JP7808326B2 - Item Grasping System - Google Patents

Description

The present invention relates to an item gripping system.

A known item gripping system is one that grips and ejects a selection of items from a group of items stored in a container. Patent Document 1, for example, describes an example of this type of technology: a device that grips a selection of items from a group of items using a gripping means (gripping unit), measures the weight of the gripped items using a weighing means, and deposits the items in a predetermined location.

Japanese Patent Application Publication No. 6-3182

In the above-described article gripping system, the gripper typically moves relative to the container along a fixed path. Therefore, when an article gripped by the gripper is separated from a group of articles, depending on the article, the gripper and container may move farther apart than necessary. In this case, the amount of movement of the gripper may be excessive, which may result in longer operation time (the time required for operation).

The present invention was made to solve the above problems, and aims to provide an item gripping system that can shorten operation time.

The item gripping system of the present invention is an item gripping system that grips and discharges some items from a group of items stored in a container, and includes a gripping unit including a gripper that grips the items, a drive unit that moves at least one of the gripper unit and the container, and a control unit that controls the drive unit to transition from a first state in which the items gripped by the gripper and the group of items stored in the container are continuous to a second state in which the items gripped by the gripper and the group of items stored in the container are separated, and the control unit controls the distance between the container and the gripper in the second state based on the items.

In this item gripping system, when an item gripped by the gripping unit is to be separated from the group of items, the distance between the container and the gripping unit in the second state is controlled depending on the item. For example, if the item is a long noodle, the item is difficult to separate from the group of items, so the control unit controls the distance between the container and the gripping unit in the second state to be larger. On the other hand, if the item is a short penne, the item is easy to separate from the group of items, so the control unit controls the distance between the container and the gripping unit in the second state to be smaller. In this way, by controlling the distance between the gripping unit and the container so that it is the distance necessary and sufficient to separate the item from the group of items, excessive movement of at least one of the gripping unit and the container can be prevented. This reduces operation time.

In the article gripping system according to the present invention, the drive unit may move at least one of the gripping unit and the container at least vertically, and the control unit may control the vertical distance between the container and the gripping unit in the second state based on the type of article. This makes it possible to prevent the container and the gripping unit from moving apart in the vertical direction more than necessary based on the type of article.

In the article gripping system according to the present invention, the control unit may perform control based on the type of article to reduce the vertical distance between the container and the gripper in the second state. This prevents the container and the gripper from moving vertically farther apart than necessary based on the article.

The article gripping system according to the present invention may further include a memory unit that stores distance information regarding the vertical distance between the container and the gripper in the second state for each type of article. In this case, the distance information stored in the memory unit can be used to control the distance between the container and the gripper in the second state to a distance appropriate for the article.

The article gripping system according to the present invention may further include a detection unit that detects the vertical length of the article in the second state, and the control unit may control the distance between the container and the gripping unit in the second state based on the detection result of the detection unit. In this case, the detection result of the detection unit can be used to control the distance between the container and the gripping unit in the second state to a distance appropriate for the article.

In the article gripping system according to the present invention, the drive unit moves at least one of the gripper and the container in the horizontal and vertical directions, and the control unit can selectively change the path along which the drive unit moves at least one of the gripper and the container between at least a first path and a second path, where the first path may include a straight path and the second path may include a curved path. In this case, the path along which at least one of the gripper and the container moves can be switched between the first path and the second path depending on, for example, the type of article.

In the item gripping system according to the present invention, the gripping unit includes multiple grippers and an acquisition unit that acquires the weight values of the items gripped by each of the multiple grippers. The control unit may perform a combination calculation based on the weight values acquired by the acquisition unit, select a combination of grippers that results in a preset target weight value, and release the grip of the selected grippers to discharge the items. In this case, combination weighing can be performed, making it possible to discharge items with the target weight value.

This invention makes it possible to provide an item gripping system that can shorten operation time.

FIG. 1 is a schematic front view showing an article gripping system according to a first embodiment. FIG. 2 is a schematic perspective view showing the conveying device of FIG. FIG. 3 is a block diagram showing the functional configuration of the item gripping system of FIG. 4A and 4B are schematic diagrams showing an example of the operation of the article gripping system of FIG. 5(a) and 5(b) are schematic diagrams showing an example of the operation of the article gripping system of FIG. 1. FIG. FIG. 6 is a schematic diagram showing an example of the operation of the article gripping system of FIG. FIG. 7 is a schematic diagram showing another example of the operation of the article gripping system of FIG. FIG. 8 is a perspective view showing a separation net of an article gripping system according to the second embodiment. 9(a) and 9(b) are schematic diagrams showing an example of a path of the container.

Embodiments of the present invention will be described below with reference to the drawings. Note that in the description of the drawings, identical elements will be given the same reference numerals, and duplicate explanations will be omitted.

[First embodiment]
First, the configuration of an item gripping system 1 according to a first embodiment will be described with reference to Figures 1 and 2. The item gripping system 1 shown in Figure 1 grips and discharges some items from a group of items stored in a container 30. The item gripping system 1 removes some of the items from the container 30 so that the weight of the some of the items falls within a target weight range, and discharges the items to the outside. In other words, the item gripping system 1 is a weighing system that moves items of a predetermined target weight from a group of items.

The items discharged by the item gripping system 1 are, for example, packaged in bags in a subsequent process after the item gripping system 1, or placed in another container and shipped as a product. The items are, for example, noodles such as spaghetti, or foods that contain a lot of sugar such as penne. The items may also be foods with high viscosity. The items may also be foods that are heated and placed in a container, generating steam, etc. Alternatively, the items may be lightweight, small, and easily suspended foods.

The article gripping system 1 includes a weighing device 120 for weighing articles, and a transport device (not shown) located adjacent to the weighing device 120 for transporting the weighed articles. The weighing device 120 includes gripping units 20 each including a plurality of grippers 21, a separation net 22, a separation net drive unit 23 (see FIG. 2) that drives the separation net 22, containers 30 on which groups of articles are placed, and a container drive unit 31 that moves the containers 30 vertically and horizontally. The article gripping system 1 also includes a control unit 61 (see FIG. 3) that controls each part of the gripping unit 20 and the container drive unit 31. The gripping units 20, separation net 22, separation net drive unit 23, containers 30, and container drive unit 31 are attached to a main body frame 80 of the weighing device 120, which is, for example, rectangular.

In the item gripping system 1, for example, two gripping units 20 having the same configuration are arranged side by side on the left and right. In this embodiment, the gripping units 20 are fixedly mounted on the main body frame 80. In the following description, the gripping unit 20 arranged on the left side as viewed from the front in FIG. 1 may be referred to as the first gripping unit 20A, and the gripping unit 20 arranged on the right side as viewed from the front may be referred to as the second gripping unit 20B. However, when describing common configurations and functions, the name gripping unit 20 is simply used.

In the gripping unit 20, for example, four gripping sections 21 lined up in the left-right direction are arranged in four rows in the front-to-back direction (the direction perpendicular to the paper surface in Figure 1). Thus, if the number of gripping sections 21 lined up in the left-to-right direction is M and the number of gripping sections 21 lined up in the front-to-back direction is N (both M and N are natural numbers), the gripping unit 20 has a configuration in which (M x N) gripping sections 21 are arranged at lattice point positions. In this embodiment, the gripping unit 20 has 16 gripping sections 21. The arrangement of the gripping sections 21 in the gripping unit 20 may be changed as appropriate depending on the shape of the container 30, the type of item, etc. Either or both M and N may be a natural number other than 4.

In the entire system, including the first gripping unit 20A and the second gripping unit 20B, eight gripping sections 21 are aligned in the left-right direction, and four rows are arranged in the front-to-back direction. In other words, the weighing device 120 has four gripping sections 21 x two (pairs) x four rows = a total of 32 gripping sections 21 (generalized as (M x 2 x N)).

In the following, the left-right direction in Figure 1 may be referred to as the horizontal direction D2, and the front-to-back direction may be referred to as the front-to-back direction D3. Furthermore, the direction perpendicular to the horizontal direction D2 and the front-to-back direction D3 (the up-down direction in Figure 1) may be referred to as the vertical direction D1.

Each gripping unit 21 has, for example, multiple gripping claws 24, and grips an item by closing the multiple gripping claws 24. Each gripping unit 21 includes a gripping unit drive unit 25 that drives the multiple gripping claws 24. The gripping unit drive unit 25 drives the gripping claws 24 using, for example, a motor or fluid pressure as a drive source.

The gripping unit 20 has multiple scales (not shown) that measure the weight of the items gripped by each gripping portion 21, and an acquisition unit 27 (see Figure 3) that acquires the weight values from the scales. Sixteen ((M x N)) scales are provided for the 16 ((M x N)) gripping portions 21. The gripping unit 20 has, for example, a single plate-shaped connecting member (not shown). Each gripping portion 21 and each scale are assembled together. The top surface of each scale is fixed to the connecting member, for example, via a mounting bracket (not shown). Each gripping portion 21 is fixed to the bottom surface of each scale.

Each weighing device uses a load cell or the like to measure the weight of an item held by the gripping unit 21 in a stationary state. Each weighing device is a mass calculation unit that calculates the mass of an item held by the gripping claws 24 of each gripping unit 21. The weighing device outputs information related to the measured weight of the item to the acquisition unit 27. The acquisition unit 27 acquires the weight of the item held by the gripping unit 21. This weight value is used in the combination calculation described below.

The separation net 22 separates each of the articles held by each of the multiple gripping portions 21. As shown in FIG. 2, the separation net 22 has a rectangular grid pattern. The separation net 22 has a rectangular outer frame 22a and separation portions 22b that connect opposing sides of the outer frame 22a. The separation portions 22b are composed of three rod-shaped members that connect opposing sides of the outer frame 22a in the front-to-rear direction D3, and one rod-shaped member that connects opposing sides of the outer frame 22a in the horizontal direction D2. As a result, the separation portions 22b divide the interior of the outer frame 22a into 16 grid-like sections.

The separation net drive unit 23 moves the separation net 22 in the vertical direction D1. The separation net drive unit 23 includes a beam 41 connected to the separation net 22 and extending in the front-to-rear direction D3, a link mechanism 42 that moves the beam 41 in the vertical direction D1, and a drive unit (not shown) that drives the link mechanism 42. Note that FIG. 2 only shows the separation net 22 and separation net drive unit 23 on the first gripping unit 20A side (left side in FIG. 1); the separation net 22 and separation net drive unit 23 on the second gripping unit 20B side (right side in FIG. 1) are not shown. The beam 41 is connected to the separation net 22 along a side of the outer frame 22a extending in the front-to-rear direction D3. The beam 41 moves in the vertical direction D1 via the link mechanism 42 when driven by the drive unit. As a result, the separation net 22 connected to the beam 41 moves in the vertical direction D1.

In the example shown in Figure 1, when the separation net 22 is moved to its highest position, it is located above the tips of the gripping claws 24 (the tips of the gripping claws 24 in the vertical direction D1). When viewed from the vertical direction D1, each area defined by the outer frame 22a and separation portions 22b corresponds to the position of each of the arranged multiple gripping portions 21. As shown in Figure 1, when the separation net 22 is located above the tips of the gripping claws 24, each gripping claw 24 is located within each area.

When the gripping units 21 are gripping objects, for example, the objects gripped by adjacent gripping units 21 may become tangled. When this happens, the separation net drive unit 23 moves the separation net 22 in the vertical direction D1, causing the separation unit 22b to move between the tangled objects. This allows the separation net 22 to separate each of the objects gripped by each of the multiple gripping units 21.

The container 30 is a member on which a group of items is placed. The container 30 is a rectangular parallelepiped container that opens upward. In a plan view, the container 30 is larger than the multiple gripping sections 21 and has a shape and size that allows it to surround the multiple gripping sections 21. The container 30 has a shape and size that exactly corresponds to one gripping unit 20. The container 30 is placed on the holding section 15 of the container drive section 31, which moves horizontally and vertically. The container 30 can be moved, for example, by the container drive section 31, between a first position located below the first gripping unit 20A and a second position located below the second gripping unit 20B. The first position and the second position are separated in the left-right direction, and there is no overlap between the area occupied by the container 30 located at the first position and the area occupied by the container 30 located at the second position.

Furthermore, the container 30 can be moved, for example by the container drive unit 31, between a first gripping position where the first gripping unit 20A can grip some of the items from the group of items in the container 30, and a second gripping position where the second gripping unit 20B can grip some of the items from the group of items in the container 30. As an example, the first gripping position is located above the first position and is closer to the first gripping unit 20A than the first position. As another example, the second gripping position is located above the second position and is closer to the second gripping unit 20B than the second position. The first gripping position and the second gripping position are separated in the left-right direction, and there is no overlap between the area occupied by the container 30 located at the first gripping position and the area occupied by the container 30 located at the second gripping position.

When the container 30 is located at the first gripping position, the gripping portion 21 of the first gripping unit 20A can grip an item from the group of items in the container 30. At this time, the gripping portion 21 of the second gripping unit 20B cannot grip an item from the group of items in the container 30. Also, when the container 30 is located at the second gripping position, the gripping portion 21 of the second gripping unit 20B can grip an item from the group of items in the container 30. At this time, the gripping portion 21 of the first gripping unit 20A cannot grip an item from the group of items in the container 30.

When the amount of items stored inside a container 30 decreases, the container 30 with the reduced amount of items inside is replaced by a new container 30 (containing a larger amount of items) by a person or machine. Instead of replacing the container 30, the item gripping system 1 may also be equipped with an item supply mechanism for supplying items to the container 30.

The container driving unit 31 uses a motor and fluid pressure as driving sources to move the container 30 in the vertical direction D1 and horizontal direction D2, thereby moving the container 30 placed on the holder 15. In this embodiment, the container driving unit 31 moves the container 30 along a first path R10, which includes a first linear path (linear path) R11. More specifically, the container driving unit 31 moves the holder 15 in the vertical direction D1, thereby moving the container 30 along a second linear path R12 between the first gripping position and the first position. The container driving unit 31 moves the holder 15 in the vertical direction D1, thereby moving the container 30 along a third linear path R13 between the second gripping position and the second position. The container driving unit 31 moves the holder 15 in the horizontal direction D2, thereby moving the container 30 along the first linear path R11 between the first position and the second position.

The container drive unit 31 includes a rectangular parallelepiped frame 44, a drive box 45 fixed to the frame 44, 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 45, 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 first axis L1 and the second axis L2 extend in the front-to-rear direction D3. The tip of the first sub-arm 57A and the tip of the second sub-arm 57B are each rotatably connected to the rear end of the holder 15. The holder 15 is supported by these link mechanisms.

The first main arm portion 56A and the second main arm portion 56B are each driven by a separate motor housed in the drive box 45 to swing in any direction. 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 via a rod 58 or the like. The rotation axes of the first sub-arm portion 57A and the second sub-arm portion 57B relative to the holding portion 15 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 holding portion 15 form five sides of a hexagon. The container drive unit 31 has a two-axis parallel link mechanism due to this configuration. The container drive unit 31 is controlled by the control unit 61 to rotate each arm unit, thereby moving the holder 15 in the vertical direction D1 and horizontal direction D2.

Under the control of the control unit 61, the holding unit 15 can be moved freely between the first position, the first gripping position, the second position, and the second gripping position while maintaining a horizontal posture. This allows the relative position of the container 30 to the first gripping unit 20A and the relative position of the container 30 to the second gripping unit 20B to be adjusted freely. It should be noted that the configuration is not limited to the above, and the container drive unit 31 may have a left-right movement mechanism that moves the holding unit 15 left-right, and a vertical movement mechanism that moves the holding unit 15 vertically. The position of the container 30 can also be adjusted freely using such a two-axis drive mechanism.

The container driving unit 31 raises the holding unit 15 and container 30, thereby bringing the container 30 and the group of items closer to the gripping unit 20. It lowers the holding unit 15 and container 30, thereby moving the container 30 and the group of items away from the gripping unit 20. The container driving unit 31 inserts the gripping claws 24 into the group of items contained (placed) in the container 30, and then moves the gripping claws 24, which have gripped the items, away from the container 30. In other words, the first gripping unit 20A and the second gripping unit 20B insert the gripping claws 24 of each gripping unit 20 into the group of items in the container 30 to grip some of the items.

As shown in FIG. 1, the article gripping system 1 has one discharge chute 60. The discharge chute 60 is a funnel-shaped member. The discharge chute 60 is disposed below the gripping unit 20. A first position of the container 30 is located between the first gripping unit 20A and the discharge chute 60, and a second position of the container 30 is located between the second gripping unit 20B and the discharge chute 60.

When the container 30 is located at the second position, the discharge chute 60 receives the item that the gripping section 21 of the first gripping unit 20A releases and drops, and discharges it outside the item gripping system 1. When the container 30 is located at the first position, the discharge chute 60 receives the item that the gripping section 21 of the second gripping unit 20B releases and drops, and discharges it outside the item gripping system 1.

In this embodiment, one discharge chute 60 is used, but this is not limited to this, and two discharge chutes may be used. The two discharge chutes may, for example, have the same size and shape and be arranged side by side on the left and right. In this case, as an example, one discharge chute is located below the first gripping unit 20A, and the other discharge chute is located below the second gripping unit 20B. One discharge chute receives items that are released from grip and dropped by the first gripping unit 20A, and discharges them outside the article gripping system 1. The other discharge chute receives items that are released from grip and dropped by the second gripping unit 20B, and discharges them outside the article gripping system 1. Furthermore, the article gripping system 1 may not use the discharge chute 60, and may discharge dropped items directly to the outside.

Next, the functional configuration of the item gripping system 1 according to this embodiment will be described with reference to Figure 3.

The control unit 61 has memory such as ROM and RAM in addition to a CPU (not shown). The control unit 61 controls each of the gripper drive unit 25, container drive unit 31, and separation mesh drive unit 23. The control unit 61 is communicatively connected to each of the gripper drive unit 25, container drive unit 31, and separation mesh drive unit 23. The control unit 61 controls the operation of various components of the article gripping system 1, such as the gripper drive unit 25, container drive unit 31, separation mesh drive unit 23, and memory unit 62, and performs combination calculations, as described below, by the CPU executing programs stored in the memory. The various functions of the control unit 61 do not have to be realized by software, but may be realized by hardware, or by hardware and software working together.

The control unit 61 transitions from the first state to the second state by controlling the container driving unit 31 to move the container 30 in the vertical direction D1. The first state refers to a state in which the item held by the gripping unit 21 and the group of items stored in the container 30 are continuous. The second state refers to a state in which the item held by the gripping unit 21 and the group of items stored in the container 30 are separated.

As shown in FIG. 3, the item gripping system 1 includes a memory unit 62 and an operation unit 63 communicatively connected to the control unit 61. The memory unit 62 stores distance information for each type of item. The distance information refers to information regarding the distance in the vertical direction D1 between the container 30 and the gripping unit 21 in the second state. In other words, the distance information is information related to the distance in the vertical direction D1 between the container 30 and the gripping unit 21 in the second state, linked to information related to the type of item. The distance information may be set in advance by the user via the operation unit 63. As an example, the distance in the vertical direction D1 is a distance necessary and sufficient to prevent the item gripped by the gripping unit 21 from interfering with the container 30 when the container driving unit 31 moves the container 30 in the horizontal direction D2. For example, if the item is a long spaghetti noodle, the distance required to separate the item gripped by the gripping unit 21 from the group of items stored in the container 30 will be large. On the other hand, if the item is a short piece of penne, for example, the distance required to separate the item held by the gripping portion 21 from the group of items stored in the container 30 will be smaller.

The control unit 61 controls the distance in the vertical direction D1 between the container 30 and the gripping unit 21 in the second state to be reduced based on the item. In this embodiment, the control unit 61 controls the distance in the vertical direction D1 between the container 30 and the gripping unit 21 in the second state based on the type of item and the distance information stored in the memory unit 62. The distance in the vertical direction D1 between the container 30 and the gripping unit 21 in the second state corresponds to the amount of movement of the container 30 from the first gripping position to the first position (or the amount of movement of the container 30 from the second gripping position to the second position). The distance in the vertical direction D1 between the container 30 and the gripping unit 21 may be, for example, the distance between the top surface of the holder 15 on which the container 30 is placed and the tip of the gripping claws 24 of the gripping unit 21 in the vertical direction D1. The distance D1 in the vertical direction between the container 30 and the gripping unit 21 is not particularly limited, and may be, for example, the shortest distance between a predetermined position set in advance on the gripping claws 24 (e.g., the position of the tip of the gripping claws 24) and a predetermined position on the container 30 (e.g., the bottom surface of the container 30). Furthermore, the distance D1 in the vertical direction between the container 30 and the gripping unit 21 in the second state may be a fixed value, or a variable value that can be changed by the user via the operation unit 63.

The control unit 61 also performs a combination calculation based on the weight values of the items acquired by the acquisition unit 27. The combination calculation is a process of adding up the weight values of the items gripped by each of the multiple gripping units 21 and finding a combination of weight values whose total value equals the target weight value.

First, the control unit 61 acquires the weight values of the items gripped by each gripper 21. Next, based on the results of the combination calculation, the control unit 61 selects the gripper 21 that corresponds to the combination of weight values that results in a preset target weight value, and performs control to release the grip of the selected gripper 21. At this time, the control unit 61 releases the grip of the item by the gripper 21 above the discharge chute 60, thereby discharging the item with the target weight value from the discharge chute 60.

Note that "a combination of weight values that results in a target weight value" does not necessarily mean a combination that results in a weight value exactly equal to the target weight value. "A combination of weight values that results in a target weight value" means a combination of weight values that is close to the target weight value, as long as it does not deviate from the gist of this invention. If a combination of weight values that results in the target weight value is impossible and the control unit 61 finds a gripping claw 24 of a gripping unit 21 that corresponds to a combination of weight values that is close to the target weight value, the control unit 61 selects the gripping unit 21 that corresponds to that combination and performs control to release the grip of the selected gripping unit 21. This control is performed, for example, using the weight values of items gripped by gripping units 21 other than the gripping unit 21 that corresponds to the combination of weight values that results in the target weight value.

In this embodiment, the vicinity of the target weight value is a certain weight range that includes the target weight value, and is set in advance by the user, for example. For example, the lower limit of the vicinity of the target weight value is 90% or 95% of the target weight value, and the upper limit of the vicinity of the target weight value is 110% or 105% of the target weight value. The vicinity of the target weight value can be changed as appropriate.

If the weight value of the item gripped by the gripper 21 is extremely large (or small), it may be impossible to find a combination of weight values that is close to the target weight value. In this case, the control unit 61 performs control to release the gripper 21 that is gripping the item, thereby dropping the item back into the container 30. This control is performed before the container 30 is retracted from below the gripper unit 20 that has the gripper 21 gripping the item.

The operation unit 63 is a section for accepting operations by the user. The user inputs distance information according to the type of item, information related to the target weight value, etc. via the operation unit 63. The operation unit 63 may be composed of, for example, an output unit such as a display that outputs information to the user, and an input unit such as a mouse and keyboard for accepting input from the user. The operation unit 63 may also be a touch panel, smartphone, tablet, etc.

Next, the operation of the item gripping system 1 according to this embodiment will be described with reference to Figures 4 to 7. First, the operation of the item gripping system 1 when the item B gripped and discharged by the item gripping system 1 is item B1 will be described.

Figure 4(a) shows the container 30 in the second position. Also, although not shown in Figure 4, as shown in Figure 1, the separation net 22 is positioned above the tips of the gripping claws 24. First, as shown in Figures 4(a) and 4(b), the control unit 61 drives the container drive unit 31 to move the container 30 from the second position to the second gripping position and bring it closer to the second gripping unit 20B. In other words, the control unit 61 moves the container 30 upward from the second position to the second gripping position along the third linear path R13 (see Figure 1) so as to approach the second gripping unit 20B.

Next, the control unit 61 controls the gripping unit drive unit 25 to cause the gripping claws 24 of the gripping unit 21 to grip some of the items B1 from the group of items BS stored in the container 30. At this time, the state of the item gripping system 1 is a first state in which the item B1 gripped by the gripping unit 21 and the group of items BS stored in the container 30 are continuous.

Next, as shown in FIG. 5(a), the control unit 61 controls the container drive unit 31 to move the container 30 from the second gripping position to the second position and away from the second gripping unit 20B. In other words, the control unit 61 moves the container 30 downward, away from the second gripping unit 20B, along the third linear path R13 (see FIG. 1) from the second gripping position to the second position. As a result, the control unit 61 transitions from the first state to the second state.

At this time, the control unit 61 controls the distance A2 in the vertical direction D1 between the container 30 and the gripping unit 21 in the second state based on the type of item B1 and the distance information stored in the memory unit 62. In the example of FIG. 5(a), the distance A2 is longer than the length A1 in the vertical direction D1 of the item B1 in the second state. The distance A2 may be shorter than the distance A2 as long as it prevents interference between the item B1 gripped by the gripping unit 21 and the container 30 when the container 30 is moved in the horizontal direction D2 in a later operation. The distance A2 is, for example, a distance that is necessary and sufficient to separate the lower end of the item B1 in the vertical direction D1 from the upper end of the container 30.

The control unit 61 also controls the separation net drive unit 23 to move the separation net 22 downward along the vertical direction D1, and then move the separation net 22 upward along the vertical direction D1 again, returning the separation net 22 to a position above the tips of the gripping claws 24. This separates each of the articles B1 gripped by each of the multiple gripping units 21.

The timing at which the control unit 61 lowers the separation mesh 22 may be later than the timing at which the control unit 61 lowers the container 30, or may be simultaneous with the timing at which the control unit 61 lowers the container 30. Furthermore, as long as the lowering separation mesh 22 does not interfere with the container 30, the timing at which the control unit 61 lowers the separation mesh 22 may be earlier than the timing at which the control unit 61 lowers the container 30.

The control unit 61 then acquires each weight value of the item B1 grasped by the acquisition unit 27. The control unit 61 performs a combination calculation based on the weight values of the item B1 acquired by the acquisition unit 27. If the result of the combination calculation shows that there is a gripping unit 21 grasping the item B1 for which a combination of weight values close to the target weight value is not possible, the control unit 61 performs control to release the grip of the gripping unit 21 grasping the item B1. At this time, since the container 30 is located below the second gripping unit 20B, the item B1 is dropped into the container 30 again.

Next, as shown in FIG. 5(b), the control unit 61 controls the container driving unit 31 to move the container 30 in the horizontal direction D2. That is, the control unit 61 moves the container 30 in the horizontal direction D2 from the second position to the first position along the first linear path R11 (see FIG. 1). As a result, the control unit 61 moves the container 30 away from below the second gripping unit 20B and moves it below the first gripping unit 20A.

Next, based on the results of the combination calculation, the control unit 61 selects the gripping claws 24 of the gripping unit 21 that correspond to the combination of weight values that results in the target weight value. Next, as shown in FIG. 6 , the control unit 61 controls the gripping unit drive unit 25 to release the grip of the item B1 by the gripping claws 24 of the selected gripping unit 21 and allow it to fall. The fallen item B1 is dropped into the discharge chute 60, and as a result, the item B1 is discharged outside the item gripping system 1.

At the same time, the control unit 61 drives the container drive unit 31 to move the container 30 from the first position to the first gripping position and bring it closer to the first gripping unit 20A. In other words, the control unit 61 moves the container 30 upward along the second linear path R12 (see Figure 1) from the first position to the first gripping position, bringing it closer to the first gripping unit 20A.

The timing at which the control unit 61 raises the container 30 is not particularly limited, and may be earlier or later than the timing at which the gripping claws 24 of the gripping unit 21 release the grip on the item B1. Alternatively, the two timings may be simultaneous.

The above describes the operation of the item gripping system 1 for the second gripping unit 20B to grip and discharge item B1. When the first gripping unit 20A grips and discharges item B1, the item gripping system 1 simply performs a similar operation. By repeating the above operation, the item gripping system 1 can grip some of the items B1 from the group of items BS stored in the container 30 and discharge them outside the item gripping system 1.

Next, we will explain the operation of the item gripping system 1 when the item B gripped and discharged by the item gripping system 1 is item B2, which is shorter than item B1.

Figure 7 shows the state after the control unit 61 has transitioned from the first state to the second state. The control unit 61 controls the container drive unit 31 to move the container 30 from the second gripping position to the second position and away from the second gripping unit 20B. In other words, the control unit 61 moves the container 30 downward, away from the second gripping unit 20B, along the third linear path R13 (see Figure 1) from the second gripping position to the second position. As a result, the control unit 61 transitions from the first state to the second state.

At this time, the control unit 61 controls the distance C2 in the vertical direction D1 between the container 30 and the gripping unit 21 in the second state based on the type of item B2 and the distance information stored in the memory unit 62. At this time, the control unit 61 controls the distance C2 in the vertical direction D1 between the container 30 and the gripping unit 21 in the second state to be smaller based on the item. In the example of FIG. 7, the distance C2 is longer than the length C1 in the vertical direction D1 of the item B2 in the second state. The distance C2 may be shorter than the distance C2 as long as it prevents interference between the item B2 gripped by the gripping unit 21 and the container 30 when the container 30 is moved in the horizontal direction D2 in a later operation. The distance C2 is, for example, a distance that is necessary and sufficient to separate the lower end of the item B2 in the vertical direction D1 from the upper end of the container 30.

As shown in Figures 5(a) and 7, the length C1 of item B2 in the vertical direction D1 is shorter than the length A1 of item B1 in the vertical direction D1. Therefore, when the gripper 21 grips item B2, the distance necessary and sufficient for item B2 to not interfere with container 30 when the control unit 61 moves container 30 along the third linear path R13 is shorter than when the gripper 21 grips item B1. As a result, the distance C2 between the container 30 and the gripper 21 in the second state is shorter than the distance A2.

Next, we will explain the effects of the item gripping system 1 according to this embodiment.

In the item gripping system 1 according to this embodiment, when an item B gripped by the gripping unit 20 is to be separated from the group of items BS, the distance between the container 30 and the gripping section 21 in the second state is controlled depending on the item B. For example, if the item B is an item B1 such as long noodles, the item B1 is difficult to separate from the group of items BS, so the control section 61 controls the distance A2 between the container 30 and the gripping section 21 in the second state to be larger. On the other hand, if the item B is an item B2 such as short penne, the item B2 is easy to separate from the group of items BS, so the control section 61 controls the distance C2 between the container 30 and the gripping section 21 in the second state to be smaller. In this way, by controlling the distance between the gripping section 21 and the container 30 to be the distance necessary and sufficient to separate the item B from the group of items BS, excessive movement of the container 30 can be prevented. This reduces the operation time.

In the item gripping system 1 according to this embodiment, the container driving unit 31 moves the container 30 in the vertical direction D1. The control unit 61 controls the distance in the vertical direction D1 between the container 30 and the gripping unit 21 in the second state based on the type of item B. Specifically, the control unit 61 controls the distance in the vertical direction D1 between the container 30 and the gripping unit 21 in the second state to be smaller based on the type of item B. This prevents the container 30 and the gripping unit 21 from moving apart more than necessary in the vertical direction D1 based on the type of item B.

The item gripping system 1 according to this embodiment further includes a memory unit 62 that stores distance information regarding the distance in the vertical direction D1 between the container 30 and the gripping unit 21 in the second state for each type of item B. In this case, the distance information stored in the memory unit 62 can be used to control the distance between the container 30 and the gripping unit 21 in the second state to a distance appropriate for the item B.

In the item gripping system 1 according to this embodiment, the gripping unit 20 includes a plurality of gripping sections 21 and an acquisition section 27 that acquires the weight values of the items B gripped by each of the plurality of gripping sections 21. The control section 61 performs a combination calculation based on the weight values acquired by the acquisition section 27, selects a combination of gripping sections 21 that will result in a preset target weight value, and releases the grip of the selected gripping sections 21 to discharge the items B. In this case, combination weighing is performed, making it possible to discharge the items with the target weight value.

Second Embodiment
An article gripping system 1A according to a second embodiment will be described. In the description of this embodiment, differences from the first embodiment will be mainly described.

As shown in FIG. 8 , the item gripping system 1A according to the second embodiment includes a detection unit 70 that detects the length of the item B in the vertical direction D1 in the second state. The detection unit 70 is communicatively connected to the control unit 61 and is controlled by the control unit 61. In this embodiment, the detection unit 70 includes a light emission unit 71 that emits light L, and a light detection unit 72 that detects the light L from the light emission unit 71.

The light emitting unit 71 is provided on one of a pair of sides of the outer frame 22a of the separation net 22 extending along the horizontal direction D2. The light emitting unit 71 includes, for example, a laser diode. The light emitting unit 71 emits, for example, laser light toward the light detecting unit 72. The light detecting unit 72 is provided on the other of the pair of sides of the outer frame 22a of the separation net 22 extending along the horizontal direction D2. The light detecting unit 72 is provided in a position facing the light emitting unit 71 in the direction in which light L is emitted by the light emitting unit 71. The light detecting unit 72 includes, for example, a photodiode. The light detecting unit 72 detects, for example, laser light emitted from the light emitting unit 71.

Light L emitted by the light emitting unit 71 passes through the area defined by the outer frame 22a and the separating unit 22b in the separation net 22, and then enters the light detecting unit 72. Therefore, based on the detection result of light L by the light detecting unit 72, the control unit 61 can determine whether the item B gripped by the gripping unit 21 is located within that area.

Next, we will explain the operation of the item gripping system 1A according to this embodiment, focusing on the differences from the operation of the item gripping system 1.

In the article gripping system 1A, similar to the article gripping system 1, the control unit 61 controls the gripping unit drive unit 25 to cause the gripping claws 24 of the gripping unit 21 to grip some of the articles B from the group of articles BS stored in the container 30. Next, the control unit 61 controls the container drive unit 31 to move the container 30 from the second gripping position to the second position along the third linear path R13 (see Figure 1). As a result, the control unit 61 transitions from the first state to the second state.

At this time, the control unit 61 controls the detection unit 70 to start detecting the length of the item B in the vertical direction D1 in the second state. More specifically, the control unit 61 controls the light emission unit 71 to start emitting light L to the light detection unit 72.

The control unit 61 also controls the separation net driving unit 23 to move the separation net 22 downward in the vertical direction D1. As a result, the light emitting unit 71 and the light detecting unit 72 move downward along with the separation net 22. Therefore, the control unit 61 can detect the length in the vertical direction D1 of the item B gripped by the gripping unit 21 based on the amount of movement of the separation net 22 in the vertical direction D1 and the detection result of the light detecting unit 72.

At this time, the control unit 61 controls the distance in the vertical direction D1 between the container 30 and the gripping unit 21 in the second state based on the detection result of the detection unit 70. As an example, the distance in the vertical direction D1 between the container 30 and the gripping unit 21 in the second state is longer than the length in the vertical direction D1 of the item B detected by the detection unit 70. By performing this operation, the control unit 61 can set the distance in the vertical direction D1 between the container 30 and the gripping unit 21 in the second state to a distance necessary and sufficient to prevent interference between the container 30 and the item B gripped by the gripping unit 21 when the container 30 is moved in the horizontal direction D2 in a later operation.

Next, the effects of the item gripping system 1A according to this embodiment will be described. The item gripping system 1A according to this embodiment further includes a detection unit 70 that detects the length of the item B in the vertical direction D1 in the second state. The control unit 61 controls the distance between the container 30 and the gripper 21 in the second state based on the detection result of the detection unit 70. In this case, the detection result of the detection unit 70 can be used to control the distance between the container 30 and the gripper 21 in the second state to a distance appropriate for the item B.

[Modification]
Although the embodiments of the present invention have been described above, the present invention is not necessarily limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention.

In the above embodiment, an example was described in which the control unit 61 moves the container 30 along the first route R10, which includes the first straight route R11. However, as shown in FIG. 9(b), the control unit 61 may also move the container 30 along a second route R20, which includes a curved route R21. The control unit 61 may also be capable of selectively changing the route along which the container driving unit 31 moves the container 30 between the first route R10 and the second route R20. The control unit 61 may also move the container 30 along a route that is preset by the user via the operation unit 63, for example.

In Figure 9, only the movement path of the container 30 is shown, and other components are omitted. As shown in Figure 9(a), the first path R10 is composed of a first straight path R11, a second straight path R12, and a third straight path R13. In contrast, as shown in Figure 9(b), the second path R20 has a curved path R21, a first straight path R22, and a second straight path R23. The first straight path R22 and the second straight path R23 are spaced apart from each other in the horizontal direction D2 and extend in the vertical direction D1. The curved path R21 curves and connects the lower ends of the first straight path R22 and the second straight path R23.

In this modified example, after the second gripping unit 20B grips some of the items B from the group of items BS stored in the container 30, the control unit 61 moves the container 30 from the second gripping position to the second position along the second straight path R23. Next, the control unit 61 moves the container 30 from the second position to the first position along the curved path R21. At this time, the control unit 61 continuously moves the container 30, which has been moved to the second position along the second straight path R23, along the curved path R21.

The control unit 61 then moves the container 30 from the second position to the first position along the curved path R21. The control unit 61 then moves the container 30 from the first position to the first gripping position along the first linear path R22. At this time, the control unit 61 continuously moves the container 30, which has been moved to the first position along the curved path R21, along the first linear path R22.

As described above, in this modified example, the control unit 61 moves the container 30 to the second position along the first straight path R22, and then moves the container 30 to the first position along the curved path R21 without releasing the grip of the item B by the gripping portion 21 of the second gripping unit 20B and dropping the item B back into the container 30.

In the item gripping system 1 according to this modified example, the container driving unit 31 moves the container 30 in the horizontal direction D2 and the vertical direction D1. The control unit 61 can selectively change the movement path along which the container 30 is moved by the container driving unit 31 between a first path R10 and a second path R20. The first path R10 includes a first straight path R11, and the second path R20 includes a curved path R21. In this case, it is possible to switch the movement path of the container 30 between the first path R10 and the second path R20 depending on, for example, the type of item B.

For example, if item B is spaghetti noodles or the like, there is likely to be variation in the amount of item B grasped by each gripping unit 21, and it is therefore likely that a gripping unit 21 will grasp an item B that does not allow for a combination of weight values close to the target weight value. In this case, it will be necessary to release the gripping unit 21 from its grip on item B and drop item B back into the container 30. For this reason, the control unit 61 moves the container 30 along the third linear path R13 to the second position, waits until item B has been dropped into the container 30, and then moves the container 30 along the first linear path R11 to the first position.

On the other hand, for example, if item B is a granular material such as sugar, there is little variation in the amount grasped by each gripping unit 21, and therefore it is unlikely that a gripping unit 21 will grasp item B for which a weight value combination close to the target weight value is impossible. In this case, there is no need to release gripping unit 21 from gripping item B and drop item B back into container 30. Therefore, after moving container 30 to the second position along second linear path R23, control unit 61 continuously moves container 30 to the first position along curved path R21 without waiting until item B has been dropped into container 30 (without stopping container 30).

In this way, by switching the movement path of the container 30 between the first path R10 and the second path R20 depending on, for example, the type of item B, it is possible to prevent the container 30 from waiting at the second position (or the first position) for an excessively long time. Therefore, the operating time can be shortened.

In the above embodiment, an example has been described in which the control unit 61 controls the container drive unit 31 to move the container 30. However, the gripping unit 20 may be configured to be movable in the vertical direction D1 and the horizontal direction D2, and the control unit 61 may move the gripping unit 20. In this case, the weighing device 120 may include a unit drive unit that drives the gripping unit 20, and the control unit 61 may control the unit drive unit to move the gripping unit 20 in the vertical direction D1 and the horizontal direction D2.

When the control unit 61 moves the gripping unit 20, the weighing device may include, for example, a sensor unit and an internal control unit. In this case, the sensor unit 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. When the gripping device 21 gripping item B is moved by the unit drive unit, the weighing device measures the mass of item B gripped by the gripping device 21 based on the force and acceleration measured by the sensor unit. Specifically, the weighing device measures the mass of item B gripped by the gripping device 21 by dividing the force measured by the force sensor by the acceleration measured by the acceleration sensor. However, the weighing device is not limited to a method of measuring the mass of item B based on the force and acceleration measured when the gripping device 21 moves.

In the above embodiment, an example was described in which the detection unit 70 is provided on the separation net 22 and moves in conjunction with the vertical movement of the separation net 22. However, the detection unit 70 may also be fixed to, for example, the main body frame 80. In the above embodiment, an example was described in which the detection unit 70 includes a light emitter 71 and a light detector 72. However, the configuration of the detection unit 70 is not limited to that described above and various modifications are possible. For example, the detection unit 70 may include multiple light emitters 71 and multiple light detectors 72. Furthermore, for example, the detection unit 70 may be an imaging device such as a stereo camera. In this case, the detection unit 70 generates a distance image from two parallax images, which are frames captured at the same time (point in time), in which three-dimensional information including the distance (depth) to the subject is associated. The control unit 61 can detect the length of the item B in the vertical direction D1 in the second state based on the distance image generated by the detection unit 70.

1...Item gripping system, 20...Gripping unit, 21...Gripping section, 27...Acquisition section, 30...Container, 31...Container driving section (driving section), 61...Control section, 62...Memory section, 70...Detection section, A1, C1...Length, A2, C2...Distance, B, B1, B2...Item, BS...Group of items, D1...Vertical direction, D2...Horizontal direction, R10...First path, R11...First straight path (straight path), R20...Second path, R21...Curved path.

Claims (7)

An article gripping system that grips and ejects some articles from a group of articles stored in a container,
a gripping unit including a gripping portion that grips the article;
a drive unit that moves at least one of the gripping unit and the container;
a control unit that controls the drive unit to transition from a first state in which the item held by the gripper and the group of items stored in the container are continuous to a second state in which the item held by the gripper and the group of items stored in the container are separated,
the control unit controls the distance between the container and the gripper in the second state based on the item.
Item gripping system. the drive unit moves at least one of the gripping unit and the container at least in a vertical direction;
the control unit controls the vertical distance between the container and the gripper in the second state based on the type of the article.
The article handling system according to claim 1 . the control unit controls the vertical distance between the container and the gripper in the second state to be reduced based on the type of the article.
3. The article gripping system according to claim 2. a storage unit configured to store distance information regarding a distance in the vertical direction between the container and the gripper in the second state for each type of the article;
4. An article gripping system according to claim 2 or 3. a detection unit that detects the length of the article in the vertical direction in the second state;
The control unit controls the distance between the container and the gripper in the second state based on the detection result of the detection unit.
An article gripping system according to any one of claims 2 to 4. the drive unit moves at least one of the gripper and the container in a horizontal direction and a vertical direction;
the control unit is capable of selectively changing a movement path along which at least one of the gripper and the container is moved by the drive unit between at least a first path and a second path,
the first path includes a straight path;
the second path includes a curved path;
An article gripping system according to any one of claims 1 to 5. the gripping unit includes a plurality of the gripping portions and an acquisition portion that acquires weight values of the articles gripped by each of the plurality of gripping portions;
An item gripping system as described in any one of claims 1 to 6, wherein the control unit performs a combination calculation based on the weight value acquired by the acquisition unit, selects a combination of the gripping units that results in a predetermined target weight value, and releases the grip of the selected gripping unit to eject the item.