Holding system and holding method

Abstract

To control a timing in which a plurality of holding members hold ingredients more properly.SOLUTION: A holding system 1 includes: a plurality of holding members 313; a robot arm 32; a load cell 315; and a control unit 311. The plurality of holding members 313 hold ingredients independently. The robot arm 32 transports the holding members 313 to insert the holding members 313 into a group of the ingredients at the same time. The load cell 315 detects at least any of the holding members 313 receiving a reacting force from the ingredients in an insertion process. The control unit 311 causes the corresponding holding member 313 to hold the ingredient in response to the load cell 315 detecting the reaction force.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] In recent years, various operations have been performed by robots equipped with a gripping function. For example, when gripping food, the robot grips a predetermined amount of food stored in a storage container such as a vat and transfers it to a container or a discharge chute that is the release destination, and then executes the release. Techniques related to such robots equipped with a gripping function are disclosed in, for example, Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Patent Document 1 discloses that a plurality of gripping members are arranged on one robot arm and lowered simultaneously to perform gripping at the same timing. However, the states of the group of foods to be gripped are various, and the surface is not necessarily flat. For example, the surface may be inclined or may have irregularities. In this case, even if the heights of the gripping members are the same, a situation may occur where some gripping members are inserted into the group of foods, while other gripping members are not yet inserted into the group of foods. In such a situation, if the plurality of gripping members perform gripping at the same timing, a problem occurs that the gripping members that are not yet inserted into the group of foods cannot perform gripping. This would lose the meaning of arranging a plurality of gripping members in the first place.

[0005] As described above, in the prior art, there is still room for improvement in the timing at which a plurality of gripping members execute gripping. Further, such problems are not limited to the case where the object to be gripped is food, but are common to various fields in which robots perform gripping, such as the industrial field and the like.

[0006] An object of the present invention is to more appropriately control the timing at which a plurality of gripping members execute gripping.

Means for Solving the Problems

[0007] To solve the above problems, a gripping system according to an embodiment of the present invention includes a plurality of gripping members that each independently grip an object, transfer means for transferring the plurality of gripping members and simultaneously inserting them into a group of the objects, reaction force detection means for detecting that at least any one of the plurality of gripping members has received a reaction force from the object during the insertion process, control means for causing a corresponding gripping member to execute gripping in response to the reaction force detection means detecting a reaction force, and is characterized by comprising.

Effects of the Invention

[0008] According to the present invention, the timing at which a plurality of gripping members execute gripping can be more appropriately controlled.

Brief Description of the Drawings

[0009]

Figure 1

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[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [Embodiment] [Overall Configuration] FIG. 1 is a schematic diagram schematically showing the configuration of the gripping system 1 according to the present invention. Here, the gripping system 1 is assumed to apply the present invention to a system that grips and releases food as an object. Therefore, in the following description, the case where the gripping system 1 grips ingredients such as prepared vegetables and loads the gripped ingredients into a container via a discharge chute will be taken as an example for explanation.

[0011] However, this is merely an example for explanation and is not intended to limit the scope of application of the present invention. The present invention is applicable to the entire system for gripping various objects. For example, it can also be applied to a system for gripping uncooked vegetables (e.g., shredded cabbage, carrots, or bean sprouts). Further, for example, it can be applied to a system for gripping workpieces of industrial products such as electronic devices (e.g., screws, bolts, or components of products). That is, the present invention can be implemented for various gripping systems regardless of the object to be gripped or the field of application.

[0012] As shown in FIG. 1, the gripping system 1 includes a food ingredient storage unit 10, a container supply unit 20, an articulated robot 30, a discharge chute 40, a shielding unit 50, and a control device 60. Among these, the container supply unit 20, the articulated robot 30, and the control device 60 are communicatively connected by wire or wirelessly and can communicate with each other.

[0013] Also, adjacent to the processing system 1, a belt conveyor 2 for automatically transporting the container of cut vegetables downstream is installed. The belt conveyor 2 has a transport surface for transporting the container, and the container is transported while being placed on this transport surface. In FIG. 1, as indicated by the dashed arrow, the right side of the paper surface is the downstream of the transport in the belt conveyor 2.

[0014] Also, in FIG. 1, only one gripping system 1 is shown, but it is not limited thereto. In the present embodiment, a plurality of gripping systems 1 are installed along the transport direction of one belt conveyor 2, and it is assumed that a plurality of articulated robots 30 cooperate to perform work.

[0015] The ingredient storage unit 10 has a storage space for storing ingredients such as vegetables to be served in the gripping system 1. The ingredient storage unit 10 is constituted by, for example, a general-purpose container such as a large vat or a tray. And in the storage space of the ingredient storage unit 10, for example, mashed salads such as potato salad (salads containing ingredients with viscosity or adhesiveness), okara, dried grated daikon radish, namasu, hijiki, boiled beans, jellyfish, butter corn, noodles, croquettes, tempura, and other various ingredients that can be gripped by the gripping member are stored. In the present embodiment, it is assumed that the ingredient storage unit 10 stores a plurality of servings (for example, dozens to hundreds of servings) of one type of ingredient. When the remaining amount of the stored ingredients decreases, the ingredient storage unit 10 can be manually replaced by an operator or automatically replaced by the articulated robot 30.

[0016] The container supply unit 20 supplies a container to a predetermined position (here, the serving position P1 in FIG. 1) where the ingredients are served in the gripping system 1. The container supply unit 20 stores a plurality of containers. When the gripping system 1 starts operating, the containers are supplied one by one to the serving position P1. Next, when the articulated robot 30 releases the ingredients, the ingredients are served into the container supplied to the serving position P1 via the discharge chute 40. Then, by the extrusion mechanism provided in the container supply unit 20, the container is extruded onto the conveying surface of the belt conveyor 2. As a result, the served container is conveyed downstream by the belt conveyor 2.

[0017] In addition, a container detection sensor 21 is arranged near the position where the container supply unit 20 extrudes the container onto the belt conveyor 2. The container detection sensor 21 is a sensor that detects the container being conveyed on the conveying surface of the belt conveyor 2. The container supply unit 20 extrudes the container with the ingredients served onto the conveying surface at a timing when the container detection sensor 21 does not detect other containers being conveyed on the conveying surface (containers that have been served by other articulated robots 30). Thereby, it is possible to prevent the containers from colliding with each other on the conveying surface. This is the reason why other containers are conveyed from upstream. As described above, in this embodiment, a plurality of gripping systems 1 are installed.

[0018] The articulated robot 30 is constituted by, for example, a horizontal articulated robot or a vertical articulated robot, etc., and includes a plurality of gripping mechanisms 31 capable of gripping the ingredients to be packed, and a robot arm 32 that moves the gripping mechanism 31 to an arbitrary position within the movable range.

[0019] The gripping mechanism 31 is disposed at the tip of the robot arm 32 and is supported by the robot arm 32 by being coupled by a coupling member. Then, the gripping mechanism 31 can move to an arbitrary position within the movable range along with the movement of the robot arm 32 based on the control of the control device 60. Furthermore, the joint that holds the gripping mechanism 31 is provided with an axis for rotating the gripping mechanism 31 in the twisting direction with respect to the robot arm 32. Therefore, when the gripping mechanism 31 grips the ingredient, by changing the orientation of the gripping mechanism 31, the direction in which the gripping mechanism 31 grips can be adjusted. As a result, when the gripping mechanism 31 reaches near the inner wall surface of the container, it becomes possible to change the orientation of the gripping mechanism 31 in a direction parallel to the inner wall surface of the container supply unit 20, making it easier to grip the ingredient near the inner wall surface of the container. In addition, this gripping mechanism 31 not only has a gripping member for gripping the ingredient, but also has a function of measuring the weight of the gripped ingredient and measuring the reaction force from the ingredient. These data measured by the gripping mechanism 31 are output to the control device 60 as appropriate.

[0020] The discharge chute 40 is formed in a cylindrical shape having an inlet provided at one end and an outlet provided at the other end. After the discharge chute 40 receives the workpiece released by the articulated robot 30 from the inlet, it discharges the workpiece from the outlet, thereby loading the workpiece into the container supplied at the loading position P1. For this purpose, the discharge chute 40 is arranged such that the outlet is located on the vertical upper surface of the loading position P1, for example, by being fixed to the structure of the shielding part 50 or the wall surface of the container supply part 20, or by being supported by a dedicated support. Also, the opening surface of the inlet is configured to be large enough to receive all of them when the plurality of gripping mechanisms 31 release simultaneously. On the other hand, the discharge chute 40 narrows as it approaches the outlet like a funnel, and the opening surface of the outlet is configured to be sized such that the discharged workpiece fits into the container. Thereby, it is possible to prevent the workpieces released by the plurality of gripping mechanisms 31 from scattering outside the container.

[0021] The shielding part 50 is composed of a plate-like member that surrounds and encloses the area where the workpiece storage part 10, the container supply part 20, the articulated robot 30, and the discharge chute 40 are installed in the gripping system 1. The plate-like member constituting the shielding part 50 is made of a transparent material such as glass or resin, and it is possible to visually recognize the operating status of the gripping system 1 from the outside. Also, an opening / closing door is installed in a part of the side wall formed by the shielding part 50. When replacing the workpiece storage part 10 or replenishing the workpiece, adding a container to the container supply part 20, or performing maintenance on the gripping system 1, etc., the operator can open the door of the shielding part 50 and perform various operations.

[0022] The control device 60 is composed of an information processing device such as a PC (Personal Computer) or a programmable controller, and controls the entire gripping system 1 by executing various programs. For example, the control device 60 controls operations such as the operation of the container supply unit 20 to supply containers, and the operation of the articulated robot 30 to grip ingredients from the ingredient storage unit 10 and release them into the container via the discharge chute 40 to load the ingredients. More specifically, for example, the control device 60 controls the driving of the robot arm 32 to move the gripping mechanism 31 to a preset position at a preset route and speed, and controls the driving of the actuator of the gripping mechanism 31 to realize the operation of gripping and releasing the ingredients by the gripping mechanism.

[0023] [Configuration of the Gripping Mechanism 31] Figs. 2 to 6 are diagrams showing the configuration of the gripping mechanism 31. More specifically, Fig. 2 is a front view showing the configuration of the gripping mechanism 31 with the gripping members open. Fig. 3 is a front view showing the configuration of the gripping mechanism 31 with the gripping members closed. Further, Fig. 4 is a front view showing the internal configuration of the gripping mechanism 31. Further, Fig. 5 is a side view showing the arrangement of a plurality of gripping mechanisms 31. Further, Fig. 6 is a bottom view showing the arrangement of a plurality of gripping mechanisms 31.

[0024] As shown in Figs. 2 and 3, the gripping mechanism 31 includes a control unit 311, a transmission unit 312, and a gripping member 313. In addition, in this embodiment, there are a plurality of gripping mechanisms 31, each of which is connected to the connecting portion 321. And further, the connecting portion 321 is attached to the robot arm 32. Thereby, the plurality of gripping mechanisms 31 are supported by the robot arm 32 and move simultaneously with the movement of the robot arm 32.

[0025] The control unit 311 controls the gripping operation and the releasing operation performed by the gripping member 313. For this purpose, the control unit 311 has a driving mechanism that moves forward and backward in a predetermined direction (the left - right direction in the plane of the paper) at the timing of executing gripping, and transmits that force to the gripping member 313 via the transmission unit 312.

[0026] The transmission unit 312 functions as a power transmission mechanism that transmits the force for advancing and retreating in a predetermined direction in the control unit 311 as the force for opening and closing the gripping member 313.

[0027] The gripping member 313 includes a first gripping part 313a and a second gripping part 313b. The first gripping part 313a moves to open and close in the same direction as the predetermined direction (left - right direction in the paper plane) of the advancement and retreat of the control unit 311 in response to the force transmitted from the transmission unit 312.

[0028] And, as shown in FIG. 3, when the tip of the first gripping part 313a and the tip of the second gripping part 313b approach each other, the gripping member 313 is in a closed state and can grip the ingredient. On the other hand, as shown in FIG. 2, when the tip of the first gripping part 313a and the tip of the second gripping part 313b move away from each other, the gripping member 313 is in an open state and can release the gripped ingredient.

[0029] To realize the control of such a gripping operation, as shown in FIG. 4, the control unit 311 includes a pin cylinder 314 and a load cell 315 inside its housing. In FIG. 4, for the purpose of showing the pin cylinder 314 and the load cell 315, the housing of the control unit 311 is shown transparently.

[0030] The pin cylinder 314 is an air cylinder driven by compressed air supplied through a tube (not shown), and corresponds to the driving mechanism for advancing and retreating in the predetermined direction (left - right direction in the paper plane) described above. Specifically, the pin cylinder 314 is pushed out by the supplied compressed air and moves so that its tip extends in a direction away from the housing of the control unit 311. On the other hand, when the supply of compressed air stops, the pin cylinder 314 moves so that its tip contracts in a direction approaching the housing of the control unit 311. This movement is realized by the elastic force of a spring disposed inside the pin cylinder 314. And, as described above, the force corresponding to these movements is transmitted to the first gripping part 313a via the transmission unit 312, and the gripping operation and the releasing operation are realized by the gripping member 313.

[0031] The load cell 315 converts the measured force into an electrical signal proportional to its magnitude and detects it as weight. In the present embodiment, the load cell 315 measures the vertical weight acting on the gripping member 313. For this purpose, for example, the pin cylinder 314, the transmission unit 312, and the gripping member 313 are attached to a single plate-like member (substrate), and the entire plate-like member is supported by the load cell 315.

[0032] The weight measured by the load cell 315 is used for two determinations: whether the gripping member 313 is receiving a reaction force from the workpiece and whether the gripping member 313 is gripping the workpiece. For this purpose, the weight measured in a state where the gripping member 313 is not gripping the workpiece and the gripping member 313 is not receiving a reaction force from the workpiece is measured and set as the reference weight.

[0033] When the measured current weight is smaller than the reference weight, it is determined that the gripping member 313 is receiving a reaction force from the workpiece in the accommodation space. In this case, the magnitude of the received reaction force can also be calculated based on the difference between the reference weight and the current weight. The magnitude of the received reaction force is used for detecting the timing at which the gripping member 313 executes gripping.

[0034] When the measured current weight is larger than the reference weight, it is determined that the gripping member 313 is gripping the workpiece. In this case, the weight of the gripped workpiece can also be calculated based on the difference between the reference weight and the current weight. The weight of the gripped workpiece is used for combined weighing. Since these determinations are made by the control device 60, the weight measured by the load cell 315 is sequentially output to the control device 60.

[0035] [[ID=2I]]As shown in FIG. 5, the plurality of gripping mechanisms 31 are each connected to and supported by the connecting portion 321. Also, as shown in FIG. 6, when viewed from the bottom surface, the plurality of gripping mechanisms 31 are arranged alternately so that their directions are different in the longitudinal direction of the connecting portion 321 (the left - right direction of the paper surface). In this example, four gripping mechanisms 31 are arranged in two rows in the longitudinal direction. If all the gripping mechanisms 31 were arranged in the same direction, the weight balance applied to the connecting portion 321 would be biased, and the moment of inertia (inertia) would become large. However, by arranging them alternately so that their directions are different as in this embodiment, the weight balance applied to the connecting portion 321 becomes uniform, and the moment of inertia does not become larger than necessary. Therefore, the followability of the gripping mechanism 31 when moving the gripping mechanism 31 by the robot arm 32 can be enhanced.

[0036] Also, by arranging them in this way, a pitch (interval) is provided between each gripping mechanism 31 and the adjacent gripping mechanism 31 located in the same row.

[0037] Returning to FIG. 5, the plurality of gripping mechanisms 31 are connected to the plate - shaped connecting portion 321 via support portions . Also, a spacer is arranged between the connecting portion 321 and the support portion, and the distance between each gripping mechanism 31 and the connecting portion 321 is adjusted . The number of these spacers is different step - by - step. In FIG. 5, no spacer is arranged for the gripping mechanism 31 arranged on the left - most side of the paper surface, and more spacers are arranged as going to the right side of the paper surface. And since the size (vertical length) of each gripping mechanism 31 itself is the same, the position of the tip of the gripping member 313 of each gripping mechanism 31 also differs step - by - step according to the number of spacers. That is, in this embodiment, the position of the tip of the gripping member 313 of each gripping mechanism 31 is intentionally made different.

[0038] In this way, by providing a pitch (interval) between adjacent gripping mechanisms 31 and making the position of the tip of the gripping member 313 different, it is possible to prevent adjacent gripping members 313 from gripping the same ingredient. For example, it is possible to prevent gripping a long object (e.g., a single strand of noodles or a single strand of bean sprouts) simultaneously with two gripping members 313.

[0039] Further, a spring is disposed inside the support portion and expands and contracts in the vertical direction (the up-and-down direction in the drawing plane) due to its elastic force. Along with this, the relative positional relationship between the connecting portion 321 and the tip of each gripping member 313 of the plurality of gripping mechanisms 31 is variable in the vertical direction. Thus, even if the tip of a part of the gripping members 313 (for example, the gripping member 313 on the right side in the drawing plane) comes into contact with the bottom surface of the ingredient storage portion 10 that stores the ingredients, the gripping member can be inserted into the ingredients stored in the other gripping members by shrinking in the insertion direction. Therefore, the ingredients present on the bottom surface of the ingredient storage portion 10 can be gripped without leaving any.

[0040] Furthermore, the first gripping portion 313a and the second gripping portion 313b are configured to form a closed loop shape when viewed from the side. Specifically, it is composed of two extending portions that are separated from each other and extend in a predetermined direction (vertically downward in the state of the drawing) from the main body side of the gripping member 313, and a tip portion that couples the two extending portions at the tips of the extending portions. The first gripping portion 313a and the second gripping portion 313b can be created, for example, by bending a single wire. In this case, as the material, it is preferable to use a material with a wide elastic range such as spring steel that elastically deforms during gripping and returns to the shape before elastic deformation when not gripping. Thereby, it elastically deforms according to the reaction force from the ingredients during gripping, becomes a shape suitable for gripping the ingredients, and excessive force does not act on the ingredients during gripping. Also, when not gripping, it returns to the shape before elastic deformation, so it can be used repeatedly.

[0041] [Hardware Configuration of Control Device 60] FIG. 7 is a schematic diagram showing the hardware configuration of the control device 60. As shown in FIG. 7, the control device 60 includes a CPU (Central Processing Unit) 711, a ROM (Read Only Memory) 712, a RAM (Random Access Memory) 713, a bus 714, an input portion 715, an output portion 716, a storage portion 717, a communication portion 718, and a drive 719.

[0042] The CPU 711 executes various processes according to the program recorded in the ROM 712 or the program loaded from the storage unit 717 to the RAM 713. The RAM 713 appropriately stores data and the like necessary for the CPU 711 to execute various processes.

[0043] The CPU 711, ROM 712, and RAM 713 are interconnected via a bus 714. The input unit 715, output unit 716, storage unit 717, communication unit 718, and drive 719 are connected to the bus 714.

[0044] The input unit 715 includes input devices such as a mouse and a keyboard, and receives input of various information to the control device 60. Note that the input unit 715 may include a microphone and receive input of various information by voice input of an operator. The output unit 716 is composed of a display, a speaker, etc., and outputs images and sounds. The storage unit 717 is composed of a hard disk or a DRAM (Dynamic Random Access Memory), etc., and stores various data managed by each server. The communication unit 718 controls communication with other devices via a network.

[0045] A removable medium 731 made of a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, etc. is appropriately mounted on the drive 719. The program read from the removable medium 731 by the drive 719 is installed in the storage unit 717 as necessary. Note that the above hardware configuration is the basic configuration of the control device 60, and it is possible to have a configuration without some hardware, a configuration with additional hardware, or a change in the implementation form of the hardware.

[0046] [Functional Configuration] Next, the functional configuration of the control device 60 will be described. FIG. 8 is a block diagram showing a functional configuration of the control device 60. As shown in FIG. 8, by executing a program for controlling the operation of the gripping system 1, in the CPU 711 of the control device 60, a sensor information acquisition unit 151, a reaction force determination unit 152, a gripping amount determination unit 153, a multi-joint robot control unit 154, a container supply control unit 155, and a recording control unit 156 function. Further, in the storage unit 717, a parameter storage unit 171 and a history database (history DB) 172 are formed.

[0047] The parameter storage unit 171 stores various parameters used when the gripping system 1 operates. For example, the parameter storage unit 171 stores the position and shape of the ingredient storage unit 10, the position and shape of the container supplied from the container supply unit 20, the position of the area for scooping the ingredients in the container, parameters defining the operation pattern of the multi-joint robot 30, and the like.

[0048] The history DB 172 stores, as history, the control parameters acquired when the gripping system 1 operates or the measurement data of the weight of the ingredients scooped by the gripping system 1.

[0049] The sensor information acquisition unit 151 acquires sensor information, which is information detected by various sensors installed in the gripping system 1. For example, the sensor information acquisition unit 151 sequentially acquires the current weight data of each gripping member 313 measured by the load cell 315 of each gripping mechanism 31.

[0050] The reaction force determination unit 152 determines whether or not the gripping member 313 is receiving a reaction force from the ingredient based on the current weight data of each gripping mechanism 31 measured by the load cell 315. Specifically, as described above in the description of the load cell 315, when the measured current weight is smaller than the reference weight, it is determined that the gripping member 313 is receiving a reaction force from the ingredient in the accommodation space. In this case, the magnitude of the received reaction force is calculated based on the difference between the reference weight and the current weight. Then, when the gripping member 313 of any of the gripping mechanisms 31 receives a reaction force of a predetermined magnitude or more, the reaction force determination unit 152 issues an instruction to execute gripping to the corresponding gripping member 313. As a result, the gripping member 313 can be inserted into the ingredients in the accommodation space, and gripping can be executed after reaching an appropriate timing at which reliable gripping is possible.

[0051] The gripping amount determination unit 153 determines whether the gripping member 313 is gripping an ingredient based on the current weight data for each gripping mechanism 31 measured by the load cell 315. Specifically, as described above when explaining the load cell 315, when the measured current weight is greater than the reference weight, it is determined that the gripping member 313 is gripping an ingredient. In this case, the weight of the gripped ingredient is calculated based on the difference between the reference weight and the current weight.

[0052] Then, when each gripping member 313 executes gripping, the gripping amount determination unit 153 performs combined weighing so as to conform to a specified amount, which is the weight of the ingredient to be released, based on the weights of the ingredients gripped by the respective gripping members 313. Then, the gripping member 313 corresponding to the combination that conforms to the specified amount is made to release the ingredient to the discharge chute 40, and the other gripping members 313 are not made to release the ingredient to the discharge chute 40. Further, if there is no combination that conforms to the specified amount, the gripping amount determination unit 153 makes the gripping operation be performed again.

[0053] Here, an explanation is added regarding combined weighing. For example, assume that the weights of the ingredients gripped by the respective gripping members 313 are "gripping member A: 30 grams", "gripping member B: 17 grams", "gripping member C: 25 grams", and "gripping member D: 18 grams". In this assumption, when the specified amount is 35 grams, when combined weighing is performed, the total weight of the ingredients gripped by the gripping member B and the gripping member D becomes 35 grams, which conforms to the specified amount. Therefore, the gripping amount determination unit 153 causes the gripping members A and B to release the ingredient to the discharge chute 40, and does not cause the other gripping members C and D to release the ingredient to the discharge chute 40. Alternatively, in this assumption, when the specified amount is 50 grams and combined weighing is performed, there is no combination that conforms to the specified amount. Therefore, the gripping amount determination unit 153 causes the gripping operation to be performed again. Note that a margin may be provided for the specified amount, and even if there is a slight difference (for example, a difference of several percent) from the specified amount, it may be allowed to determine that it conforms to the specified amount.

[0054] In this way, the reaction force determination unit 152 appropriately controls the gripping execution timing for each of the plurality of gripping members, and on top of that, the gripping amount determination unit 153 performs combined weighing. Therefore, the amount of the ingredient to be released can be made highly accurately equal to the specified amount. Note that the reference weights used by the reaction force determination unit 152 and the gripping amount determination unit 153 for determination are measured in advance and stored in the parameter storage unit 171 or the like.

[0055] The articulated robot control unit 154 controls the operation of the articulated robot 30 and causes the articulated robot 30 to execute a series of operations for loading the ingredient according to the operation pattern defined in the gripping system 1. For example, the articulated robot control unit 154 causes the articulated robot 30 to perform an operation of gripping the ingredient by the gripping mechanism 31 of the articulated robot 30 (gripping operation), an operation of transferring the gripped ingredient to the container (transfer operation), an operation of releasing the gripped ingredient (release operation), etc.

[0056] The container supply control unit 155 controls the container supply unit 20 and causes the container for loading the ingredient to be loaded in the gripping system 1 to be supplied to the loading position P1. Further, the container supply control unit 155 controls the container supply unit 20 and pushes out the container in which the ingredient has been loaded onto the transport surface at a timing when the container detection sensor 21 does not detect another container being transported on the transport surface (a container that has already been loaded by another articulated robot 30).

[0057] The recording control unit 156 stores in the history DB 172 the parameters related to control acquired when the gripping system 1 performs a gripping operation, the measurement data of the weight of the ingredients packed by the gripping system 1, and the like. These data are utilized as log data or the like for an administrator or the like of the gripping system 1 to analyze the operation of the gripping system 1.

[0058] [Gripping and releasing operations] Next, details of the gripping and releasing operations performed by the articulated robot 30 and the plurality of gripping mechanisms 31 based on the control of the articulated robot control unit 154 will be described. Figs. 9 to 11 are schematic views showing the situations of the gripping and releasing operations performed by the articulated robot 30. In Figs. 9 to 11, the ingredient storage unit 10 and the plurality of gripping mechanisms 31 are illustrated as observed from the side. Note that, to clarify the state of each gripping mechanism 31, it is illustrated through the wall surface of the ingredient storage unit 10. Further, since a large amount of ingredients are stored in the storage space of the ingredient storage unit 10, these large amounts of ingredients are hereinafter referred to as "groups of ingredients".

[0059] First, as shown in Fig. 9(a), the plurality of gripping mechanisms 31 are transferred vertically above the storage space of the ingredient storage unit 10. Then, the robot arm 32 starts to lower the plurality of gripping mechanisms 31 simultaneously vertically downward.

[0060] As shown in Fig. 9(b), the robot arm 32 further lowers the plurality of gripping mechanisms 31. Along with this, the plurality of gripping mechanisms 31 are inserted into the group of ingredients in the storage space. Here, the surface of the group of ingredients is not necessarily flat. For example, the surface may be inclined or may have irregularities. Further, in the present embodiment, in order to prevent adjacent gripping members 313 from gripping the same ingredient, the positions of the tips of the gripping members 313 are made different. Furthermore, the individual ingredients included in the group of ingredients are not uniform in terms of their properties, shapes, and the density at which they are arranged (for example, ingredients are concentrated only in some regions), and may be amorphous. That is, the situations when the gripping members 313 of each gripping mechanism 31 are inserted into the group of ingredients are various. Under such circumstances, if each gripping mechanism 31 is made to grip simultaneously, there may be a case where some of the gripping mechanisms 31 cannot grip the workpiece properly. Therefore, in the present embodiment, when the reaction force determination unit 152 determines that the gripping member 313 has received a reaction force of a predetermined magnitude or more during the insertion process, it issues an instruction to execute gripping on the corresponding gripping member 313. Then, the gripping members 313 of the plurality of gripping mechanisms 31 grip the workpiece independently of each other.

[0061] In the illustrated example, the central region of the surface of the group of workpieces is slightly concave and sunken. Therefore, the gripping member 313 of the gripping mechanism 31 inserted into this region has not received a reaction force greater than a predetermined value yet during the insertion process, so gripping is not executed. On the other hand, the region of the group of workpieces near the wall surface of the workpiece storage unit 10 is relatively raised. Also, the plurality of gripping mechanisms 31 have different tip heights in steps. Therefore, the gripping member 313 of the gripping mechanism 31 that is inserted into this raised region and has a lower height has received a reaction force of a predetermined magnitude or more during the insertion process and is executing gripping. As described above, in the present embodiment, even if the state of the group of workpieces and the state of the workpieces are various as described above, each gripping member 313 is inserted into the workpiece in the accommodation space, and gripping can be executed at an appropriate timing when reliable gripping is possible.

[0062] As shown in FIGS. 10(c1) and 10(c2), the robot arm 32 further inserts the plurality of gripping mechanisms 31 into the group of workpieces. However, for any of the gripping mechanisms 31, since it has not received a reaction force greater than a predetermined value yet during the insertion process, gripping is not executed. In this case, if the insertion is continued further, the working time will become long. For example, there may not be much of the group of workpieces in only the region where the gripping mechanism 31 is inserted, and even if it is inserted to the bottom surface, it may not receive a reaction force greater than a predetermined value from the workpiece.

[0063] Therefore, when a predetermined condition is satisfied, the multi-joint robot control unit 154 forcibly executes gripping on the gripping member 313 of the gripping mechanism 31 that is receiving a reaction force less than a predetermined value. This can prevent the working time from being unnecessarily prolonged. Here, as the predetermined condition, for example, two conditions can be cited.

[0064] The first condition is that, as shown in FIG. 10(c1), with the bottom surface of the ingredient storage unit 10 as a reference, a position at a predetermined height from this bottom surface is set as the first reference position. Then, when the tip of the gripping member 313 is inserted up to the first reference position, the multi-joint robot control unit 154 determines that the predetermined condition is satisfied and forcibly executes gripping. Note that the multi-joint robot control unit 154 can grasp the position of the bottom surface of the ingredient storage unit 10 to be used as a reference from the data stored in the parameter storage unit 171.

[0065] The second condition is that, as shown in FIG. 10(c2), with the surface of the group of ingredients in the ingredient storage unit 10 as a reference, a position at a predetermined depth from this bottom surface is set as the second reference position. Then, when the tip of the gripping member 313 is inserted up to the second reference position, the multi-joint robot control unit 154 determines that the predetermined condition is satisfied and forcibly executes gripping. Note that the multi-joint robot control unit 154 can grasp, based on the measurement result of the load cell 315, the position where the gripping member 313 first receives the reaction force from the group of ingredients as the position of the surface of the group of ingredients to be used as the reference position. [[ID=A]] [[ID=B]]

[0066] [[ID=C]] [[ID=D]] [[ID=E]]

[0067] [[ID=F]] Note that although the positions of the tips of the gripping members 313 are different step by step, it can be arbitrarily determined which tip position of the gripping member 313 is to be compared with the reference position. It is possible to compare the gripping member 313 with the lowest tip position with the reference position, or the gripping member 313 with the highest tip position with the reference position, or any other gripping member 313 with the reference position. This is common both when making a determination under the first condition and when making a determination under the second condition.Also, the determination may be made under any conditions, or it may be made under both conditions. For example, when the group of ingredients in the ingredient storage section 10 is small, even if it is not inserted from the surface of the group of ingredients to a predetermined depth, it may be inserted to the bottom surface of the ingredient storage section 10. Therefore, in such a scenario, it may be appropriate to make the determination based on the second condition. On the other hand, when there is a large amount of the group of ingredients in the ingredient storage section 10, it may be inserted deeper than necessary up to a predetermined height from the bottom surface of the ingredient storage section 10. Therefore, in such a scenario, it may be appropriate to make the determination based on the first condition. Considering such various conditions, whether to make the determination under any condition or under both conditions can be arbitrarily determined.

[0068] As shown in FIG. 11(d), when the gripping members 313 of all the gripping mechanisms 31 execute gripping, the robot arm 32 raises the plurality of gripping mechanisms 31 and pulls them out from the group of ingredients. Here, as the case where the gripping members 313 of all the gripping mechanisms 31 execute gripping, there are considered "the case where the gripping members 313 of all the gripping mechanisms 31 execute gripping after receiving a reaction force of a predetermined size or more" and "the case where gripping is forcibly executed as shown in FIG. 10". Thus, in this embodiment, by a series of processes, gripping is performed on all of the plurality of gripping mechanisms 31, so that all of the plurality of gripping mechanisms 31 can be effectively utilized. In the figure, the ingredients gripped by each gripping member 313 are described as "gripped ingredients".

[0069] Thereafter, the gripping amount determination unit 153 performs combined weighing so as to conform to a specified amount that is the weight of the ingredient to be released. Also, the robot arm 32 transfers the plurality of gripping mechanisms 31 above the discharge chute 40 vertically.

[0070] As shown in Figure 11(e), the articulated robot control unit 154 causes the gripping members 313 corresponding to the combination that matches the specified amount to release ingredients into the discharge chute 40, and does not cause the other gripping members 313 to release ingredients into the discharge chute 40. The released ingredients discharged into the discharge chute 40 are then placed into containers in an amount that matches the specified amount via the discharge chute 40. In the figure, the ingredients released by each gripping member 313 are referred to as "released ingredients."

[0071] According to the present embodiment described above, gripping can be performed when a reaction force is received from the ingredients in the process of inserting the gripping member 313 into the group of ingredients. In other words, gripping can be performed after the gripping member 313 has been inserted into the group of ingredients and is in a state where it can reliably grip the ingredients. Therefore, with common technology, a problem occurs in which a gripping member that has not yet been inserted into a group of food is used to grip the ingredients, and the ingredients cannot be gripped, but this problem does not occur with the gripping system 1. Therefore, multiple gripping members that are arranged can be used appropriately. Furthermore, since the combined weighing is then performed, the amount of ingredients released can be set to a specified amount with high precision. That is, the gripping system 1 makes it possible to more appropriately control the timing at which the multiple gripping members perform gripping.

[0072] [Overall operation] Next, the overall operation of the gripping system 1 will be described. 12 and 13 are flowcharts showing the flow of the ingredient plating process executed by the gripping system 1. The ingredient plating process is started, for example, when an operator performs an operation to start the ingredient plating process.

[0073] When the ingredient loading process starts, in step S11 of FIG. 12, the articulated robot control unit 154 reads data for operations (e.g., data on operation patterns, data on the position and shape of the ingredient storage unit 10, etc.) for a series of operations in the ingredient loading process from the parameter storage unit 171 to prepare for gripping the ingredients.

[0074] In step S12, the articulated robot control unit 154 transfers each gripping mechanism 31 vertically above the ingredient storage unit 10 according to the data on the operation pattern. In step S13, the articulated robot control unit 154 inserts each gripping mechanism 31 into the group of ingredients in the storage space of the ingredient storage unit 10.

[0075] In step S14, the reaction force determination unit 152 determines whether there is a gripping member 313 that has received a reaction force of a predetermined magnitude or more during the insertion process. If there is a gripping member 313 that has received a reaction force of a predetermined magnitude or more, it is determined as Yes in step S14, and the process proceeds to step S15. On the other hand, if there is no gripping member 313 that has received a reaction force of a predetermined magnitude or more, it is determined as No in step S14, and the process proceeds to step S16.

[0076] In step S15, the reaction force determination unit 152 issues an instruction to execute gripping to the gripping member 313 that has received a reaction force of a predetermined magnitude or more. In step S16, the articulated robot control unit 154 determines whether the gripping members 313 of all the gripping mechanisms 31 have executed gripping. If the gripping members 313 of all the gripping mechanisms 31 have executed gripping, it is determined as Yes in step S16, and the process proceeds to step S10. On the other hand, if the gripping members 313 of all the gripping mechanisms 31 have not executed gripping, it is determined as No in step S16, and the process proceeds to step S17.

[0077] In step S17, the articulated robot control unit 154 determines whether the tip of the gripping member 313 has been inserted to the reference position (the above-described first reference position or second reference position). If the tip of the gripping member 313 has been inserted to the reference position, it is determined as Yes in step S17, and the process proceeds to step S18. On the other hand, if the tip of the gripping member 313 has not been inserted to the reference position, it is determined as No in step S17, and the process is repeated from step S13.

[0078] In step S18, the articulated robot control unit 154 forcibly executes gripping on the gripping member 313 of the gripping mechanism 31 that has received only a reaction force less than a predetermined value. In step S19, the articulated robot control unit 154 raises each gripping member 313 and pulls it out from the group of ingredients.

[0079] In step S20, the gripping amount determination unit 153 performs combined weighing so as to conform to a specified amount that is the weight of the ingredient to be released. In step S21, the gripping amount determination unit 153 determines whether there is a combination of gripping members 313 that conforms to the specified amount. If there is a combination of gripping members 313 that conforms to the specified amount, it is determined as Yes in step S21, and the process proceeds to step S23. On the other hand, if there is no combination of gripping members 313 that conforms to the specified amount, it is determined as No in step S21, and the process proceeds to step S22.

[0080] In step S22, the gripping amount determination unit 153 releases the ingredients being gripped by the gripping members 313 of all the gripping mechanisms 31 into the storage space of the ingredient storage unit 10. Then, the process is repeated from step S13. That is, the gripping operation is done again from the beginning.

[0081] Moving to FIG. 13, in step S23, the articulated robot control unit 154 transfers each gripping mechanism 31 vertically above the discharge chute 40. In step S24, the multi-joint robot control unit 154 causes the gripping member 313 corresponding to the combination conforming to the specified amount to release the material to the discharge chute 40, and does not cause the other gripping members 313 to release the material to the discharge chute 40. Then, the released material discharged into the discharge chute 40 is filled into the container in an amount conforming to the specified amount via the discharge chute 40.

[0082] In step S25, the multi-joint robot control unit 154 transfers each gripping mechanism 31 vertically above the material storage unit 10 according to the data of the operation pattern. In step S26, the multi-joint robot control unit 154 causes the other gripping members 313 that do not correspond to the combination conforming to the specified amount to release the gripped material into the storage space of the material storage unit 10.

[0083] In step S26, the recording control unit 156 stores the control-related parameters obtained in the material filling process and the measurement data (history data) of the weight of the filled material in the history DB172.

[0084] In step S27, the multi-joint robot control unit 154 determines whether the condition for ending the material filling process is met. In this case, as the condition for ending the material filling process, it can be defined that the material has been filled into the planned number of containers, or an operation to end the material filling process has been performed by the operator, etc. If the condition for ending the material filling process is not met, it is determined as No in step S27, and the process moves to FIG. 12, and the process is performed again from step S12. On the other hand, if the condition for ending the material filling process is met, it is determined as Yes in step S27, and the material filling process ends.

[0085] As described above, when the gripping system 1 according to the present embodiment receives a reaction force from the ingredients during the process of inserting the gripping member 313 into the group of ingredients, it can execute gripping. That is, after the gripping member 313 is inserted into the group of ingredients and a state where reliable gripping can be achieved, gripping can be executed. That is, according to the gripping system 1, the timing at which the plurality of gripping members execute gripping can be controlled more appropriately.

[0086] [Modification Example 1] In the above-described embodiment, as described above with reference to FIG. 5, the first gripping portion 313a and the second gripping portion 313b were in a closed loop shape formed by a line like a wire when viewed from the side. And the gripping member 313 was realized by the loop-shaped first gripping portion 313a and second gripping portion 313b. Not limited to this, the gripping member 313 may be realized by the first gripping portion 313a and the second gripping portion 313b having various shapes.

[0087] FIG. 14 is a diagram showing an example of a modified shape of the first gripping portion 313a and the second gripping portion 313b. For example, as shown in FIG. 14(a), the first gripping portion 313a and the second gripping portion 313b may each be in a plate-like shape instead of a closed loop shape formed by a line like a wire. And they may be arranged such that their respective surfaces face each other, and by opening and closing the first gripping portion 313a in the same manner as in the above-described embodiment, gripping and releasing may be performed as the gripping member 313.

[0088] Also, for example, as shown in FIG. 14(b), they may each be in a finger-shaped (rod-shaped) shape. And by opening and closing the first gripping portion 313a in the same manner as in the above-described embodiment, gripping and releasing may be performed as the gripping member 313. Also, for example, as shown in FIG. 14(c), the first gripping portion 313a and the second gripping portion 313b may be formed in a linear shape like a wire and in a closed loop shape, or may be formed in a shape that bends in the center when viewed from the front. Further, for example, by combining these, they may be in a plate shape or a finger shape (rod shape) and in a shape that bends in the center when viewed from the front. Additionally, for example, they may be in the shape of cooking tongs.

[0089] Also, the number of gripping portions is not limited to two. For example, three or more gripping portions may be arranged at substantially equal intervals on the same circumference, and these three or more gripping portions may be in a shape that opens and closes in the central direction of the circle. By providing a plurality of pin cylinders 314 according to the number of gripping portions, the gripping member 313 having such three or more gripping portions can realize the same operation as the above-described embodiment. In this way, the gripping member 313 of the above-described embodiment can be arbitrarily deformed according to the shape and characteristics of the object to be gripped.

[0090] [Modification Example 2] In the above-described embodiment, the reaction force determination unit 152 issues an instruction to execute gripping to the corresponding gripping member 313 when the gripping member 313 of any one of the gripping mechanisms 31 receives a reaction force of a predetermined magnitude or more. This can be modified such that the reaction force of a predetermined magnitude or more varies for each gripping mechanism 31. That is, for a certain gripping mechanism 31, gripping may be executed when receiving a reaction force of a first magnitude, and for another gripping mechanism 31, gripping may be executed when receiving a reaction force of a second magnitude greater than the first magnitude. Further, the predetermined magnitude may be varied in detail, such as a third magnitude.

[0091] By doing so, variations will occur in the weight of the ingredients held by the holding members 313 of each holding mechanism 31. For example, variations will occur in the weight of the ingredients, such as a holding member 313 that holds 35 grams, a holding member 313 that holds only 10 grams, or a holding member 313 that holds only 5 grams. However, in combined weighing, there is also an aspect that the options for combinations expand due to variations in the weight of the ingredients. For example, assume a case where all the holding members 313 hold approximately 30 grams. In this assumption, when the specified quantity is 50 grams, no combination that meets the specified quantity exists when performing combined weighing.

[0092] On the other hand, as in this modified example, when variations occur in the weight of the ingredients, such as a holding member 313 that holds 35 grams, a holding member 313 that holds only 10 grams, or a holding member 313 that holds only 5 grams, when the specified quantity is 50 grams, a combination that meets the specified quantity will exist when performing combined weighing. In this way, by deliberately causing variations in the weight of the ingredients, the possibilities for combined weighing can also be expanded.

[0093] Also, there may be cases where some error in the specified quantity is tolerated. For example, when the sales mode of prepared foods is by weight and the selling price is determined in proportion to the weight, it doesn't matter if the weights of the ingredients contained in each container are different. In such cases, it is not necessarily necessary to hold with the holding members 313 of all the holding mechanisms 31. Instead, for example, only some of the holding members 313, such as some holding members 313 that have received a reaction force greater than a predetermined magnitude first, or only predetermined holding members 313, may be used for holding. That is, the holding members 313 used for holding may be thinned out. As a result, some error from the specified quantity will occur, but it becomes possible to improve the working speed.

[0094] [Modified Example 3] The functions of the reaction force determination unit 152 in the above-described embodiment may be independently realized by each of the control units 311 of the respective gripping mechanisms 31. In this case, the control unit 311 determines whether or not the gripping member 313 is receiving a reaction force from the workpiece based on the current weight data of the gripping mechanism 31 measured by the load cell 315. Then, when the gripping member 313 is receiving a reaction force of a predetermined magnitude or more, the control unit 311 causes the gripping member 313 to execute gripping. Thereby, the processing load on the control device 60 can be reduced, and by completing the control inside each gripping mechanism 31, it becomes possible to execute gripping more quickly.

[0095] [Configuration Example] As described above, the gripping system 1 in the present embodiment includes a plurality of gripping members 313, a robot arm 32, a load cell 315, and a control unit 311. The plurality of gripping members 313 each independently grip a workpiece. The robot arm 32 transfers the plurality of gripping members 313 and simultaneously inserts them into a group of workpieces. The load cell 315 detects that at least one of the plurality of gripping members 313 has received a reaction force from the workpiece during the insertion process. The control unit 311 causes the corresponding gripping member 313 to execute gripping in response to the load cell 315 detecting a reaction force. Thereby, during the process of inserting the gripping member 313 into the group of workpieces, when a reaction force is received from the workpiece, gripping can be executed. That is, gripping can be executed after the gripping member 313 has been inserted into the group of workpieces and is in a state where gripping can be reliably performed. Therefore, in general techniques, there has been a problem that gripping is performed on a gripping member that has not yet been inserted into the group of foods, and the workpiece cannot be gripped, but such a problem does not occur with the gripping system 1. Therefore, the plurality of arranged gripping members can be appropriately utilized. That is, according to the gripping system 1, the timing at which the plurality of gripping members execute gripping can be more appropriately controlled.

[0096] The load cell 315 detects, for each of the plurality of gripping members 313 (i.e., the plurality of gripping members), that a reaction force has been received from the workpiece. The load cell 315 detects, for each of the plurality of gripping members 313, the weight of the workpiece being gripped by the gripping member 313. Based on the weight detected by the load cell 315, the control unit 311 performs combined weighing of the weights being gripped by the gripping members 313, and based on the weighing result, determines the gripping member 313 that releases the workpiece to the release destination. Thereby, the execution timing of gripping is appropriately controlled for each of the plurality of gripping members, and combined weighing is performed thereon, so that the amount of the workpiece to be released can be accurately set to a specified amount.

[0097] When the weight detected by the load cell 315 is heavier than the reference weight, assuming the weight when the gripping member 313 is not gripping the workpiece as the reference weight, the control unit 311 determines that the gripping member 313 is gripping the workpiece, and when the weight detected by the load cell 315 is lighter than the reference weight, determines that the gripping member 313 is receiving a reaction force from the workpiece. Thereby, using one load cell 315, it is possible to determine whether the gripping member is in a state of gripping the workpiece, in a state of receiving a reaction force from the workpiece, or in neither state.

[0098] The gripping system 1 grips, as the workpiece, one in which at least any one of the properties, shape, and density at which each is arranged is not uniform. Thereby, in a situation where the workpiece is such that the timing at which each of the plurality of gripping members should execute gripping is different, it is possible to control the timing at which gripping is executed.

[0099] The robot arm 32 supports the plurality of gripping members 313 such that the relative positional relationship with the tip of each of the plurality of gripping members 313 is variable in the inserting direction. As a result, even if the tips of some of the gripping members come into contact with the bottom surface of the container that houses the ingredients, etc., the gripping members can be further inserted into the group of ingredients by shrinking in the direction in which they are inserted.

[0100] When the control unit 311 inserts the gripping member 313 until the robot arm 32 reaches a predetermined depth from the surface of the group of ingredients, or when the control unit 311 inserts the gripping member 313 until it reaches a predetermined height from the bottom surface of the container that houses the group of ingredients, the control unit 311 causes the gripping member 313 that has not yet executed gripping to execute gripping in at least one of these cases. This can prevent the gripping member from being inserted deeper than necessary.

[0101] After all of the plurality of gripping members 313 have executed gripping, the robot arm 32 transfers the ingredients held by the plurality of gripping members 313 to a release destination where they are released. As a result, since gripping is executed on all of the gripping members, the plurality of gripping members can be effectively utilized.

[0102] In response to the physical quantity of the reaction force detected by the load cell 315 becoming equal to or greater than a reference value, the control unit 311 causes the corresponding gripping member 313 to execute gripping and makes the reference values different for the plurality of gripping members 313. As a result, the weights of the ingredients to be gripped can be intentionally varied, increasing the possibility that an appropriate combination exists in the combined weighing.

[0103] Note that the above-described embodiments and modified examples are examples of embodiments of the present invention, and various embodiments that implement the functions of the present invention are included in the scope of the present invention. For example, in the above-described embodiments and variations, the case where the present invention is applied to a gripping system for plating side dishes was described as an example. However, the present invention can be applied to systems for gripping various objects. For example, the present invention can be applied to a system for gripping materials with high viscosity or adhesiveness, such as kneaded mortar, concrete, plaster, clay, etc. The present invention is suitable for gripping an object having a viscosity of medium viscosity or higher (5000 mPa·s) or higher at the working temperature or room temperature. In addition, it is possible to implement the present invention by appropriately combining the examples described in the above-described embodiments. The above-described series of processes can be executed by hardware or by software. In other words, the functional configuration of FIG. 8 is merely illustrative and is not particularly limited. That is, it is sufficient that the gripping system 1 is provided with a function capable of executing the above-described series of processes as a whole, and the functional blocks used to realize this function are not particularly limited to the example of FIG. 8. Also, one functional block may be configured by hardware alone, by software alone, or by a combination thereof.

[0104] When the series of processes are executed by software, the program constituting the software is installed in a computer or the like from a network or a recording medium. The computer may be a computer incorporated in dedicated hardware. Also, the computer may be a computer capable of executing various functions by installing various programs, for example, a general-purpose personal computer.

[0105] The storage medium for storing the program is composed of a removable medium distributed separately from the device body, or a storage medium pre-installed in the device body, etc. The removable medium is composed of, for example, a magnetic disk, an optical disk, a magneto-optical disk, or a flash memory, etc. The optical disk is composed of, for example, a CD-ROM (Compact Disk-Read Only Memory), a DVD (Digital Versatile Disk), a Blu-ray Disc (registered trademark), etc. The magneto-optical disk is composed of an MD (Mini-Disk), etc. The flash memory is composed of, for example, a USB (Universal Serial Bus) memory or an SD card. Also, the storage medium pre-installed in the device body is composed of, for example, a ROM or a hard disk in which the program is stored, etc.

[0106] Note that in this specification, the steps of describing the program recorded on the recording medium include not only the processes performed in chronological order according to that order, but also the processes that are not necessarily processed in chronological order and are executed in parallel or individually. Also, in this specification, the term "system" shall mean the entire device composed of a plurality of devices, a plurality of means, etc.

[0107] The above embodiments show an example to which the present invention is applied, and do not limit the technical scope of the present invention. That is, the present invention can be variously modified such as omission and substitution without departing from the gist of the present invention, and various embodiments other than the above embodiments can be adopted. The various embodiments and their modifications that the present invention can adopt are included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0108] 1 Gripping system, 2 Belt conveyor, 10 Material storage section, 20 Container supply section, 21 Container detection sensor, 30 Multi-joint robot, 31 Gripping mechanism, 311 Control section, 312 Transmission section, 313 Gripping member, 313a First gripping portion, 313b Second gripping portion, 314 Pin cylinder, 315 Load cell, 32 Robot arm, 321 Connecting section, 40 Discharge chute, 50 Shielding section, 60 Control device, 151 Sensor information acquisition section, 152 Reaction force determination section, 153 Gripping amount determination section, 154 Multi-joint robot control section, 155 Container supply control section, 156 Recording control section, 171 Parameter storage section, 172 History database (History DB), 711 CPU, 712 ROM, 713 RAM, 714 Bus, 715 Input section, 716 Output section, 717 Storage section, 718 Communication section, 719 Drive, 731 Removable media

Claims

1. A plurality of gripping members each independently gripping an object, transfer means for transferring the plurality of gripping members and simultaneously inserting them into a group of the objects, reaction force detection means for detecting, for at least any one of the plurality of gripping members, that a reaction force has been received from the object during the insertion process, control means for causing the corresponding gripping member to execute gripping in response to the reaction force detection means detecting a reaction force, A gripping system characterized by comprising.

2. The reaction force detection means detects, for each of the plurality of gripping members, that a reaction force has been received from the object, The reaction force detection means further comprises weight detection means for detecting, for each of the plurality of gripping members, the weight of the object being gripped by the gripping member, The control means performs a combined weighing of the weights being gripped by the gripping members based on the weight detected by the weight detection means, and determines, based on the weighing result, the gripping member that releases the object to the release destination, The gripping system according to claim 1, characterized in that.

3. The weight detection means also functions as the reaction force detection means, When the control means uses the weight when the gripping member is not gripping the object and not receiving a reaction force from the object as a reference weight, if the weight detected by the weight detection means is greater than the reference weight, it is determined that the gripping member is gripping the object, and if the weight detected by the weight detection means is less than the reference weight, it is determined that the gripping member is receiving a reaction force from the object, The gripping system according to claim 2, characterized in that.

4. The gripping system grips, as the object, one in which at least any one of the properties, shape, and density at which each is arranged is not uniform, The gripping system according to any one of claims 1 to 3, characterized in that.

5. The transfer means supports the plurality of gripping members such that the relative positional relationship with the tip of each of the plurality of gripping members is variable in the insertion direction, The gripping system according to any one of claims 1 to 3, characterized in that.

6. When the transfer means inserts the gripping member until it reaches a predetermined depth from the surface of the group of objects, or when the transfer means inserts the gripping member until it reaches a predetermined height from the bottom surface of the container that houses the group of objects, the control means causes the gripping member that has not yet executed gripping to execute gripping in at least one of these cases. The gripping system according to any one of claims 1 to 3, characterized in that.

7. After all of the plurality of gripping members have executed gripping, the transfer means transfers the objects held by the plurality of gripping members to a release destination for releasing them. The gripping system according to any one of claims 1 to 3, characterized in that.

8. In response to the physical quantity of the reaction force detected by the reaction force detection means becoming equal to or greater than a reference, the control means causes the corresponding gripping member to execute gripping and varies the reference among the plurality of gripping members. The gripping system according to claim 1, characterized in that.

9. A gripping method performed by a gripping system including a plurality of gripping members each independently gripping an object, comprising: a transfer step of transferring the plurality of gripping members and simultaneously inserting them into the group of objects; a reaction force detection step of detecting, for at least one of the plurality of gripping members, that a reaction force has been received from the object during the insertion process; a control step of causing the corresponding gripping member to execute gripping in response to detecting a reaction force in the reaction force detection step; A gripping method, characterized by comprising the above steps.

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