated, leading to improved production efficiency.

[0301] <Other structures>

[0302] (A)

[0303] In the weighing device 100 , the control unit 70 moves the gripper 30 and the article group storage container 52 relative to each other when returning the article A gripped by the gripper 30 to the article group storage container 52 .

[0304] In the above case, when returning to the place where the item A was last grabbed, the possibility of obtaining the appropriate amount of item A when grabbing the next time is low. Therefore, by moving the gripper 30 and the item group storage container 52 relative to each other, the place where the item A is returned is staggered, thereby increasing the possibility of grabbing the appropriate amount of item A.

[0305] (B)

[0306] In the weighing device 100, the article group container 52 is movable in first and second horizontal directions that are orthogonal to each other. When returning the article A held by the gripper 30 to the article group container 52, the control unit 70 causes the gripper 30 to move relative to the article group container 52 in either the first or second direction.

[0307] In this case, the article A is returned to the article group storage container 52 after the positional relationship between the gripper 30 and the article group storage container 52 is understood in plane coordinates. This allows for a method of returning the articles so that the articles in the container are evenly distributed.

[0308] (C)

[0309] In the weighing device 100, at least one of the gripper 30 and the article group container 52 is rotatable about a vertical axis. The control unit 70 rotates the gripper 30 and the article group container 52 by a predetermined relative angle when viewed from above. This allows the location of the returned articles A to be staggered, increasing the likelihood of grasping an appropriate amount of articles A.

[0310] (D)

[0311] In the first embodiment, whether the amount of movement of the holding component 32 holding the article A is greater or smaller than the prescribed range is determined based on whether the minimum inscribed circle relative to each holding component 32 when clamping the article A is located closer to the outside or inside than the prescribed range R, that is, the arrival position (coordinate) of the holding component 32.

[0312] However, when the gripping member 32 is in the fully open state at the start of the gripping operation, the movement amount of the gripping member 32 is greater when the weight of the gripped article is less than the target weight than when gripping an article of the target weight.

[0313] On the contrary, the movement amount of the gripping member 32 is smaller when the weight value of the gripped article is greater than the target weight value than when the gripping member 32 is gripping an article with the target weight value.

[0314] Therefore, if the gripping member 32 is in the fully open state at the start of the gripping operation, and if the amount of movement is considered as "displacement" based on the fully open state of the gripping member 32, "the amount of movement of the gripping member to grip the object is greater than a predetermined range" means that the weight of the object is less than a target weight. Furthermore, "the amount of movement of the gripping member to grip the object is less than a predetermined range" means that the weight of the object is greater than a target weight.

[0315] Explanation of symbols

[0316] 10…Robotic arm; 30…Gripper (gripping part); 32…Gripping component (claw); 40…Weighing part; 52…Article group storage container (container); 60…Discharge chute; 70…Control part; 100…Weighing device; A…Article.

[0317] Prior art literature

[0318] Patent Literature

[0319] Patent Document 1: Japanese Patent Application Laid-Open No. 6-3182.

Claims

1. A weighing device for weighing articles contained in a container and discharging the articles to a predetermined discharge destination, characterized in that: The metering device comprises: robotic arm; a plurality of gripping parts mounted on the front end of the robotic arm for gripping a portion of the items from the group of items in the container; a plurality of measuring parts for respectively measuring the weight values ​​of the articles held by the plurality of holding parts; as well as a control unit for controlling the movement of the gripping unit; The control unit causes the plurality of gripping units to grip an article simultaneously, and when it is determined that at least one of an operating state of any one of the plurality of gripping units and a measurement result of the measurement unit corresponding to the gripping unit meets a specified condition, the control unit causes the article gripped by the gripping unit that meets the specified condition to be returned to the container instead of being discharged to the discharge destination.

2. A weighing device for weighing articles of a group of articles contained in a container and discharging the articles to a predetermined discharge destination, characterized in that: The metering device comprises: robotic arm; a plurality of gripping parts mounted on the front end of the robotic arm for gripping a portion of the items from the group of items in the container; a plurality of measuring parts for respectively measuring the weight values ​​of the articles held by the plurality of holding parts; a control unit for controlling the movement of the gripping unit; as well as The discharge chute receives and discharges the items discharged from the holding portion. The control unit calculates the weight of the articles respectively held by the plurality of holding parts and selects a combination that becomes a preset target weight value. Furthermore, the control unit causes the plurality of gripping units to grip articles simultaneously, and when a measurement result of the measuring unit corresponding to at least any one of the plurality of gripping units meets specified conditions, the control unit causes the articles gripped by the gripping units that meet the specified conditions to be returned to the container, and thereafter discharges the articles gripped by the gripping units that do not meet the specified conditions into the discharge chute.

3. The metering device according to claim 1 or 2, characterized in that The predetermined condition includes that the weight value of the article measured by the measuring unit is not a preset target weight value.

4. The metering device according to claim 1 or 2, characterized in that The predetermined condition includes that the amount of movement of the gripping portion gripping the article is greater than a predetermined range.

5. The metering device according to claim 1 or 2, characterized in that The predetermined condition includes that the amount of movement of the gripping portion gripping the article is smaller than a predetermined range.

6. The metering device according to claim 4, characterized in that The gripping portion has at least two claws for grasping the object. The movement amount is the opening degree of the two claws.

7. The metering device according to claim 5, characterized in that The gripping portion has at least two claws for grasping the object. The movement amount is the opening degree of the two claws.

8. The metering device according to claim 2, characterized in that The predetermined condition includes a combination in which the weighing result is not selected as the target weight value.

9. The metering device according to claim 8, characterized in that If there is no combination that meets the target weight value, the control unit discharges the articles gripped by all the gripping units into the container.

10. The metering device according to claim 1 or 2, characterized in that The control unit moves the gripping unit and the container relative to each other when returning the article gripped by the gripping unit to the container.

11. The metering device according to claim 1 or 2, characterized in that: The container is movable in a first direction and a second direction that are orthogonal to each other. The control unit moves the gripping unit and the container relative to each other in either the first direction or the second direction when returning the article gripped by the gripping unit to the container.

12. The metering device according to claim 1 or 2, characterized in that At least one of the gripping portion and the container is rotatable about a vertical axis. The control unit rotates the gripping unit and the container by a predetermined relative angle in a plan view.

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