JP2017202528A - Picking method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a picking method for suppressing the damage of a component at the time when the component is extracted from a portion, in which a plurality of parts gather.SOLUTION: In a picking method to be disclosed in the present application, the upper face of a low-repulsive material, on which a plurality of parts are borne, is pressed to move any one of a plurality of parts to a recess formed in the low-repulsive material bearing the parts, and the moved predetermined part is grasped.SELECTED DRAWING: Figure 5

Description

  The present application relates to a picking method.

  Various parts are handled in an industrial product production line (see, for example, Patent Document 1-2).

JP 2012-183616 A JP 2012-192478 A

  When a specific part is taken out from a place where a plurality of parts are collected by an automatic machine such as a robot hand, there is a possibility that another part may come into contact with the automatic machine. When an automatic machine contacts a part, the part may be damaged.

  Therefore, the present application discloses a picking method that suppresses damage to a component when the component is taken out from a location where a plurality of components are gathered.

  The present application discloses the following picking method. That is, in the picking method disclosed in the present application, the upper surface of the low-repulsion material on which a plurality of parts are placed is pressed, and any one of the plurality of parts is placed in the recess formed in the low-repulsion material by the pressing. Move and grab the moved part.

  With the picking method described above, it is possible to suppress damage to the component when the component is taken out from a location where a plurality of components are gathered.

FIG. 1 is a diagram illustrating an example of a picking apparatus. FIG. 2 is a diagram illustrating a flowchart of operations realized by the picking apparatus. FIG. 3 is a first diagram illustrating the contents of the arithmetic processing executed by the control device. FIG. 4 is a second diagram illustrating the contents of the arithmetic processing executed by the control device. FIG. 5 is a diagram illustrating an example of the movement of a component realized by the operation of the robot. FIG. 6 is a diagram showing the movement of the finger when the robot grabs the part. FIG. 7 is a diagram illustrating an example of a positional relationship between a finger and a component when the components are placed close to each other.

Hereinafter, embodiments will be described. The embodiment described below is merely an example, and the technical scope of the present disclosure is not limited to the following aspect.

  FIG. 1 is a diagram illustrating an example of a picking apparatus. The picking device 100 includes a table 10 on which the component 20 is placed, a robot 1 that holds the component 20, a camera 6 that obtains an image of the table 10, and a control device 7 that controls the robot 1 based on information from the camera 6. . Examples of the parts 20 handled by the picking apparatus 100 include screws, connectors, and other various parts.

  The base 10 on which the component 20 is placed is formed of a mat of a low repulsion material. As the low-repulsion material forming the base 10, urethane foam having both elasticity and viscosity (sometimes called "low-repulsion elastic urethane foam"), gel-like material, and any other low-repulsive material can be applied. It is. The low repulsion material suitable for the table 10 depends on the operation speed of the robot 1 and the shape and size of the component 20, but for example, a material having a rebound elastic modulus of 10% or less (JIS K 6400-3) is suitable. It is. In addition, the stand 20 is not limited to what is formed with the low repulsion material which exhibits a mat-like form. The base 20 only needs to have a flat upper surface, and may be formed of, for example, a low resilience material having a block shape.

  The robot 1 is a so-called articulated robot, and includes a robot arm 2 and a robot hand 3 provided at the tip of the robot arm 2. The robot arm 2 is a so-called articulated robot arm and includes a plurality of links and joints. The robot hand 3 is provided at the tip of the robot arm 2. The robot hand 3 has two fingers 4 and 4. The two fingers 4 and 4 can be moved by an actuator 5 that opens and closes between the fingers 4 and 4.

  The camera 6 is an imaging device that acquires an image of the table 10 that can be analyzed by the control device 7, and provides the control device 7 with an image of the table 10 viewed from above. In FIG. 1, two cameras 6 and 6 are illustrated, and an image of the table 10 captured from two different viewpoints is provided to the control device 7. Therefore, the control device 7 can capture the component 20 placed on the table 10 in three dimensions. However, the control device 7 is not limited to the form connected to the two cameras 6 and 6, and may be connected to one camera 6.

The control device 7 reads and executes a computer program stored in a memory or the like by a CPU (Central Processing Unit) so that the control unit 7A controls the analysis amount of the image provided from the camera 6 and the control amount of the robot 1. Various functional units such as a calculation unit 7B that performs various calculations such as calculation are realized.

  Hereinafter, an example of a picking method realized by the picking apparatus 100 will be described. FIG. 2 is a diagram illustrating a flowchart of operations realized by the picking apparatus 100. FIG. 3 is a first diagram illustrating the contents of the arithmetic processing executed by the control device 7. FIG. 4 is a second diagram illustrating the contents of the arithmetic processing executed by the control device 7. For example, when the assembly operation of the component 20 to the electronic device is performed by the robot 1 in the assembly line of the electronic device, the picking device 100 realizes the following operation.

That is, the control device 7 captures the table 10 with the camera 6 and acquires an image as shown in FIG. 3A as an example (S101). Next, the control device 7 analyzes the image captured by the camera 6 to recognize the component 20, and extracts the position and outer shape of the component 20 as shown as an example in FIG. 3B (S102). The recognition of the component 20 can be performed using various general-purpose image analysis techniques for identifying an object shown in an image. Next, the control device 7 sets the proximity region R1 around the image of each component 20 (S103). FIG. 3C shows an example of the proximity region R1. For example, as shown in FIG. 3C, the proximity region R <b> 1 is a region where the finger 4 enters when each component 20 is gripped by the robot hand 3. This is a range in which the thicknesses of the fingers 4 are added. The control device 7 sets the proximity region R1 based on information on the dimension of the finger 4 that is set in advance.

  After executing the process of step S103, the control device 7 extracts the edge of the outer shape of the proximity region R1, and when the fingers 4 and 4 are closed, the fingertip shape formed by the tips of the fingers 4 and 4 is the fingertip shape. A candidate for a hand pressure region (corresponding to an example of a “pressed part” in the present application) that is adjacent to each side in a state where the longitudinal direction of each side is parallel to each side is extracted (S104). FIG. 4A shows an example of the hand pressurizing region R2. As shown in FIG. 4A, the hand pressurizing region R2 is formed so that the fingertip shape formed by the tips of the fingers 4 and 4 when the fingers 4 and 4 are closed corresponds to the longitudinal direction of the fingertip shape and the proximity region R1. This is an area that is adjacent to each side in a state in which each side of the outer shape is parallel.

  After executing the process of step S104, the control device 7 narrows down the selectable hand pressurizing region R2 (S105). FIG. 4B is an image of processing related to narrowing of the hand pressurizing region R2. That is, in this step S104, as shown in FIG. 4B, the control device 7 does not overlap with the proximity region R1 of the other component 20 from among the extracted candidates for the hand pressure region R2. Extract things. Then, as shown in FIG. 4 (B), the control device 7 assumes that the part 20 to which each of the extracted one or more hand pressurizing regions R2 is targeted has moved to the center of the hand pressurizing region R2. In this case, the setting of the virtual proximity region R3, which is the proximity region, is performed in the same manner as the setting of the proximity region R1 in step S103. Then, as shown in FIG. 4B, the control device 7 excludes the hand pressurizing region R2 in which the virtual proximity region R3 overlaps with the other components 20 from the candidates.

  After executing the process of step S105, the control device 7 selects the hand pressurizing region R2 that is closest to the current coordinates of the robot hand 3 from the remaining hand pressurizing region R2 candidates (S106). When the control device 7 determines a region to be pressurized by the robot hand 3 by executing a series of processing from step S101 to step S106, the control device 7 operates the robot 1 as follows.

  FIG. 5 is a diagram illustrating an example of the movement of the component 20 realized by the operation of the robot 1. After executing the process of step S106, the control device 7 moves the robot 1 so that the robot hand 3 moves toward the hand pressurizing region R2 determined in step S106. Then, as shown in FIG. 5A, the control device 7 moves the robot 1 so that the robot hand 3 is lowered toward the table 10, and sets the hand pressurizing region R <b> 2 determined in step S <b> 106 to the robot hand 3. Pressure is applied at the tips of the fingers 4 and 4 (S107). When the hand pressurizing region R2 is pressed and depressed by the fingers 4 and 4, the part 20 targeted by the hand pressurizing region R2 is inclined toward the fingers 4 and 4 as shown in FIG. And start moving. The control device 7 captures an image of the table 10 with the camera 6 (S108). The control device 7 determines whether or not the component 20 has started moving toward the fingers 4 and 4 from the image of the camera 6 (S109). When the control device 7 makes an affirmative determination in step S109, the control device 7 moves the robot 1 so that the fingers 4 and 4 are separated from the table 10 (S110). When the fingers 4 and 4 are separated from the base 10, as shown in FIG. 5C, the component 20 moves to the recess 11 formed in the base 10 by the pressure of the fingers 4 and 4.

Note that the depth of pressure applied by the fingers 4 and 4 is, for example, not less than the distance from the center of gravity of the component 20 to the fingers 4 and 4. Depending on the friction coefficient of the surface of the material used for the base 10 and the shape of the part 20, if the pressure applied by the fingers 4, 4 is greater than the distance from the center of gravity of the part 20 to the fingers 4, 4 There is a high possibility that the component 20 is sufficiently inclined and moves toward the fingers 4 and 4. In addition to the depth calculated based on the positional relationship between the component 20 and the fingers 4, 4, the depth to which the fingers 4, 4 are pressed is captured by the image of the camera 6. It may be the depth of the event. For example, when the control device 7 makes a negative determination in step S109, if the robot is moved so that the pressurization amount increases (S111), the pressurization amount gradually increases until the component 20 starts to move. Become.

  After executing the process of step S110, the control device 7 opens the fingers 4 and 4 to lower the robot hand 3 again and grasps the moved component 20 with the robot 1, as shown in FIG. The timing at which the control device 7 executes this step S110 is the timing at which the shape of the base 10 formed with the recess 11 returns to its original shape, and is appropriately determined according to the rebound resilience of the low resilience material used for the base 10 or the like. It depends on the elapsed time from step S110 to be set. The component 20 gripped by the robot 1 is assembled to an electronic device flowing through a production line in which the picking device 100 is installed. The control device 7 repeatedly executes a series of processes from step S101 to step S110 according to the flow of products flowing through the production line in which the picking device 100 is installed.

  FIG. 6 is a diagram illustrating the movement of the fingers 4 and 4 when the robot 1 grips the component 20. FIG. 7 is a diagram showing an example of the positional relationship between the fingers 4 and 4 and the component 20 when the components 20 are placed close to each other on the table 10. When the parts 20 stacked on the table 10 are sufficiently separated from each other, as shown in FIG. 6, when the fingers 4, 4 open and close to grip the part 20, the fingers 4, 4 are in contact with the other parts 20. The possibility of contact with is extremely low. On the other hand, when the parts 20 are placed close to each other on the table 10, if the part 20 is gripped by the robot 1 without performing the series of processing from step S101 to step S111 described above, it is shown in FIG. As shown, the finger 4 contacts the other component 20. If the finger 4 mistakenly contacts the component 20 that is not the object to be gripped, the component 20 may be damaged. In this regard, in the picking device 100 according to the above-described embodiment, even when the plurality of components 20 are stacked on the table 10, the robot hand 3 is used when the specific component 20 is taken out from the table 10 by the robot hand 3. The possibility of erroneous contact with the component 20 that is not the object to be gripped can be reduced. Thereby, damage of the component 20 in picking operation | movement is suppressed.

  In the above embodiment, the hand pressurizing region R2 is selected in detail. For example, the picking device 100 is configured such that, for example, the base 10 on which a plurality of components 20 are stacked, and the fingers 4 and 4 are the components 20 are used. Each component 20 may be picked after the stacked components 20 are appropriately scattered on the table 10 by appropriately pressurizing them so that they do not come into contact with each other.

  Although the details of the parts 20 are not described in the above embodiment, a plurality of the same kinds of parts 20 may be stacked on the base 10 of the picking apparatus 100, or a plurality of kinds of parts 20 may be stacked together. It may be. In addition, the component 20 is not limited to a rectangular shape as viewed from the top of the table 10, and may be, for example, a circular shape, a triangular shape, a pentagonal shape or more, and other various external shapes. May be.

  Moreover, although the robot 1 of the said embodiment had two fingers 4 and 4, a robot with three or more fingers may be sufficient, and it replaces with the two fingers 4 and 4, and other than a finger. It may have a gripping mechanism.

  In the above embodiment, the hand pressurizing region R2 closest to the current coordinates of the robot hand 3 is selected in step S106, but other appropriate hand pressurizing region R2 may be selected.

1. Robot: 2. Robot arm: 3. Robot hand: 4. Finger: 5. Actuator: 6. Camera: 7. Control device: 7A ... Recognition unit: 7B ... Calculation unit: 10. · Stage: 11 ·· Recess: 20 ·· Part: 100 ·· Picking device: R1 ·· Proximity region: R2 ·· Hand pressurization region: R3 ·· Virtual proximity region

Claims (5)

Pressing the upper surface of the low repulsion material on which a plurality of parts are placed, and moving one predetermined part of the plurality of parts to the recess formed in the low repulsion material by the pressing,
Grabbing the predetermined part that has moved,
Picking method. When the predetermined part is moved, the predetermined part is moved by pressing a side portion of the predetermined part.
The picking method according to claim 1. When the predetermined part is moved, a candidate for a pressed part when moving by the pressing is extracted for each of the plurality of parts, and then the pressed part is separated from at least another part among the extracted candidates for the pressed part Pressing the part to move the predetermined part,
The picking method according to claim 1 or 2. The predetermined part is a part that looks rectangular when viewed from above the low resilience material,
When the predetermined part is moved, the upper surface of the low repulsion member is pressed so that the concave part is formed in parallel with the side of the predetermined part when viewed from above the low repulsion material. Move,
The picking method according to any one of claims 1 to 3. When moving the predetermined part, the robot hand moves the predetermined part by pressing the upper surface of the low resilience member,
When grasping the predetermined part, the robot hand grasps the predetermined part,
The picking method according to any one of claims 1 to 4.

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