Gripping system and control device

Abstract

To provide a gripping system which can improve accuracy of a weight value of an object to be gripped or released.SOLUTION: A control device 50 of a gripping system 1 has: a first control part 51 for performing at least one of first distance changing operation of changing a distance La between two first gripping members 100a to a distance different from a distance in opening operation and a distance in closing operation when a first object T1 is gripped or released, and second distance changing operation of changing a distance Lb between two second gripping members 100b to a distance different from a distance in opening operation and a distance in closing operation when a second object T2 is gripped or released; and a second control part 52 for determining a second weight value which is at least one of a weight value of the second object T2 gripped by the two second gripping members 100b and a weight value of the second object T2 to be released, using a first weight value which is at least one of a weight value of the first object T1 gripped by the two first gripping members 100a and a weight value of the released first object T1.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a gripping system and a control device.

Background Art

[0002] Conventionally, a gripping system including a plurality of robots that grip an object with two gripping members is known. For example, Patent Document 1 discloses a weighing system (gripping system) including a first gripping part having a first gripping hand, a second gripping part having a second gripping hand having a shape different from that of the first gripping hand, an acquisition part that acquires at least one of the weight value of a first article gripped by the first gripping part and the weight value of the first article discharged from the first gripping part, and a control part that controls the discharge of a second article from the second gripping part based on the weight value.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described conventional gripping system, there is a possibility that the weight adjustment of an object to be gripped or released cannot be appropriately performed. For example, in Patent Document 1 above, weight adjustment is performed by a second gripping part having a shape different from that of the first gripping part, but there is a possibility that it cannot cope with a case where the weight adjustment amount by the second gripping part becomes large due to the weight value by the first gripping part deviating from the target weight more than expected. Thus, in a gripping system, it is desirable to accurately perform weight adjustment of an object to be gripped or released.

[0005] The present invention has been made by the inventor of the present application newly focusing on the above problems, and an object thereof is to provide a gripping system and a control device capable of improving the accuracy of the weight value of an object to be gripped or released.

Means for Solving the Problem

[0006] A gripping system according to an aspect of the present invention includes a first robot having two first gripping members for gripping a first object, a second robot having two second gripping members for gripping a second object, and a control device for controlling at least one of the operations of the first robot and the second robot. The control device includes a first distance changing operation for changing the distance between the two first gripping members to a distance different from the distance during the opening operation and the closing operation when the two first gripping members grip or release the first object, and a second distance changing operation for changing the distance between the two second gripping members to a distance different from the distance during the opening operation and the closing operation when the two second gripping members grip or release the second object. The control device further includes a first control unit that performs at least one of the above operations, and a second control unit that determines a second weight value, which is at least one of the weight value of the second object gripped by the two second gripping members and the weight value of the second object released by the two second gripping members, using a first weight value, which is at least one of the weight value of the first object gripped by the two first gripping members and the weight value of the first object released by the two first gripping members.

[0007] A control device according to an aspect of the present invention is a control device that controls the operation of at least one of a first robot having two first gripping members that grip a first object and a second robot having two second gripping members that grip a second object, the control device including: a first control unit that performs at least one of a first distance changing operation of changing the distance between the two first gripping members to a distance different from a distance during an opening operation and a distance during a closing operation when the two first gripping members grip or release the first object, and a second distance changing operation of changing the distance between the two second gripping members to a distance different from a distance during an opening operation and a distance during a closing operation when the two second gripping members grip or release the second object; and a second control unit that determines a second weight value, which is at least one of a weight value of the second object gripped by the two second gripping members and a weight value of the second object released by the two second gripping members, using a first weight value, which is at least one of a weight value of the first object gripped by the two first gripping members and a weight value of the first object released by the two first gripping members).

Advantages of the Invention

[0008] According to the gripping system and the like in the present invention, the accuracy of the weight value of an object to be gripped or released can be improved.

Brief Description of the Drawings

[0009]

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Best Mode for Carrying Out the Invention

[0010] A gripping system according to one aspect of the present invention includes a first robot having two first gripping members for gripping a first object, a second robot having two second gripping members for gripping a second object, and a control device for controlling at least one of the operations of the first robot and the second robot. The control device includes a first distance changing operation for changing the distance between the two first gripping members to a distance different from the distance during an opening operation and a closing operation when the two first gripping members grip or release the first object, and a second distance changing operation for changing the distance between the two second gripping members to a distance different from the distance during an opening operation and a closing operation when the two second gripping members grip or release the second object. The control device further includes a first control unit for performing at least one of the first distance changing operation and the second distance changing operation, and a second control unit for determining a second weight value, which is at least one of the weight value of the second object gripped by the two second gripping members and the weight value of the second object released by the two second gripping members, using a first weight value, which is at least one of the weight value of the first object gripped by the two first gripping members and the weight value of the first object released by the two first gripping members.

[0011] According to this, in the gripping system, the first control unit of the control device performs at least one of a first distance changing operation for changing the distance between two first gripping members and a second distance changing operation for changing the distance between two second gripping members. In this way, by the first control unit performing the first distance changing operation or the second distance changing operation, the first object or the second object can be accurately gripped or released. Further, the second control unit of the control device determines a second weight value of a second object to be gripped or released by the two second gripping members using a first weight value of a first object gripped or released by the two first gripping members. In this way, by the second control unit determining the second weight value using the first weight value, the amount of the second object to be gripped or released can be adjusted according to the amount of the first object that has been gripped or released. Therefore, according to the gripping system, with a configuration that can accurately grip or release the first object or the second object, the amount of the second object can be adjusted according to the amount of the first object, so that the accuracy of the weight value of the object to be gripped or released can be improved.

[0012] The first control unit may perform both the first distance changing operation and the second distance changing operation.

[0013] According to this, by the control device performing both the first distance changing operation and the second distance changing operation, the two first gripping members can accurately grip or release the first object, and the two second gripping members can accurately grip or release the second object. Thereby, according to the gripping system, the accuracy of the weight value of the object to be gripped or released can be further improved.

[0014] When the second control unit determines that the weight value of the first object that the two first gripping members can grip is smaller than the target weight value of the first object, the second control unit performs a process of determining the second weight value, and the first control unit may cause the two second gripping members to grip the second object having the second weight value.

[0015] According to this, when the control device determines that the weight value of the first object that can be grasped by the two first grasping members is smaller than the target weight value of the first object, since the two first grasping members cannot grasp the first object with the target weight value, it is necessary to make the two second grasping members grasp the second object. For this reason, the control device performs a process of determining the second weight value, and makes the two second grasping members grasp the second object with the second weight value. Thereby, according to the grasping system, the accuracy of the weight value of the object to be grasped can be further improved.

[0016] When the second control unit determines that the weight value of the first object that can be grasped by the two first grasping members is equal to or greater than the target weight value of the first object and the first weight value is the target weight value, the second control unit may not perform the process of determining the second weight value, and the first control unit may not make the two second grasping members grasp the second object.

[0017] According to this, when the control device determines that the weight value of the first object that can be grasped by the two first grasping members is equal to or greater than the target weight value of the first object and the first weight value is the target weight value, since the two first grasping members can grasp the first object with the target weight value, it is not necessary to make the two second grasping members grasp the second object. For this reason, the control device does not perform the process of determining the second weight value and does not make the two second grasping members grasp the second object. In this way, when the two first grasping members can grasp the first object with the target weight value, by not making the second grasping members grasp the second object, the object can be grasped efficiently.

[0018] When the second control unit determines that the first weight value is greater than the target weight value of the first object, the second control unit may determine the value obtained by subtracting the target weight value from the first weight value as the second weight value, and the first control unit may use the first object released by the two first grasping members as the second object and make the two second grasping members grasp the second object with the second weight value.

[0019] According to this, when the control device determines that the first weight value is greater than the target weight value of the first object, since the two first gripping members grip the first object too much, it is necessary to reduce the amount of the first object. Therefore, the control device determines a value obtained by subtracting the target weight value from the first weight value as the second weight value, and uses the first object released by the two first gripping members as the second object, and causes the two second gripping members to grip the second object with the second weight value. Thus, according to the gripping system, by causing the two second gripping members to grip the surplus of the first object that the two first gripping members have gripped (released) too much, the accuracy of the weight value of the object can be improved.

[0020] The first control unit may separate the position where the two first gripping members grip the first object from the position where the two second gripping members grip the second object.

[0021] If the two first gripping members and the two second gripping members grip the object at the same position, the position of the object may be overly recessed. If the object is overly recessed, the accuracy of gripping the object by the two first gripping members and the two second gripping members may decrease. Therefore, the control device separates the position where the two first gripping members grip the first object from the position where the two second gripping members grip the second object. Thereby, it is possible to suppress the object from being overly recessed and make the object flatter, so that the accuracy of the weight value of the object to be gripped or released can be further improved.

[0022] The first control unit may make the position where the two first gripping members release the first object different from the position where the two second gripping members release the second object.

[0023] When the two first gripping members and the two second gripping members release the object at the same position, the released object may become too convex (too high). If the object released into the container becomes too convex, it may be difficult to close the lid of the container, or the object may be displaced within the container. For this reason, the control device makes the position at which the two first gripping members release the first object different from the position at which the two second gripping members release the second object. Thereby, it is possible to suppress the object from becoming too convex and make the object flatter, so that it is possible to easily close the lid of the container and suppress the object from being displaced within the container. In particular, when releasing an object into an elongated container, by varying the release positions, the object can be arranged in the container faster and more evenly.

[0024] The first control unit may be configured to align the position at which the two first gripping members release the first object with the position at which the two second gripping members release the second object.

[0025] There may be a case where it is desired to arrange a large number of objects in a container with a narrow width, or where it is desired to stack the objects high in the container to make it look good (make it look impressive). In this case, the control device makes the position at which the two first gripping members release the first object coincide with the position at which the two second gripping members release the second object. Thereby, since the object released into the container can be stacked high, it is possible to arrange a large number of objects in a container with a narrow width or stack the objects high in the container to make it look good (make it look impressive).

[0026] A control device according to an aspect of the present invention is a control device that controls the operation of at least one of a first robot having two first gripping members for gripping a first object and a second robot having two second gripping members for gripping a second object, the control device comprising: a first control unit configured to perform at least one of a first distance changing operation for changing the distance between the two first gripping members to a distance different from a distance during an opening operation and a distance during a closing operation when the two first gripping members grip or release the first object, and a second distance changing operation for changing the distance between the two second gripping members to a distance different from a distance during an opening operation and a distance during a closing operation when the two second gripping members grip or release the second object; and a second control unit configured to determine a second weight value, which is at least one of a weight value of the second object gripped by the two second gripping members and a weight value of the second object released by the two second gripping members, using a first weight value, which is at least one of a weight value of the first object gripped by the two first gripping members and a weight value of the first object released by the two first gripping members.

[0027] According to this, in the control device, the first control unit performs at least one of a first distance changing operation for changing the distance between the two first gripping members and a second distance changing operation for changing the distance between the two second gripping members. Further, the second control unit determines a second weight value, which is at least one of a weight value of the second object gripped or released by the two second gripping members, using a first weight value, which is at least one of a weight value of the first object gripped or released by the two first gripping members. Accordingly, also in the control device, as in the gripping system, the accuracy of the weight value of the object to be gripped or released can be improved.

[0028] The present invention can be realized not only as such a gripping system and control device, but also as a gripping method or control method including characteristic processing steps performed by the gripping system or control device. The present invention can also be realized as a program for causing a computer to execute the gripping method or control method, or as a recording medium such as a computer-readable CD-ROM (Compact Disc-Read Only Memory) on which the program is recorded. And such a program can be distributed via a recording medium such as a CD-ROM and a transmission medium such as the Internet. The present invention can also be realized as an integrated circuit including a processing unit that performs the gripping method or control method.

[0029] Hereinafter, with reference to the drawings, a gripping system and a control device according to an embodiment (including a modified example thereof) of the present invention will be described. Each of the embodiments described below shows comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, each step in the method, the order of the steps, etc. shown in the following embodiments are examples and are not intended to limit the present invention. In each figure, the dimensions and the like are not shown precisely. In each figure, the same or similar components are denoted by the same reference numerals.

[0030] (Embodiment) [1 General description of the gripping system 1] First, a general description of the gripping system 1 in the present embodiment will be given with reference to FIG. 1. FIG. 1 is a perspective view showing the appearance of the gripping system 1 according to the present embodiment.

[0031] The gripping system 1 is a system that grips and releases an object and distributes the object. Examples of the object include food ingredients such as vegetables. For example, the gripping system 1 grips the food ingredient and releases it into a container 31 such as a container for a whole vegetable or a container for a bento box, and distributes (dishes up) the food ingredient into the container 31. For example, a plurality of gripping systems 1 are arranged, and various food ingredients are sequentially released into the container 31, so that various food ingredients are arranged in the container 31.

[0032] As shown in FIG. 1, the gripping system 1 includes a robot 10, an object storage unit 20, a container supply unit 30, a cover unit 40, and a control device 50. A belt conveyor 2 that automatically transports the container 31 is arranged at a position adjacent to the gripping system 1.

[0033] The robot 10 is an articulated robot such as a horizontal articulated robot or a vertical articulated robot, and grips and releases an object. The robot 10 includes a hand 11 and a robot arm 12. In the present embodiment, the gripping system 1 includes a plurality of robots 10 (specifically, a first robot 10a and a second robot 10b which are two robots 10). The plurality of robots 10 have the same configuration and the same functions, and each of the plurality of robots 10 includes a hand 11 and a robot arm 12.

[0034] The hand 11 is a part that grips and releases an object. The hand 11 is provided with a sensor (not shown) that acquires the amount of the object gripped or released, the reaction force from the contacted object, and the like. The sensor is a weight sensor that measures the weight of the object gripped or released, a force sensor that measures the reaction force from the contacted object (including the force sense obtained by contacting the surface), and the like. In the present embodiment, the sensor is provided at the connection part of the hand 11 with the robot arm 12 (connection part 400 shown in FIG. 2). The data acquired by the sensor is output to the control device 50. A detailed description of the configuration of the hand 11 will be described later.

[0035] The robot arm 12 is a multi-joint arm that moves the hand 11 to a desired position within its range of motion. The robot arm 12 also has an axis at the connection part with the hand 11 that rotates the hand 11 in a twisting direction with respect to the robot arm 12. This enables the orientation of the hand 11 to be changed when the hand 11 grasps or releases an object, thereby adjusting the direction in which the hand 11 opens and closes.

[0036] The object storage unit 20 is a part that stores the objects grasped by the robot 10. The object storage unit 20 is a bat (weight) or a tray, etc. For example, the object storage unit 20 stores a plurality of servings (tens to hundreds of servings, etc.) of food ingredients. The robot 10 grasps the food ingredients from within the object storage unit 20 and releases them into the container 31, thereby portioning (plating) the food ingredients into the container 31.

[0037] The container supply unit 30 supplies the container 31 to the position P where the robot 10 releases the object. The container supply unit 30 stores a plurality of containers 31 inside and supplies the containers 31 to the position P one by one. A weight sensor (not shown) for measuring the weight of the container 31 is arranged at the position P. When an object is placed on the container 31 at the position P, the weight of the object (the increased weight before and after the placement of the object) is measured by the weight sensor. The data measured by the weight sensor is output to the control device 50. When the measurement by the weight sensor is completed, the container 31 with the object placed on it is carried out onto the belt conveyor 2 by an extrusion mechanism (not shown) provided in the container supply unit 30.

[0038] The cover part 40 is a cover having a plate-like member that surrounds the periphery and above of the area where the robot 10, the object storage unit 20, and the container supply unit 30 are arranged. The plate-like member is formed of a transparent material such as glass or resin, and the operating status of the robot 10, etc. can be visually recognized from the outside of the cover part 40. An openable and closable door is provided on the side wall of the cover part 40, and through this door, various operations such as replacement of the object storage unit 20, addition of the container 31 to the container supply unit 30, or maintenance of the robot 10, etc. can be performed.

[0039] The control device 50 is a device that controls the operation of the robot 10. The control device 50 controls the operation of at least one of the plurality of robots 10 (at least one of the first robot 10a and the second robot 10b). In the present embodiment, the control device 50 controls the operations of the plurality of robots 10 (both the first robot 10a and the second robot 10b). The control device 50 is a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input unit (such as a keyboard, a touch panel, a mouse, a microphone, etc.), an output unit (such as a liquid crystal display, a speaker, etc.), a communication unit that communicates via a network, and a drive, etc., and executes various processes according to a program. The control device 50 may be realized by a general-purpose computer system such as a personal computer executing a program, or may be realized by a dedicated computer system such as a programmable controller.

[0040] The control device 50 is connected to the robot 10, the container supply unit 30, etc. by wire or wirelessly, and controls the operation of the entire gripping system 1 of the robot 10, the container supply unit 30, etc. For example, the control device 50 controls the operation of the container supply unit 30 supplying the container 31 to the position P, the operation of the robot 10 gripping an object from the object storage unit 20 and releasing it into the container 31, and the operation of the container supply unit 30 carrying out the container 31 to the belt conveyor 2, etc. The control device 50 may be arranged at a location away from the robot 10, etc., or may be arranged in the vicinity of the robot 10, etc., such as being attached to the cover unit 40. The gripping system 1 includes a plurality of sets of configurations in which the robot 10, etc. are accommodated in the cover unit 40, and the control device 50 may control the operations of the plurality of sets of robots 10, etc. A detailed description of the configuration of the control device 50 will be described later.

[0041] [Explanation of the hand 11 of the 2 robots 10] Next, the configuration of the hand 11 of the robot 10 in the gripping system 1 of the present embodiment will be described in detail. FIG. 2 is a perspective view showing the configuration of the hand 11 of the robot 10 according to the present embodiment. In FIG. 2, the illustration of the configuration above the upper part of the connection portion 400 of the hand 11 with the robot arm 12 is omitted. FIG. 3 is a perspective view showing the configuration of the gripping member 100 of the hand 11 of the robot 10 according to the present embodiment. FIG. 4 is a front view showing the opening and closing operation of the gripping member 100 of the hand 11 of the robot 10 according to the present embodiment. Specifically, FIG. 4(a) shows a state where the two gripping members 100 are closed, and FIG. 4(b) shows a state where the two gripping members 100 are open. FIG. 5 is a schematic diagram showing the gripping member 100 of the hand 11 of the robot 10 (the first robot 10a and the second robot 10b) according to the present embodiment and the object housing portion 20.

[0042] In the following description and drawings, the direction in which the hand 11 (two gripping members 100) of the robot 10 faces forward is defined as the X-axis direction, the direction in which the two gripping members 100 open and close is defined as the Y-axis direction, and the vertical direction is defined as the Z-axis direction. These X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect (orthogonal in the present embodiment) with each other. As described above, the hand 11 (two gripping members 100) is configured to be rotatable about an axis parallel to the Z-axis. However, when the hand 11 rotates, the X-axis and the Y-axis will also rotate accordingly. Also, in the following description, the X-axis plus direction indicates the arrow direction of the X-axis, and the X-axis minus direction indicates the direction opposite to the X-axis plus direction. When simply referring to the X-axis direction, it indicates the bidirectional or either one of the X-axis plus direction and the X-axis minus direction. The same applies to the Y-axis direction and the Z-axis direction. Expressions indicating relative directions or postures such as parallel and orthogonal include cases where they are not strictly in that direction or posture. For example, when two directions are parallel, it means not only that the two directions are completely parallel, but also that they are substantially parallel, that is, including a difference of about several percent.

[0043] As shown in FIG. 2, in addition to the above-described connecting portion 400, the hand 11 of the robot 10 includes two (a pair of) gripping members 100, two (a pair of) moving portions 200, and a guide portion 300.

[0044] The two gripping members 100 are members for gripping an object. Specifically, the two gripping members 100 grip and release the object. That is, the two gripping members 100 grip and release a part of the object accommodated in the object accommodating portion 20. In the present embodiment, the gripping member 100 is a metal member, but may be a member other than metal such as a resin member. As shown in FIG. 3, each of the two gripping members 100 has a plate-like portion 110 for gripping an object, a pair of side plate portions 120 disposed on both sides of the plate-like portion 110 and facing each other, and a top plate portion 130 disposed above the plate-like portion 110. Hereinafter, the gripping member 100 located in the minus Y-axis direction among the two gripping members 100 is also referred to as a gripping member 101, and the gripping member 100 located in the plus Y-axis direction is also referred to as a gripping member 102. That is, as shown in FIG. 3, the gripping member 101 has a plate-like portion 111, a pair of side plate portions 121, and a top plate portion 131. The gripping member 102 has a plate-like portion 112, a pair of side plate portions 122, and a top plate portion 132. The gripping member 101 and the gripping member 102 have a configuration that is symmetric with respect to the XZ plane.

[0045] The plate-like portions 111 and 112 are main body portions of the gripping members 101 and 102. When the gripping members 101 and 102 grip an object, they are disposed on both sides in the Y-axis direction of the object and sandwich the object in the Y-axis direction to grip the object. The plate-like portion 111 is a flat plate-like and rectangular portion that is inclined in the minus Y-axis direction from the XZ plane as it goes in the plus Z-axis direction. The plate-like portion 112 is a flat plate-like and rectangular portion that is inclined in the plus Y-axis direction from the XZ plane as it goes in the plus Z-axis direction. That is, the plate-like portions 111 and 112 are inclined so as to be separated from each other (the interval widens) as they go in the plus Z-axis direction. Note that as long as the object can be gripped by the plate-like portions 111 and 112, one or both of the plate-like portions 111 and 112 may not be inclined and may be a plate-like portion (vertical plate) parallel to the XZ plane.

[0046] The pair of side plate portions 121 are flat plate-shaped and inverted triangular portions parallel to the YZ plane that protrude in the plus Y-axis direction from both ends of the plate-shaped portion 111 in the X-axis direction. When the gripping members 101 and 102 grip an object, the pair of side plate portions 121 are arranged on both sides of the object in the X-axis direction and sandwich the object in the X-axis direction. The pair of side plate portions 122 are flat plate-shaped and inverted triangular portions parallel to the YZ plane that protrude in the minus Y-axis direction from both ends of the plate-shaped portion 112 in the X-axis direction. When the gripping members 101 and 102 grip an object, the pair of side plate portions 122 are arranged on both sides of the object in the X-axis direction and sandwich the object in the X-axis direction.

[0047] The top plate portion 131 is a flat plate-shaped and rectangular portion parallel to the XY plane that protrudes in the plus Y-axis direction from the end of the plate-shaped portion 111 in the plus Z-axis direction. The top plate portion 132 is a flat plate-shaped and rectangular portion parallel to the XY plane that protrudes in the minus Y-axis direction from the end of the plate-shaped portion 112 in the plus Z-axis direction. When the gripping members 101 and 102 grip an object, the top plate portions 131 and 132 are arranged in the plus Z-axis direction of the object.

[0048] The two moving portions 200 are portions configured to be movable (slidable) in the Y-axis direction with respect to the guide portion 300. The two moving portions 200 are connected to the plus Z-axis direction ends of the two gripping members 100 and move (slide) the two gripping members 100 in the Y-axis direction. Hereinafter, among the two moving portions 200, the moving portion 200 located in the minus Y-axis direction is also referred to as the moving portion 201, and the moving portion 200 located in the plus Y-axis direction is also referred to as the moving portion 202. The moving portion 201 is connected to the plus Z-axis direction end of the gripping member 101 and moves (slides) the gripping member 101 in the Y-axis direction. The moving portion 202 is connected to the plus Z-axis direction end of the gripping member 102 and moves (slides) the gripping member 102 in the Y-axis direction.

[0049] As shown in FIG. 4, the moving parts 201 and 202 move away from each other or approach each other in the Y-axis direction, thereby increasing or decreasing the distance between the gripping members 101 and 102, and opening or closing the gripping members 101 and 102. In the present embodiment, the moving parts 201 and 202 are configured to be able to move stepwise with respect to the guide part 300, and the distance between the gripping members 101 and 102 can be adjusted stepwise. Only one of the moving parts 201 and 202, instead of both, may be configured to be movable with respect to the guide part 300.

[0050] The guide part 300 is a guide that guides the two moving parts 200 to be movable (slidable) in the Y-axis direction. In the present embodiment, the guide part 300 has a linear rail extending in the Y-axis direction, and the two moving parts 200 move (slide) in the Y-axis direction along this rail.

[0051] As shown in FIG. 4(a), in the state where the gripping member 101 and the gripping member 102 are completely closed, the minus Z-axis direction end of the plate-like part 111 and the minus Z-axis direction end of the plate-like part 112 are in contact with each other, and the side plate part 121 and the side plate part 122 are in contact with each other. Thereby, the gripping members 101 and 102 have an inverted isosceles triangle container shape when viewed from the X-axis direction. In the present embodiment, slight gaps are formed at both ends in the Z-axis direction of the side plate part 121 and the side plate part 122, but these gaps may not be formed. The gripping members 101 and 102 may be opened and closed by the rotation of the moving parts 201 and 202 around an axis parallel to the X-axis. However, when the moving parts 201 and 202 move in the Y-axis direction, the gripping members 101 and 102 can grip more objects at a deeper position in the object accommodating part 20.

[0052] As described above, the gripping system 1 includes a first robot 10a and a second robot 10b, which are two robots 10 having the same configuration and the same functions. Therefore, as shown in FIG. 5, the first robot 10a has two first gripping members 100a (101a and 102a) as two gripping members 100 (101 and 102). The second robot 10b has two second gripping members 100b (101b and 102b) as two gripping members 100 (101 and 102). The two first gripping members 100a (101a and 102a) grip the first object T1 accommodated in the first region R1 among the objects T accommodated in the region R in the object accommodating portion 20. The two second gripping members 100b (101b and 102b) grip the second object T2 accommodated in the second region R2 among the objects T accommodated in the region R in the object accommodating portion 20. Also, hereinafter, the distance between the two gripping members 100 (101 and 102) is also referred to as the distance L. And the distance between the two first gripping members 100a (101a and 102a) is also referred to as the distance La, and the distance between the two second gripping members 100b (101b and 102b) is also referred to as the distance Lb.

[0053] [Description of the Functional Configuration of the Control Device 50] Next, the functional configuration of the control device 50 will be described in detail below. FIG. 6 is a block diagram showing the functional configuration of the control device 50 according to the present embodiment.

[0054] As shown in FIG. 6, the control device 50 includes a first control unit 51, a second control unit 52, a third control unit 53, and a storage unit 54. The first control unit 51 is a processing unit that controls the distance L between the two gripping members 100 of the robot 10 and the depth at which the gripping member 100 is inserted into the object T, and performs a process of gripping and releasing the object T by the two gripping members 100. The second control unit 52 is a processing unit that controls the weight value of the object T that the two gripping members 100 of the robot 10 grip or release. The third control unit 53 is a processing unit that controls various devices other than the robot 10 in the gripping system 1. The storage unit 54 is a memory that stores data and the like for performing various controls in the gripping system 1. Hereinafter, each of these processing units will be described in detail.

[0055] The first control unit 51 changes the distance L between the two gripping members 100 of the robot 10. Specifically, the first control unit 51 changes the distance L between the two gripping members 100 of the robot 10 to a third distance different from the first distance during the opening operation and the second distance during the closing operation when the two gripping members 100 grip or release the object T. The first distance is the maximum distance (maximum opening width) between the two gripping members 100 during the opening operation when the two gripping members 100 grip or release the object T. The second distance is the minimum distance (minimum opening width (closing width)) between the two gripping members 100 during the closing operation when the two gripping members 100 grip the object T. That is, the third distance is a width (distance) different from the maximum opening width and the minimum opening width during the gripping operation and the releasing operation of the two gripping members 100. The third distance is not a constant value and is appropriately changed according to the situation. Here, the gripping system 1 includes two robots 10, a first robot 10a and a second robot 10b. Therefore, the first control unit 51 changes at least one of the distance La between the two first gripping members 100a of the first robot 10a and the distance Lb between the two second gripping members 100b of the second robot 10b to the third distance.

[0056] In other words, the first control unit 51 performs at least one of the above-described operations on the first robot 10a, i.e., the first distance changing operation, and the above-described operation on the second robot 10b, i.e., the second distance changing operation. The first distance changing operation is an operation of changing the distance La between the two first gripping members 100a of the first robot 10a to a distance different from the distance during the opening operation and the closing operation when the two first gripping members 100a grip or release the first object T1. That is, the first distance changing operation is an operation of changing the distance La between the two first gripping members 100a to a width (distance) different from the maximum opening width and the minimum opening width during the gripping operation and the releasing operation of the two first gripping members 100a. The second distance changing operation is an operation of changing the distance Lb between the two second gripping members 100b of the second robot 10b to a distance different from the distance during the opening operation and the closing operation when the two second gripping members 100b grip or release the second object T2. That is, the second distance changing operation is an operation of changing the distance Lb between the two second gripping members 100b to a width (distance) different from the maximum opening width and the minimum opening width during the gripping operation and the releasing operation of the two second gripping members 100b. In the present embodiment, the first control unit 51 performs both the first distance changing operation and the second distance changing operation.

[0057] Further, the first control unit 51 determines the depth at which the two gripping members 100 are inserted into the object T according to the distance between the two gripping members 100. The "distance between the two gripping members 100" here is the maximum distance (maximum opening width) between the two gripping members 100 during the opening operation when the two gripping members 100 grip the object T. That is, the first control unit 51 determines the depth at which the two gripping members 100 are inserted into the object T according to the maximum opening width during the gripping operation of the two gripping members 100. Also, the "depth of insertion into the object T" is the depth of penetration into the object T, the depth of insertion (penetration distance) from the surface of the object T, or the depth after contacting the object T, etc. The first control unit 51 may determine the depth after both of the two gripping members 100 contact the object T, but in the present embodiment, it is determined to be the depth after at least one of the gripping members 100 contacts the object T.

[0058] Specifically, the first control unit 51 determines the depth at which the two first gripping members 100a are inserted into the first object T1 according to the distance between the two first gripping members 100a of the first robot 10a (the maximum opening width during the gripping operation). In the present embodiment, the first control unit 51 determines the depth after at least one of the two first gripping members 100a contacts the first object T1. Further, the first control unit 51 determines the depth at which the two second gripping members 100b are inserted into the second object T2 according to the distance between the two second gripping members 100b of the second robot 10b (the maximum opening width during the gripping operation). In the present embodiment, the first control unit 51 determines the depth after at least one of the two second gripping members 100b contacts the second object T2.

[0059] In addition, the first control unit 51 causes the two gripping members 100 to grip the object T in the object storage unit 20 and release the object T into the container 31. That is, the first control unit 51 causes the two first gripping members 100a of the first robot 10a to grip the first object T1 in the object storage unit 20 and release the first object T1 into the container 31. Further, the first control unit 51 causes the two second gripping members 100b of the second robot 10b to grip the second object T2 in the object storage unit 20 and release the second object T2 into the container 31. In the present embodiment, the first control unit 51 first causes the first robot 10a to grip and release the first object T1, and then causes the second robot 10b to grip and release the second object T2.

[0060] The second control unit 52 acquires a first weight value which is at least one of the weight value of the first object T1 held by the two first gripping members 100a of the first robot 10a and the weight value of the first object T1 released by the two first gripping members 100a. The first weight value is at least one of the weight value of the first object T1 gripped by the two first gripping members 100a from within the object storage unit 20 and the weight value of the first object T1 released by the two first gripping members 100a into the container 31. Also, the second control unit 52 uses the acquired first weight value to determine a second weight value which is at least one of the weight value of the second object T2 held by the two second gripping members 100b of the second robot 10b and the weight value of the second object T2 released by the two second gripping members 100b. The second weight value is at least one of the weight value of the second object T2 gripped by the two second gripping members 100b from within the object storage unit 20 and the weight value of the second object T2 released by the two second gripping members 100b into the container 31.

[0061] The third control unit 53 controls devices not controlled by the first control unit 51 and the second control unit 52 in the gripping system 1. That is, the first control unit 51 and the second control unit 52 control the operation of the robot 10, and the third control unit 53 controls devices other than the robot 10 such as the container supply unit 30. Specifically, the third control unit 53 controls the operation of the container supply unit 30 supplying the container 31 to the position P and the operation of the container supply unit 30 carrying out the container 31 from the position P to the belt conveyor 2.

[0062] The storage unit 54 is composed of a hard disk or a DRAM (Dynamic Random Access Memory) etc., and is a memory that stores data etc. for controlling various operations in the gripping system 1. Specifically, the storage unit 54 stores control data 54a including data etc. for the control device 50 to control the operation of the robot 10 (the first robot 10a and the second robot 10b).

[0063] [Explanation of the processing flow of the control device 50] Next, the control process performed by the control device 50 will be described. In particular, the process in which the first control unit 51 and the second control unit 52 of the control device 50 control the operations of the robot 10 (the first robot 10a and the second robot 10b) will be described in detail. FIG. 7 is a flowchart showing the process in which the control device 50 according to the present embodiment controls the operation of the robot 10.

[0064] As shown in FIG. 7, first, the first control unit 51 of the control device 50 causes the two first gripping members 100a of the first robot 10a to grip the first object T1 in the object storage unit 20 and release the first object T1 into the container 31 (step S11). At this time, the first control unit 51 performs a first distance changing operation of changing the distance between the two first gripping members 100a to a distance different from the distance during the opening operation and the closing operation when the two first gripping members 100a grip or release the first object T1. Further, the first control unit 51 determines the depth at which the two first gripping members 100a are inserted into the first object T1 according to the distance between the two first gripping members 100a. A detailed description of the process in step S11 will be given later.

[0065] Next, the second control unit 52 of the control device 50 acquires a first weight value that is at least one of the weight value of the first object T1 gripped by the two first gripping members 100a of the first robot 10a and the weight value of the first object T1 released by the two first gripping members 100a (step S12). The second control unit 52 may acquire either the weight value gripped or the weight value released by the two first gripping members 100a. For example, the second control unit 52 acquires the weight value released by the two first gripping members 100a as the first weight value. The second control unit 52 measures and acquires the first weight value by a weight sensor provided on the hand 11 or a weight sensor provided on the container supply unit 30 or the like. The second control unit 52 writes the acquired first weight value into the control data 54a of the storage unit 54 and stores it in the storage unit 54.

[0066] Next, the second control unit 52 determines a second weight value that is at least one of the weight value of the second object T2 grasped by the two second gripping members 100b of the second robot 10b and the weight value of the second object T2 released by the two second gripping members 100b, using the first weight value (step S13). The second control unit 52 may acquire either the weight value grasped or the weight value released by the two second gripping members 100b. For example, the second control unit 52 acquires the weight value grasped by the two second gripping members 100b as the second weight value. The second control unit 52 reads the first weight value from the control data 54a in the storage unit 54 and determines the second weight value using the first weight value. The second control unit 52 writes the determined second weight value into the control data 54a in the storage unit 54 and stores it in the storage unit 54. Details of the processing in step S13 will be described later.

[0067] Next, the first control unit 51 causes the two second gripping members 100b of the second robot 10b to grasp the second object T2 in the object storage unit 20 and release the second object T2 into the container 31 (step S14). Specifically, the first control unit 51 reads the second weight value determined in step S13 from the control data 54a in the storage unit 54 and causes the two second gripping members 100b to grasp or release the second object T2 with the second weight value. At this time, the first control unit 51 performs a second distance changing operation of changing the distance between the two second gripping members 100b to a distance different from the distance during the opening operation and the distance during the closing operation when the two second gripping members 100b grasp or release the second object T2. Further, the first control unit 51 determines the depth at which the two second gripping members 100b are inserted into the second object T2 according to the distance between the two second gripping members 100b. The processing in step S14 is the same as the processing in step S11.

[0068] Next, the first control unit 51 performs various processes when the depth of the object T in the object storage unit 20 is shallow (step S15). That is, in steps S11 and S14, since the object T in the object storage unit 20 is gripped by the two first gripping members 100a and the two second gripping members 100b and released into the container 31, the amount of the object T decreases. As a result, the depth of the object T in the object storage unit 20 becomes shallow, so the first control unit 51 performs various processes when the depth of the object T in the object storage unit 20 is shallow. A detailed description of the process in step S15 will be described later.

[0069] As described above, the process in which the first control unit 51 and the second control unit 52 of the control device 50 control the operations of the robot 10 (the first robot 10a and the second robot 10b) ends.

[0070] [4.1 Explanation of Steps S11 and S14] Next, the process in which the first control unit 51 causes the two first gripping members 100a to grip and release the first object T1 (step S11 in FIG. 7), and the process in which the two second gripping members 100b grip and release the second object T2 (step S14 in FIG. 7) will be described in detail. Note that the process in step S14 in FIG. 7 is the same as the process in step S11 in FIG. 7, with the first gripping member 100a and the first object T1, etc., replaced with the second gripping member 100b and the second object T2, etc. Therefore, hereinafter, the first gripping member 100a and the first object T1, etc., and the second gripping member 100b and the second object T2, etc., are generalized as the gripping member 100 and the object T, etc., and the process in step S11 in FIG. 7 and the process in step S14 in FIG. 7 will be described.

[0071] FIG. 8 is a flowchart showing the process in which the first control unit 51 according to the present embodiment causes the two gripping members 100 to grip and release the object T (steps S11 and S14 in FIG. 7).

[0072] As shown in FIG. 8, first, the first control unit 51 changes the distance L between the two gripping members 100 to a third distance different from the first distance during the opening operation and the second distance during the closing operation when the two gripping members 100 grip or release the object T (step S110). For example, the first control unit 51 changes the distance L between the two gripping members 100 to a third distance according to the object T gripped by the two gripping members 100. That is, when the first control unit 51 determines that it is difficult to grip the object T at the preset distance L because the size of the object T to be gripped is large or small, the object T has a distorted shape, or the object T is likely to collapse, the first control unit 51 changes the distance L to the third distance. Or, when the first control unit 51 determines that the depth of the object T has become equal to or less than a predetermined value (first depth), the first control unit 51 widens the distance L between the two gripping members 100. In this way, the first control unit 51 determines the distance L between the two gripping members 100 according to the object T. Also in the subsequent processing, when the first control unit 51 changes the distance L between the two gripping members 100, the first control unit 51 may appropriately determine the distance L according to the object T.

[0073] For example, information on the object T is written in the control data 54a, and the first control unit 51 can determine what value to change the distance L to by reading and acquiring the information on the object T from the control data 54a. The first control unit 51 can also acquire the depth of the object T in the process of detecting the shape of the object T in step S152 described later. Note that the above-mentioned first distance, second distance, third distance, and first depth are respectively preset or determined by the first control unit 51 and written in the control data 54a of the storage unit 54 to be stored in the storage unit 54. When any of these first distance, second distance, third distance, and first depth is changed, the data written in the control data 54a is rewritten.

[0074] Next, the first control unit 51 determines the depth at which the two gripping members 100 are inserted into the object T according to the distance L between the two gripping members 100 (step S120). In the present embodiment, since the first control unit 51 changes the distance L between the two gripping members 100 to a third distance, it determines the insertion depth corresponding to the case where the distance L is the third distance. For example, when the first control unit 51 widens the distance L between the two gripping members 100, in order to grip an object T of relatively regular quantity, etc., it shallows the depth at which the two gripping members 100 are inserted into the object T. To shallows the depth means to make it shallower than the depth (a preset value, an initial value, or, if the depth has been changed afterwards, the changed value) immediately before the shallowing operation (immediately before the process, immediately before the judgment). The same applies to the case of deepening the depth.

[0075] Note that when the first control unit 51 widens the distance L between the two gripping members 100 and determines that the object T is large and the object T cannot be gripped unless the insertion depth is deepened, the first control unit 51 may deepen the depth at which the two gripping members 100 are inserted into the object T. Thus, the first control unit 51 determines the depth at which the two gripping members 100 are inserted into the object T according to the situation of the object T, etc. In the subsequent processing as well, when the first control unit 51 changes the depth at which the two gripping members 100 are inserted into the object T, it may appropriately determine the insertion depth according to the situation of the object T, etc.

[0076] For example, the first control unit 51 can determine what value to set for the insertion depth by reading and obtaining information on the object T from the control data 54a. Note that the insertion depth and the relationship (relation formula, etc.) between the distance between the two gripping members 100 and the insertion depth are preset or determined by the first control unit 51 and written into the control data 54a of the storage unit 54 for storage in the storage unit 54. When the insertion depth or the relationship (relation formula, etc.) between the distance between the two gripping members 100 and the insertion depth is changed, the data written into the control data 54a is rewritten.

[0077] Next, the first control unit 51 moves the two gripping members 100 toward the object T (step S130). That is, the first control unit 51 changes the distance L between the two gripping members 100 to a third distance and, after determining the depth at which the two gripping members 100 are inserted into the object T, moves the two gripping members 100 toward the object T. Note that the first control unit 51 may change the distance L to the third distance or determine the insertion depth while moving the two gripping members 100 toward the object T.

[0078] Next, the first control unit 51 determines whether a force in a direction away from the object T is applied to at least one of the two gripping members 100 (step S140). Specifically, the first control unit 51 determines whether a force equal to or greater than a first stress (a value close to 0) in a direction away from the object T is applied to at least one of the gripping members 100. For example, the value of the first stress is pre-written in the control data 54a, and the first control unit 51 reads and obtains the first stress from the control data 54a and obtains the force applied to the gripping member 100 by a weight sensor, a force sensor, or the like provided in the hand 11. Then, when the force applied to the gripping member 100 becomes equal to or greater than the first stress, the first control unit 51 determines that a force in a direction away from the object T is applied to the gripping member 100. The first control unit 51 moves the two gripping members 100 toward the object T until it determines that a force in a direction away from the object T is applied to at least one of the gripping members 100 (when NO in step S140, step S130 is repeated). When the first control unit 51 determines that a force in a direction away from the object T is applied to at least one of the two gripping members 100 (YES in step S140), it proceeds to the next step S150.

[0079] Then, the first control unit 51 changes the distance L between the two gripping members 100 and changes the depth at which the gripping member 100 is inserted into the object T (step S150). Hereinafter, this step S150 will be described in detail.

[0080] [4.1.1 Explanation of Step S150] FIG. 9 is a flowchart showing a process (step S150 in FIG. 8) in which the first control unit 51 according to the present embodiment changes the distance L between the two gripping members 100 and the depth at which the gripping member 100 is inserted into the object T. FIG. 10 is a schematic diagram for explaining the process (step S150 in FIG. 8) in which the first control unit 51 according to the present embodiment changes the distance L between the two gripping members 100 and the depth at which the gripping member 100 is inserted into the object T.

[0081] As shown in FIG. 9, when the first control unit 51 determines that a force in a direction away from the object T is applied to at least one of the two gripping members 100 (YES in step S140), the first control unit 51 determines that the gripping member 100 has come into contact with the object T (step S151). That is, as shown in FIG. 10(a), when the two gripping members 100 move in the negative Z-axis direction toward the object T and at least one of the gripping members 100 comes into contact with the object T, a force in the positive Z-axis direction is applied to the gripping member 100. Therefore, when the first control unit 51 determines that a force in the positive Z-axis direction is applied to at least one of the gripping members 100, the first control unit 51 determines that the gripping member 100 has come into contact with the object T.

[0082] Then, the first control unit 51 detects the shape of the object T (step S152). That is, the first control unit 51 detects the shape of the object T by determining that at least one of the two gripping members 100 has come into contact with the object T. When the gripping member 100 comes into contact with the object T, the first control unit 51 writes data such as which gripping member 100 has come into contact with the object T, and the position and height at which the gripping member 100 has come into contact with the object T into the control data 54a and stores it in the storage unit 54. Thereby, the first control unit 51 estimates the shape of the surface of the object T by accumulating the data in the control data 54a.

[0083] Next, the first control unit 51 determines whether or not a force equal to or greater than a predetermined value in a direction away from the object T is applied to at least one of the two gripping members 100 (step S153). Specifically, the first control unit 51 determines whether or not a force equal to or greater than a second stress (a value greater than the first stress) in a direction away from the object T is applied to at least one of the gripping members 100. For example, the value of the second stress is written in advance in the control data 54a, and the first control unit 51 reads and acquires the second stress from the control data 54a, and acquires the force applied to the gripping member 100 by a weight sensor, a force sensor, or the like provided in the hand 11. Then, when the force applied to the gripping member 100 becomes equal to or greater than the second stress, the first control unit 51 determines that a force equal to or greater than a predetermined value in a direction away from the object T is applied to the gripping member 100.

[0084] When the first control unit 51 determines that a force equal to or greater than a predetermined value in a direction away from the object T is applied to at least one of the two gripping members 100 (YES in step S153), the first control unit 51 changes the distance L between the two gripping members 100 and the depth at which the gripping member 100 is inserted into the object T (step S154).

[0085] For example, when the first control unit 51 determines that a force equal to or greater than a predetermined value is applied to at least one of the gripping members 100, since there is a possibility that the gripping member 100 is in contact with the object T at an inappropriate position, the first control unit 51 changes the distance L between the two gripping members 100 to a distance greater than a third distance. Specifically, as shown in FIGS. 10(a) and 10(b), the first control unit 51 changes the distance L between the two gripping members 100 to a distance L2 greater than the third distance L1.

[0086] Further, in the present embodiment, as shown in FIG. 10(a), the surface of the object T is uneven, and only one of the two gripping members 100, i.e., the gripping member 101, is in contact with the object T. In this case, if the object T is gripped with the value of the distance L between the two preset gripping members 100, the amount of the object T to be gripped may be reduced. Therefore, as shown in FIG. 10(b), the first control unit 51 increases the distance L between the two gripping members 100. That is, when the first control unit 51 determines that only one of the two gripping members 100, i.e., one gripping member 100, is in contact with the object T (a force equal to or greater than a predetermined value is applied), the first control unit 51 increases the distance L between the two gripping members 100.

[0087] Alternatively, as shown in FIG. 10(a), when only one gripping member 101 is in contact with the object T, if the object T is gripped with the preset value of the depth at which the gripping member 100 is inserted into the object T, the amount of the object T to be gripped may be reduced. Therefore, as shown in FIG. 10(c), the first control unit 51 increases the depth at which the gripping member 100 is inserted into the object T. That is, when the first control unit 51 determines that only one of the two gripping members 100, i.e., one gripping member 100, is in contact with the object T (a force equal to or greater than a predetermined value is applied), the first control unit 51 increases the depth at which the gripping member 100 is inserted into the object T.

[0088] In this way, the first control unit 51 changes the distance L between the two gripping members 100 or changes the depth at which the gripping member 100 is inserted into the object T. Note that the first control unit 51 may change both the distance L between the two gripping members 100 and the depth at which the gripping member 100 is inserted into the object T.

[0089] Further, when the first control unit 51 determines that a force equal to or greater than a predetermined value in the direction away from the object T is not applied to both of the two gripping members 100 (NO in step S153), the process ends. As described above, the process (step S150 in FIG. 8) in which the first control unit 51 changes the distance L between the two gripping members 100 and the depth at which the gripping member 100 is inserted into the object T ends.

[0090] Returning to FIG. 8, next, the first control unit 51 causes the two gripping members 100 to grip the object T (step S160). Hereinafter, this step S160 will be described in detail.

[0091] [4.1.2 Explanation of Step S160] FIG. 11 is a flowchart showing the process in which the first control unit 51 according to the present embodiment causes the two gripping members 100 to grip the object T (step S160 in FIG. 8). FIGS. 12 to 14 are schematic diagrams for explaining the process in which the first control unit 51 according to the present embodiment causes the two gripping members 100 to grip the object T (step S160 in FIG. 8).

[0092] As shown in FIG. 11, first, when the two gripping members 100 perform a closing operation for gripping the object T, the first control unit 51 determines whether the two gripping members 100 grip the object T while the distance L between the two gripping members 100 remains the second distance (step S161).

[0093] When the first control unit 51 determines that the two gripping members 100 grip the object T while the distance L during the closing operation remains the second distance (YES in step S161), the first control unit 51 causes the two gripping members 100 to grip the object T and determines whether to change the distance L from the second distance (step S162). When the first control unit 51 determines not to change the distance L from the second distance (NO in step S162), the process ends. Specifically, as shown in FIGS. 12(a) to 12(c), when the two gripping members 100 perform a closing operation, the first control unit 51 closes the distance L from, for example, the distance L2 to the second distance L3 and causes the two gripping members 100 to grip the object T.

[0094] Here, in the state of (c) in FIG. 12, when the amount of the object T gripped by the two gripping members 100 is too large or in other cases where it is desired to reduce the amount of the object T gripped by the two gripping members 100, the first control unit 51 determines to change the distance L from the second distance (YES in step S162), and changes the distance L between the two gripping members 100 from the second distance to a third distance greater than the second distance (step S163). Then, the first control unit 51 returns the distance L between the two gripping members 100 to the second distance (step S164).

[0095] Specifically, as shown in (a) of FIG. 13, the first control unit 51 changes the distance L between the two gripping members 100 from the second distance L3 shown in (c) of FIG. 12 to a third distance L4 greater than the second distance L3. Thereby, the object T falls from between the two gripping members 100, and the amount of the object T gripped by the two gripping members 100 is reduced. Then, as shown in (b) of FIG. 13, the first control unit 51 returns the distance L between the two gripping members 100 to the second distance L3 and grips the object T. Thereby, the amount of the object T gripped by the two gripping members 100 is adjusted. Note that, from the state of (b) in FIG. 12, without lifting the two gripping members 100, by changing the distance L between the two gripping members 100 to the third distance L4, the object T may be dropped from between the two gripping members 100. As described above, the first control unit 51 changes the distance L between the two gripping members 100 during the closing operation to be the second distance L3, then changes it to a third distance L4 greater than the second distance L3, and then returns it to the second distance L3.

[0096] When the first control unit 51 determines that the object T cannot be grasped by the two gripping members 100 if the distance L during the closing operation remains the second distance (NO in step S161), the first control unit 51 changes the distance L between the two gripping members 100 during the closing operation from the second distance to a third distance greater than the second distance (step S165). That is, when it is difficult for the two gripping members 100 to grasp the object T if the distance L during the closing operation remains the second distance, the first control unit 51 widens the distance L during the closing operation to make it easier for the two gripping members 100 to grasp the object T. Then, the first control unit 51 causes the two gripping members 100 to grasp the object T at the third distance (step S166). Specifically, as shown in FIG. 14, the first control unit 51 changes the distance L between the two gripping members 100 during the closing operation not to the second distance L3 but to a third distance L4 greater than the second distance L3, and causes the two gripping members 100 to grasp the object T at the third distance L4.

[0097] In FIGS. 12 to 14, the second distance, which is the distance between the two gripping members 100 during the closing operation of the two gripping members 100, is L3 (a positive value) instead of 0, but the second distance may be 0 (the two gripping members 100 may be completely closed). Alternatively, the first control unit 51 may change the distance L between the two gripping members 100 from the second distance L3 to a third distance (such as 0) smaller than the second distance L3 during the closing operation of the two gripping members 100. Thus, the first control unit 51 may appropriately change the distance L between the two gripping members 100 during the closing operation according to the situation of the object T and the like.

[0098] Further, the first control unit 51 may lock the distance L between the two gripping members 100 at the second distance or the third distance during the closing operation so that the distance L does not become smaller (so that the closing width of the two gripping members 100 does not further shrink). That is, when the first control unit 51 determines the closing width of the two gripping members 100, it may prohibit further shrinkage from that width. Thereby, the closing operation of the two gripping members 100 can be appropriately performed.

[0099] Further, it is preferable that the first control unit 51 separates the position where the two first gripping members 100a grip the first object T1 from the position where the two second gripping members 100b grip the second object T2. That is, it is preferable that the first region R1 and the second region R2 shown in FIG. 5 are different regions within the region R. In the present embodiment, in step S14 of FIG. 7, the first control unit 51 causes the two second gripping members 100b to grip the second object T2 from a position different from the position where the two first gripping members 100a grip the first object T1.

[0100] As described above, the process in which the first control unit 51 causes the two gripping members 100 to grip the object T (step S160 in FIG. 8) ends.

[0101] Returning to FIG. 8, next, the first control unit 51 releases the object T from the two gripping members 100 (step S170). Hereinafter, this step S170 will be described in detail.

[0102] [4.1.3 Explanation of Step S170] FIG. 15 is a flowchart showing the process (step S170 in FIG. 8) in which the first control unit 51 according to the present embodiment releases the object T from the two gripping members 100.

[0103] As shown in FIG. 15, first, when the two gripping members 100 release the object T during the opening operation, the first control unit 51 determines whether to release the object T while the distance L between the two gripping members 100 remains the first distance (step S171).

[0104] When the first control unit 51 determines that the two gripping members 100 release the object T while the distance L during the opening operation remains the first distance (YES in step S171), the first control unit 51 sets the distance L between the two gripping members 100 to the first distance and releases the object T from the two gripping members 100.

[0105] When the first control unit 51 determines that the object T will not be released to the two gripping members 100 if the distance L during the opening operation remains at the first distance (NO in step S171), the first control unit 51 changes the distance L between the two gripping members 100 during the opening operation from the first distance to a third distance smaller than the first distance (step S172). Then, the first control unit 51 releases the object T to the two gripping members 100 at the third distance (step S173).

[0106] That is, when the first control unit 51 determines that it is better to reduce the distance L during the opening operation, for example, because the size of the container 31 is small and the object T may protrude from the container 31, the first control unit 51 changes the distance L to a third distance smaller than the first distance. For example, information about the container 31 is written in the control data 54a of the storage unit 54, and the first control unit 51 can determine what value to change the distance L to by reading and obtaining the information about the container 31 from the control data 54a. In this way, the first control unit 51 changes the distance L between the two gripping members 100 to a third distance corresponding to the size of the container 31 from which the object T gripped by the two gripping members 100 is released.

[0107] Note that the first control unit 51 may change the distance L between the two gripping members 100 during the opening operation to a third distance smaller than the first distance after setting the distance L to the first distance. Thereby, the object T can be released more to the central portion of the container 31. In particular, by raising the gripping members 100 while gradually narrowing the distance L until it becomes the third distance, the object T can be released in a mountain shape into the container 31 (the food ingredients can be arranged in a mountain shape), improving the appearance.

[0108] From the same perspective, when it is desired to place a large number of objects T in a narrow container 31, or when it is desired to stack the objects T high in the container 31 to improve the appearance, the first control unit 51 may align the position where the two first gripping members 100a release the first object T1 with the position where the two second gripping members 100b release the second object T2. Conversely, when it is desired to suppress the objects T released into the container 31 from becoming too convex (too high), the first control unit 51 may make the position where the two first gripping members 100a release the first object T1 different from the position where the two second gripping members 100b release the second object T2.

[0109] Further, when the two gripping members 100 are opened, the first control unit 51 may change the distance L between the two gripping members 100 from the first distance to a third distance greater than the first distance. In this way, the first control unit 51 may appropriately change the distance L between the two gripping members 100 during the opening operation according to the situation of the object T or the container 31, etc.

[0110] Also, during the opening operation, after setting the distance L between the two gripping members 100 to the first distance or the third distance, the first control unit 51 may lock it so that the distance L does not increase (so that the opening width of the two gripping members 100 does not further widen). That is, when the first control unit 51 determines the opening width of the two gripping members 100, it may prohibit further widening from that width. Thereby, the opening operation of the two gripping members 100 can be appropriately performed.

[0111] As described above, the process in which the first control unit 51 releases the object T to the two gripping members 100 (step S170 in FIG. 8) ends, and the processes in which the first control unit 51 grips and releases the object T to the two gripping members 100 (steps S11 and S14 in FIG. 7) also end.

[0112] [Explanation of Step S13 in 4.2] Next, a process in which the second control unit 52 determines a second weight value for gripping and releasing the two second gripping members 100b using the first weight values gripped and released by the two first gripping members 100a (step S13 in FIG. 7) will be described in detail.

[0113] FIG. 16 is a flowchart showing a process in which the second control unit 52 according to the present embodiment determines a second weight value for gripping and releasing the two second gripping members 100b using the first weight values gripped and released by the two first gripping members 100a (step S13 in FIG. 7).

[0114] As shown in FIG. 16, first, the second control unit 52 determines whether the weight value of the first object T1 that can be gripped by the two first gripping members 100a (hereinafter also referred to as the grippable weight value) is smaller than the target weight value of the first object T1 (hereinafter simply referred to as the target weight value) (step S200). The target weight value is the target value of the weight to be released into the container 31, and in the present embodiment, it is a value within a predetermined range having a certain width. For example, the grippable weight value and the target weight value are pre-written in the control data 54a, and the second control unit 52 reads and acquires the grippable weight value and the target weight value from the control data 54a. Then, the second control unit 52 determines whether the acquired grippable weight value is smaller than the target weight value.

[0115] When the second control unit 52 determines that the weight value of the first object T1 that can be gripped by the two first gripping members 100a is smaller than the target weight value of the first object T1 (YES in step S200), the second control unit 52 performs a process of determining a second weight value (step S201). That is, when the grippable weight value is smaller than the target weight value, the two first gripping members 100a cannot grip the entire amount of the target weight value of the first object T1. Therefore, it is necessary to make the two second gripping members 100b grip a second object T2 of a sufficient amount (it is necessary to supplement the first object T1). For this reason, the second control unit 52 determines the second weight value using the first weight value. In this case, in step S14, the first control unit 51 causes the two second gripping members 100b to grip the second object T2 of the second weight value, and releases the second object T2 of the second weight value into the container 31 from which the two first gripping members 100a have released the first object T1 of the first weight value. Note that the first object T1 and the second object T2 are objects of the same type (such as food ingredients). As a result, an object T of the target weight value is released into the container 31.

[0116] When the second control unit 52 determines that the weight value of the first object T1 that can be gripped by the two first gripping members 100a is equal to or greater than the target weight value of the first object T1 (NO in step S200), the second control unit 52 determines whether the first weight value is equal to the target weight value (step S202). That is, when the grippable weight value is equal to or greater than the target weight value, there is a possibility that the two first gripping members 100a can grip (release) the entire amount of the target weight value of the first object T1. Therefore, the second control unit 52 determines whether the first weight value is within the target weight value.

[0117] When the second control unit 52 determines that the first weight value is the target weight value (YES in step S202), it does not perform the process of determining the second weight value (step S203). That is, when the first weight value is within the target weight value, since the total amount of the target weight value of the first object T1 can be gripped (released) by the two first gripping members 100a, it is not necessary to grip the second object T2 with the two second gripping members 100b (it is not necessary to replenish the first object T1). Therefore, in this case, in step S14, the first control unit 51 does not cause the two second gripping members 100b to grip the second object T2 (does not cause the second object T2 to be released into the container 31 from which the two first gripping members 100a have released the first object T1). As a result, the object T with the target weight value is released into the container 31.

[0118] When the second control unit 52 determines that the first weight value is not the target weight value (is not within the target weight value) (NO in step S202), it determines whether the first weight value is greater than the target weight value of the first object T1 (step S204). When the second control unit 52 determines that the first weight value is greater than the target weight value of the first object T1 (YES in step S204), it determines the value obtained by subtracting the target weight value from the first weight value as the second weight value (step S205). That is, when the first weight value is greater than the target weight value, since the two first gripping members 100a have gripped too much of the first object T1, it is desired to have the two second gripping members 100b grip the excess amount of the first object T1. Therefore, the second control unit 52 determines the value obtained by subtracting the target weight value from the first weight value as the second weight value as the excess amount. In this case, in step S14, the first control unit 51 causes the two second gripping members 100b to grip the second object T2 with the second weight value, using the first object T1 released by the two first gripping members 100a as the second object T2. Then, the first control unit 51 causes the two second gripping members 100b to release the second object T2 at a position different from the container 31. That is, the first control unit 51 causes the two second gripping members 100b to grip the excess of the first object T1 in the container 31 released by the two first gripping members 100a and release it outside the container 31. As a result, the object T with the target weight value remains in the container 31.

[0119] When the second control unit 52 determines that the first weight value is smaller than the target weight value of the first object T1 (NO in step S204), the second control unit 52 determines the second weight value as the value obtained by subtracting the first weight value from the target weight value (step S206). That is, when the first weight value is smaller than the target weight value, since the two first gripping members 100a cannot grip the entire amount of the target weight value of the first object T1, it is necessary to make the two second gripping members 100b grip the second object T2 of the insufficient amount (it is necessary to replenish the first object T1). Therefore, the second control unit 52 determines the value obtained by subtracting the first weight value from the target weight value as the second weight value as the insufficient amount. In this case, in step S14, the first control unit 51 causes the two second gripping members 100b to grip the second object T2 of the second weight value, and releases the second object T2 of the second weight value into the container 31 from which the two first gripping members 100a have released the first object T1 of the first weight value. As a result, the object T of the target weight value is released into the container 31.

[0120] As described above, the process in which the second control unit 52 determines the second weight value that the two second gripping members 100b grip and release by using the first weight value that the two first gripping members 100a grip and release (step S13 in FIG. 7) ends.

[0121] [Explanation of step S15 in 4.3] Next, various processes (step S15 in FIG. 7) performed by the first control unit 51 when the depth of the object T in the object storage unit 20 is shallow will be described in detail.

[0122] FIG. 17 is a flowchart showing various processes (step S15 in FIG. 7) performed by the first control unit 51 according to the present embodiment when the depth of the object T in the object storage unit 20 is shallow. FIG. 18 is a schematic diagram for explaining various processes (step S15 in FIG. 7) performed by the first control unit 51 according to the present embodiment when the depth of the object T in the object storage unit 20 is shallow.

[0123] As shown in FIG. 17, first, the first control unit 51 determines whether or not the depth of the object T in the object storage unit 20 has become equal to or less than a predetermined value (second depth) (step S300). The depth of the object T is the depth of the object T at the position where the two gripping members 100 attempt to grip the object T (the distance from the bottom surface of the object storage unit 20 to the surface of the object T). For example, the value of the second depth is written in advance in the control data 54a, and the first control unit 51 reads and acquires the second depth from the control data 54a, and acquires the depth of the object T by a process of detecting the shape of the object T in step S152 described above. Then, the first control unit 51 determines whether or not the acquired depth of the object T has become equal to or less than the second depth.

[0124] When the first control unit 51 determines that the depth of the object T has become equal to or less than a predetermined value (second depth) (YES in step S300), at least one of the two gripping members 100 of the two gripping members 100 is caused to perform a leveling operation for flattening the surface of the object T (step S301).

[0125] In the present embodiment, as shown in FIGS. 18(a) and 18(b), the first control unit 51 causes both of the two gripping members 100 to perform a leveling operation. The leveling operation is an operation of bringing the tips of the two gripping members 100 (the tips in the negative Z-axis direction of the plate-shaped portions 110) into contact with the surface portion of the object T and moving (reciprocating) the two gripping members 100 in the Y-axis direction to flatten the surface of the object T. In the present embodiment, since the tips in the negative Z-axis direction of the plate-shaped portions 110 of the two gripping members 100 extend in the X-axis direction, the surface of the object T can be easily flattened by moving (reciprocating) the two gripping members 100 in the Y-axis direction. Note that the first control unit 51 may flatten the surface of the object T by pressing any surface of the two gripping members 100 against the object T or stroking the surface of the object T with the surface.

[0126] Furthermore, the first control unit 51 determines whether the depth of the object T in the object storage unit 20 is equal to or less than a predetermined value (second depth) (step S302). That is, the first control unit 51 determines whether the depth of the object T remains equal to or less than the predetermined value (second depth) even after the leveling operation is performed. When the first control unit 51 determines that the depth of the object T is equal to or less than the predetermined value (second depth) (YES in step S302), it causes at least one of the two gripping members 100 to execute a scraping operation for gathering the object T (step S303).

[0127] In the present embodiment, as shown in FIG. 18(c), the first control unit 51 causes both of the two gripping members 100 to execute the scraping operation. The scraping operation is an operation of inserting the two gripping members 100 into a deep position of the object storage unit 20 and moving them in the Y-axis direction to gather the object T. In the present embodiment, since the surface of the gripping member 100 in the Y-axis direction is flat, the configuration is such that the object T can be easily gathered by moving it in the Y-axis direction. Note that the first control unit 51 may gather the object T by causing a part of the object T to be gripped by the two gripping members 100, releasing it onto another part of the object T, and stacking it up.

[0128] After performing the scraping operation, the first control unit 51 returns to step S300 again and determines whether the depth of the object T in the object storage unit 20 is equal to or less than a predetermined value (second depth). When the first control unit 51 determines that the depth of the object T has become greater than the predetermined value (second depth) (NO in step S300 or NO in step S302), the process ends.

[0129] Note that the first control unit 51 may execute the scraping operation (step S303) before the leveling operation (step S301). The predetermined value (second depth) in the leveling operation (step S301) and the predetermined value (second depth) in the scraping operation (step S303) may be different values. The first control unit 51 may be configured to execute only one of the leveling operation and the scraping operation.

[0130] As described above, the various processes (step S15 in FIG. 7) performed by the first control unit 51 when the depth of the object T in the object storage unit 20 is shallow are completed.

[0131] [Description of Effects] Next, the effects exhibited by the gripping system 1 in the present embodiment will be described. Note that, although the following will describe the effects of the gripping system 1, these effects are also the effects of the control device 50.

[0132] The first control unit 51 of the control device 50 performs at least one of a first distance changing operation for changing the distance La between the two first gripping members 100a and a second distance changing operation for changing the distance Lb between the two second gripping members 100b. In this way, by the first control unit 51 performing the first distance changing operation or the second distance changing operation, the first object T1 or the second object T2 can be accurately gripped or released. Further, the second control unit 52 of the control device 50 determines a second weight value of the second object T2 to be gripped or released by the two second gripping members 100b using the first weight value of the first object T1 gripped or released by the two first gripping members 100a. In this way, by the second control unit 52 determining the second weight value using the first weight value, the amount of the second object T2 to be gripped or released can be adjusted according to the amount of the first object T1 that has been gripped or released. Therefore, according to the gripping system 1, since the amount of the second object T2 can be adjusted according to the amount of the first object T1 with a configuration that can accurately grip or release the first object T1 or the second object T2, the accuracy of the weight value of the object T to be gripped or released can be improved.

[0133] By the control device 50 performing both the first distance changing operation and the second distance changing operation, the two first gripping members 100a can accurately grip or release the first object T1, and the two second gripping members 100b can accurately grip or release the second object T2. Thereby, according to the gripping system 1, the accuracy of the weight value of the object T to be gripped or released can be further improved.

[0134] Since both the first robot 10a and the second robot 10b are configured to be able to change the distance L between the two gripping members 100, it is sufficient to prepare two robots 10 of the same type as the first robot 10a and the second robot 10b. For this reason, the configuration of the gripping system 1 is simplified, and the manufacture of the gripping system 1 becomes easier. When either the first robot 10a or the second robot 10b can be arranged at the arrangement positions of the two robots 10, there is no risk of misarranging the two robots 10, and this also enables the manufacture of the gripping system 1 to be facilitated.

[0135] When the control device 50 determines that the weight value of the first object T1 that can be gripped by the two first gripping members 100a is smaller than the target weight value of the first object T1, since the first object T1 with the target weight value cannot be gripped by the two first gripping members 100a, it is necessary to make the two second gripping members 100b grip the second object T2. For this reason, the control device 50 performs a process of determining the second weight value, and makes the two second gripping members 100b grip the second object T2 with the second weight value. Thereby, according to the gripping system 1, the accuracy of the weight value of the object T to be gripped can be further improved.

[0136] When the control device 50 determines that the weight value of the first object T1 that can be gripped by the two first gripping members 100a is equal to or greater than the target weight value of the first object T1 and the first weight value is the target weight value, since the first object T1 with the target weight value can be gripped by the two first gripping members 100a, it is not necessary to make the two second gripping members 100b grip the second object T2. For this reason, the control device 50 does not perform a process of determining the second weight value and does not make the two second gripping members 100b grip the second object T2. In this way, when the first object T1 with the target weight value can be gripped by the two first gripping members 100a, by not making the second gripping members 100b grip the second object T2, the object T can be efficiently gripped.

[0137] When the control device 50 determines that the first weight value is greater than the target weight value of the first object T1, since the two first gripping members 100a grip the first object T1 too much, it is necessary to reduce the amount of the first object T1. Therefore, the control device 50 determines a value obtained by subtracting the target weight value from the first weight value as the second weight value, and uses the first object T1 released by the two first gripping members 100a as the second object T2, and causes the two second gripping members 100b to grip the second object T2 with the second weight value. Thus, according to the gripping system 1, by causing the two second gripping members 100b to grip the excess portion of the first object T1 that the two first gripping members 100a have gripped (released) too much, the accuracy of the weight value of the object T can be improved.

[0138] If the two first gripping members 100a and the two second gripping members 100b grip the object T at the same position, there is a possibility that the position of the object T may be overly recessed. If the object T is overly recessed, the accuracy of gripping the object T by the two first gripping members 100a and the two second gripping members 100b may decrease. Therefore, the control device 50 separates the position where the two first gripping members 100a grip the first object T1 from the position where the two second gripping members 100b grip the second object T2. Thereby, since it is possible to suppress the object T from being overly recessed and make the object T flatter, the accuracy of the weight value of the object T to be gripped or released can be further improved.

[0139] When the two first gripping members 100a and the two second gripping members 100b release the object T at the same position, the released object T may become too convex (too high). If the object T released into the container 31 becomes too convex, it may be difficult to close the lid of the container 31, or the object T may be displaced within the container 31. For this reason, the control device 50 makes the position where the two first gripping members 100a release the first object T1 different from the position where the two second gripping members 100b release the second object T2. Thereby, it is possible to suppress the object T from becoming too convex and to make the object T flatter, so that the lid of the container 31 can be easily closed and the object T can be prevented from being displaced within the container 31. In particular, when releasing the object T into the elongated container 31, by making the release positions different, the object T can be arranged in the container 31 faster and more evenly.

[0140] Alternatively, there may be a case where it is desired to arrange a large number of objects T in a container 31 with a narrow width, or a case where it is desired to stack the objects T high in the container 31 to improve the appearance (make it look more impressive). In this case, the control device 50 may make the position where the two first gripping members 100a release the first object T1 coincide with the position where the two second gripping members 100b release the second object T2. Thereby, since the object T released into the container 31 can be stacked high, it is possible to arrange a large number of objects T in a container 31 with a narrow width or to stack the objects T high in the container 31 to improve the appearance (make it look more impressive).

[0141] The control device 50 changes the distance L between the two gripping members 100 having the plate-shaped portion 110 that grips the object T to a third distance different from the first distance during the opening operation and the second distance during the closing operation when the two gripping members 100 grip or release the object T. Thereby, even when the object T is gripped by the two gripping members 100 having the plate-shaped portion 110, the distance L between the two gripping members 100 can be changed to a more appropriate distance, so that it is possible to suppress the object T from being uselessly condensed or damaged. Also, according to the shape and size of the object T, the distance L between the two gripping members 100 can be changed to a more appropriate distance. The object T can be applied to various things such as food ingredients, things that are not food ingredients but are easily deformed or damaged, and things whose shape and size are not determined. Therefore, according to the gripping system 1, the object T can be gripped or released more appropriately.

[0142] When the object T cannot fit between the two gripping members 100 at the first distance during the opening operation of the two gripping members 100 due to the shape and size of the object T, or when it is desired to grip more objects T, etc., it may be possible to grip the object T more appropriately by changing the distance L between the two gripping members 100 and then gripping the object T. For this reason, after changing the distance L between the two gripping members 100 to the third distance, the control device 50 moves the two gripping members 100 toward the object T. Thereby, according to the gripping system 1, the object T can be gripped more appropriately.

[0143] When a force in a direction away from the object T is applied to the gripping member 100, it is conceivable that the object T may not fit between the two gripping members 100, or that the gripping member 100 may contact an inappropriate position depending on the shape of the object T. For this reason, when the control device 50 determines that a force equal to or greater than a predetermined value in a direction away from the object T is applied to at least one of the gripping members 100, the control device 50 widens the distance L between the two gripping members 100 to be greater than the third distance. Thereby, according to the gripping system 1, the gripping member 100 can be arranged at a more appropriate position, so that the object T can be gripped more appropriately.

[0144] By changing the distance L between the two gripping members 100 during the closing operation to a third distance greater than the second distance, it is possible to prevent the distance L between the two gripping members 100 from being reduced too much and deforming or crushing the object T. Thereby, according to the gripping system 1, the object T can be gripped more appropriately.

[0145] Since each of the two gripping members 100 has a pair of side plate portions 120 on both sides of the plate-like portion 110, the object T can be gripped by the plate-like portion 110 and the pair of side plate portions 120, making it easy to grip the object T. In this case, since there are fewer escape routes for the object T and there is a risk of deforming or crushing the object T, the effect of changing the distance L between the two gripping members 100 during the closing operation to a third distance greater than the second distance is high.

[0146] After the control device 50 sets the distance L between the two gripping members 100 to the second distance during the closing operation, by changing it to a third distance greater than the second distance, when there are many objects T being gripped, some of the objects T can be released to reduce the amount of the objects T. Then, by the control device 50 returning the distance L between the two gripping members 100 to the second distance, an appropriate amount of the object T can be gripped. Thereby, according to the gripping system 1, the object T can be gripped more appropriately.

[0147] By the control device 50 changing the distance L between the two gripping members 100 to a third distance corresponding to the size of the container 31, the object T can be gripped or released more appropriately according to the size of the container 31. Thereby, it is possible to prevent the object T from protruding from the container 31 or the amount of the object T in the container 31 from being too small.

[0148] By the control device 50 changing the distance L between the two gripping members 100 to a third distance corresponding to the object T, the object T can be gripped, released (loaded) more appropriately by the two gripping members 100.

[0149] The control device 50 determines the weight value of the second object T2 that the two second gripping members 100 of the second robot 10b grip or release, using the weight value of the first object T1 that the two first gripping members 100 of the first robot 10a grip or release. Thereby, an object T that could not be gripped or released by the first robot 10a can be gripped or released by the second robot 10b. Therefore, according to the gripping system 1, the accuracy of the weight value of the object T to be gripped or released can be improved, so that the object T can be gripped or released more appropriately.

[0150] The control device 50 determines the depth at which the two gripping members 100 are inserted into the object T according to the distance L between the two gripping members 100. Thereby, the control device 50 can change the distance L between the two gripping members 100 according to the shape and size of the object T, and determine the depth at which the two gripping members 100 are inserted into the object T according to the distance L. That is, the control device 50 can determine the depth at which the two gripping members 100 are inserted into the object T according to the shape and size of the object T even for objects T having various shapes and sizes. Therefore, according to the gripping system 1, the object T can be gripped more appropriately.

[0151] When the control device 50 widens the distance L between the two gripping members 100, a relatively quantitative object T can be gripped by making the depth at which the two gripping members 100 are inserted into the object T shallower. By making the depth at which the two gripping members 100 are inserted into the object T shallower, the time until the gripping member 100 reaches the bottom of the object T can be lengthened. Thereby, the time and man-hours for leveling the object T or replenishing the object T can be reduced. Therefore, it is possible to shorten the time (tact time) for gripping and releasing the object T and arranging the object T in the container 31. Thus, according to the gripping system 1, the object T can be gripped more appropriately.

[0152] When the control device 50 determines that the depth of the object T has become equal to or less than a predetermined value, the distance L between the two gripping members 100 can be increased, so that the time until the gripping member 100 reaches the bottom of the object T can be lengthened. Thereby, the time and man-hours for leveling the object T or replenishing the object T can be reduced, and the tact time can be shortened. Therefore, according to the gripping system 1, the object T can be gripped more appropriately.

[0153] When the control device 50 determines that the depth of the object T has become equal to or less than a predetermined value, by causing the leveling operation to be performed on the gripping member 100, the surface of the object T can be leveled. Thereby, since the time until the gripping member 100 reaches the bottom of the object T can be lengthened, shortening of the tact time and the like can be achieved. Therefore, according to the gripping system 1, the object T can be gripped more appropriately.

[0154] When the control device 50 determines that the depth of the object T has become equal to or less than a predetermined value, by causing the scraping operation to be performed on the gripping member 100, the depth of the object T can be increased. Thereby, since the time until the gripping member 100 reaches the bottom of the object T can be lengthened, shortening of the tact time and the like can be achieved. Therefore, according to the gripping system 1, the object T can be gripped more appropriately.

[0155] When the control device 50 determines that a force in a direction away from the object T has been applied to the gripping member 100, by determining that the gripping member 100 has come into contact with the object T, it is possible to easily detect that the gripping member 100 has come into contact with the object T.

[0156] When only one gripping member 100 contacts the object T and then inserts into the object T, compared with the case where two gripping members 100 contact the object T and then insert into the object T to the same depth, the amount of the object T gripped by the two gripping members 100 will be reduced. For this reason, when the control device 50 determines that only one gripping member 100 contacts the object T, the control device 50 increases the depth at which the gripping member 100 inserts into the object T. Thereby, it is possible to suppress the reduction in the amount of the object T gripped by the two gripping members 100. Therefore, according to the gripping system 1, the object T can be gripped more appropriately.

[0157] When only one gripping member 100 contacts the object T and then inserts into the object T, compared with the case where two gripping members 100 contact the object T and then insert into the object T to the same depth, the amount of the object T gripped by the two gripping members 100 will be reduced. For this reason, when the control device 50 determines that only one gripping member 100 contacts the object T, the control device 50 increases the distance L between the two gripping members 100. Thereby, it is possible to suppress the reduction in the amount of the object T gripped by the two gripping members 100. Therefore, according to the gripping system 1, the object T can be gripped more appropriately.

[0158] The control device 50 detects the shape of the object T by determining that at least one of the gripping members 100 contacts the object T. For example, when the control device 50 determines that only one gripping member 100 contacts the object T, it can detect that the object T is on a slope. When the control device 50 determines that the two gripping members 100 contact the object T, it can detect that the object T is relatively flat. Thus, according to the gripping system 1, by detecting the shape of the object T, the object T can be gripped more appropriately.

[0159] Since the control device 50 is configured to determine the depth at which the two gripping members 100 are inserted into the object T according to the distance L between the two gripping members 100, by determining the distance L between the two gripping members 100 according to the object T, the depth at which the two gripping members 100 are inserted into the object T can be determined according to the object T. Thereby, according to the gripping system 1, the object T can be gripped more appropriately according to the object T.

[0160] For example, when the object T is a food such as deep-fried chicken with potatoes, by widening the distance L between the two gripping members 100, damage to the food can be reduced and the appearance can be improved. In particular, when the gripping member 100 includes the plate-shaped portion 110, since there is a possibility of cutting the food, the effect is high. Further, when the object T is a brittle food such as a cherry blossom omelette or scrambled eggs, if the distance L between the two gripping members 100 is wide, it may collapse from the middle when being gripped by the two gripping members 100, or the brittle food may be condensed when the two gripping members 100 are closed. Therefore, it is preferable to narrow the distance L between the two gripping members 100. In this way, by determining the distance L between the two gripping members 100 so as not to roughen (not make uneven) the surface of the object T (such as food) to be gripped, the next gripping accuracy can be improved. Thereby, the frequency of depth adjustment of the object T can be reduced, so that the tact time can be shortened or the like. Therefore, according to the gripping system 1, the object T can be gripped more appropriately.

[0161] [Description of Modification Example 6] As described above, the gripping system 1 according to the present embodiment has been described. However, the present invention is not limited to the above embodiment. The embodiments disclosed this time are illustrative in all respects and not restrictive, and the scope of the present invention includes all modifications within the meaning and scope equivalent to the claims.

[0162] In the above-described embodiment, the first object T1 and the second object T2 are the same type of food material, but they may be different types of food materials or may be other than food materials. That is, the object T (the first object T1 and the second object T2) can be any object as long as it can be grasped and released by the two gripping members 100.

[0163] In the above-described embodiment, both of the two robots 10 (the first robot 10a and the second robot 10b) are configured to be able to adjust the distance between the two gripping members 100. However, it is sufficient that at least one robot 10 is configured to be able to adjust the distance between the two gripping members 100. In this case, however, it is preferable that the second robot 10b that later grasps or releases the object T is configured to be able to adjust the distance between the two second gripping members 100b.

[0164] In the above-described embodiment, the first robot 10a (the first gripping member 100a) and the second robot 10b (the second gripping member 100b) are assumed to have the same configuration and the same function, but they may have different configurations or different functions. For example, when the first object T1 and the second object T2 are different types of objects (such as food materials), the first gripping member 100a and the second gripping member 100b may have different configurations or different functions and may be used separately according to the application.

[0165] In the above-described embodiment, the robot 10 is assumed to have two gripping members 100, but it may have three or more gripping members 100. That is, the robot 10 may be configured to grasp the object with three or more gripping members 100 (the object is grasped by the opening and closing operations of the three or more gripping members 100). In this case, the "two gripping members 100" such as the "distance between the two gripping members 100" in the above description indicates any two of the three or more gripping members 100.

[0166] In the above-described embodiment, each of the gripping members 100 of the robot 10 has been described as having the plate-like portion 110, the pair of side plate portions 120, and the top plate portion 130. However, any one of the gripping members 100 may not have one or both of the side plate portions 120, or may not have the top plate portion 130. In addition to, or instead of, the plate-like portion 110, the gripping member 100 may have a member other than a plate-like member such as a rod shape (column shape) or a block shape.

[0167] In the above-described embodiment, the gripping system 1 is not necessarily limited to including all of the above-described components, such as not including the cover portion 40. The gripping system 1 may include three or more robots 10. In this case, any two of the three or more robots 10 may be defined as the first robot 10a and the second robot 10b. The control device 50 is not necessarily limited to including all of the above-described processing units, such as not including the storage unit 54 and acquiring data from an external memory. The control device 50 is not necessarily limited to executing all of the above-described steps, and each step executed by the control device 50 is not necessarily performed in the above-described order.

[0168] Furthermore, the present invention can be realized not only as the gripping system 1 and the control device 50, but also as a gripping method or a control method including characteristic processing steps performed by the gripping system 1 or the control device 50. The present invention can be realized as a program for causing a computer to execute steps included in the gripping method or the control method. That is, each component included in the control device 50 may be realized by a program execution unit such as a CPU or a processor reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory. Further, the present invention can be realized as a computer-readable non-transitory recording medium on which the program is recorded, for example, a flexible disk, a hard disk, a CD-ROM, an MO, a DVD, a DVD-ROM, a DVD-RAM, a BD (Blu-ray (registered trademark) Disc), a semiconductor memory, a flash memory, a magnetic storage device, an optical disk, a paper tape, or any other medium. And the program can be distributed via the recording medium and a transmission medium such as the Internet. Also, the present invention can be realized as an integrated circuit including a processing unit included in the control device 50. That is, each functional block of the control device 50 shown in FIG. 6 may be realized as a large-scale integration (LSI) which is an integrated circuit. These may be individually formed into one chip, or may be formed into one chip so as to include part or all of them. Thus, the control device 50 may be configured such that each component is constituted by dedicated hardware, or may be realized by executing a software program suitable for each component.

[0169] A form constructed by arbitrarily combining the components included in the above-described embodiment and its modifications is also included in the scope of the present invention.

Explanation of Reference Numerals

[0170] 1 Gripping system 2 Belt conveyor 10 Robot 10a First robot 10b Second robot 11 Hand 12 Robot Arm 20 Object Storage Unit 30 Container Supply Unit 31 Container 40 Cover Unit 50 Control Device 51 First Control Unit 52 Second Control Unit 53 Third Control Unit 54 Memory Unit 54a Control Data 100, 101, 102 Gripping Members 100a, 101a, 102a First Gripping Members 100b, 101b, 102b Second Gripping Members 110, 111, 112 Plate-Like Parts 120, 121, 122 Side Plate Parts 130, 131, 132 Top Plate Parts 200, 201, 202 Moving Parts 300 Guide Unit 400 Connection Unit

Claims

1. A first robot having two first gripping members for gripping a first object, a second robot having two second gripping members for gripping a second object, and a control device for controlling the operation of at least one of the first robot and the second robot, wherein the control device performs at least one of a first distance changing operation of changing the distance between the two first gripping members to a distance different from the distance during the opening operation and the closing operation when the two first gripping members grip or release the first object, and a second distance changing operation of changing the distance between the two second gripping members to a distance different from the distance during the opening operation and the closing operation when the two second gripping members grip or release the second object; a first control unit; and a second control unit that determines a second weight value, which is at least one of the weight value of the second object gripped by the two second gripping members and the weight value of the second object released by the two second gripping members, using a first weight value, which is at least one of the weight value of the first object gripped by the two first gripping members and the weight value of the first object released by the two first gripping members. A gripping system.

2. The first control unit performs both the first distance changing operation and the second distance changing operation. The gripping system according to Claim 1.

3. When the second control unit determines that the weight value of the first object that can be gripped by the two first gripping members is smaller than the target weight value of the first object, the second control unit performs a process of determining the second weight value. The first control unit causes the two second gripping members to grip the second object having the second weight value. The gripping system according to Claim 1 or 2.

4. When the second control unit determines that the weight value of the first object that can be gripped by the two first gripping members is equal to or greater than the target weight value of the first object and the first weight value is equal to the target weight value, the second control unit does not perform a process of determining the second weight value. The first control unit does not cause the two second gripping members to grip the second object. The gripping system according to Claim 3.

5. When the second control unit determines that the first weight value is greater than the target weight value of the first object, the second control unit determines the value obtained by subtracting the target weight value from the first weight value as the second weight value. The first control unit causes the two second gripping members to grip the second object, which is the first object released by the two first gripping members, with the second weight value of the second object. The gripping system according to claim 1 or 2.

6. The first control unit separates the position where the two first gripping members grip the first object from the position where the two second gripping members grip the second object. The gripping system according to claim 1 or 2.

7. The first control unit makes the position where the two first gripping members release the first object different from the position where the two second gripping members release the second object. The gripping system according to claim 1 or 2.

8. The first control unit makes the position where the two first gripping members release the first object coincide with the position where the two second gripping members release the second object. The gripping system according to claim 1 or 2.

9. A control device that controls the operation of at least one of a first robot having two first gripping members for gripping a first object and a second robot having two second gripping members for gripping a second object, a first control unit that performs at least one of a first distance changing operation of changing the distance between the two first gripping members to a distance different from the distance during the opening operation and the closing operation when the two first gripping members grip or release the first object, and a second distance changing operation of changing the distance between the two second gripping members to a distance different from the distance during the opening operation and the closing operation when the two second gripping members grip or release the second object; a second control unit that determines a second weight value, which is at least one of the weight value of the second object gripped by the two second gripping members and the weight value of the second object released by the two second gripping members, using a first weight value, which is at least one of the weight value of the first object gripped by the two first gripping members and the weight value of the first object released by the two first gripping members; A control device comprising the above.

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