Article weighing and moving system and article weighing and moving method

Abstract

To suppress deterioration of weighing accuracy of an article to be discharged.SOLUTION: The article weighing and moving system 1 grips, weighs, and moves some of the articles from the article group X. An article measuring and moving system 1 includes a gripping part 30 for gripping an article, a moving mechanism for moving the gripping part 30, a plurality of measuring instruments 40 for measuring the weight value of the article gripped by the gripping part 30, and a control part 70 for releasing the gripping of the article by the gripping part 30 using the measurement result of the measuring instruments 40 and discharging the article. The control unit 70 does not set the gripping unit 30 as a discharge target when the weight value of the gripped article has decreased by a predetermined value or more within a predetermined time.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a system for weighing and transferring items and a method for weighing and transferring items. [Background technology]

[0002] As an example of technology related to an item weighing and moving system, Patent Document 1 describes an item discharge system that removes and discharges some items from a group of items. In the item discharge system described in Patent Document 1, some items in the group of items are gripped by multiple grippers (grippers), and a weight acquisition unit (weighing unit) measures the weight values ​​of the items gripped by each gripper. Based on the results of a combination calculation using the weight values, a predetermined gripper is released from its grip, and the item is discharged. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-1808 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described technology, when a sticky item such as noodles is held by the gripper, the state of the held item may become unstable after the combination calculation is performed, causing a part of the item to unintentionally fall off the gripper, resulting in a weight value of the item that is significantly lower than the weight value at the time of the combination calculation. In this case, the accuracy of weighing the item to be discharged may decrease.

[0005] Therefore, one aspect of the present invention aims to provide an article weighing and moving system and an article weighing and moving method that can suppress a decrease in the weighing accuracy of the articles being discharged. [Means for solving the problem]

[0006] One aspect of the present invention is an item weighing and moving system that grasps, weighs, and moves some items from a group of items, and is equipped with a gripping unit that grasps the items, a moving mechanism that moves the gripping unit, a weighing unit that measures the weight value of the item grasped by the gripping unit, and a control unit that uses the weighing result of the weighing unit to release the grip of the item by the gripping unit and discharge the item, and the control unit does not target the gripping unit for discharge if the weight value of the grasped item decreases by more than a predetermined value within a predetermined time.

[0007] In the article weighing and transferring system according to one aspect of the present invention, a plurality of gripping units may be provided, and the weighing unit may weigh each of the plurality of gripping units.

[0008] In one aspect of the item weighing and movement system of the present invention, the control unit may perform a combination calculation using the weighing results of the weighing unit, select a combination of multiple gripping units as the object to be discharged based on the results of the combination calculation, and release the grip of the item by the multiple gripping units associated with the selected combination.

[0009] One aspect of the present invention is a method for weighing and moving items, which is a method for grasping, weighing and moving some items from a group of items, and includes the steps of grasping the items with a gripping unit, moving the gripping unit, weighing the weight value of the items grasped by the gripping unit with a weighing unit, and releasing the grip of the items by the gripping unit using the weighing result of the weighing unit, and discharging the items; in the step of discharging the items, if the weight value of the grasped items decreases by more than a predetermined value within a predetermined time, the gripping unit is not targeted for discharge. [Effects of the Invention]

[0010] According to one aspect of the present invention, it is possible to provide an article weighing and moving system and an article weighing and moving method that can suppress a decrease in the weighing accuracy of the articles being discharged. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a front view showing an article weighing and transferring system according to one embodiment. [Figure 2]FIG. 2 is a schematic perspective view showing a plurality of gripping portions. [Figure 3] FIG. 3 is a block diagram illustrating an article weighing and transferring system. [Figure 4] FIG. 4 is a flowchart showing the operation of the robot hand. [Figure 5] FIG. 5 is a flowchart showing the operations of the first robot hand and the second robot hand. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicated description will be omitted.

[0013] First, an article weighing and transferring system 1 according to this embodiment will be described with reference to Figures 1 and 2. The article weighing and transferring system 1 shown in Figure 1 is a system that removes and transfers some articles from a group of articles X contained in a container 50. The article weighing and transferring system 1 removes some articles from the container 50 so that the weight (mass) of the some articles falls within a target weight range, and discharges the articles to the outside. In other words, the article weighing and transferring system 1 is a weighing system that transfers articles of a predetermined target weight from the group of articles X. The article weighing and transferring system 1 is a system that grasps, weighs, and transfers some articles from the group of articles X.

[0014] The items discharged by the item weighing and transferring system 1 are, for example, packaged in bags or placed in other containers in a subsequent process of the item weighing and transferring system 1 and shipped as merchandise. The items are, for example, noodles such as spaghetti, or foods that contain a lot of sugar. The items may also be highly sticky foods. The items may also be foods that are heated and placed in the container 50, generating steam or the like. Alternatively, the items may be lightweight, fine, and easily airborne foods.

[0015] The article weighing and moving system 1 includes a weighing device 120 for weighing articles. The weighing device 120 includes two robot hands 15, each having a plurality of grippers 30, two hand driving units 10 for moving the robot hands 15 in the horizontal direction, a container (mounting unit) 50 on which the group of articles X is placed, and a container driving unit (moving mechanism) 54 for moving the container 50 in the vertical and horizontal directions. The article weighing and moving system 1 also includes a control unit 70 for controlling each unit of the robot hand 15, the hand driving unit 10, and the container driving unit 54. The robot hands 15, the hand driving unit 10, and the container driving unit 54 are attached to a main body frame 121 of the weighing device 120, which is, for example, a rectangular parallelepiped.

[0016] In the article weighing and transporting system 1, for example, a pair of robot hands 15 having the same configuration are arranged side by side on the left and right. In the following description, the robot hand 15 arranged in the area (first area) on the left side as viewed from the front in Fig. 1 may be referred to as the first robot hand 15A, and the robot hand 15 arranged in the area (second area) on the right side as viewed from the front may be referred to as the second robot hand 15B. However, when describing common configurations and functions, the name robot hand 15 is simply used.

[0017] In the robot hand 15, for example, four grippers 30 aligned in the left-right direction are arranged in four rows in the front-rear direction (the direction perpendicular to the plane of the paper in FIG. 1). In this way, if the number of grippers 30 aligned in the left-right direction is M and the number of grippers 30 aligned in the front-rear direction is N (both M and N are natural numbers), the robot hand 15 has a configuration in which (M × N) grippers 30 are arranged at lattice point positions. In this embodiment, each robot hand 15 has 16 grippers 30. The arrangement of the grippers 30 in the robot hand 15 may be changed as appropriate depending on the shape of the container 50, the type of article, etc. Both or either one of M and N may be a natural number other than 4.

[0018] As shown in Fig. 2, each gripping unit 30 has, for example, multiple gripping claws 30a, and grips an article by closing the gripping claws 30a. Each gripping unit 30 includes a gripping member drive mechanism 30b that drives the multiple gripping claws 30a. The gripping member drive mechanism 30b uses, for example, a motor or fluid pressure as a drive source to drive the gripping claws 30a. The mechanism by which the gripping claws 30a open and close to grip an article will be described later.

[0019] The robot hand 15 has a plurality of scales 40 that measure the weight of an article held by each gripper 30. That is, 16 ((M×N)) scales 40 are provided for 16 ((M×N)) grippers 30. The robot hand 15 has, for example, a single plate-shaped connecting member 16. Each gripper 30 and each scale 40 are integrally assembled via a connecting portion 40a. The top surface of each scale 40 is fixed to the connecting member 16 via a mounting bracket 400. Each gripper 30 is fixed to the bottom surface of each scale 40.

[0020] Each weighing device 40 includes a sensor unit housed within the housing of the weighing device 40 and an internal control unit (neither is shown). The sensor unit includes, for example, 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. The multiple weighing devices 40 form a weighing unit that measures the weight values ​​of the multiple items held by the multiple gripping units 30 for each of the multiple gripping units 30.

[0021] In the article weighing and moving system 1, for example, two hand driving units 10 having the same configuration are provided corresponding to the first robot hand 15A and the second robot hand 15B. In the following description, the hand driving unit 10 located on the left side as viewed from the front of FIG. 1 and moving the first robot hand 15A may be referred to as the first hand driving unit 10A, and the hand driving unit 10 located on the right side as viewed from the front and moving the second robot hand 15B may be referred to as the second hand driving unit 10B. However, when describing common configurations and functions, the name hand driving unit 10 is simply used.

[0022] In the entire system including the first robot hand 15A and the second robot hand 15B, eight grippers 30 are aligned in the left-right direction, and are arranged in four rows in the front-to-back direction. That is, the weighing device 120 is equipped with 4 × 2 (pairs) × 4 rows = a total of 32 grippers 30 (generalized as (M × 2 × N)). The multiple grippers 30 aligned in the first robot hand 15A correspond to the multiple first grippers, and the multiple grippers 30 aligned in the second robot hand 15B correspond to the multiple second grippers.

[0023] The hand driving unit 10 has two frames 12 extending parallel to one another and a forward / backward movement mechanism 11 that moves the robot hand 15 horizontally along the frames 12. The hand driving unit 10 can move a block 111 that holds the robot hand 15 forward or backward using the forward / backward movement mechanism 11. The hand driving unit 10 has, for example, a servo motor or an air cylinder that moves the block 111. The connecting member 16 described above is connected to the block 111 by, for example, screws. Note that the hand driving unit 10 or the forward / backward movement mechanism 11 may be omitted from the weighing device 120.

[0024] In the article weighing and moving system 1, the first hand driving unit 10A moves the first robot hand 15A in the front-to-back direction (horizontally), and the second hand driving unit 10B moves the second robot hand 15B in the front-to-back direction (horizontally). This allows the position of the article group X in the container 50 to be aligned with the article gripping position set for each robot hand 15.

[0025] The internal control unit of the weighing device 40 measures the weight of the item gripped by the gripping unit 30 based on the force measured by the sensor unit. Note that the weighing device 40 is not limited to a method of measuring the weight of an item based on the force measured when the gripping unit 30 is moving. The weighing device 40 may also use a load cell or the like to measure the weight of an item gripped by the gripping unit 30 in a stationary state. Each weighing device 40 is a weight calculation unit that calculates the weight of the item gripped by the gripping jaws 30a of each gripping unit 30.

[0026] The container 50 is a member on which the group of articles X is placed. The container 50 is held or placed on a holding unit 52 that moves horizontally and vertically. The container 50 can be moved, for example, by a container driving unit 54, between a first position P1 located below the first robot hand 15A and a second position P2 located below the second robot hand 15B. The first position P1 and the second position P2 are separated in the left-right direction, and the area occupied by the container 50 located at the first position P1 does not overlap with the area occupied by the container 50 located at the second position P2. The container 50 is a rectangular parallelepiped container that opens upward. In a plan view, the container 50 is slightly larger than the area in which the multiple grippers 30 are arranged. In a plan view, the container 50 has a shape and size that can surround the multiple grippers 30. The container 50 has a shape and size that exactly corresponds to one robot hand 15.

[0027] When the container 50 is located at the first position P1, the container 50 can be moved upward and closer to the gripper 30 of the first robot hand 15A, allowing the gripper 30 to grasp an item from the group of items X in the container 50. At this time, the gripper 30 of the second robot hand 15B cannot grasp an item from the group of items X in the container 50. When the container 50 is located at the second position P2, the container 50 can be moved upward and closer to the gripper 30 of the second robot hand 15B, allowing the gripper 30 to grasp an item from the group of items X in the container 50. At this time, the gripper 30 of the first robot hand 15A cannot grasp an item from the group of items X in the container 50.

[0028] When the amount of the group of articles X contained inside the container 50 decreases, the container 50 with the reduced amount of the group of articles X inside is replaced by a new container 50 (containing a larger amount of the group of articles X) by a person or a machine. Note that instead of replacing the container 50, the article weighing and transferring system 1 may be provided with an article supply mechanism for supplying articles to the container 50.

[0029] The container driving unit 54 uses a motor and fluid pressure as driving sources to move the container 50 in the up-down (vertical) and left-right (horizontal) directions. The container driving unit 54 includes a drive box 55 fixed to a frame (not shown) adjacent to the weighing device 120, a first main arm 56A and a second main arm 56B that can swing around two parallel axes, a first axis L1 and a second axis L2, respectively, provided on the drive box 55, and a first sub-arm 57A and a second sub-arm 57B that are rotatably connected to the tip of the first main arm 56A and the tip of the second main arm 56B, respectively. The drive box 55 is fixed, for example, to another frame adjacent to and behind the frame to which the robot hand 15 is attached. The first axis L1 and the second axis L2 extend in the front-to-rear direction (the direction perpendicular to the plane of FIG. 1 and the horizontal direction). The tip of the first sub-arm portion 57A and the tip of the second sub-arm portion 57B are each rotatably connected to the rear end of the holding portion 52. The holding portion 52 is supported by these link mechanisms.

[0030] The first main arm portion 56A and the second main arm portion 56B are each swung in any direction by a separate motor housed in a drive box 55. The rotation axes of the first sub-arm portion 57A and the second sub-arm portion 57B relative to the first main arm portion 56A and the second main arm portion 56B are parallel to the first axis L1 and the second axis L2. For example, the rotation angle of the second sub-arm portion 57B relative to the second main arm portion 56B is adjustable. The rotation axes of the first sub-arm portion 57A and the second sub-arm portion 57B relative to the holder 52 are also parallel to the first axis L1 and the second axis L2. With the positions of the first axis L1 and the second axis L2 as fixed points, the first main arm portion 56A, the first sub-arm portion 57A, the second main arm portion 56B, the second sub-arm portion 57B, and the holder 52 form five sides of a hexagon. With this configuration, the container driving unit 54 has a two-axis parallel link mechanism. The container driving unit 54 is controlled by the control unit 70 to rotate each arm, thereby moving the holding unit 52 in the vertical and horizontal directions. The position of the holding unit 52 is maintained horizontally by the rod 58.

[0031] Under the control of the control unit 70, the holder 52 can be moved freely to a first position P1, a position closer to the first robot hand 15A than the first position P1, a second position P2, and a position closer to the second robot hand 15B than the second position P2 while maintaining a horizontal posture. This allows the relative position of the container 50 with respect to the first robot hand 15A and the relative position of the container 50 with respect to the second robot hand 15B to be adjusted freely. The configuration is not limited to the above, and the container drive unit 54 may have a left-right movement mechanism that moves the holder 52 left-right and a vertical movement mechanism that moves the holder 52 vertically. The position of the container 50 can also be adjusted freely using such a two-axis drive mechanism.

[0032] The container driving unit 54 raises the holder 52 and the container 50, thereby bringing the container 50 and the group of articles X closer to the robot hand 15. The container driving unit 54 lowers the holder 52 and the container 50, thereby moving the container 50 and the group of articles X away from the robot hand 15. The container driving unit 54 inserts the gripping claws 30a into the group of articles X contained (placed) in the container 50, and then moves the gripping claws 30a, which have gripped the articles, away from the container 50. In other words, the first robot hand 15A and the second robot hand 15B insert the gripping claws 30a of each gripping unit 30 into the group of articles X in the container 50, to grip a portion of the articles.

[0033] The article weighing and transferring system 1 is equipped with two discharge chutes 60. For example, two discharge chutes 60 having the same size and shape are arranged side by side on the left and right. In the following description, the discharge chute 60 arranged on the left side as viewed from the front in FIG. 1 may be referred to as the first discharge chute 60A, and the discharge chute 60 arranged on the right side as viewed from the front may be referred to as the second discharge chute 60B. However, when describing common configurations and functions, the name discharge chute 60 is simply used.

[0034] The discharge chute 60 is a funnel-shaped member. Items are thrown into the discharge chute 60 from above. The discharge chute 60 is disposed below the robot hand 15. Specifically, the first discharge chute 60A is disposed directly below the multiple grippers 30 of the first robot hand 15A, and the second discharge chute 60B is disposed directly below the multiple grippers 30 of the second robot hand 15B. A first position P1 of the container 50 is located between the first robot hand 15A and the first discharge chute 60A, and a second position P2 of the container 50 is located between the second robot hand 15B and the second discharge chute 60B.

[0035] When the container 50 is located at the second position P2, the first discharge chute 60A receives the item that the gripper 30 of the first robot hand 15A releases from its grip and drops, and discharges it outside the article weighing and moving system 1. Similarly, when the container 50 is located at the first position P1, the second discharge chute 60B receives the item that the gripper 30 of the second robot hand 15B releases from its grip and drops, and discharges it outside the article weighing and moving system 1. In this way, the first robot hand 15A and the second robot hand 15B transfer the items gripped by their respective grippers 30 to their destination positions. In other words, in this specification, the "releasing of grip" by each robot hand 15 and the accompanying "dropping of the item" refer to the transfer of the item to the discharge chute 60.

[0036] Although two discharge chutes are used in this embodiment, the present invention is not limited to this, and the first robot hand 15A and the second robot hand 15B may share one discharge chute. In this case, the upper opening of one discharge chute is set to a size and position that encompasses the entire first position P1 and the second position P2 in a plan view. Also, an object dropped from the robot hand 15 may be discharged directly to the outside without using a discharge chute.

[0037] FIG. 2 is a block diagram of the article weighing and moving system 1. In FIG. 2, a control unit 70 controls the operation of various components of the article weighing and moving system 1, such as the gripping member driving mechanism 30b and the container driving unit 54. The control unit 70 performs combination calculations and the like using the weight values ​​(measurement values) of the articles weighed by the weighing device 40. The control unit 70 is configured as a computer device including a processor such as a CPU, memories such as ROM and RAM, storage, and communication devices. The control unit 70 is electrically (or communicably) connected to the hand driving unit 10, the gripping member driving mechanism 30b, the weighing device 40, and the container driving unit 54. The ideal weight value and the like are input to the control unit 70 via an operation panel 100.

[0038] The control unit 70 controls the operation of various components of the article weighing and moving system 1, such as the hand driving unit 10, the gripping member driving mechanism 30b, and the container driving unit 54, by having the CPU execute a program stored in the memory, and performs combination calculations using the weight values ​​of the articles weighed by the weighing device 40. The various functions of the control unit 70 do not have to be realized by software, but may be realized by hardware, or by a combination of hardware and software.

[0039] The control unit 70 moves the hand driving unit 10 and the container 50 to bring the gripping unit 30 and the container 50 closer together. The control unit 70 controls the gripping member driving mechanism 30b to cause the gripping claws 30a of each gripping unit 30 to grip some of the articles of the article group X placed on the container 50.

[0040] Each weighing device 40 measures the weight of an item gripped by the corresponding gripping unit 30. The weight of the item gripped by each gripping unit 30 is acquired by the control unit 70. The control unit 70 performs a combination calculation based on the weight of the item gripped by the gripping unit 30. The combination calculation is a process of adding up the weights of the items gripped by each gripping unit 30 and finding a combination of weights that results in a target weight value. The control unit 70 first acquires each weight value. Next, based on the result of the combination calculation, the control unit 70 selects the gripping claws 30a of the gripping unit 30 that corresponds to the combination of weights that results in the target weight value, and performs control to release the grip of the selected gripping unit 30. At this time, the control unit 70 releases the grip of the item by the gripping unit 30 above the discharge chute 60, causing the item to fall into the discharge chute 60. The item with the target weight value is then discharged from the discharge chute 60. If a combination of weight values ​​that results in the target weight value is impossible, and if the gripping claws 30a of the gripping unit 30 that corresponds to a combination of weight values ​​that is close to the target weight value are found, the control unit 70 selects the gripping unit 30 that corresponds to that combination and performs control to release the grip of the selected gripping unit 30. This control is performed, for example, using the weight values ​​of the gripping units 30 other than the gripping unit 30 that corresponds to the combination of weight values ​​that results in the target weight value.

[0041] The target weight value is a predetermined weight range that includes the target weight value (target weight value or ideal weight value). For example, the lower limit of the target weight value is 90% or 95% of the target weight value, and the upper limit of the target weight value is 110% or 105% of the target weight value. Furthermore, the vicinity of the target weight value may be, for example, 90% or more but less than 100% of the lower limit, or 95% or more but less than 100% of the lower limit, or may be greater than 100% but less than 110% of the upper limit, or greater than 100% but less than 105% of the upper limit.

[0042] As described above, in the article weighing and moving system 1 of this embodiment, the control unit 70 controls the gripping member driving mechanism 30b (gripping unit 30) and the container driving unit 54, performs combination calculations based on the calculation results of the weighing machine 40, and selects a combination of gripping units 30 that will result in a preset target weight value. The control unit 70 causes the selected multiple gripping units 30 to discharge articles.

[0043] As shown in Figures 1 and 3, a plurality of sensors 9 are arranged in the front-to-rear direction (the direction perpendicular to the plane of the paper in Figure 1) above the movable area of ​​the holding unit 52. In this embodiment, four sensors 9 are attached, corresponding to the number of rows of the gripping unit 30 in that direction (the above-mentioned N, specifically four rows). The four sensors 9 are fixed, for example, to the main body frame 121, and irradiate light vertically downward and detect light reflected from the surface of the group of articles X. As a result, each sensor 9 detects the height of the articles (height of the group of articles X) in the insertion direction (vertical direction) of the gripping claws 30a in the group of articles X in the container 50.

[0044] Each sensor 9 emits and receives light at a central position between the first robot hand 15A and the second robot hand 15B. While the container drive unit 54 moves the holder 52 and the container 50 between the first position P1 and the second position P2, each sensor 9 detects the height of the item a number of times corresponding to the position and number of grippers 30 in the left-right direction (M, specifically, four). The detection timing may be adjusted by the control unit 70 (e.g., to be synchronized with the movement of the container drive unit 54) taking into account the left-right movement speed of the container drive unit 54. As a result, height detection signals are output for 16 points (multiple points corresponding to the planar arrangement of the grippers 30) distributed in a grid pattern in the left-right direction (movement direction) and the front-back direction within the container 50 each time the container 50 moves (passes) from the first position P1 to the second position P2 or from the second position P2 to the first position P1.

[0045] The control unit 70 is electrically (or communicably) connected to the multiple sensors 9. Based on the detection results of each sensor 9, the control unit 70 calculates the insertion amount and opening angle of the gripping jaws 30a of each gripping unit 30 relative to the group of articles X. The height of the articles varies in each part of the container 50. Meanwhile, the container 50 (holding unit 52) ​​is brought close to the robot hand 15 while maintaining a horizontal posture. Therefore, the insertion amount of the gripping jaws 30a of each gripping unit 30 is not constant (uniform) for a container 50 located at a certain height.

[0046] The control unit 70 stores, for example, a correspondence relationship between insertion amounts and opening angles for gripping a desired amount of articles. When the control unit 70 receives height detection signals from each sensor 9, it sets the vertical positions of the container 50 and the group of articles X and calculates the insertion amount for each gripping unit 30 accordingly. The control unit 70 further refers to the stored correspondence relationship and calculates the opening angle of the gripping jaws 30a corresponding to the insertion amount for each gripping unit 30. The control unit 70 controls the gripping operation of either the first robot hand 15A or the second robot hand 15B (whichever is to grip the article) so that the calculated insertion amount and opening angle are achieved.

[0047] In the item weighing and moving system 1 of this embodiment, the control unit 70 causes the first robot hand 15A and the second robot hand 15B to grip the items in the container 50 with the grippers 30, and then performs a combination calculation using the weighing results of the weighing scale 40. The control unit 70 selects a combination of multiple grippers 30 as the items to be discharged based on the results of the combination calculation in each of the first robot hand 15A and the second robot hand 15B, and causes the multiple grippers 30 associated with the selected combination to release their grips, and drops the items of the target weight into the discharge chute 60.

[0048] At this time, if there is a specific gripping part, which is a gripping part 30 whose weight value of the gripped item has decreased by a predetermined value or more within a predetermined time, the control part 70 does not select a combination pattern including the specific gripping part as a discharge target. An example of such processing by the control part 70 will be specifically described below with reference to FIG. 4.

[0049] First, the container driving unit 54 moves the container 50 so that it enters directly below the robot hand 15, and positions the container 50 directly below the multiple gripping units 30 of the robot hand 15 (step S1). The container driving unit 54 raises the container 50 until the distance between the container 50 and the multiple gripping units 30 reaches a set distance, and brings the container 50 closer to the multiple gripping units 30. At the same time, the gripping member driving mechanism 30b closes the gripping claws 30a of the gripping unit 30, and the article is gripped by at least one of the multiple gripping units 30 (step S2).

[0050] The container 50 is lowered by the container driving unit 54, and the items gripped by the multiple grippers 30 are separated from the group of items inside the container 50. In this state, the weighing results of the multiple weighing devices 40 are obtained (initial weighing process (first weighing process): step S3). The weighing results obtained in the initial weighing process of step S3 above are used to perform a combination calculation (initial combination calculation process (combination calculation process): step S4). In step S4 above, multiple weighing devices 40 whose total weight value is the target weight value or a value close to it are identified, and one or more combinations (hereinafter also referred to as "combination patterns") consisting of multiple grippers 30 corresponding to these multiple weighing devices 40 are selected.

[0051] After the initial combination calculation process in step S4, the weighing results of the multiple weighing devices 40 are acquired again (weighing process after calculation completion (second weighing process): step S5). Specific gripping parts that will not be selected for discharge are calculated (step S6). In step S6, based on the weighing results of the initial weighing process in step S3 and the weighing results of the weighing process after calculation completion in step S5, gripping parts 30 whose weight values ​​have decreased by more than a predetermined value within a predetermined time are calculated as specific gripping parts.

[0052] The specific gripping unit is a gripping unit 30 that is likely to have a weighing error and is a gripping unit 30 that is continuing to decrease the number of items it is holding (its gripping state is deteriorating). The predetermined time corresponds to the time from the initial weighing process to the weighing process after calculation is completed. The predetermined value is a value that is determined in advance depending on the item. The predetermined value is not particularly limited and may be a fixed value or a variable value.

[0053] Among the multiple combination patterns selected in step S4, a combination pattern that does not include a specific gripping part is selected as a combination pattern to be discharged (step S7). In other words, in step S7, a combination pattern that includes a specific gripping part is not selected as a combination pattern to be discharged.

[0054] A return process is executed in which the specific gripping unit releases its grip on the item and drops the item to return it to the container 50 (step S8). In step S8, if there is a gripping unit 30 whose weight value of the gripped item is greater than the upper threshold or less than the lower threshold and which is not included in the combination pattern selected in step S7, the grip of the item by this gripping unit 30 is also released, and the item is dropped and returned to the container 50.

[0055] The container driving unit 54 moves the container 50 away from directly below the robot hand 15, and retracts the container 50 from the position directly below the multiple gripping units 30 of the robot hand 15 (step S9). For one or more combination patterns selected as the discharge target in step S7, the gripping units 30 included in that combination are released, and the objects held by those gripping units 30 are dropped and introduced into the discharge chute 60 (step S10). This discharges the objects of the target weight.

[0056] The weighing results of the multiple weighing devices 40 are obtained (weighing process: step S11). A combination calculation is performed using the weighing results obtained in the weighing process of step S11 (combination calculation process: step S12). In step S12, multiple weighing devices 40 whose total weighing values ​​is the target weight value or a value close to it are identified, and one or more combinations consisting of multiple gripping units 30 corresponding to these multiple weighing devices 40 are selected as combination patterns to be discharged. In other words, in step S12, each time an item is discharged in step S10, a combination calculation is performed again without using the weighing results corresponding to the specific gripping unit, and the selected combination pattern is updated.

[0057] As a result of the combination calculation process in step S12, if one or more combination patterns remain (YES in step S13), the process returns to step S10. If as a result of the combination calculation process in step S12, there are no combination patterns (NO in step S13), the series of processes S100 for this cycle is terminated, and the process is repeated again from step S1 in the next cycle.

[0058] 5, in the article weighing and moving system 1 of this embodiment, a series of processes S100 consisting of the above steps S1 to S13 is repeatedly executed by the control unit 70 at different times in each of the first robot hand 15A and the second robot hand 15B. At this time, the control unit 70 controls the container driving unit 54 to move a container 50 that has been retracted from either the first robot hand 15A or the second robot hand 15B directly below the multiple grippers 30 of the other robot hand.

[0059] In addition, the control unit 70 causes either the first robot hand 15A or the second robot hand 15B to grasp an item with the multiple gripping units 30, and simultaneously and in parallel causes the other of the first robot hand 15A or the second robot hand 15B to release the grip of the multiple gripping units 30 and drop the item (step S10 above).

[0060] As described above, in the item weighing and moving system 1, the gripping unit 30 from which items are likely to fall off is designated as the specific gripping unit, and if the specific gripping unit is included in a combination pattern of multiple gripping units 30 based on the results of the combination calculation, that combination pattern is not selected for discharge. As a result, when gripping sticky items such as noodles, for example, if the state of the gripped items becomes unstable after the combination calculation, and many of the items unintentionally fall off the gripping units 30 in a clump, resulting in a significant decrease in the weight values ​​of the items compared to when the combination calculation was performed, this can be prevented from adversely affecting the weighing accuracy of the items to be discharged. In other words, the item weighing and moving system 1 makes it possible to suppress a decrease in the weighing accuracy of the items to be discharged.

[0061] In the goods weighing and moving system 1, the control unit 70 executes the initial weighing process (step S3 above), the initial combination calculation process (step S4 above), and the post-calculation weighing process (step S5 above). The predetermined time corresponds to the time from the initial weighing process to the post-calculation weighing process. In this case, it is possible to specifically define the predetermined time.

[0062] In the article weighing and moving system 1, the control unit 70 executes a return process in which the specific gripping unit releases the grip of the article and returns the article to the container 50. In this case, it becomes possible to return to the container 50 an article that is easily dropped and is being held by a gripping unit 30 that is not a target for discharge.

[0063] In the item weighing and moving system 1, in the return process, if the weight value of the held item is greater than the upper threshold or less than the lower threshold, and there is a gripping unit 30 that is not included in the selected combination, the gripping unit 30 releases its grip on the item and returns the item to the container 50. In this case, it is possible to return to the container 50 an item that is held by a gripping unit 30 that is prone to falling off and is not to be discharged.

[0064] In the item weighing and moving system 1, when executing a return process, the control unit 70 causes the container driving unit 54 to position the container 50 directly below the gripping unit 30. When the control unit 70 releases the grip of the item by the multiple gripping units 30 and discharges the item, the control unit 70 causes the container driving unit 54 to retract the container 50 from the position directly below the gripping unit 30. In this case, it is possible to efficiently discharge the item and return the item to the container 50.

[0065] In the article weighing and moving system 1, the control unit 70 causes the multiple gripping units 30 of the first robot hand 15A to grip an article (step S2), and simultaneously and in parallel with this, causes the multiple gripping units 30 of the second robot hand 15B to release the grip of the article and introduce the article into the discharge chute 60. In this case, it is possible to efficiently grip and discharge the article.

[0066] In the goods weighing and moving system 1, the control unit 70 performs combination calculation again without using the weighing result corresponding to the specific gripper 30 each time the gripping units 30 release the goods and discharge the goods (each time the process of step S10 above is performed), and updates the combination of the goods to be selected (step S12 above). In this case, it is possible to improve the weighing accuracy of the goods to be discharged.

[0067] The present invention has been described in detail above based on the above embodiment and modifications. However, the present invention is not limited to the above embodiment and modifications. The present invention can be further modified within the scope of the gist thereof.

[0068] In the above embodiment, a configuration has been described in which the robot hand 15 grasps an article by moving the container 50 (holding unit 52) ​​and bringing it close to the robot hand 15. However, unlike this configuration, a configuration has been adopted in which the robot hand 15 or the gripping unit 30 grasps an article by moving (e.g., lowering) the robot hand 15 or the gripping unit 30 and bringing it close to the container 50, in which case an appropriate known movement mechanism is provided in the robot hand 15 or the gripping unit 30. By moving (e.g., raising) the robot hand 15 or the gripping unit 30, the gripping claws 30a that have grasped the article can be separated from the container 50.

[0069] In the above embodiment and modified example, the transfer of an item by the gripper 30 is not limited to "releasing the grip" and the accompanying "dropping of the item into the discharge chute 60." The gripper 30 that has gripped an item may move horizontally or vertically to transfer the item to another container, another hopper, or a transport device such as a conveyor. In the above embodiment and modified example, the robot hand 15 may have only one gripper 30. In the above embodiment and modified example, the time from when the initial weighing process is performed to when the post-calculation weighing process is performed is set to the predetermined time, but the predetermined time is not particularly limited and may be various times. The predetermined time may be a fixed time or a variable time.

[0070] In the above, "gripping" may mean that multiple gripping claws 30a (see Figure 2) located at distances from each other move radially inward to move closer to each other, and "releasing gripping" may mean that after gripping, they return to a distanced position again. [Explanation of symbols]

[0071] 1...Item weighing and moving system, 9...sensor, 10...hand driving unit, 15...robot hand, 15A...first robot hand, 15B...second robot hand, 30...gripping unit (first gripping unit, second gripping unit), 30a...gripping claws, 40...weighing device (weighing unit), 50...container (placing unit), 52...holding unit, 54...container driving unit (moving mechanism), 60...discharge chute, 70...control unit, 100...operation panel, 120...weighing device, X...group of items.

Claims

1. An article weighing and moving system that grasps, weighs, and moves some articles from a group of articles, a gripping portion that grips the article; a moving mechanism that moves the gripping portion; a weighing unit that measures the weight of the item held by the holding unit; a control unit that uses the weighing result of the weighing unit to release the grip of the item by the gripping unit and discharge the item, An item weighing and moving system, wherein the control unit does not target the gripping unit for discharge if the weight value of the item being gripped decreases by more than a predetermined value within a predetermined time.

2. The gripping portion is provided in plurality, The article weighing and moving system according to claim 1 , wherein the weighing unit weighs each of the plurality of grippers.

3. The control unit The item weighing and moving system of claim 2, wherein a combination calculation is performed using the weighing results of the weighing unit, a combination of multiple gripping units is selected as the item to be discharged based on the results of the combination calculation, and the gripping of the item by the multiple gripping units associated with the selected combination is released.

4. 1. A method for grasping, weighing and transferring a portion of an item from a group of items, comprising: gripping the article with a gripping portion; moving the gripper; a step of measuring a weight value of the object held by the holding unit with a weighing unit; and releasing the grip of the item by the gripping unit using the weighing result of the weighing unit and discharging the item, In the step of discharging the item, if the weight value of the gripped item decreases by more than a predetermined value within a predetermined time, the gripping unit is not targeted for discharge.

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