Robot hand and robot system
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Filing Date
- 2024-10-31
- Publication Date
- 2025-05-15
AI Technical Summary
Existing robotic hands are designed to be difficult to effectively rotate objects of various shapes and sizes, causing objects to fall or rotate to stop.
A robotic hand is designed, which includes two knuckles, each with a raised band structure. These protrusions mesh when the knuckles come into contact, ensuring that the object does not slip off when it rotates, and the movement of the knuckles is controlled by the drive device to achieve the rotation of the object.
The stable rotation of objects of various shapes and sizes is achieved, avoiding the problem of objects falling or rotating stopping, and improving the operation reliability of the robot.
Abstract
Description
Robot hand and robot system
[0001] The present disclosure relates to a robotic hand and a robotic system.
[0002] Conventionally, devices equipped with robotic hands that mimic human hands have become widespread in order to perform various tasks in place of humans. Human hands are capable of delicate movements such as grasping objects, and robotic hands are required to be able to perform movements equivalent to those of human hands. For example, Patent Literature 1 discloses a configuration in which protrusions are provided on the fingers of a robotic hand, enabling the robotic hand to rotate at any angle while grasping an object.
[0003] JP 2009-255191 A
[0004] The present disclosure has been devised in view of the above-described conventional circumstances, and aims to enable rotation of a grasped object.
[0005] The present disclosure provides a robot hand comprising: a first finger portion having a plurality of first protrusions on a first surface that grasps an object; a second finger portion having a plurality of second protrusions on a second surface that grasps the object; and a drive unit that causes the first finger portion and the second finger portion to grasp the object and rotate the object about a rotation axis, wherein the spacing between the plurality of first protrusions is defined to be longer than the maximum width of the object along the extension direction of the first finger portion when grasping and rotating the object, and the spacing between the plurality of second protrusions is defined to be longer than the maximum width of the object along the extension direction of the second finger portion when grasping and rotating the object.
[0006] The present disclosure also provides a robot system including a robot hand and a control device for controlling a drive unit, wherein the robot hand includes first fingers having a plurality of first protrusions on a first surface that grasps an object, second fingers having a plurality of second protrusions on a second surface that grasps the object, and a drive unit that causes the first fingers and the second fingers to grasp the object and rotate the object about an axis of rotation, wherein the spacing between the plurality of first protrusions is defined to be longer than the maximum width of the object along the extension direction of the first fingers when holding and rotating the object, and the spacing between the plurality of second protrusions is defined to be longer than the maximum width of the object along the extension direction of the second fingers when grasping and rotating the object.
[0007] Any combination of the above components, and conversion of the present disclosure into a method, device, system, storage medium, computer program, etc., are also valid aspects of the present disclosure.
[0008] According to the present disclosure, it is possible to prevent a grasped object from falling or stopping its rotation, and to perform rotation appropriately.
[0009] Schematic diagram for explaining an example of the configuration of a belt surface according to the first embodiment; Schematic diagram for explaining an example of the configuration of a belt surface according to the first embodiment; Schematic diagram for explaining an example of the configuration of an object; Schematic diagram for explaining the configuration of a comparative example of a robot hand; Schematic diagram for explaining the rotation of an object according to the first embodiment; Schematic diagram for explaining the rotation of an object according to the first embodiment; Schematic diagram for explaining the rotation of an object according to the first embodiment; Schematic diagram for explaining the rotation of an object according to the first embodiment;
[0010] (Background to the present disclosure) Conventionally, for purposes such as reducing workload and remote control, there has been a demand for systems equipped with robotic hands to perform various tasks instead of human hands. Human hands are capable of delicate movements, such as grasping an object using fingers or palms and changing the orientation of the object while grasping it. For example, the above-mentioned Patent Document 1 discloses a robotic hand with protrusions on the fingers that allows the grasped object to be rotated. However, objects grasped by robotic hands come in a variety of shapes, and depending on the shape, the object may fall or stop rotating during rotation. Therefore, further improvements to robotic hands are required to reliably rotate objects.
[0011] Hereinafter, with appropriate reference to the accompanying drawings, embodiments specifically disclosing a robot hand and a robot system according to the present disclosure will be described in detail. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters or redundant descriptions of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure and are not intended to limit the subject matter recited in the claims.
[0012] 1 is a block diagram showing an example of the configuration of a robot system 1 according to embodiment 1. The robot system 1 includes a robot part 10 that performs tasks such as grasping an object, and a control device 20 that controls the robot part 10.
[0013] The robot unit 10 includes a robot hand 100 that grasps an object. The robot hand 100 may be installed, for example, at the tip of a multi-joint (multi-axis) robot arm (not shown) in the robot unit 10 that is made up of multiple joints. An example configuration of the robot hand 100 will be described in detail using FIG. 2 and other figures. There are no particular limitations on the configuration or installation location of the robot unit 10.
[0014] The control device 20 includes a processing unit 21, a storage unit 22, a user interface (UI) unit 23, and an external interface 24, and each unit is connected to each other so as to be able to communicate with each other.
[0015] The processing unit 21 may be configured using, for example, a central processing unit (CPU), a micro processing unit (MPU), a digital signal processor (DSP), a graphic processing unit (GPU), or a field programmable gate array (FPGA). The storage unit 22 is a storage area for storing and holding various data, and may be configured, for example, with a non-volatile storage area such as a read only memory (ROM) or a hard disk drive (HDD), or a volatile storage area such as a random access memory (RAM). For example, the processing unit 21 reads out and executes various data and programs stored in the storage unit 22, thereby realizing various controls related to the rotational operation of an object, as will be described later.
[0016] The UI unit 23 receives data of instructions from a user via, for example, a mouse or keyboard (not shown). The UI unit 23 may further include an output unit for outputting various types of information data via a display (not shown).
[0017] The external interface 24 is connected to the robot unit 10 and further to the robot hand 100 via a wired or wireless network (not shown) and transmits and receives various data signals. Furthermore, the external interface 24 communicates with an external device (not shown) and transmits and receives various data and signals. The communication method used by the external interface 24 is not particularly limited, and multiple communication methods may be supported. For example, a wide area network (WAN), a local area network (LAN), power line communication, short-range wireless communication (e.g., Bluetooth (registered trademark)), etc. may be used.
[0018] The robot unit 10 and the control device 20 constituting the robot system 1 may be installed in separate locations, with the control device 20 remotely controlling the operation of the robot unit 10. While Fig. 1 shows the robot system 1 as including one robot unit 10 and one robot hand 100, the present invention is not limited to this. For example, one control device 20 may be configured to control the operation of multiple robot units 10 and multiple robot hands 100.
[0019] In the figures described below, the correspondence in three-dimensional space is shown using three-dimensional coordinate axes consisting of the X-axis, Y-axis, and Z-axis. The directions of the three-dimensional coordinate axes here are just an example, but in each figure, the directions of the axes will be described as corresponding to each other.
[0020] [Robot Hand] An example of the configuration of a robot hand 100 according to this embodiment will be described using Figure 2. In the following description, when components of the same type need to be individually explained, suffixes (a, b, ...) will be added to the reference numbers. On the other hand, when components of the same type can be generally explained, the suffixes will be omitted.
[0021] The robot hand 100 according to this embodiment is a two-fingered robot hand including two fingers 101a and 101b. The fingers 101a and 101b are each provided with a belt 102a and a belt 102b, respectively. The belts 102a and 102b are each an endless loop belt that can move along a predetermined direction by the operation of a motor (not shown) serving as a drive unit. In the example of FIG. 2, the belts 102a and 102b are each configured so that the surface that grips an object can move up and down along the Z-axis direction. Protrusions 103 and 104 are provided on the surfaces of the belts 102a and 102b that come into contact with the object. Details of the surface shapes of the belts 102a and 102b will be described later. The fingers 101a and 101b move along a predetermined direction by the operation of sliders 105a and 105b, respectively. In the example of FIG. 2, the fingers 101a and 101b are each configured to move along the X-axis direction. This movement along the X-axis direction causes the fingers 101 a and 101 b to move closer to or apart from each other. Note that a force sensor (not shown) and an imaging unit for determining the posture of the object being grasped may also be provided, and the opening and closing of the fingers 101 a and 101 b may be controlled based on the detection results thereof.
[0022] For example, the upper part of the robot hand 100 shown in Fig. 2 is connected to the tip of a robot arm (not shown) and is configured to be controllable by the control device 20. In this embodiment, an object grasped by being pinched between the fingers 101a and 101b is controlled to rotate around the Y axis. Therefore, the operations of the motors (not shown) for operating the belts 102a and 102b and the sliders 105a and 105b for moving the fingers 101a and 101b are controlled by control signals from the control device 20.
[0023] The robot hand 100 may be configured to be detachable from a robot arm (not shown) of the robot unit 10. For example, it is expected that the configuration of the robot hand 100, particularly the shape and arrangement of the surface of the belt 102 (described later), will be changed depending on the type and size of the object to be grasped by the robot hand 100. Therefore, the robot hand 100 may be switchable depending on the object.
[0024] [Belt Configuration] FIG. 3 is a schematic diagram illustrating the surface shape of a belt 102 according to this embodiment. Protrusions 103 and 104 are provided on the surface of the belt 102 according to this embodiment. FIG. 3(a) is a schematic cross-sectional view and a schematic perspective view showing a portion of the belt 102. Protrusions 103a, 103b, and 103c are shown as recesses on the surface (first surface) of the belt 102a. Protrusions 104a, 104b, and 104c are shown as convex portions on the surface (second surface) of the belt 102b. For convenience, the portions of the surface of the belt 102 between the protrusions 103 and 104 are also referred to as "grooves." As shown in FIGS. 3(b) and 3(c), the shapes of the protrusions 103 and 104 are defined so that the protrusions 103 on the surface of the belt 102a and the protrusions 104 on the surface of the belt 102b mesh with each other. In this embodiment, protrusions 103 and 104 have a concave-convex shape that interlocks with each other. Furthermore, as shown in FIG. 3C , when finger 101 a and finger 101 b are closest to each other along the X-axis direction and protrusions 103 and 104 are interlocked, the gap between belt 102 a and belt 102 b (the distance between opposing grooves) may be determined based on the minimum width Wmin of the size of object 200 that is expected to be grasped and rotated. Details of the size of object 200 and the size of the protrusions will be described later.
[0025] FIG. 4( a) is a schematic diagram showing a portion of the finger 101a. Two protrusions 103a and 103b are shown on a belt 102a provided on the finger 101a. In this embodiment, the protrusions 103 as recesses all have the same shape. Similarly, in this embodiment, the protrusions 104 as convex portions provided on the belt 102b all have the same shape. For convenience, the height of the protrusion 103 from the surface of the belt 102a on the surface that grips an object is defined as Hc. The length (width) of the protrusion 103 along the Z-axis direction is defined as Wc. The length (spacing) between the protrusions 103 (i.e., the grooves) along the Z-axis (in this example, the extension direction of the fingers) is defined as Lc.
[0026] Taking into consideration the relationship with the object 200 during a rotation operation, Wc is preferably smaller than the minimum width Wmin of the object 200, which will be described later. On the other hand, the length along the Y-axis direction in which each of the protrusions 103 and 104 can come into contact with the object 200 is preferably larger, taking into consideration securing a grippable area during a rotation operation. Furthermore, each of the protrusions 103 and 104 has a flat surface at the location where it comes into contact with the object 200. By specifying the dimensions and shape of the protrusions 103 and 104, it is possible to generate appropriate friction during rotation and secure a desired contact area.
[0027] In the example shown in Figure 4, the groove lengths Lc of the belts 102a and 102b are the same, but this is not limiting. For example, the Lc of the belt 102a and the Lc of the belt 102b may be different. Also, the spacing (plurality of Lc) between the multiple protrusions 103 provided on the belt 102a may be different. Similarly, the spacing (plurality of Lc) between the multiple protrusions 104 provided on the belt 102b may be different.
[0028] Furthermore, it is preferable that Hc is sufficiently smaller than Lf, which is the length of the finger portion 101. This is useful, for example, in preventing the object to be grasped from getting caught on the protrusions 103 and 104 more than necessary.
[0029] 4B is a schematic diagram illustrating the positional relationship between the opposing fingers 101a and 101b. The movement range of the fingers 101a and 101b in the X-axis direction is defined so that the movement range is at least greater than the maximum width Wmax of the object to be grasped and rotated at the position where the tip of the protrusion 103 of the finger 101a and the tip of the protrusion 104 of the finger 101b face each other. Therefore, under the above conditions, the width Wo between the opposing protrusions 103 and 104 of the belts 102a and 102b is defined.
[0030] Furthermore, the grooves and the surfaces of the protrusions 103 and 104, i.e., the surfaces that may come into contact with the object 200, have characteristics that generate a certain level of friction with the object 200 to be grasped. The friction realized on the surfaces of the protrusions 103 and 104 is specified to prevent slippage when grasping and rotating the object 200. The friction here may be specified by the shape and material of the surfaces of the protrusions 103 and 104, and may also be specified based on the relationship with the object 200 to be grasped. Furthermore, in the belts 102a and 102b, the friction and hardness characteristics with respect to the object 200 may be different between the protrusions 103 and 104 and the grooves. For example, the friction between the surface of the grooves and the object 200 may be configured to be lighter than the friction between the surface of the protrusions 103 and 104 and the object 200. Furthermore, the grooves of the belts 102a and 102b may be configured to allow slack.
[0031] Figure 5 conceptually shows the shape of an object to be grasped by the robot hand 100 according to this embodiment. Here, a conceptual diagram is shown as viewed along the rotation axis direction (the Y-axis direction in the case of Figure 2). Generally, when viewed along the rotation axis direction, square or circular objects can be easily rotated by the robot hand. In contrast, when viewed along the rotation axis direction, it can be difficult to rotate objects that are oval or polygonal, for example, and have a large difference between their long and short sides.
[0032] For example, FIG. 5( a) shows an example of object 200a having an elliptical cross section along the rotation axis (Y-axis in this example). Object 200a has a large difference (ratio) between its maximum width Wmax and minimum width Wmin, which can cause the object to fall or stop rotating during a rotation operation. FIG. 5( b) shows an example of object 200b having a triangular cross section along the rotation axis. Like FIG. 5( a), this example also has a large difference (ratio) between its maximum width Wmax and minimum width Wmin, which can cause the object to fall or stop rotating during a rotation operation. More specifically, as the longitudinal direction of the object corresponding to the maximum width Wmax approaches the vertical direction, i.e., the Z-axis direction, with the rotation operation, the object is more likely to fall. Furthermore, when the longitudinal direction of the object corresponding to the maximum width Wmax moves away from the vertical direction, i.e., the Z-axis direction, with the rotation operation, the rotational force cannot be applied appropriately, which can cause the rotation to stall.
[0033] The object 200 assumed in this embodiment is a rigid object having a certain degree of hardness. A soft object is generally easier to rotate than a rigid object because its surface shape can be deformed (crushed) to conform to the shape of a belt or the like, ensuring a certain or greater contact area and generating frictional force. Therefore, this embodiment will be described assuming a rigid object, which is more useful for rotating the object 200 by hooking it onto a protrusion.
[0034] FIG. 6 is a schematic diagram showing an example of the configuration of a robot hand as a comparative example to the robot hand 100 according to the present embodiment. In the robot hand shown in FIG. 6, similar to FIG. 4, finger 301a includes belt 302a, and finger 301b includes belt 302b. Here, belts 302a and 302b each have protrusions, but the distance between the protrusions is narrower than in the configuration of FIG. 4 according to the present embodiment. In other words, the distance between the protrusions provided on belts 302a and 302b (the length of the groove in the Z-axis direction) is smaller than the minimum width of object 200. Other than the configuration of the belts, the robot hand is the same as FIG. 4.
[0035] [Rotation Operation Example] FIG. 7 is a schematic diagram illustrating the rotation operation of an object 200 performed by the robot hand 100 according to this embodiment. Here, the object 200 is rotated counterclockwise around the rotation axis. For convenience, a circle (◯) is drawn around the object 200 to clearly indicate the rotation state. As shown in FIG. 7( a), the corners of the object 200 (indicated by the dashed circle) are in contact with the protrusions 103b and 104a on the belts 102a and 102b, respectively, so that a certain frictional force is generated. When rotating the object 200, the belt 102a of the finger 101a and the belt 102b of the finger 101b are moved along the Z-axis direction according to the rotation direction. Furthermore, the drive units (not shown) of the sliders 105a and 105b also control the movement of at least one of the fingers 101a and 101b in the X-axis direction to apply an appropriate force in the X-axis direction to the object 200.
[0036] 7(b) shows a state where the rotation operation has progressed from that shown in FIG. 7(a), and the longitudinal direction of the object 200 is aligned with the Z-axis direction. In this state, the corners of the object 200 (shown by the dashed circles) are caught on the protrusions 103a and 104b provided on the belts 102a and 102b, respectively.
[0037] 8 is a diagram for explaining the flow of the object 200 rotating half a turn (180°) by the robot hand 100 according to this embodiment. Here, a case where the object 200 is rotated counterclockwise will be explained, focusing on the protrusions 103 and 104 provided on each belt. Although the three-dimensional coordinate system is omitted in FIG. 8, the state viewed in the direction of the rotation axis (Y-axis) is shown, similar to FIG. 7 and the like.
[0038] 8A, in an initial state, the robot hand 100 grasps an object 200 placed at an arbitrary position. At this time, the object 200 is grasped in a region (groove) surrounded by the protrusions 103b, 103c, 104b, and 104c.
[0039] Next, as shown in FIG. 8B, the belts 102a and 102b are moved upward along the Z-axis direction to move the object 200 to a position where it will be rotated (for example, near the center position of the fingers 101a and 101b).
[0040] Next, as shown in FIG. 8C, the belt 102a is moved downward in the Z-axis direction, and the belt 102b is moved upward in the Z-axis direction.
[0041] 8(d), as each belt moves, diagonal corners of object 200 get caught on protrusions 103b of belt 102a and protrusions 104c of belt 102b, starting to rotate object 200. At this time, the drive units (not shown) of sliders 105a and 105b also control the movement of at least one of fingers 101a and 101b in the X-axis direction to apply an appropriate force in the X-axis direction to object 200.
[0042] Furthermore, as shown in Figures 8(e) to 8(g), by moving belt 102a downward in the Z-axis direction and moving belt 102b upward in the Z-axis direction, the rotation of object 200 progresses so that object 200 is grasped by protrusion 103b of belt 102a and protrusion 104c of belt 102b.
[0043] Furthermore, as shown in Figure 8 (h), by moving belt 102a downward in the Z-axis direction and moving belt 102b upward in the Z-axis direction, object 200 becomes grasped in the area (groove) surrounded by protrusions 103a, 103b, 104c, and 104d.
[0044] 8(i) to 8(j), belt 102a is moved downward in the Z-axis direction, and belt 102b is moved upward in the Z-axis direction, thereby completing a half rotation of object 200. When object 200 is further rotated counterclockwise (for example, one rotation), the process is repeated from the state corresponding to FIG. 8(d). At this time, the combination of protrusions gripping object 200 is changed appropriately.
[0045] When the object 200 is rotated clockwise, the moving directions of the belts 102a and 102b in FIGS. 8(b) to 8(j) are reversed.
[0046] In the comparative example configuration shown in FIG. 6 , the distance between the protrusions on each belt is relatively short compared to the shape and size of the object, making it difficult to hook the corners or tip of the object 200 onto the protrusions on the belt. Therefore, with the conventional configuration, sufficient force cannot be applied to the object 200 during the rotation operation, which may cause the object 200 to fall or stop rotating. In contrast, with the configuration shown in FIG. 7 according to the present embodiment, the corners of the object 200 can be reliably hooked onto the protrusions 103 and 104. Therefore, an appropriate force can be applied to the object 200 during the rotation operation, making it possible to prevent the object 200 from falling or stopping its rotation.
[0047] Furthermore, in this embodiment, since protrusions 103 and 104 are shaped to interlock with each other, the opposing surfaces of belts 102a and 102b, i.e., the opening width in the X-axis direction, can be made as close as possible to each other, making it possible to properly grip even objects with a relatively small minimum width Wmin.
[0048] (Modification) [Robot Hand] Fig. 9 is an external perspective view showing a modification of a robot hand 900 according to the present embodiment. In the example shown in Fig. 2, two fingers 101a, 101b are equipped with endless looped belts 102a, 102b, respectively, which operate independently to rotate an object around the Y axis. In contrast, in this modification, a configuration will be described in which the fingers themselves move up and down instead of the belts at the object gripping portions.
[0049] The robot hand 900 according to this embodiment includes two fingers 901a and 901b. Finger 901a includes a gripping member 902a, and finger 901b includes a gripping member 902b. Finger 901a and gripping member 902a move together. Finger 901b and gripping member 902b move together. Gripping member 902a includes a concave protrusion 903 on its surface. Gripping member 902b includes a convex protrusion 904 on its surface. The surface shapes of gripping members 902a and 902b may be equivalent to the configuration described using FIG. 4 .
[0050] Finger 901a is connected to drive unit 906a, and finger 901b is connected to drive unit 906b. Drive units 906a and 906b respectively move fingers 901a and 901b along the Z-axis direction by the operation of a motor (not shown) or the like. As a result, finger 901a and gripping member 902a, and finger 901b and gripping member 902b, respectively, move integrally along the Z-axis direction. Furthermore, finger 901a and finger 901b move in a predetermined direction by the operation of slider 905a and slider 905b. In the example of FIG. 9 , finger 901a and finger 901b move along the X-axis direction. This movement along the X-axis direction causes finger 901a and finger 901b to approach or move apart.
[0051] For example, the upper part of the robot hand 100 shown in Fig. 9 is connected to the tip of a robot arm (not shown) and is configured to be controllable by the control device 20. In this modification, an object grasped by being pinched between the fingers 901a and 901b is controlled to be rotated around the Y axis. Specific examples of the rotation operation will be described later using Figs. 10 to 12.
[0052] [Example of Rotation Operation] Fig. 10 is a schematic diagram of a rotation operation of the object 200 performed by the robot hand 900 according to this modification. Here, the object 200 is rotated counterclockwise. For convenience, a circle (o) is drawn around the object 200 to clearly indicate the rotation state. In this modification, the finger 901a and the finger 901b themselves move up and down, respectively, to achieve rotation of the object 200 around the Y axis. As shown in Fig. 10(a), the corners of the object 200 are in contact with the protrusions 903b and 904a provided on the gripping members 902a and 902b, respectively, so as to generate a certain frictional force.
[0053] 10(b) shows a state where the rotation operation has progressed from that shown in FIG. 10(a), with the longitudinal direction of object 200 aligned with the Z-axis direction. In this state, object 200 is gripped by contact with the groove between protrusions 903a and 903b of gripping member 902a and the groove between protrusions 904a and 904b of gripping member 902b.
[0054] 11 is a diagram illustrating the flow of the object 200 rotating counterclockwise in a half-rotation by the robot hand 900 according to this modification. Here, the description focuses on the protrusions 903 and 904 provided on the gripping members 902a and 902b. Although the three-dimensional coordinate system is omitted in FIGS. 11 and 12, the state viewed in the direction of the rotation axis (Y-axis) is shown, similar to FIG. 10 and the like.
[0055] 11A, in an initial state, the robot hand 100 grasps the object 200 placed at an arbitrary position. At this time, the object 200 is grasped in a region (groove) surrounded by the protrusions 903b, 903c, 904a, and 904b.
[0056] 11B, the finger 901b is moved upward in the Z-axis direction. Note that the finger 901a and the finger 901b can move independently in the Z-axis direction or the X-axis direction, but here, an example is shown in which the finger 901a is fixed and the finger 901b is moved in the Z-axis direction to rotate the object 200 counterclockwise.
[0057] 11(c), as the fingers move, diagonal corners of object 200 get caught on protrusions 903b of gripping member 902a and protrusions 904b of gripping member 902b, starting to rotate object 200. At this time, the drive units (not shown) of sliders 905a and 905b also control the movement of at least one of fingers 901a and 901b in the X-axis direction in order to apply an appropriate force in the X-axis direction to object 200.
[0058] Furthermore, as shown in Figures 11(d) to 11(e), by moving finger portion 901b upward in the Z-axis direction, the rotation of object 200 progresses so that object 200 is grasped by protrusion portion 903b of grasping member 902a and protrusion portion 904b of grasping member 902b.
[0059] Furthermore, as shown in Figures 11(f) to 11(g), by moving finger portion 901b upward in the Z-axis direction, object 200 is grasped in the area (groove portion) surrounded by protrusions 903a, 903b, 904b, and 904c.
[0060] Furthermore, as shown in FIG. 11( h ), by moving the finger 901 b upward in the Z-axis direction, the object 200 completes a half rotation.
[0061] 12 is a diagram illustrating the flow of the object 200 rotating half a clockwise direction by the robot hand 900 according to this modification. Here, the description focuses on the protrusions 903 and 904 provided on the gripping members 902 a and 902 b, respectively.
[0062] 12A, in an initial state, the robot hand 100 grasps an object 200 placed at an arbitrary position. At this time, the object 200 is grasped in a region (groove) surrounded by the protrusions 903a, 903b, 904b, and 904c.
[0063] 12B, the finger 901a is moved upward in the Z-axis direction. Here, an example is shown in which the finger 901b is fixed and the finger 901a is moved in the Z-axis direction to rotate the object 200 clockwise.
[0064] 12(c), as the fingers move, diagonal corners of object 200 get caught on protrusions 903b of gripping member 902a and protrusions 904b of gripping member 902b, starting to rotate object 200. At this time, the drive units (not shown) of sliders 905a and 905b also control the movement of at least one of fingers 901a and 901b in the X-axis direction in order to apply an appropriate force in the X-axis direction to object 200.
[0065] Furthermore, as shown in Figures 12(d) to 12(e), by moving finger portion 901a upward in the Z-axis direction, the rotation of object 200 progresses so that object 200 is grasped by protrusion 903b of grasping member 902a and protrusion 904b of grasping member 902b.
[0066] Furthermore, as shown in Figures 12(f) to 12(g), by moving finger portion 901a upward in the Z-axis direction, object 200 is grasped in the area (groove portion) surrounded by protrusions 903b, 903c, 904a, and 904b.
[0067] Furthermore, as shown in FIG. 12( h ), by moving the finger 901 a upward in the Z-axis direction, the object 200 completes a half rotation.
[0068] Note that the movement of the fingers 901a and 901b in the Z-axis direction during the rotation operation described above is an example and is not limited to this. For example, in FIGS. 11 and 12 , the object 200 is rotated by moving one of the fingers 901a and 901b in the Z-axis direction and fixing the other. However, the rotation operation may be achieved by moving both fingers in a predetermined direction in the Z-axis direction. Furthermore, the movement of each finger in the Z-axis direction during the rotation operation may be switched depending on the size of the object 200 to be grasped, etc.
[0069] 9 according to the modified example, the finger 901 and the gripping member 902 are integrally movable along the Z-axis direction, but the present invention is not limited to this. For example, the finger 901 itself may not move along the Z-axis direction, and only the gripping member having the protrusion may move along the Z-axis direction.
[0070] As described above, according to this embodiment, the robot hand (for example, the robot hand 100) includes a first finger (for example, the finger 101a) having a plurality of first protrusions (for example, the protrusions 103a and 103b) on a surface that grips an object (for example, the object 200), a second finger (for example, the finger 101b) having a plurality of second protrusions (for example, the protrusions 104a and 104b) on a surface that grips the object, and the first finger and the second finger are used to grip the object. and a drive unit (e.g., sliders 105a, 105b, motor) that rotates the object around a rotation axis (e.g., the Y axis), wherein the spacing between the multiple first protrusions is defined to be longer than the maximum width of the object along the extension direction of the first finger portions when grasping and rotating the object, and the spacing between the multiple second protrusions is defined to be longer than the maximum width of the object along the extension direction of the second finger portions when grasping and rotating the object.
[0071] This makes it possible to provide a robot hand that can prevent an object from falling or stopping rotation when rotating the object.
[0072] In addition, in the robot hand, the first protrusion and the second protrusion have concave and convex shapes that interlock when the surface of the first finger that grips the object and the surface of the second finger that grips the object approach each other via a drive unit. In addition, in the robot hand, the height of the first protrusion from the surface of the first finger that grips the object is smaller than the minimum width of the object and greater than half of the minimum width of the object, and the height of the second protrusion from the surface of the second finger that grips the object is smaller than the minimum width of the object and greater than half of the minimum width of the object. In addition, in the robot hand, the height of the first protrusion from the surface of the first finger that grips the object and the height of the second protrusion from the surface of the second finger that grips the object are the same.
[0073] This allows the protrusions on the surface of the fingers that grip the object to interlock, making it possible to reduce the minimum width of the object that can be handled, and making it possible to grip and rotate even thinner objects.
[0074] In addition, in the robot hand, the length of the first protrusion along the extension direction of the first finger and the length of the second protrusion along the extension direction of the second finger are each smaller than the minimum width of the object.
[0075] This makes it possible to prevent sliding between the object and the protrusions and unnecessary friction when the object is rotated.
[0076] In addition, in the robot hand, the intervals between the multiple first protrusions along the extension direction of the first finger portion are different from the intervals between the multiple second protrusions along the extension direction of the second finger portion. In addition, in the robot hand, the multiple intervals between the multiple first protrusions along the extension direction of the first finger portion are different from each other, and the multiple intervals between the multiple second protrusions along the extension direction of the second finger portion are different from each other.
[0077] This makes it possible to determine the arrangement of the protrusions in consideration of the size and shape of the object to be grasped.
[0078] Furthermore, in the robot hand, the drive unit causes the first finger portion and the second finger portion to grasp the object by bringing the surface of the first finger portion that grasps the object and the surface of the second finger portion that grasps the object closer together, and rotates the object grasped by the first finger portion and the second finger portion around the rotation axis by moving at least one of the surface of the first finger portion that grasps the object and the surface of the second finger portion that grasps the object along the extension direction of the corresponding finger portion.
[0079] This makes it possible to grasp and rotate an object by moving the surfaces of the fingers that grasp the object.
[0080] In the robot hand, the surface of the first finger that grips an object is formed by a first belt (e.g., belt 102a) driven by a drive unit along the extension direction of the first finger, the first protrusion being provided on the surface of the first belt, the surface of the second finger that grips an object is formed by a second belt (e.g., belt 102b) driven by a drive unit along the extension direction of the second finger, the second protrusion being provided on the surface of the second belt, and the drive unit rotates the object gripped by the first finger and the second finger around the rotation axis by moving at least one of the first belt and the second belt along the extension direction of the corresponding finger. In the robot hand, at least two first protrusions and two second protrusions are provided along the extension direction of the corresponding finger.
[0081] This makes it possible to rotate an object by moving a belt having at least two protrusions on the surface of the finger.
[0082] In the robot hand, the drive unit rotates an object grasped by the first finger and the second finger around a rotation axis by moving at least one of the first finger and the second finger along the extension direction. In the robot hand, at least three first protrusions and at least three second protrusions are provided along the extension direction of the corresponding finger.
[0083] This makes it possible to rotate an object by moving the finger itself, which has at least three protrusions on its surface.
[0084] In addition, in the robot hand, the surfaces of the first protrusions and the second protrusions are configured to generate a predetermined frictional force against an object, and in the robot hand, the surfaces between the plurality of first protrusions and the surfaces between the plurality of second protrusions are configured to generate a predetermined frictional force against an object.
[0085] This allows the desired friction force to be provided between the object and the surface of the protrusion, or between the object and the groove, thereby preventing the object from slipping during gripping or rotation, and enabling proper gripping and rotation.
[0086] In addition, in the robot hand, the multiple first protrusions have the same shape, and the multiple second protrusions have the same shape.
[0087] This allows the projections provided on the two fingers to have a unified configuration.
[0088] The robot system (e.g., robot system 1) also includes a robot hand (e.g., robot hand 100) and a control device (e.g., control device 20) for controlling the drive unit (e.g., sliders 105a, 105b, motor).
[0089] This makes it possible to provide a robot system equipped with a robot hand that can prevent an object from falling or stopping rotation when rotating the object.
[0090] <Other Embodiments> In the above embodiment, an example is shown in which an object is grasped from above in the Z-axis direction defined in the figure, but similar control is possible when the object is grasped from the X-axis or Y-axis direction. In this case, the direction of the rotation axis changes. Furthermore, by combining the operation of the robot arm to which the robot hand is connected and the operation of the connection between the robot hand and the robot arm, rotation around the Z-axis and rotation around the X-axis by the robot hand may be performed simultaneously in parallel.
[0091] Furthermore, in the above embodiment, three orthogonal axes (X-axis, Y-axis, and Z-axis) were shown, and the movement of the robot hand was described in relation to these axes. However, the axis and direction of the movement of the robot hand do not necessarily need to be orthogonal to the rotation axis (Y-axis in the above example). Depending on the joints and opening / closing direction of the fingers of the robot hand, the movement direction and direction of the movement of the robot hand may not be orthogonal to the rotation axis. For example, in the above embodiment, the opening and closing direction of the fingers is the X-axis direction, which is orthogonal to the Y-axis direction. However, this opening and closing direction may form a certain angle with respect to the X-axis direction. Furthermore, the movement direction of the fingers or gripping members may form a certain angle with respect to the Z-axis direction. Even in such cases, the above embodiment can be applied by adjusting the configuration of the fingers, particularly the configuration of the gripping members.
[0092] In addition, although the above embodiment shows an example of a robot hand with two fingers, the present invention is not limited to this. For example, a robot hand with three or more fingers may be configured such that at least two of the fingers have the above-described structure.
[0093] In addition, the functions of one or more of the above-described embodiments can be realized by supplying a program and application to a system or device using a network or storage medium, and having one or more processors in the computer of the system or device read and execute the program.
[0094] Alternatively, the functions may be realized by a circuit that realizes one or more functions (for example, an Application Specific Integrated Circuit (ASIC) or a Field Programmable Gate Array (FPGA)).
[0095] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to these examples. It is clear to those skilled in the art that various modifications, alterations, substitutions, additions, deletions, and equivalents may be made within the scope of the claims, and it is understood that these also fall within the technical scope of the present disclosure. Furthermore, the components of the various embodiments described above may be combined in any manner without departing from the spirit of the invention.
[0096] (Additional Note) The above-described embodiments disclose the following techniques.
[0097] (Technology 1) A robot hand comprising: a first finger having a plurality of first protrusions on a surface that grips an object; a second finger having a plurality of second protrusions on a surface that grips the object; and a drive unit that causes the first finger and the second finger to grip the object and rotate the object about a first axis, wherein the spacing between the plurality of first protrusions is defined to be longer than a maximum width of the object along the extension direction of the first finger when gripping and rotating the object; and the spacing between the plurality of second protrusions is defined to be longer than a maximum width of the object along the extension direction of the second finger when gripping and rotating the object.
[0098] This configuration makes it possible to provide a robot hand that can prevent an object from dropping or stopping when rotating it.
[0099] (Technology 2) The robot hand according to Technology 1, wherein the first protrusion and the second protrusion have shapes of protrusions and recesses that interlock when a surface of the first finger that grips the object and a surface of the second finger that grips the object approach each other by the drive unit.
[0100] With this configuration, the protrusions on the surface of the fingers that grip the object can interlock, making it possible to reduce the minimum width of the object that can be handled, making it possible to grip and rotate even thinner objects.
[0101] (Technology 3) A robot hand according to Technology 1 or Technology 2, wherein a height of the first protrusion from a surface of the first finger portion that grips the object is smaller than a minimum width of the object and larger than half the minimum width of the object, and a height of the second protrusion from a surface of the second finger portion that grips the object is smaller than a minimum width of the object and larger than half the minimum width of the object.
[0102] This configuration allows for the gripping and rotation of thinner objects.
[0103] (Technology 4) The robot hand according to any one of Technology 1 to Technology 3, wherein a height of the first protrusion from a surface of the first finger portion that grips the object and a height of the second protrusion from a surface of the second finger portion that grips the object are the same.
[0104] This configuration allows the heights of the recesses and protrusions to be matched, narrowing the minimum distance between the grooves, and enabling gripping and rotational manipulation of thinner objects.
[0105] (Technology 5) The robot hand according to any one of Technology 1 to Technology 4, wherein a length of the first protrusion along the extension direction of the first finger portion and a length of the second protrusion along the extension direction of the second finger portion are each smaller than a minimum width of the object.
[0106] This configuration makes it possible to suppress the occurrence of sliding between the object and the protrusions and the occurrence of excessive friction when the object is rotated.
[0107] (Technology 6) The robot hand according to any one of Technology 1 to Technology 5, wherein an interval between the plurality of first protrusions along the extension direction of the first finger portion is different from an interval between the plurality of second protrusions along the extension direction of the second finger portion.
[0108] This configuration makes it possible to determine the arrangement of the protrusions in consideration of the size and shape of the object to be grasped.
[0109] (Technology 7) A robot hand according to any one of Technology 1 to Technology 6, wherein a plurality of intervals between the plurality of first protrusions along the extension direction of the first finger portion are different from each other, and a plurality of intervals between the plurality of second protrusions along the extension direction of the second finger portion are different from each other.
[0110] This configuration makes it possible to determine the arrangement of the protrusions in consideration of the size and shape of the object to be grasped.
[0111] (Technology 8) The robot hand according to any one of Technology 1 to Technology 7, wherein the drive unit causes a surface of the first finger portion that grips the object and a surface of the second finger portion that grips the object to approach each other, thereby gripping the object with the first finger portion and the second finger portion, and rotates the object gripped by the first finger portion and the second finger portion around the first direction by moving at least one of the surface of the first finger portion that grips the object and the surface of the second finger portion that grips the object along an extension direction of the corresponding finger portion.
[0112] With this configuration, it is possible to grasp and rotate an object by moving the surfaces of the fingers that grasp the object.
[0113] (Technology 9) A robot hand according to Technology 8, wherein a surface of the first finger portion that grips the object is formed by a first belt that is driven by the driving unit along the extension direction of the first finger portion, the first protrusion is provided on a surface of the first belt, a surface of the second finger portion that grips the object is formed by a second belt that is driven by the driving unit along the extension direction of the second finger portion, the second protrusion is provided on a surface of the second belt, and the driving unit rotates the object gripped by the first finger portion and the second finger portion around the rotation axis by moving at least one of the first belt and the second belt along the extension direction of the corresponding finger portion.
[0114] With this configuration, it is possible to rotate an object by moving the belt with the protrusions on the surface of the finger.
[0115] (Technology 10) The robot hand according to Technology 9, wherein at least two of the first protrusions and at least two of the second protrusions are provided along the extension direction of the corresponding finger portions.
[0116] This configuration makes it possible to grasp and rotate an object using a belt having at least two protrusions on its surface.
[0117] (Technology 11) The robot hand according to Technology 8, wherein the drive unit rotates the object grasped by the first finger portion and the second finger portion around the rotation axis by moving at least one of the first finger portion and the second finger portion along an extension direction.
[0118] With this configuration, it is possible to rotate an object by moving the finger itself.
[0119] (Technology 12) The robot hand according to Technology 11, wherein at least three of the first protrusions and at least three of the second protrusions are provided along the extension direction of the corresponding finger.
[0120] With this configuration, it is possible to rotate an object by moving the finger itself, which has at least three protrusions on its surface.
[0121] (Technology 13) The robot hand according to any one of Technology 1 to Technology 12, wherein surfaces of the first protrusion and the second protrusion are configured to generate a predetermined friction force with respect to the object.
[0122] This configuration can provide a desired friction force between the object and the surface of the protrusion, allowing for proper gripping and rotation.
[0123] (Technology 14) The robot hand according to any one of Technology 1 to Technology 13, wherein a surface between the plurality of first protrusions and a surface between the plurality of second protrusions are configured to generate a predetermined friction force with respect to the object.
[0124] This configuration can provide a desired friction force between the object and the grooves on the surface of the fingers, allowing for proper gripping and rotation.
[0125] (Technology 15) The robot hand according to any one of Technology 1 to Technology 14, wherein the plurality of first protrusions have the same shape, and the plurality of second protrusions have the same shape.
[0126] This configuration allows the projections provided on the two fingers to have a single configuration.
[0127] (Technology 16) A robot system comprising: the robot hand according to any one of Technology 1 to Technology 15; and a control device for controlling the drive unit.
[0128] This configuration makes it possible to provide a robot system equipped with a robot hand that can prevent an object from falling or stopping rotation when rotating the object.
[0129] The present disclosure is useful as a robot hand and a robot system including the robot hand.
[0130] DESCRIPTION OF SYMBOLS 1...ROBOT SYSTEM 10...ROBOT SECTION 20...CONTROL DEVICE 21...PROCESSING UNIT 22...MEMORY UNIT 23...USER INTERFACE (UI) UNIT 24...EXTERNAL INTERFACE (IF) 100...ROBOT HAND 101...FINGER SECTION 102...BELT 103, 104...PROJECTION SECTION 105...SLIDER 900...ROBOT HAND 901...FINGER SECTION 902...GRIP MEMBER 903, 904...PROJECTION SECTION 905...SLIDER 906...DRIVE UNIT
Claims
1. A robot hand comprising: a first finger portion having a plurality of first protrusions on a first surface for gripping an object; a second finger portion having a plurality of second protrusions on a second surface for gripping the object; and a drive unit that causes the first finger portion and the second finger portion to grip the object and rotate the object about an axis of rotation, wherein the spacing between the plurality of first protrusions is defined to be longer than a maximum width of the object along the extension direction of the first finger portion when gripping and rotating the object; and the spacing between the plurality of second protrusions is defined to be longer than a maximum width of the object along the extension direction of the second finger portion when gripping and rotating the object.
2. A robot hand as described in claim 1, wherein the shapes of the first protrusion and the second protrusion are concave and convex shapes that interlock when the first surface of the first finger portion and the second surface of the second finger portion are brought close together by the driving unit.
3. The robot hand described in claim 1, wherein a height of the first protrusion from the first surface of the first finger portion is smaller than the minimum width of the object and greater than half of the minimum width of the object, and a height of the second protrusion from the second surface of the second finger portion is smaller than the minimum width of the object and greater than half of the minimum width of the object.
4. A robot hand as described in claim 1, wherein the height of the first protrusion from the first surface of the first finger portion and the height of the second protrusion from the second surface of the second finger portion are the same.
5. A robot hand as described in claim 1, wherein the length of the first protrusion along the extension direction of the first finger portion and the length of the second protrusion along the extension direction of the second finger portion are each smaller than the minimum width of the object.
6. A robot hand as described in claim 1, wherein the spacing between the multiple first protrusions along the extension direction of the first finger portion is different from the spacing between the multiple second protrusions along the extension direction of the second finger portion.
7. The robot hand described in claim 1, wherein a plurality of intervals between the plurality of first protrusions along the extension direction of the first finger portion are different from each other, and a plurality of intervals between the plurality of second protrusions along the extension direction of the second finger portion are different from each other.
8. The robot hand described in claim 1, wherein the driving unit causes the first surface of the first finger portion and the second surface of the second finger portion to approach each other, thereby gripping the object with the first finger portion and the second finger portion, and the driving unit causes the object gripped by the first finger portion and the second finger portion to rotate around the rotation axis by moving the first surface along the extension direction of the first finger portion.
9. The robot hand described in claim 8, wherein the first surface of the first finger portion is formed by a first belt driven by the driving unit along the extension direction of the first finger portion, the first protrusion portion is provided on a surface of the first belt, the second surface of the second finger portion is formed by a second belt driven by the driving unit along the extension direction of the second finger portion, the second protrusion portion is provided on the surface of the second belt, and the driving unit rotates the object grasped by the first finger portion and the second finger portion around the rotation axis by moving the first belt along the extension direction of the first finger portion.
10. A robot hand as described in claim 9, wherein the plurality of first protrusions are arranged along the extension direction of the first finger portion, and the plurality of second protrusions are arranged along the extension direction of the second finger portion.
11. The robot hand described in claim 8, wherein the drive unit rotates the object grasped by the first finger portion and the second finger portion around the rotation axis by moving the first finger portion along the extension direction of the first finger portion.
12. A robot hand as described in claim 11, wherein the plurality of first protrusions includes at least three first protrusions arranged along the extension direction of the first finger portion, and the plurality of second protrusions includes at least three second protrusions arranged along the extension direction of the second finger portion.
13. The robot hand according to claim 1, wherein the surface of the first protrusion and the surface of the second protrusion are configured to generate a predetermined frictional force against the object.
14. The robot hand according to claim 1, wherein the surfaces between the plurality of first protrusions and the surfaces between the plurality of second protrusions are configured to generate a predetermined frictional force against the object.
15. The robot hand of claim 1, wherein the first protrusions have the same shape, and the second protrusions have the same shape.
16. A robot system comprising: a robot hand according to any one of claims 1 to 15; and a control device for controlling the drive unit.