JP7619079B2 - Robot hand and item pick-up system - Google Patents

Description

This disclosure relates to a robot hand and an item pick-up system.

Conventionally, an item picking system using an industrial robot is known in which a large number of items randomly stacked on an item placement section (e.g., inside an item storage box) are recognized by an imaging section (e.g., a camera device), and the robot hand is used to grasp and transport each item, and then place it in a specific posture on a specified installation target.

JP 2017-052094 A

In this type of item picking system, when an item is picked individually from a pile of bulk items, it is required that the item then be placed accurately, with the correct posture and without misalignment. However, in a pile of bulk items, the posture of each item is random, and the item being grasped may overlap or come into contact with other items, making it difficult for the robot hand to grasp it properly.

Against this background, for example, Patent Document 1 proposes an item-taking system that uses gravity to change the posture of an item that has been grasped in a robot hand. The item-taking system in Patent Document 1 describes a method of grasping a position where a moment is generated in the item and rotating the item by changing the gripping force of the robot hand.

However, the method described in Patent Document 1 involves changing the position of an item by sliding it in the robot hand, which requires delicate control of the gripping force when changing the position of the item, resulting in the problem of complex control of the robot hand and robot arm. In addition, this method also has the problem that the gripping position of the item is easily shifted, which results in variation in the placement position when placing the item.

The present disclosure has been made in consideration of the above problems, and aims to provide a robot hand and an item removal system that can change the position of an item removed from an item placement unit to a target position and hold the item with a simple configuration.

The present disclosure, which solves the above-mentioned problems, is
a pickup unit that picks up an individual article from a group of articles placed on the article placement unit and holds the article in a releasable state;
an article holding section having a storage groove directly below the pickup section, the article holding section receiving the article in the storage groove when the pickup section releases the article;
The article holding portion is
a posture changing unit that, when receiving the object in the storage groove, rolls the object in the storage groove by utilizing an external force acting on the object in a non-contact manner, and changes the object to a target posture by regulating the rolling manner of the object in the storage groove;
a gripping portion that grips the article that has been changed to the target posture in the storage groove,
This is a robot hand for an article pick-up system.

In other respects,
An article picking system having the above robot hand.

The robot hand disclosed herein has a simple configuration and is capable of changing the posture of an item removed from an item placement section to a target posture and then holding the item.

FIG. 1 is a diagram showing an overall configuration of an article pick-up system according to a first embodiment; FIG. 1 is a diagram showing a configuration of a control system of an article pickup system according to a first embodiment; FIG. 1 is a diagram showing an article to be picked up by the article pick-up system according to the first embodiment; FIG. 1 is a diagram showing a configuration of a robot hand according to a first embodiment; FIG. 1 is a diagram showing a configuration of an item holding portion (accommodation groove) of a robot hand according to a first embodiment; FIG. 1 is a diagram showing an example of a manner in which an article rolls in a storage groove formed by an article holding portion of a robot hand according to a first embodiment; 1 is a flowchart showing an example of a process performed by a control unit when operating a robot hand according to a first embodiment. FIG. 13 is a diagram showing an example of a configuration of a robot hand according to a second embodiment; FIG. 13 is a diagram showing the configuration of an item holding portion (accommodation groove) of a robot hand according to a second embodiment; FIG. 13 is a diagram showing an example of a manner in which an article rolls in a storage groove formed by an article holding portion of a robot hand according to a second embodiment; 11 is a flowchart showing an example of a process performed by a control unit when operating a robot hand according to a second embodiment. FIG. 13 is a diagram showing an example of a configuration of a robot hand according to a third embodiment; FIG. 13 is a diagram showing an example of a manner in which an article rolls in a storage groove formed by an article holding portion of a robot hand according to a third embodiment; 13 is a flowchart showing an example of a process performed by a control unit when operating a robot hand according to a third embodiment. FIG. 13 is a diagram showing an example of a configuration of a robot hand according to a fourth embodiment; FIG. 13 is a diagram showing an example of a manner in which an article rolls in a storage groove formed by an article holding portion of a robot hand according to a fourth embodiment; FIG. 13 is a diagram showing an example of a configuration of a robot hand according to a fifth embodiment; FIG. 13 is a diagram showing an example of a manner in which an article rolls in a storage groove formed by an article holding portion of a robot hand according to a fifth embodiment; 13 is a flowchart showing an example of a process performed by a control unit when operating a robot hand according to a fifth embodiment. FIG. 13 is a diagram showing an example of a configuration of a robot hand according to a sixth embodiment; FIG. 13 is a diagram showing an example of a configuration of a robot hand according to a sixth embodiment; FIG. 23 is a diagram for explaining the operation of a robot hand according to the seventh embodiment; FIG. 23 is a diagram for explaining the operation of a robot hand according to the seventh embodiment;

A preferred embodiment of the present disclosure will be described in detail below with reference to the attached drawings. In this specification and drawings, components having substantially the same functions are designated by the same reference numerals to avoid redundant description.

In addition, unless otherwise specified, in each drawing, the upward direction in the drawing represents the vertical upward direction, the downward direction in the drawing represents the vertical downward direction, and the horizontal direction in the drawing represents the horizontal direction. In the following explanations, the upward direction in the drawing will be referred to as the "upward direction", the downward direction in the drawing will be referred to as the "downward direction", and the horizontal direction in the drawing will be referred to as the "horizontal direction".

(First embodiment)
<Overall configuration of the article pick-up system>
Hereinafter, the configuration of an article pick-up system according to one embodiment of the present invention will be described with reference to FIGS.

Figure 1 is a diagram showing the overall configuration of the item pick-up system 1 according to this embodiment. Figure 2 is a diagram showing the configuration of a control system of the item pick-up system 1 according to this embodiment. Figure 3 is a diagram showing an item 10 to be picked up by the item pick-up system 1 according to this embodiment.

The item removal system 1 according to this embodiment is a system for removing items 10 (i.e., workpieces) that are piled in bulk on an item placement section 2 (e.g., a container), holding and transporting the removed items 10, and placing them in an aligned state on an installation target 20.

In the article removal system 1 according to this embodiment, the bolt member is the article 10 (hereinafter simply referred to as "article 10") to be removed from the article placement section 2. The article 10 (bolt member) has a long and slender leg 10a and a head 10b formed at one end of the leg 10a and wider than the leg 10a. The installation target 20 has, for example, a number of holes 21 through which the legs 10a of the article 10 can be inserted. After removing the article 10 from the article placement section 2, the article removal system 1 changes the position of the article 10 to a position corresponding to the hole shape of the hole 21 of the installation target 20, and then installs the article 10 in the hole 21 of the installation target 20.

In this embodiment, the target posture of the article 10 is one in which the head 10b faces upward and the legs 10a face downward, corresponding to the shape of the hole 21 of the installation target 20 (hereinafter simply referred to as the "target posture").

The item pick-up system 1 includes a robot arm 30, a robot hand 40, an imaging unit 50, and a control unit 60.

<Imaging unit>
The imaging unit 50 is, for example, a camera device that captures an image of the group of articles 10W placed on the article placement unit 2 and outputs image data obtained by the image capture to the control unit 60. Note that the imaging unit 50 performs imaging multiple times while shifting the imaging position so that, for example, the image data can be used to detect the position and orientation of the articles 10 placed on the article placement unit 2 in three-dimensional space. The imaging unit 50 may also be configured with an imaging device capable of acquiring distance data from the imaging unit 50 to the articles 10, such as a stereo camera or a radar device.

The imaging unit 50 may also be arranged to capture an image of the item 10 held by the robot hand 40. This makes it possible to detect the state of the item 10 held by the robot hand 40 (i.e., the position and orientation of the item 10 in the storage groove T, which will be described later) from the image data obtained by imaging with the imaging unit 50.

<Control Unit>
The control unit 60 is, for example, a microcomputer including a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), an input port, an output port, etc. The control unit 60 communicates with each part (the robot arm 30, the robot hand 40, and the imaging unit 50) of the article picking system 1 to control them and receive data from them.

The control unit 60, for example, acquires image data from the imaging unit 50, and detects the position and orientation in three-dimensional space of one or more items 10 from the group of items 10W placed on the item placement unit 2 based on the image data. The control unit 60 then determines, for example, the item 10 located at the top of the group of items 10W placed on the item placement unit 2 as the item to be removed, and controls the robot arm 30 and the robot hand 40 based on the position and orientation of the item 10. That is, through such control, the control unit 60 causes the robot hand 40 to hold the item 10 and place the held item 10 in the hole 21 of the placement target 20.

<Robot arm>
The robot arm 30 is, for example, a vertical articulated robot arm, and changes the position and orientation of the robot hand 40 in three dimensions.

The robot arm 30 includes, for example, a base 31 that is placed on a floor surface or the like, a number of links 32 that are connected in series to the base 31, a number of joints 33 that are provided at the connection points, and a number of joint motors 34 that drive the joints 33 (see FIG. 2).

<Robot Hand>
The robot hand 40 is provided at the tip of the robot arm 30 via a joint 33, and picks up the articles 10 one by one from the group of articles 10W placed on the article placement unit 2, and holds the articles 10. Then, the robot hand 40 changes the posture of the article 10 to a target posture (a posture in which the head 10b of the article 10 faces upward and the leg 10a of the article 10 faces downward), and then transports the article 10 to the installation target 20 and places the article 10 in the hole 21 of the installation target 20.

Figure 4 is a diagram showing the configuration of the robot hand 40 according to this embodiment. Note that Figures 4A to 4C show the state of each part in chronological order from when the robot hand 40 picks up an item 10 to when it grasps the item 10.

Figure 5 is a diagram showing the configuration of the item holding part 42 (storage groove T) of the robot hand 40 according to this embodiment. Figure 5A is a diagram showing the item holding part 42 as viewed diagonally from above, Figure 5B is a diagram showing the item holding part 42 as viewed from above, and Figure 5C is a diagram showing the item holding part 42 as viewed from the side. Note that Figure 5C shows the state in which the item 10 is gripped by the item holding part 42.

Figure 6 is a diagram showing an example of the manner in which the item 10 rolls in the storage groove T formed by the item holding unit 42 of the robot hand 40 according to this embodiment. Figures 6A to 6E show an example of the manner in which the item 10 rolls in time after it is dropped from the pickup unit 41 into the storage groove T of the item holding unit 42 until it is grasped by the item holding unit 42.

The robot hand 40 includes a pickup unit 41, an item holding unit 42, and a sensor unit 43 (see Figures 2 and 4).

The pickup unit 41 is, for example, an air-type or magnetic-type suction head, and picks up the items 10 individually from the group of items 10W placed on the item placement unit 2 (hereinafter referred to as the "picking operation") (see FIG. 4A). The pickup unit 41 then holds the items 10 in a releasable state. The suction head can generate a suction force at the head tip (i.e., the nozzle tip) to suction one side (e.g., the upper surface) of the item 10 located in a position opposite the suction head, and hold the item 10, so that the items 10 can be picked up individually without being affected by differences in the posture of the item 10. The pickup unit 41 is, for example, configured in a nozzle shape, and extends downward from the center position of the hand base 40T attached to the tip of the robot arm 30. The pickup unit 41 may be configured to be able to rise and fall.

The group of items 10W placed on the item placement section 2 is in a bulk state, with each item 10 placed in various positions. From this perspective, the robot hand 40 according to this embodiment is configured to first individually remove the items 10 placed in various positions from the item placement section 2 using the pickup section 41.

The picking operation of the pickup unit 41 is performed under the control of the control unit 60. The control unit 60 determines the approach posture of the pickup unit 41 with respect to the item 10 based on, for example, the position and posture in three-dimensional space of the item 10 to be picked up, and operates the robot arm 30 according to the approach posture. Then, when the pickup unit 41 faces the item 10, the control unit 60 causes the pickup unit 41 to hold the item 10 by generating a suction force on the pickup unit 41. Then, when the item holding unit 42 forms a storage groove T directly below the pickup unit 41, the control unit 60 causes the pickup unit 41 to release the holding state of the item 10 (see FIG. 4B).

The item holding unit 42 forms a storage groove T directly below the pickup unit 41, and receives the item 10 that drops from the pickup unit 41 in the storage groove T. The item holding unit 42 then uses an external force (here, gravity) acting on the item 10 without contact to regulate the rolling behavior of the item 10 in the storage groove T (see FIG. 6), changing the item 10 to the target posture, and then grasps the item 10 that has been changed to the target posture. Note that the item pick-up system 1 according to this embodiment is configured to regulate the rolling behavior of the item 10 in the storage groove T by using gravity acting on the item 10, but the external force for regulating the rolling behavior of the item 10 may be other external forces, such as magnetic force, centrifugal force, inertial force, or fluid pressure (see, for example, the third to sixth embodiments described later).

The item holding section 42 is composed of, for example, a pair of gripping members 42A, 42B arranged in a pair below the hand base 40T. The storage groove T is formed in the spatial area between the opposing surfaces of the gripping members 42A and 42B, which have uneven shapes, by butting them together. The left gripping member 42A and the right gripping member 42B of the pair of gripping members 42A, 42B are arranged on the left and right of the pickup section 41, respectively.

The pair of gripping members 42A, 42B are connected to a gripping member drive mechanism that adjusts the lateral distance between the left gripping member 42A and the right gripping member 42B (hereinafter referred to as the "inter-member distance"), and performs opening and closing operations under the control of the control unit 60. The gripping member drive mechanism may have any configuration, but is, for example, composed of a link mechanism driven by a motor or cylinder. In the following, the operation of bringing gripping member 42A and gripping member 42B close to each other is referred to as the "closing" operation, and the operation of moving gripping member 42A and gripping member 42B away from each other is referred to as the "opening" operation.

The general operation of the item removal system 1 is as follows (see FIG. 4), for example:

First, the item taking out system 1 performs a picking operation of an item 10 using the pickup section 41. In this stage, the item taking out system 1 holds the pair of gripping members 42A, 42B in a state where they are lifted above the lower end of the pickup section 41 (i.e., in an open state) so that the lower end of the pickup section 41 protrudes downward (see FIG. 4A).

Next, the item taking out system 1 controls the pair of gripping members 42A, 42B to operate in the "closed side" and butts the opposing surfaces of the left gripping member 42A and the right gripping member 42B together to form a storage groove T for receiving the item 10 directly below the pickup unit 41. The item taking out system 1 then causes the pickup unit 41 to release the holding state of the item 10, and causes the item holding unit 42 to receive the item 10 that falls from the pickup unit 41 in the storage groove T (see FIG. 4B). At this time, the item 10 rolls along the groove shape of the storage groove T due to an external force (here, gravity) acting on the item 10 without contact, changes to a target posture, and is positioned at a predetermined position in the storage groove T (the mating groove Tb shown in FIG. 5C) (described later with reference to FIG. 6).

Next, with the item 10 positioned in the target posture in the storage groove T by the item holding section 42, the item retrieval system 1 controls the pair of gripping members 42A, 42B to further move to the "closed side" to grip the item 10 in the storage groove T (see FIG. 4C). Note that the "gripped state" here refers to a state in which the pair of gripping members 42A, 42B clamp and fix the item 10 (the same applies below). In the item retrieval system 1 according to this embodiment, the item 10 is held in a gripped state (i.e., fixed state) in the storage groove T, thereby stabilizing the holding state of the item 10, and then it becomes possible to insert the item 10 into the hole 21 of the installation target 20.

Now, with reference to Figures 5 and 6, we will explain the detailed configuration of the item holding section 42.

When the item holding unit 42 receives the item 10 in the storage groove T, it uses an external force acting on the item 10 in a non-contact manner to roll the item 10 in the storage groove T, and has a posture changing unit 42x that changes the item 10 to a target posture by regulating the rolling manner of the item 10 in the storage groove T at that time, and a gripping unit 42y that grips the item that has been changed to the target posture in the storage groove T.

In this embodiment, the posture changing section 42x is formed in an area (here, the area of the top surface of the storage groove T) (hereinafter referred to as the "receiving area") where the item 10 dropping from the pickup section 41 of the storage groove T first lands, and includes a guide groove Ta that guides the item 10 from the receiving area to the fitting groove Tb. The gripping section 42y is formed in an area guided by the guide groove Ta in the storage groove T, and includes a fitting groove Tb that positions the item 10 whose posture has been changed to the target posture. The gripping section 42y grips the item 10 in the fitting groove Tb by pinching the item 10 positioned in the fitting groove Tb from both sides.

In other words, in this embodiment, when the opposing surfaces of the gripping members 42A and 42B are butted against each other, the guide groove Ta and the fitting groove Tb are formed in the spatial region between them to form the storage groove T. The storage groove T in this embodiment has a groove structure that uses gravity to roll the item 10 from above to below, and has a guide groove Ta in the region where the item 10 that falls from the pickup section 41 of the storage groove T first lands, and a fitting groove Tb directly below the guide groove Ta.

More specifically, the guide groove Ta has an inclined surface Taa and a posture change guide hole Tab (see Figs. 5A and 5B). Note that the guide groove Ta according to this embodiment has a structure in which, for example, in a plan view, the posture change guide hole Tab is formed vertically so as to divide the guide groove Ta into two at the center, and the inclined surfaces Taa are formed adjacent to both sides of the posture change guide hole Tab.

The inclined surface Taa is inclined with respect to the horizontal direction, and has a surface shape that restricts the movement direction of the article 10 that lands on the inclined surface Taa so that it rolls toward the posture change guide hole Tab due to the action of gravity. More specifically, the inclined surface Taa restricts the rolling manner of the article 10 so that the longitudinal direction of the article 10 is aligned with the formation direction of the posture change guide hole Tab.

The posture change induction hole Tab changes the posture of the article 10 guided from the inclined surface Taa to a target posture (here, the head 10b of the article 10 faces upward and the legs 10a face downward). The posture change induction hole Tab has a hole shape (for example, a through hole having a width larger than the width of the legs 10a and smaller than the width of the head 10b) through which only the legs 10a of the article 10 can pass and the head 10b of the article 10 cannot pass, and is configured such that the head 10b of the article 10 guided from the inclined surface Taa to the posture change induction hole Tab gets caught at the entrance of the posture change induction hole Tab and only the legs 10a fall into the posture change induction hole Tab due to the action of gravity. As a result, the article 10 is induced to change its posture to one in which the head 10b faces upward and the legs 10a face downward in the process of passing through the posture change induction hole Tab.

The article 10, whose posture has been changed to the target posture by the posture change induction hole Tab, is forced to move by, for example, opening the pair of gripping members 42A, 42B or applying vibration to the pair of gripping members 42A, 42B using the robot arm 30, so that the head 10b of the article 10, which is caught at the entrance of the posture change induction hole Tab, is released from the caught state and is further moved toward the fitting groove Tb (here, the lower side of the storage groove T).

The fitting groove Tb has a shape that fits into the article 10 that has been changed to the target posture (a posture in which the head 10b of the article 10 faces upward and the legs 10a face downward), and by fitting into the article 10, the article 10 is positioned in the target posture. Note that the fitting groove Tb in this embodiment is formed directly below the posture change guide hole Tab, and the article 10 that has been changed to the target posture by the posture change guide hole Tab falls downward in the same posture due to the action of gravity, fitting into the fitting groove Tb.

At the lower end of the fitting groove Tb, a through hole Tbb (see FIG. 5C) is formed through which the leg 10a of the article 10 can be inserted so that the leg 10a of the article 10 protrudes downward from the fitting groove Tb. In other words, when the article 10 is fitted into the fitting groove Tb, the leg 10a protrudes downward from the through hole Tbb of the fitting groove Tb, and the head 10b is held in the fitting groove Tb with the leg 10a protruding downward from the through hole Tbb of the fitting groove Tb and the head 10b abutting against the bottom and side surfaces of the fitting groove Tb.

The movement of the article 10 from the posture change induction hole Tab to the fitting groove Tb is induced, for example, by the opening and closing operation of the pair of gripping members 42A, 42B. For example, by slightly expanding the distance between the pair of gripping members 42A, 42B, the article 10 can be moved from the posture change induction hole Tab to the fitting groove Tb by the action of gravity. On the other hand, the movement of the article 10 may be promoted by applying vibration to the article holding part 42 using the robot arm 30, and the article 10 may be guided from the posture change induction hole Tab to the fitting groove Tb. These operations are performed under the control of the control unit 60.

The behavior of the item 10 that falls into the storage groove T is as shown in Figures 6A to 6E.

The item 10 released from the holding state by the pickup unit 41 first lands in the guide groove Ta. Then, the item 10 that has landed in the guide groove Ta rolls along the inclined surface Taa in the guide groove Ta due to the action of gravity (FIG. 6A). At this time, the rolling manner of the item 10 is restricted by the inclined surface Taa, and the item 10 is guided to the posture change guide hole Tab so that its longitudinal direction is aligned with the longitudinal direction of the posture change guide hole Tab (FIG. 6B). Since the head 10b of the item 10 cannot pass through the posture change guide hole Tab, the leg 10a of the item 10 falls below the posture change guide hole Tab, and the head 10b of the item 10 gets caught in the posture change guide hole Tab, and the posture of the item 10 is changed to a state in which the leg 10a faces downward and the head 10b faces upward (FIG. 6C). In this state, the distance between the pair of gripping members 42A, 42B is slightly increased, and the article 10 fits into the fitting groove Tb with the legs 10a facing down and the head 10b facing up (FIG. 6D). Then, under the control of the control unit 60, the pair of gripping members 42A, 42B are operated in the closing direction, so that the article 10 is gripped in the fitting groove Tb (FIG. 6E).

The sensor unit 43 detects that the article 10 is fitted into the fitting groove Tb (see FIG. 4C). The sensor unit 43 is, for example, a light transmission type object detection sensor in which a light emitting unit and a light receiving unit are arranged facing each other with the fitting groove Tb in between.

By providing the sensor unit 43, it is possible to detect that the item 10 released from the pickup unit 41 becomes stuck midway while moving to the fitting groove Tb in the storage groove T. In other words, this makes it possible to retry the rolling operation of the item 10 as necessary. The rolling operation of the item 10 can be retried, for example, by controlling the robot arm 30 to tilt the storage groove T of the item holding unit 42, moving the item 10 in a direction different from when it fell into the guide groove Ta, and then returning the position of the item holding unit 42 to its original position (for example, the position of the item holding unit 42 to the horizontal direction).

<Example of the item pick-up system operation>
Next, a description will be given of an example of the operation of the article pickup system 1. The article pickup system 1 according to this embodiment operates under the control of the control unit 60.

Figure 7 is a flowchart showing an example of the processing performed by the control unit 60 when operating the robot hand 40 according to this embodiment.

In step S1, the control unit 60 causes the imaging unit 50 to capture an image of the group of items 10W placed on the item placement unit 2. The control unit 60 then acquires image data from the imaging unit 50 and recognizes the state of the group of items 10W placed on the item placement unit 2 using the image data. At this time, the control unit 60 determines, for example, based on the positions of each item 10 in the group of items 10W, one item 10 that is easy to remove from the group of items 10W (for example, the item 10 located at the top of the group of items 10W) as the item to be removed, and detects the position and orientation of that item 10.

In step S2, the control unit 60 controls the robot arm 30 to bring the robot hand 40 closer to the item 10 determined to be picked up in step S1. The control unit 60 then generates a suction force in the pickup unit 41, causing the pickup unit 41 to adsorb the top surface of the item 10, and after the pickup unit 41 holds the item 10, the control unit 60 causes the robot hand 40 to retract from the item placement unit 2 (FIG. 4A).

In step S3, the control unit 60 closes the pair of gripping members 42A, 42B of the item holding unit 42 to form a storage groove T directly below the pickup unit 41. The control unit 60 adjusts the distance between the pair of gripping members 42A, 42B based on, for example, a preset size of the item 10.

In step S4, the control unit 60 causes the pickup unit 41 to release the item 10, and causes the item 10 to drop from the pickup unit 41 into the storage groove T formed by the item holding unit 42 (FIG. 4B). At this time, the item 10 lands in the area of the guide groove Ta in the storage groove T, and naturally moves from the guide groove Ta to the fitting groove Tb due to the action of gravity. In addition, in this step S4, the control unit 60 may, for example, slightly increase the distance between the pair of gripping members 42A, 42B or apply vibration to the pair of gripping members 42A, 42B after a predetermined time has elapsed after the pickup unit 41 releases the item 10, in order to promote the movement of the item 10 from the posture change guide hole Tab of the guide groove Ta to the fitting groove Tb.

In step S5, the control unit 60 determines whether the item 10 has been fitted into the fitting groove Tb and changed to the target posture based on the sensor signal from the sensor unit 43 after a predetermined time has elapsed since the pickup unit 41 released the item 10 in step S4. If the item 10 has changed to the target posture (S5: YES), the control unit 60 proceeds to step S7, and if the item 10 has not changed to the target posture (S5: NO), the control unit 60 proceeds to step S6.

In step S6, the control unit 60 causes the article 10 to retry the rolling motion. In this step S6, the control unit 60 temporarily tilts the storage groove T of the article holding unit 42 so that the article 10 moves in the opposite direction to the intended direction of movement in the guide groove Ta, and then returns the attitude of the article holding unit 42 to its original attitude (for example, the attitude of the article holding unit 42 is horizontal). This eliminates the state in which the article 10 was stuck midway before fitting into the fitting groove Tb. The control unit 60 then returns to step S5 again and determines whether the article 10 has changed to the target attitude based on the sensor signal from the sensor unit 43.

In step S7, the control unit 60 controls the pair of gripping members 42A, 42B to further narrow the distance between the members, causing the pair of gripping members 42A, 42B to grip the item 10 that is fitted into the fitting groove Tb.

In step S8, the control unit 60 moves the robot hand 40 using the robot arm 30, and transports the item 10 held by the robot hand 40 from the item placement unit 2 to above the hole 21 of the installation target 20. The control unit 60 then inserts the leg 10a of the item 10 into the hole 21 of the installation target 20, and then opens the pair of gripping members 42A, 42B to release the item 10 from its holding state in the pair of gripping members 42A, 42B. As a result, the item 10 is installed on the installation target 20 with the leg 10a accommodated in the hole 21 and the head 10b abutting the periphery of the opening of the hole 21.

In step S9, the control unit 60 refers to the image data obtained from the imaging unit 50 to determine whether removal of all the items 10 from the item placement unit 2 has been completed. If removal of all the items 10 has been completed (S9: YES), the control unit 60 ends the operation of the series of flowcharts in FIG. 7. On the other hand, if removal of all the items 10 has not been completed (S9: NO), the control unit 60 returns to step S1, determines the next item 10 to be removed from the group of items 10W placed on the item placement unit 2, and performs the same process.

In the item removal system 1 according to this embodiment, the above-described operations make it possible to individually remove the items 10 from the group of items 10W placed on the item placement section 2 and place them in an aligned state on the placement target 20.

[effect]
As described above, the robot hand 40 according to this embodiment has the following features:
a pickup unit 41 that picks up an article 10 individually from the group of articles 10W placed on the article placement unit 2 and holds the article 10 in a releasable state;
a storage groove T is formed directly below the pickup section 41, and an article holding section 42 receives the article 10 in the storage groove T when the pickup section 41 releases the article 10;
The article holding unit 42 is
a posture changing unit 42x that, when receiving the article 10 in the storage groove T, rolls the article 10 in the storage groove T by utilizing an external force acting on the article 10 in a non-contact manner, and changes the posture of the article 10 to a target posture by regulating the rolling manner of the article 10 in the storage groove T at that time;
and a gripping portion 42y that grips the article 10 that has been changed to the target posture within the storage groove T.

Therefore, with the robot hand 40 according to this embodiment, it is possible to pick up an item 10 placed in various postures with a simple configuration, change the posture to a target posture, and grasp the item. In particular, with the robot hand 40 according to this embodiment, it is possible to suppress deviations in the grasping position of the item 10, which is useful in that it is possible to reduce uncertainties in the movement of the item 10 and simplify the control of the robot hand 40. This also makes it possible to suppress variation in the placement position when placing the item 10 on the installation target 20.

Second Embodiment
Next, the configuration of an article pick-up system 1 according to a second embodiment will be described with reference to FIGS.

Figure 8 is a diagram showing an example of the configuration of a robot hand 40 according to the second embodiment. Note that Figures 8A to 8D show the state of each part in chronological order from when the robot hand 40 picks up an item 10 until it grasps the item 10.

Figure 9 is a diagram showing the configuration of the item holding portion 42 (storage groove T) of the robot hand 40 according to the second embodiment.

Figure 10 is a diagram showing an example of the manner in which an item 10 rolls in a storage groove T formed by an item holding unit 42 of a robot hand 40 according to the second embodiment. Note that Figures 10A to 10E show an example of the manner in which the item 10 rolls in time series from when the item 10 falls from the pickup unit 41 into the storage groove T of the item holding unit 42 until when the item 10 fits into the fitting groove Tb.

The item taking out system 1 according to this embodiment differs from the item taking out system 1 according to the first embodiment in that the robot arm 30 controls the inclination angle of the storage groove T with respect to the vertical direction in order to regulate and promote the movement of the item 10 that has fallen into the storage groove T. In other words, in the item taking out system 1 according to this embodiment, the external force caused by gravity acting on the item 10 as it rolls in the storage groove T is controlled in accordance with the position of the item 10, thereby regulating the movement of the item 10 within the storage groove T. Note that a description of the configuration common to the first embodiment will be omitted (the same applies to the other embodiments below).

The operation of the item pick-up system 1 according to this embodiment is, for example, as follows.

First, the item taking out system 1 first performs a picking operation of an item 10 using the pickup unit 41. In this stage, the item taking out system 1 holds the pair of gripping members 42A, 42B in a state where they are lifted above the lower end of the pickup unit 41 (i.e., in an open state) so that the lower end of the pickup unit 41 protrudes downward (see FIG. 8A).

Next, the item removal system 1 controls the pair of gripping members 42A, 42B to operate in the "closed side," and the opposing surfaces of the left gripping member 42A and the right gripping member 42B are butted together to form a storage groove T for receiving the item 10 directly below the pickup unit 41. The item removal system 1 then causes the pickup unit 41 to release the item 10 from its holding state, and causes the item 10 that falls from the pickup unit 41 to be received in the storage groove T formed by the item holding unit 42 (see FIG. 8B). In this embodiment, the state of the storage groove T when receiving the item 10 that falls from the pickup unit 41 is referred to as the "horizontal state," and the state in which the storage groove T is tilted 90 degrees vertically from this horizontal state is referred to as the "vertical state."

Next, the item removal system 1 tilts the item holding portion 42 in stages so that the storage groove T changes from a horizontal state to a vertical state in stages (FIG. 8C). As a result, the item 10 rolls along the groove shape of the storage groove T due to an external force (here, gravity) acting on the item 10 without contact, changes to the target posture, and is positioned at a predetermined position within the storage groove T (the mating groove Tb shown in FIG. 9).

Next, the item removal system 1 further operates the pair of gripping members 42A, 42B to the "closing side" to grip the item 10 positioned within the storage groove T (see FIG. 8D).

The item removal system 1 according to this embodiment employs a structure of the storage groove T that is suitable for controlling the movement of the item 10 from the guide groove Ta to the fitting groove Tb by variable control of the external force acting on the item 10.

Specifically, the storage groove T according to this embodiment has the guide groove Ta and the fitting groove Tb in the same curved rolling surface, and the groove formation direction of the guide groove Ta and the groove formation direction of the fitting groove Tb are configured to face in different directions (for example, they are perpendicular to each other) (see FIG. 9). That is, the storage groove T according to this embodiment is formed so that when the item 10 dropped from the pickup unit 41 is received in the storage groove T, the groove formation direction of the guide groove Ta faces the vertical direction (i.e., the item receiving area of the guide groove Ta becomes a horizontal plane) (see FIGS. 10A and 10B), and when the item take-out system 1 changes the inclination angle of the item holding unit 42 from the angle at which the storage groove T is formed, the groove formation direction of the fitting groove Tb faces the vertical direction. Also, the storage groove T according to this embodiment is formed so that the posture change guide hole Tab and the fitting groove Tb are connected to each other.

The rolling behavior of the item 10 in the storage groove T in the item removal system 1 according to this embodiment is as follows:

First, the item 10 lands on the guide groove Ta from the pickup unit 41 (see FIG. 10A) and rolls along the groove shape of the guide groove Ta toward the posture change guide hole Tab (see FIG. 10B). Then, as the item take-out system 1 tilts the storage groove T vertically, the item 10 moves toward the posture change guide hole Tab of the guide groove Ta and falls into the posture change guide hole Tab, changing to the target posture (a posture with the legs 10a facing down and the head 10b facing up) (see FIG. 10C and FIG. 10D). Then, as the item take-out system 1 further tilts the storage groove T vertically, the item 10 moves from the posture change guide hole Tab to the fitting groove Tb in the target posture (see FIG. 10E).

Figure 11 is a flowchart showing an example of processing performed by the control unit 60 when operating the robot hand 40 according to the second embodiment. The flowchart in Figure 11 differs from the flowchart in Figure 7 only in that processing of step S3a is added between steps S3 and S4, and processing of step S4a is added between steps S4 and S5.

That is, in this embodiment, the control unit 60 first performs a process (step S3a) of changing the article holding unit 42 to a horizontal state so that the article 10 can be received from the pickup unit 41 after having the pickup unit 41 pick up the article 10 in step S3. Then, in step S4, the control unit 60 releases the article 10 from the pickup unit 41, and then performs a process (step S4a) of gradually changing the article holding unit 42 from a horizontal state to a vertical state while the article 10 is rolling in the guide groove Ta. As a result, the article 10 that has landed in the guide groove Ta moves to the fitting groove Tb of the storage groove T, as described with reference to Figures 8 and 10.

As described above, the item removal system 1 according to this embodiment is configured to regulate and promote the movement of the item 10 within the storage groove T by controlling the inclination angle of the storage groove T. This makes it possible to efficiently regulate the rolling behavior of the item 10 within the storage groove T and smoothly control the posture of the item 10.

Third Embodiment
Next, the configuration of an article pick-up system 1 according to a third embodiment will be described with reference to FIGS.

Figure 12 is a diagram showing an example of the configuration of a robot hand 40 according to the third embodiment. Figures 12A to 12D show the operation of the robot hand 40 according to the third embodiment in chronological order.

Figure 13 is a diagram showing an example of the manner in which an item 10 rolls in a storage groove T formed by an item holding unit 42 of a robot hand 40 according to the third embodiment. Figures 13A to 13E show an example of the manner in which the item 10 rolls in time after it is dropped from the pickup unit 41 into the storage groove T of the item holding unit 42 until it is fitted into the fitting groove Tb.

The item taking out system 1 according to this embodiment differs from the item taking out system 1 according to the second embodiment in that it utilizes centrifugal force acting on the item 10 to regulate and promote the movement of the item 10 that has fallen into the storage groove T. In other words, in the item taking out system 1 according to this embodiment, the external force acting on the item 10 that has fallen into the storage groove T is controlled by centrifugal force. Note that in the item taking out system 1 according to this embodiment, the configuration of the item holding unit 42 (i.e., the shape of the storage groove T) is the same as that of the item holding unit 42 according to the second embodiment. Note that the centrifugal force acting on the item 10 can be controlled by the robot arm 30 rotating the robot hand 40.

The operation of the item pick-up system 1 according to this embodiment is, for example, as follows.

First, the item taking out system 1 first performs a picking operation of an item 10 using the pickup unit 41. In this stage, the item taking out system 1 holds the pair of gripping members 42A, 42B in a state where they are lifted above the lower end of the pickup unit 41 (i.e., in an open state) so that the lower end of the pickup unit 41 protrudes downward (see FIG. 12A).

Next, the item removal system 1 controls the pair of gripping members 42A, 42B to operate in the "closed side," and the opposing surfaces of the left gripping member 42A and the right gripping member 42B are butted together to form a storage groove T for receiving the item 10 directly below the pickup unit 41. The item removal system 1 then causes the pickup unit 41 to release the item 10 from its holding state, and causes the item 10 that falls from the pickup unit 41 to be received in the storage groove T formed by the item holding unit 42 (see FIG. 12B). In this embodiment, the state of the storage groove T when it receives the item 10 that falls from the pickup unit 41 is referred to as the "horizontal state."

Next, while the storage groove T is facing horizontally, the item removal system 1 rotates the item holder 42 in a horizontal plane using the robot arm 30 (FIG. 12C). As a result, the item 10 rolls along the groove shape of the storage groove T due to an external force (here, centrifugal force) acting on the item 10 without contact, changes to the target posture, and is positioned at a predetermined position in the storage groove T (the mating groove Tb shown in FIG. 9) (see FIG. 12D).

Next, the item removal system 1 further operates the pair of gripping members 42A, 42B to the "closing side" to grip the item 10 positioned within the storage groove T (not shown).

The rolling behavior of the item 10 in the storage groove T in the item removal system 1 according to this embodiment is as follows:

In the item pick-up system 1 according to this embodiment, the item 10 first lands on the guide groove Ta from the pickup unit 41 (see FIG. 13A), and rolls along the groove shape of the guide groove Ta toward the position change guide hole Tab (see FIG. 13B). Then, the item 10 falls into the position change guide hole Tab of the guide groove Ta by the action of gravity, taking advantage of the effect of promoting movement due to centrifugal force (see FIG. 13C). Then, the item 10 that has fallen into the position change guide hole Tab changes to the target position (a position in which the legs 10a face down and the head 10b faces up) (see FIG. 13D), and moves in that position to the fitting groove Tb due to the influence of centrifugal force (see FIG. 13E).

Figure 14 is a flowchart showing an example of processing performed by the control unit 60 when operating the robot hand 40 according to the third embodiment. The flowchart in Figure 14 differs from the flowchart in Figure 11 only in that processing in step S4b is added between steps S4 and S5 instead of processing in step S4a.

In other words, the control unit 60 according to this embodiment is configured to perform a process (step S4b) of applying centrifugal force to the item holding unit 42 after releasing the item 10 from the pickup unit 41 in step S4. As a result, as described with reference to Figures 12 and 13, the item 10 that has landed in the guide groove Ta moves to the fitting groove Tb of the storage groove T.

As described above, the item removal system 1 according to this embodiment is configured to regulate and promote the movement of the item 10 in the storage groove T by controlling the centrifugal force acting on the item holding portion 42. This makes it possible to efficiently regulate the rolling behavior of the item 10 in the storage groove T and smoothly control the posture of the item 10.

(Fourth embodiment)
Next, the configuration of an article pick-up system 1 according to a fourth embodiment will be described with reference to FIGS.

Figure 15 is a diagram showing an example of the configuration of a robot hand 40 according to the fourth embodiment.

Figure 16 is a diagram showing an example of the manner in which an item 10 rolls in a storage groove T formed by an item holding unit 42 of a robot hand 40 according to the fourth embodiment. Figures 16A to 16C show an example of the manner in which the item 10 rolls in time after it is dropped from the pickup unit 41 into the storage groove T of the item holding unit 42 until it is fitted into the fitting groove Tb.

The item removal system 1 according to this embodiment differs from the item removal system 1 according to the third embodiment in that it utilizes an inertial force acting on the item 10 to regulate and promote the movement of the item 10 that has fallen into the storage groove T. In other words, in the item removal system 1 according to this embodiment, the external force acting on the item 10 that has fallen into the storage groove T is controlled by an inertial force, thereby regulating and promoting the movement of the item 10 within the storage groove T.

The inertial force acting on the item 10 can be controlled by accelerating the robot hand 40 with the robot arm 30. In the item pick-up system 1 according to this embodiment, for example, the robot hand 40 can be translated at an accelerated rate in the opposite direction to the direction in which the guide groove Ta faces the fitting groove Tb, thereby rolling the item 10 from the guide groove Ta toward the fitting groove Tb.

As shown in Figures 15 and 16, the item removal system 1 according to this embodiment has the same configuration and operates as the item removal system 1 according to the third embodiment, except that the external force acting on the item 10 that has fallen into the storage groove T is controlled by inertial force instead of centrifugal force.

As described above, the item removal system 1 according to this embodiment is configured to regulate and promote the movement of the item 10 within the storage groove T by controlling the inertial force acting on the item 10. This makes it possible to efficiently regulate the rolling behavior of the item 10 within the storage groove T and smoothly control the posture of the item 10.

Fifth Embodiment
Next, the configuration of an article pick-up system 1 according to a fifth embodiment will be described with reference to FIGS.

Figure 17 is a diagram showing an example of the configuration of a robot hand 40 according to the fifth embodiment. Figures 17A to 17B show the operation of the robot hand 40 according to the fifth embodiment in chronological order.

Figure 18 is a diagram showing an example of the manner in which the item 10 rolls in the storage groove T formed by the item holding unit 42 of the robot hand 40 according to the fifth embodiment. Figures 18A to 18C show an example of the manner in which the item 10 rolls in time after it is dropped from the pickup unit 41 into the storage groove T of the item holding unit 42 until it is fitted into the fitting groove Tb.

The item removal system 1 according to this embodiment differs from the item removal system 1 according to the second embodiment in that it utilizes the magnetic force generated by the magnet MG disposed adjacent to or within the item holding section 42 to regulate and promote the movement of the item 10 that has fallen into the storage groove T. In other words, the item removal system 1 according to this embodiment controls the external force acting on the item 10 that has fallen into the storage groove T by magnetic force. Note that, in addition to the external force due to the magnetic force generated by the magnet MG, the item removal system 1 according to this embodiment is configured to regulate and promote the movement of the item 10 in the storage groove T by controlling the inclination angle of the storage groove T with respect to the vertical direction, similar to the item removal system 1 according to the second embodiment.

The operation of the item pick-up system 1 according to this embodiment is, for example, as follows.

First, the item taking out system 1 first performs a picking operation of the item 10 using the pickup unit 41. Then, the item taking out system 1 causes the pickup unit 41 to release the item 10 from its holding state, and causes the item 10 that falls from the pickup unit 41 to be received in the storage groove T of the item holding unit 42 (see Figures 17A and 18A). Note that in the item taking out system 1 according to this embodiment, the item holding unit 42 is configured from a container-shaped member having a storage groove T. When the item 10 fits into the fitting groove Tb, the item holding unit 42 according to this embodiment grips the item 10 by covering the item 10 from above the container-shaped member with a separate gripping member 42C.

Next, while the item 10 is rolling in the storage groove T, the item retrieval system 1 applies a magnetic force from the magnet MG to the item 10 to guide the item 10 to a predetermined position (here, a position facing the fitting groove Tb) and change the posture of the item 10 to the target posture (see FIG. 18B). After the item 10 has changed to the target posture, the item retrieval system 1 retracts the magnet MG from the item holding unit 42 and releases the magnetic force of the magnet MG. The item retrieval system 1 then changes the item holding unit 42 to a vertical state. As a result, the item 10, having been changed to the target posture, fits into the fitting groove Tb in the storage groove T and is positioned within the fitting groove Tb (see FIG. 17B and FIG. 18C).

Figure 19 is a flowchart showing an example of processing performed by the control unit 60 when operating the robot hand 40 according to the fifth embodiment. The flowchart in Figure 19 differs from the flowchart in Figure 11 in that step S4c is added immediately after step S4, and step S4d is added instead of step S4a. In addition, in the item pick-up system 1 according to this embodiment, the item holding unit 42 is configured from a container-shaped member having a storage groove T, and therefore step S3 in the flowchart in Figure 11 is omitted in the flowchart in Figure 19.

In other words, in step S4, after the control unit 60 according to this embodiment releases the item 10 from the pickup unit 41, while the item 10 is rolling in the storage groove T, the control unit 60 attracts the item 10 with the magnet MG and changes the position of the item 10 to the target position (step S4c). The control unit 60 is then configured to move the magnet MG away from the item holding unit 42 and change the position of the item holding unit 42 to a vertical position (step S4d). As a result, as described with reference to Figures 17 and 18, the item 10 that has landed in the storage groove T moves to the fitting groove Tb.

The magnet MG may be a permanent magnet or an electromagnet. When the magnet MG is an electromagnet, the control unit 60 may variably control the magnetic force of the magnet MG to change the external force acting on the article 10.

As described above, the item removal system 1 according to this embodiment is configured to restrict and promote the movement of the item 10 within the storage groove T by controlling the magnetic force that the magnet MG exerts on the item 10. This makes it possible to accurately control the position of the item 10 rolling within the storage groove T.

Sixth Embodiment
Next, the configuration of the article pick-up system 1 according to the sixth embodiment will be described with reference to FIGS.

Figures 20 and 21 are diagrams showing an example of the configuration of a robot hand 40 according to the sixth embodiment.

The item removal system 1 according to this embodiment differs from the item removal system 1 according to the second embodiment in that it utilizes fluid pressure generated by an air pump MF disposed adjacent to or within the item holding section 42 to regulate and promote the movement of the item 10 that has fallen into the storage groove T. In other words, in the item removal system 1 according to this embodiment, the external force acting on the item 10 that has fallen into the storage groove T is controlled by fluid pressure.

This makes it possible to precisely control the position of the item 10 rolling within the storage groove T.

Seventh Embodiment
Next, the configuration of an article pick-up system 1 according to a seventh embodiment will be described with reference to FIGS.

Figures 22 and 23 are diagrams explaining the operation of the robot hand 40 according to the seventh embodiment.

The item removal system 1 according to the seventh embodiment differs from the item removal system 1 according to each of the above embodiments in that it can accommodate items 10 of various sizes by variably controlling the distance between the members of the item holding section 42.

Depending on the manufacturing site of the product, there may be cases where the group of items 10W placed on the item placement section 2 includes items 10 of different sizes, such as items 10s and 10t in FIG. 22. The items 10s and 10t shown in FIG. 22 are the same type of items 10 (e.g., bolt members) with different heights and widths (here, item 10s with height Hs and width Ws, and item 10t with height Ht and width Wt). In the item removal system 1 according to this embodiment, in order to be able to handle such a situation, the inter-member distance of the item holding section 42 is changed according to the size of the item 10 to be removed (see FIG. 23A and FIG. 23B). In the item removal system 1 according to this embodiment, the hole size of the posture change guide hole Tab of the storage groove T and the groove size of the fitting groove Tb are thereby changed, and it is possible to change the posture of the items 10 of different sizes to the target posture and to grip the items 10 in the target posture.

The item removal system 1 according to this embodiment may be configured to determine the distance between the members of the item holding section 42 according to the size of the item 10 specified by the user, but more preferably, when an item 10 to be removed is determined from the group of items 10W placed on the item placement section 2, the size of the item 10 is detected from image data obtained from the imaging section 50, and the distance between the members of the item holding section 42 is adjusted based on the detected size of the item 10. This makes it possible to accurately change the posture of the item 10 to the target posture even when the group of items 10W placed on the item placement section 2 contains a mixture of items 10 of different sizes.

As described above, the item pick-up system 1 according to this embodiment can be applied to items 10 of different sizes with the same configuration.

Other Embodiments
The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the article pick-up system 1 may have a configuration in which the aspects shown in the respective embodiments are combined in various ways.

In the above embodiment, a bolt member is shown as an example of the item 10, but the item 10 may be any item other than a bolt member, such as an L-shaped fastener, a cap, a cylindrical member attached to part of a rod-shaped member, a cap, etc. However, from the viewpoint of changing the position by rolling in the guide groove Ta, it is preferable that the item 10 is a member having a shape with a long and thin leg 10a and a head 10b formed at one end of the leg 10a and wider than the leg 10a.

In addition, in the above embodiment, a suction head is shown as an example of the configuration of the pickup unit 41, but the pickup unit 41 may be configured as a two-jaw hand that holds the item 10 by clamping the item 10 from the side. However, it is preferable that the pickup unit 41 be configured as a suction head, since it can pick up the item 10 placed in various positions without being affected by differences in position.

In addition, in the above embodiment, one example of the configuration of the item holding part 42 is shown, but the configuration of the item holding part 42 can be changed in various ways. For example, the item holding part 42 may be configured by combining a member that forms a guide groove Ta that changes the posture of the item 10 to a target posture and a member that forms a fitting groove Tb (i.e., a member that grips the item 10). Also, instead of the item holding part 42 that forms the storage groove T with a pair of gripping members 42A, 42B, the item holding part 42 may be configured with a container-shaped item holding part 42 in which the storage groove T is formed in advance.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples given above.

The robot hand disclosed herein has a simple configuration and is capable of changing the posture of an item removed from an item placement section to a target posture and then holding the item.

REFERENCE SIGNS LIST 1 Item removal system 2 Item placement section 10 Item 10W Item group 20 Installation target 21 Hole section 30 Robot arm 40 Robot hand 40T Hand base section 41 Pickup section 42 Item holding section 42A, 42B Grip member 42C Grip member 42x Posture change section 42y Grip section 43 Sensor section 50 Imaging section 60 Control section MF Air pump MG Magnet T Storage groove Ta Guide groove Taa Inclined surface Tab Posture change guide hole Tb Fitting groove Tbb Through hole

Claims (20)

a pickup unit that picks up an individual article from a group of articles placed on the article placement unit and holds the article;
an article holding section that receives the article released by the pickup section;
The article holding portion is
a posture changing unit that changes the posture of the article to a target posture by rolling the article released from the pickup unit and regulating the rolling manner of the article;
a gripping unit that grips the article whose posture has been changed to the target posture,
Robot hand for item picking system. the position change unit is formed in a receiving area in a storage groove formed directly below the pickup unit where the article released from the pickup unit lands, and includes a guide groove that changes the position of the article to the target position while rolling the article;
The gripping portion is formed in a region guided by the guide groove in the storage groove, and includes a fitting groove for positioning the article changed to the target posture.
The robot hand according to claim 1 . The article has an elongated leg and a head formed at one end of the leg and wider than the leg;
The guide groove includes a posture change guide hole that does not allow the head of the article to pass through and allows the leg of the article to pass through in a path that guides the article from the receiving area to the fitting groove, and changes the posture of the article to the target posture in the process of the article passing through the posture change guide hole.
The robot hand according to claim 2. A sensor unit for detecting whether the article is fitted in the fitting groove is provided.
The robot hand according to claim 2 or 3. The article holding portion holds the article such that a portion of the article protrudes from a storage groove formed by the article holding portion directly below the pickup portion.
The robot hand according to any one of claims 1 to 4. The force that rolls the article at the posture changing unit includes gravity.
The robot hand according to any one of claims 1 to 5. The force that rolls the article in the position changing section includes a magnetic force generated by a magnet disposed adjacent to the article holding section or within the article holding section.
The robot hand according to any one of claims 1 to 6. The force that rolls the article in the posture changing unit includes a centrifugal force generated by the rotational motion of the article holding unit.
The robot hand according to any one of claims 1 to 7. The force that rolls the article in the posture changing unit includes an inertial force generated by the accelerated motion of the article holding unit.
The robot hand according to any one of claims 1 to 8. The force that rolls the article in the position changing section includes a fluid pressure generated by an air pump disposed adjacent to the article holding section or within the article holding section.
The robot hand according to any one of claims 1 to 9. The article holding section is composed of a pair of gripping members arranged opposite to each other and abutting their respective opposing surfaces to form a storage groove directly below the pickup section,
The distance between the pair of gripping members can be controlled by a control unit that controls the article pick-up system.
The robot hand according to any one of claims 1 to 10. By adjusting the inter-member distance between the pair of gripping members, the gripping state and the non-gripping state of the article in the article holding portion are changed.
The robot hand according to claim 11. The movement of the article in the storage groove is restricted by adjusting the distance between the pair of gripping members.
The robot hand according to claim 11 or 12. The distance between the pair of gripping members is adjusted based on the size of the article.
The robot hand according to any one of claims 11 to 13. The inclination angle of the storage groove formed by the article holding unit directly below the pickup unit with respect to the vertical direction can be controlled by a control unit that controls the article pick-up system.
The robot hand according to any one of claims 1 to 14. The inclination angle of the storage groove is adjusted to restrict movement of the article within the storage groove.
The robot hand according to claim 15. By adjusting the inclination angle of the storage groove, the article is caused to perform a retry of the rolling motion in the storage groove.
The robot hand according to claim 15 or 16. The article holding unit is configured to be capable of vibrating, and the vibrating motion promotes movement of the article within a storage groove that the article holding unit forms directly below the pickup unit.
A robot hand according to any one of claims 1 to 17. The pickup unit is constituted by a suction head.
A robot hand according to any one of claims 1 to 18. An article picking system having a robot hand according to any one of claims 1 to 19.

Images