Robot hand

Abstract

To provide a robot hand which can hold various objects.SOLUTION: A robot hand 10 comprises one or more finger parts 20, 30, and has a cross direction movement mechanism 60 which moves at least one finger part 30 in a cross direction of the robot hand 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a robotic hand. [Background technology]

[0002] A gripper that grips an object has been proposed (see Patent Document 1). This gripper can hold and transport an object. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6678648 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for robotic hands that can hold a variety of objects.

[0005] Therefore, an object of the present disclosure is to provide a robot hand that can hold a variety of objects. [Means for solving the problem]

[0006] In order to achieve the above object, a robot hand according to an embodiment of the present disclosure includes: A robotic hand having one or more fingers, It has a mechanism for moving one or more fingers back and forth, The front-rear direction is (1) A direction connecting the tip of one of the one or more fingers and the center of gravity of the base member of the robot hand, which is a point directly connected to a mechanical device composed of multiple parts; (2) a direction along the normal vector of the connection surface directly connecting the mechanical device and the robot hand; (3) A direction connecting the center of gravity of the robot hand and the center of gravity of the part directly connected to the robot hand among the multiple parts constituting the mechanical device; (4) the direction of the longest diameter of an ellipsoid when the outer shape of the robot hand is approximated by an ellipsoid with the one or more fingers fully extended; The present invention is characterized in that the above is any one of the above. [Effects of the Invention]

[0007] The present disclosure provides a robotic hand that can hold a variety of objects. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of the appearance of a robot hand according to an embodiment. [Figure 2] Fig. 2 is a perspective view of the appearance of the robot hand shown in Fig. 1 with one finger moved backward, while the other finger is hidden inside a cover. [Figure 3] FIG. 3 is a perspective view of the appearance of the robot hand shown in FIG. 1 in a state in which the other finger portion is moved backward and one finger portion is sucking the top surface of the object, thereby attempting to hold the object. [Figure 4] FIG. 4 is a perspective view of the appearance of the robot hand shown in FIG. 1 in a state in which one finger is sucking the top surface of an object, and the other finger is moving backward while changing the angle of the finger tip to suck the side of the object, thereby attempting to hold the object. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Embodiment) Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that each embodiment described below represents a specific example of the present disclosure. The numerical values, shapes, materials, components, component placement and connection configurations, steps, step order, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, each drawing is not necessarily an exact illustration. In each drawing, substantially identical configurations are assigned the same reference numerals, and duplicated explanations may be omitted or simplified.

[0010] (Perspective view of exterior) Fig. 1 is a perspective view of the exterior of a robot hand 10 according to an embodiment. The robot hand 10 includes fingers 20 and 30, a base member 12, and a control unit 15. Fig. 1 shows the two fingers 20, 30 of the robot hand 10 in a loosely closed state. The figure also shows a mechanical device 50 to which the robot hand 10 is attached.

[0011] The robot hand 10 is a robotic hand capable of grasping and holding an object. For example, the robotic hand 10 is attached to a mechanical device 50. As needed, each of the two fingers 20, 30 can be rotated about a first rotation axis A1, a second rotation axis A2, a third rotation axis A3, and a fourth rotation axis A4, and can rotate toward or away from the other of the two fingers 20, 30. This allows the relative positions of the fingers to be changed, allowing the object to be sandwiched between the fingers 20 and 30 and held. Mechanisms (finger drive units) for driving the first rotation axis A1, the second rotation axis A2, the third rotation axis A3, and the fourth rotation axis A4 are installed inside the fingers around each axis (not shown). The shapes of the joints around each rotation axis of the fingers in FIG. 1 are merely schematic representations and do not represent the exact physical structure.

[0012] Note that the robot hand 10 according to the present disclosure does not necessarily have to have joints around the rotation axes of the fingers shown in Fig. 1. Similarly, the robot hand 10 according to the present disclosure does not necessarily have to have the control unit 15 shown in Fig. 1.

[0013] The robot hand 10 is also a robot hand that can suck and hold an object. Similarly, the robot hand 10 is attached to a mechanical device 50, for example.

[0014] The robot hand 10 also includes a forward / backward direction movement mechanism 60 that moves the fingers 30 backward (negative y direction) or forward (positive y direction) (see FIG. 2). Note that the y-axis indicates the forward / backward direction defined in this specification, the x-axis indicates a direction perpendicular to the y-axis, and the z-axis indicates a direction perpendicular to the x-axis and y-axis.

[0015] The control unit 15 is a controller that controls the robot hand 10, and is comprised of a memory that stores programs and object information, a processor that executes the programs, a camera as object detection means that detects the status of the object to be held, etc., and is housed in the mechanical device 50, etc. Note that in Figure 1, the control unit 15 is illustrated functionally.

[0016] 2 is a perspective view of the appearance of a state in which one finger (here, finger portion 30) of the robot hand 10 according to the embodiment is moved backward (in the negative y direction) by the forward / backward direction movement mechanism 60 under the control of the control unit 15. Note that in FIG. 2, the mechanical device 50 and the control unit 15 in FIG. 1 are not shown. The same applies to the subsequent figures.

[0017] (forward and backward movement) Here, forward and backward movement may mean that the relative positional relationship of the fingers with respect to the base member 12 of the robot hand or the part 51 to which the robot hand is attached can be changed in the forward and backward directions.

[0018] (Explanation of front-to-back direction) The front-rear direction may be any of the following directions:

[0019] (1) A direction connecting the tip of one of the one or more fingers and the center of gravity of the base member 12 of the robot hand 10, which is the part directly connected to the mechanical device 50 composed of multiple parts; (2) a direction along the normal vector of the connection surface 11 that directly connects the mechanical device 50 and the robot hand 10; (3) A direction connecting the center of gravity of the part 51 that is directly connected to the robot hand 10 among the parts that make up the mechanical device 50 and the center of gravity of the robot hand 10; (4) The direction of the longest diameter of an ellipsoid when the external shape of the robot hand 10 is approximated by an ellipsoid with one or more fingers fully extended.

[0020] The mechanical device 50 may be a machine called a robot arm. Furthermore, "directly connected" means connected by contact, and simply "connected" does not only mean "directly connected" but also includes indirectly connected via another object.

[0021] Furthermore, the tip of a finger means the end point of the finger that is opposite the base of the robot hand when the finger is considered to be rod-shaped.

[0022] 1, when the external shape of the robot hand 10 is approximated by an ellipsoid with one or more fingers fully extended, the direction of the longest diameter of the ellipsoid is the y-axis direction shown in FIG. 1. Approximating the robot hand by an ellipsoid may also mean approximating the coordinates of the surface shape of the robot hand to an ellipse using the least squares method. Furthermore, (4) may be the direction obtained by expanding the long axis direction in three dimensions when the robot hand is considered to have an elongated shape such as a rectangle or ellipse, rather than a uniform shape such as a circle or square.

[0023] (Meaning included in forward and backward movement) The forward-backward movement of the finger does not necessarily mean a movement completely along any one of the directions (1) to (4) (e.g., a linear movement), but may also mean a movement that includes a directional component of any one of the directions (1) to (4). That is, for example, it may be a diagonal movement that includes a left-right movement component in addition to a forward-backward movement, or a movement along a curved path that includes a movement component along any one of the directions (1) to (4). Furthermore, to be considered a forward-backward movement, the main component of the movement may need to be in any one of the directions (1) to (4).

[0024] Furthermore, the forward and backward movement may be a movement accompanied by a change in the angle of the finger orientation.

[0025] (suction port) Furthermore, at least one of the fingers or members of the robot hand 10 other than the fingers may be provided with a vacuum (vacuum suction) suction port.

[0026] In this embodiment, the fingers 20 and 30 are provided with suction ports 20a, 20b, 30a, and 30b, respectively. As a result, under the control of the control unit 15, air is sucked through the suction ports by a pump (not shown) or the like, and the resulting negative pressure can be used to suck and hold an object. The suction ports may also be provided on the side surfaces of the fingers, which are on the inside of the robot hand 10, as shown in FIG. 1 . The suction ports may also be provided at the tips of the fingers. The suction ports may also be provided on the side surfaces of the fingers, which are on the outside of the robot hand 10.

[0027] (If the finger part is not the suction port itself) In addition, when the finger portions have suction ports, the finger portions may be capable of holding an object only by physically pinching or holding down an object using one or more fingers (i.e., physical pinching or holding down between fingers or between fingers and other parts of the robot hand) under the control of the control unit 15, without using a vacuum at the suction ports of the fingers. In this case, the fingers that pinch or hold down an object do not have to be fingers that have suction ports, or they may be different fingers.

[0028] (movable part of the finger) As in the present embodiment, the finger unit may have one or more movable parts such as the finger unit drive unit described above. Also, the movable part of the finger unit may not overlap with the movable mechanism that moves the finger unit in the forward and backward directions (i.e., they are not shared, and if the finger unit has one forward and backward direction movement mechanism 60, it is necessary for the finger unit to have another movable part).

[0029] (The effect of moving the finger backward and retracting it) The robot hand 10 according to this embodiment has one or more fingers, or two or more fingers, or one or more of the two or more fingers that are movable in the front-rear direction.

[0030] As a result, when sucking the upper part of an object with the suction port of one finger part 20, by moving the other finger part 30 backward and retracting it in advance with the forward / backward movement mechanism 60, the object can be held by the robot hand 10 using the suction port of one finger part 20 without the other finger part 30 interfering with the object.

[0031] This holding method is effective when there are restrictions on the environment around the object to be held. For example, if there is another object above the object, the other finger 30 can be retracted backward, and one finger 20 can be inserted between the target object and the other object to hold the target object (see FIG. 3, which shows the appearance of the robot hand 10 shown in FIG. 1 in a state where the other finger 30 is moved backward, the top surface of the object 40 is sucked by one finger 20, and the object 40 is being held by the robot hand 10 shown in FIG. 1).

[0032] (The angle of the fingers can be changed.) It is also possible to change the angle of the tip 31 of the finger 30. By changing the angle of the tip 31 of the finger 30 under the control of the control unit 15 and aligning it with the side of the object, not only the top surface of the object but also the side of the object can be sucked. In other words, two or more suction ports can be aligned with differently oriented surfaces of the object to perform vacuuming. In this case, the angle of the tip 31 of the finger 30 can be changed under the control of the control unit 15 using shape information, which is one type of object information stored in the memory of the control unit 15, or information on the surface shape of the object detected by a camera or other object detection means, such as a camera, included in the control unit 15. Similarly, the angle of the tip 21 of the finger 20 can be changed.

[0033] This allows the object to be held more firmly (see FIG. 4, which shows the appearance of the robot hand 10 shown in FIG. 1 in a state where one finger 20 is sucking the top surface of the object 40, and the other finger 30 is moving backward while changing the angle of the tip 31 of the finger 30 to suck the side of the object 40).

[0034] Also, Fig. 4 shows one example. That is, in Fig. 4, the surfaces of tip 21 and tip 31 are aligned to fit the surface of a 90-degree corner of an object, but it is also possible to change the relative angle or relative position of tip 21 and tip 31 to fit along a surface of any angle or curved surface, not just a 90-degree corner surface.

[0035] Furthermore, by allowing the finger portion 30 to move in the forward and backward directions, the distance and relative positional relationship between the suction port of the finger portion 20 and the suction port of the finger portion 30 can be changed, making it possible to hold a wider variety of objects.

[0036] Furthermore, the suction port of the tip 31 in Figure 4 can be adjusted in the vertical direction by changing the joint angles of the third rotation axis A3 and the fourth rotation axis A4, allowing the suction port to hold various objects at a position that follows the surface of the object. This adjustment in the vertical direction also involves a shift in the front-to-rear direction, and the front-to-rear movement mechanism 60 is also effective in adjusting this. Note that this change in the vertical position is not limited to changing the joint angle, and it may also be achieved by, for example, using a vertical sliding mechanism.

[0037] (The forward / backward movement mechanism is a sliding mechanism that allows sliding movement) A specific example of the forward / backward direction movement mechanism 60, which is a mechanism for moving the finger in the forward / backward direction, is a slide mechanism constituted by a slide drive unit, in which the movement is a sliding movement. Another specific example is a mechanism that moves the finger in the forward / backward direction by a rotational drive. However, other movement mechanisms may also be used as specific examples of the forward / backward direction movement mechanism 60.

[0038] (Description of the finger's retreat and the space it occupies) Furthermore, the forward / backward direction movement mechanism 60 may be a mechanism that can retract the spatial area of ​​the range of effect of one or more finger units that are moved in the forward / backward direction from the spatial area of ​​the range of effect of one or more other arbitrary finger units (i.e., prevent these two spatial areas from overlapping). Here, the spatial area of ​​the range of effect of a finger unit may be defined as the spatial area that the finger unit can occupy when the finger unit is moved by a movable unit other than the forward / backward direction movement mechanism 60 possessed by the finger unit. Furthermore, the retraction of the spatial area of ​​the range of effect of a finger unit may target not only the spatial area of ​​the range of effect of each finger unit, but also a spatial area that includes the surrounding spatial area (i.e., space as a margin). Here, the spatial area that includes the surrounding spatial area may be a spatial area that extends outside the spatial area of ​​the range of effect of the finger unit by the distance from the center of gravity of the spatial area of ​​the spatial area of ​​the range of effect of the finger unit to the boundary position of the spatial area of ​​the spatial area of ​​the spatial area of ​​the finger unit's effect, or by half that distance.

[0039] Conversely, the retraction of the spatial area of ​​the range of effect of the finger parts may be performed by reducing the spatial area of ​​the range of effect of each finger part. The reduced spatial area may be obtained by moving the boundary of the spatial area of ​​the range of effect of the finger parts inward by a distance equal to one-third of the distance between the boundary and the center of gravity of the spatial area.

[0040] (Robot hand size) Furthermore, if the thickness of one or more fingers (in FIG. 1, the thickness of each finger in the z direction when each finger is fully extended in the y direction) is small and the width of the finger (in FIG. 1, the x direction) is narrow, it is effective when there are stricter constraints on the environment around the object. For example, a combination of a thickness of 70 mm or less and a width of 120 mm or less. Another example is a combination of a thickness of 50 mm or less and a width of 100 mm or less. Another example is a combination of a thickness of 40 mm or less and a width of 70 mm or less.

[0041] (Example of control by the control unit) As described above, the control unit 15 may perform at least one of the following controls: (1) control to hold the object 40 by vacuuming the suction ports 20a and 20b, etc. (see Figures 3 and 4); (2) control to vacuum two or more suction ports 20a and 30a, etc. along surfaces of the object facing different directions (see Figure 4); and (3) control to hold the object 40 only by physically pinching or pressing down the object using one or more of the finger portions 20 and 30, without using vacuuming the suction ports 20a and 20b, etc.

[0042] While the robot hand according to the present disclosure has been described above based on the embodiments and modifications, the present disclosure is not limited to these embodiments and modifications. As long as they do not deviate from the gist of the present disclosure, various modifications that a person skilled in the art could conceive of to the present embodiments and modifications, and other forms constructed by combining some of the components in the embodiments and modifications, are also included within the scope of the present disclosure. [Industrial Applicability]

[0043] The robot hand according to the present disclosure can be used as a robot hand that can hold various objects. [Explanation of symbols]

[0044] 10 Robot Hand 11. Interface between robot hand and mechanical device 12 Base component of robot hand 15 Control Unit 20,30 fingers 20a,20b,30a,30b Suction port 21 Tip of finger 20 31 Tip of finger 30 40 Object 50 Mechanical equipment 51 Parts of mechanical equipment that are directly connected to the robot hand 60 Forward-backward movement mechanism A1 First rotation axis A2 2nd rotation axis A3 Third rotation axis A4 4th rotation axis

Claims

1. A robotic hand having one or more fingers, A mechanism for moving one or more fingers in a forward and backward direction is provided, The front-rear direction is (1) A direction connecting a tip of any one of the one or more fingers and a center of gravity of a base member of the robot hand, which is a point directly connected to a mechanical device composed of a plurality of parts; (2) a direction along a normal vector of a connection surface directly connecting the mechanical device and the robot hand; (3) A direction connecting the center of gravity of a part directly connected to the robot hand among a plurality of parts constituting the mechanical device and the center of gravity of the robot hand; (4) a direction in which a diameter of an ellipsoid is longest when an outer shape of the robot hand is approximated by an ellipsoid in a state in which the one or more fingers are fully extended; A robotic hand that is either

2. Further, a control unit for controlling the robot hand is provided, At least one of the one or more fingers has a suction port; The control unit is (1) controlling the suction port to hold the object by vacuum; (2) Controlling the two or more suction ports to suction along surfaces of the object in different directions, The robot hand according to claim 1 .

3. The control unit further controls the object to be held only by physically pinching or pressing down the object using the one or more finger portions, without using a vacuum at the suction ports of the finger portions. The robot hand according to claim 2.

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