JP7201377B2 - End effector and robot equipped with it - Google Patents

Description

The present invention relates to an end effector and a robot equipped with the same.

An end effector for gripping a workpiece, which is attached to an arm of a robot, for example, is known. In recent years, the growth of collaborative robots has been remarkable, and the development of end effectors to be attached to them is underway.

Japanese Utility Model Laid-Open No. 63-140391

The inventor searched for an end effector with a relatively simple mechanism capable of gripping irregular-shaped workpieces, and arrived at the present invention.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an end effector with a relatively simple mechanism that can grip irregular-shaped workpieces.

In order to solve the above problems, an end effector according to one aspect of the present invention provides first and second gripping members for gripping a workpiece, and for swinging the first gripping member independently of the second gripping member. and a guide that restricts the movement of the first gripping member that is swung by the actuator.

Arbitrary combinations of the above constituent elements, and mutual replacement of the constituent elements and expressions of the present invention between apparatuses, methods, systems, etc. are also effective as aspects of the present invention.

According to the present invention, it is possible to provide an end effector with a relatively simple mechanism that is capable of gripping irregular-shaped workpieces.

1 is a diagram showing a schematic configuration of a robot according to an embodiment; FIG. 2 is a perspective view of the end effector of FIG. 1; FIG. 3(a)-(c) are respectively a top view, a front view and a side view of the end effector of FIG. 2 is a block diagram showing the functions and configuration of a control device in FIG. 1; FIG.

Hereinafter, the same or equivalent constituent elements, members, and steps shown in each drawing are denoted by the same reference numerals, and redundant description will be omitted as appropriate. In addition, the dimensions of the members in each drawing are appropriately enlarged or reduced for easy understanding. Also, in each drawing, some of the members that are not important for explaining the embodiments are omitted.

FIG. 1 is a diagram showing a schematic configuration of a robot 1 according to an embodiment. A robot 1 is a device for handling a work. The robot 1 is preferably used as a robot that assists a person in need of care in eating, specifically as a robot that assists in holding food and carrying it to the mouth. The robot 1 includes an end effector 10 for gripping a workpiece, an arm 12 that supports the end effector 10 and changes the position and posture of the end effector 10, a controller 14 that controls the end effector 10 and the arm 12, Prepare.

FIG. 2 is a perspective view of the end effector 10. FIG. 3A to 3C are a top view, a front view and a side view of the end effector 10, respectively. The end effector 10 includes a connecting portion 20, a base portion 21, a first gripping member 31, a second gripping member 32 and a third gripping member 33, a first actuator 41 and a second actuator 42, a first guide 51 and a third gripping member 33. 2 guides 52;

The connecting part 20 is connected to the arm 12 (not shown in FIGS. 2 and 3), for example, in a detachable manner. The base portion 21 is fixed to the connection portion 20 . The base portion 21 is not particularly limited in shape, but includes a body portion 22 and a reinforcing portion 23 in the illustrated example. The body portion 22 is an elongated member, and one end side (the upper end side in the illustrated example) is fixed to the connection portion 20 . The body portion 22 has a substantially pentagonal cross section perpendicular to the extending direction, which has a substantially home base shape. The reinforcing portion 23 is a substantially triangular plate-like member in a side view, and reinforces fixing between the connecting portion 20 and the main body portion 22 .

The first actuator 41 is fixed to the first surface 22 a of the body portion 22 and parallel to the extending direction of the body portion 22 . The second actuator 42 is fixed to the second surface 22b of the body portion 22, which is parallel to the extending direction of the body portion 22 and intersects the first surface 22a. The first actuator 41 and the second actuator 42 are air actuators that are operated by the pressure of air supplied inside them in the present embodiment. The shape of each gripping member is not particularly limited, but in the illustrated example, it is rod-shaped, particularly tapered rod-shaped.

One end of the first gripping member 31 is connected to the first actuator 41 . In the illustrated example, the first gripping member 31 extends in a direction substantially parallel to the extending direction of the main body portion 22 of the base portion 21 and in a direction intersecting with the driving direction of the first actuator 41 . One end side is connected to the first actuator 41 so as to extend in a direction substantially orthogonal to the driving direction of the actuator 41 . The first actuator 41 drives the one end side of the first gripping member 31 in a direction orthogonal to the first surface 22a (that is, a direction orthogonal to the extending direction D). As a result, the first gripping member 31 swings with respect to the base portion 21 with the portion surrounded by the first guide 51 as a fulcrum.

One end of the second gripping member 32 is connected to the second actuator 42 . In the illustrated example, the second gripping member 32 particularly extends in a direction substantially parallel to the extending direction of the main body portion 22 of the base portion 21 and in a direction intersecting the driving direction of the second actuator 42 . One end side is connected to the second actuator 42 so as to extend in a direction substantially orthogonal to the driving direction of the actuator 42 . The second actuator 42 drives the one end side of the second gripping member 32 in a direction orthogonal to the second surface 22b (that is, a direction orthogonal to the extending direction D). As a result, the second gripping member 32 swings with respect to the base portion 21 with the portion surrounded by the second guide 52 as a fulcrum.

One end of the third gripping member 33 is fixed to the base portion 21 so as to extend substantially parallel to the extending direction of the main body portion 22 of the base portion 21 . That is, unlike the first gripping member 31 and the second gripping member 32 , the third gripping member 33 does not move relative to the base 21 .

The first gripping member 31, the second gripping member 32, and the third gripping member 33 are provided so that their extending directions are substantially parallel to each other and their tips are arranged in the circumferential direction.

The first guide 51 is attached to the first surface 22 a of the body portion 22 of the base portion 21 . The first guide 51 restricts movement of the first gripping member 31 that is swung by the first actuator 41 . The first guide 51 particularly restricts the movement of the first gripping member 31 so that the first gripping member 31 swings only on one plane. The plane may be, for example, a plane orthogonal to the first surface 22a of the body portion 22 of the base portion 21, or may be a plane parallel to the driving direction of the first actuator 41, for example.

Although the configuration of the first guide 51 is not particularly limited, in the present embodiment, the first guide 51 has a through hole penetrating the first guide 51 in the extending direction of the main body portion 22 of the base portion 21. The first gripping member 31 is inserted through the through hole. This through hole is configured to swing the first gripping member 31 only on one plane. Specifically, in the direction parallel to the plane, the through hole is slightly wider than the first gripping member 31 (that is, there is a play gap), and in the direction perpendicular to the plane, the through hole is It has substantially the same width as the first gripping member 31 .

The second guide 52 is attached to the second surface 22 b of the body portion 22 of the base portion 21 . The second guide 52 restricts movement of the second gripping member 32 that is swung by the second actuator 42 . The second guide 52 particularly restricts the movement of the second gripping member 32 so that the second gripping member 32 swings only on one plane. The plane may be, for example, a plane perpendicular to the second surface 22b of the body portion 22 of the base portion 21, or may be a plane parallel to the driving direction of the second actuator 42, for example.

Although the configuration of the second guide 52 is not particularly limited, in the present embodiment, the second guide 52 passes through the second guide 52 in the extending direction of the main body portion 22 of the base portion 21 in the same manner as the first guide 51. The second gripping member 32 is inserted through the through hole. This through-hole, like the through-hole of the first guide 51, is configured to swing the second gripping member 32 only on one plane.

When the first actuator 41 drives one end of the first gripping member 31 away from the first surface 22 a , the tip (other end) of the first gripping member 31 moves toward the first surface 22 a and thus the third gripping member 33 . approach the tip. Conversely, when the first actuator 41 drives the one end side of the first gripping member 31 to approach the first surface 22a, the distal end side of the first gripping member 31 moves away from the first surface 22a and further from the distal end of the third gripping member 33. Leave.

When the second actuator 42 drives one end of the second gripping member 32 away from the second surface 22b, the distal end (other end) of the second gripping member 32 moves toward the second surface 22b and thus the third gripping member. Approach the tip of 33. Conversely, when the second actuator 42 drives the one end side of the second gripping member 32 to approach the second surface 22 b , the distal end side of the second gripping member 32 moves away from the second surface 22 b and further from the distal end of the third gripping member 33 . Leave.

The end effector 10 can grip a workpiece, for example, by bringing the tips of the first gripping member 31 and the second gripping member 32 closer to the third gripping member 33, and the first gripping member 31 and the second gripping member 32, for example, can grip the workpiece. By moving the tip away from the third gripping member 33, the gripped work can be released.

FIG. 4 is a block diagram showing the functions and configuration of the control device 14. As shown in FIG. Each block shown here can be implemented by hardware such as a computer CPU (central processing unit) or other elements or mechanical devices, and is implemented by software such as a computer program. The functional blocks realized by their cooperation are drawn. Therefore, those skilled in the art who have read this specification will understand that these functional blocks can be implemented in various ways by combining hardware and software.

The controller 14 includes an arm controller 62 and an end effector controller 64 . The arm control unit 62 controls the arm 12 so that the end effector 10 moves to a desired position and assumes a desired posture.

The end effector control unit 64 individually controls the first actuator 41 and the second actuator 42 so that the end effector 10 grips a work or releases the gripped work. Specifically, for example, the end effector control unit 64 moves the tip of the first gripping member 31 and/or the second gripping member 32 closer to the tip of the third gripping member 33 so that the end effector 10 grips the workpiece. It controls the first actuator 41 and/or the second actuator 42 . Further, for example, the end effector control unit 64 moves the tip of the first gripping member 31 and/or the second gripping member 32 away from the tip of the third gripping member 33 to release the workpiece gripped by the end effector 10 . It controls the first actuator 41 and/or the second actuator 42 .

Here, when the gripping member grips the work or releases the gripped work, the reaction force that the first actuator 41 and the second actuator 42 receive from the gripping member changes. Since the first actuator 41 and the second actuator 42 of the present embodiment are air actuators as described above, the air pressure inside them changes when the reaction force received from the grip member changes. Therefore, a pressure sensor for measuring the air pressure inside the first actuator 41 and the second actuator 42 is provided, the air pressure inside the first actuator 41 and the second actuator 42 is fed back to the end effector control section 64, and the end effector The control unit 64 may adjust the force with which each gripping member presses the workpiece based on the feedback air pressure. As a result, even soft workpieces can be safely gripped.

Next, the effects of this embodiment will be described. According to this embodiment, since each gripping member is swung independently of the other gripping members, it is possible to grip, for example, irregular-shaped workpieces. In addition, since the movement of the grasping member that is swung by the actuator is restricted by the guide, the actuator itself does not need to have a guide, thus simplifying the actuator.

Moreover, in the present embodiment, since the air actuator is used as the actuator, the weight of the actuator can be reduced as compared with the case where the electric motor is used as the actuator. As a result, each member of the end effector 10 such as the base portion 21 does not require such strength, so a relatively lightweight and low-cost material such as resin can be used. Further, by adopting an air actuator as an actuator to reduce the weight of the end effector 10, the drive power for driving the arm 12 that supports the end effector 10 can be reduced. In addition, since the robot 1 as a whole is of course lightweight, its installation is facilitated.

The end effector according to the embodiment and the robot including the end effector have been described above. It should be understood by those skilled in the art that this embodiment is an example, and that various modifications can be made to the combination of each component, and that such modifications are within the scope of the present invention. Combinations of the embodiments are also possible.

Although the case where the end effector 10 has three gripping members has been described in the embodiment, the number of gripping members may be plural, and is not limited to this.

For example, the end effector 10 may comprise two gripping members. In this case, for example, one of the two gripping members may correspond to the first gripping member 31 of the embodiment, and the other may correspond to the third gripping member of the embodiment. That is, one of the two gripping members is driven by the actuator to swing relative to the base 21 and the other gripping member with the portion surrounded by the guide as a fulcrum, thereby gripping the other gripping member. The member may be fixed to the base 21 at one end so that it does not move relative to the base 21 . Further, for example, both of the two gripping members may be driven by an actuator to swing with respect to the base 21 and the other gripping member.

Also, for example, the end effector 10 may include four or more gripping members. In this case, all the gripping members may be provided such that their extending directions are substantially parallel to each other and their tips are arranged in the circumferential direction. All of the gripping members, like the first gripping member 31 and the second gripping member 32 of the embodiment, are driven by respective actuators, and the portions surrounded by the guides are used as fulcrums for the base 21 and the other gripping members. It may be one that swings against. Alternatively, one end side of some of the plurality of gripping members may be fixed to the base 21 so as not to move relative to the base 21, like the third gripping member 33 of the embodiment. .

In the embodiment, the through hole of each guide is configured to swing the gripping member only on a predetermined plane, but the present invention is not limited to this. Each guide may be configured to swing the gripping member only on a predetermined plane, and may have, for example, a hinge for swingably supporting the gripping member.

Although the case where the first guide 51 and the second guide 52 are separated has been described in the embodiment, the present invention is not limited to this, and the first guide 51 and the second guide 52 may be integrated.

Although not specifically mentioned in the embodiment, the first guide 51 may be attached to the base 21 so that the distance L1 from the first actuator 41 is adjustable. Similarly, the second guide 52 may be attached to the base 21 such that the distance L2 from the second actuator 42 is adjustable. In other words, the positions of the fulcrums of the first gripping member 31 and the second gripping member 32 may be adjustable. Note that the distance L1 and the distance L2 may be the same or different.

When the distance between the actuator and the guide is short (that is, when the fulcrum is far from the tip of the first gripping member 31), the driving range of the actuator can be shortened. On the other hand, if the distance between the actuator and the guide is long (that is, the fulcrum is close to the tip of the first gripping member 31), a stronger gripping force can be achieved with the same driving force of the actuator compared to the case where it is not.

Any combination of the above-described embodiments and modifications is also useful as embodiments of the present invention. A new embodiment resulting from the combination has the effects of the combined embodiment and modifications. In addition, those skilled in the art will understand that the function to be achieved by each component described in the claims is realized by each component shown in the embodiments and modifications alone or by their linkage. .

REFERENCE SIGNS LIST 1 robot 10 end effector 31 first gripping member 32 second gripping member 33 third gripping member 41 first actuator 42 second actuator.

Claims (4)

first and second gripping members for gripping a workpiece;
an actuator for swinging the first gripping member;
a guide that restricts movement of the first gripping member that is swung by the actuator;
The guide controls the movement of the first gripping member such that the first gripping member swings on a predetermined plane and the tip of the first gripping member approaches or separates from the tip of the second gripping member. regulate and
the connecting portion between the actuator and the first gripping member, the swinging fulcrum of the first gripping member, and the tip of the first gripping member are arranged substantially on a straight line,
the second gripping member is stationary ,
the guide is adjustable in distance from the actuator;
An end effector , wherein the position of the fulcrum relative to the connecting portion and the tip can be adjusted by adjusting the distance between the guide and the actuator . The end effector according to claim 1 , wherein said actuator is an air actuator. a third gripping member for gripping the workpiece;
another actuator for swinging the third gripping member separately from the first gripping member;
another guide that regulates the movement of the third gripping member that is swung by the another actuator;
The other guide is adapted to move the third gripping member such that the tip of the third gripping member moves toward or away from the tip of the second gripping member as the third gripping member swings on a predetermined plane. 3. The end effector according to claim 1 or 2 , which restricts movement. an end effector according to any one of claims 1 to 3 ;
an arm that supports the end effector;
and a control device that controls the end effector and the arm.

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