JP2016068192A - Robot hand and robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize one or two or more functions of a fitting mechanism, parallel opening and closing of a fingertip, amplification of a bending angle of the fingertip at the time of fitting operation and full opening of a finger portion so as to bring a palm portion into direct contact with an object body with a small number of actuators and to provide a robot hand in low costs.SOLUTION: A robot hand comprises: a base 11; a finger portion 13 provided on the base 11. The finger portion 13 includes: a first link 21; a second link 22; a third link 23; a fourth link 24; a first rotary shaft 31 connecting the first link 21 and the second link 22 in a rotatable manner; a second rotary shaft 32 connecting the second link 22 and the third link 23 in the rotatable manner; a third rotary shaft 33 connecting the third link 23 and the fourth link 24 in the rotatable manner; and a fourth rotary shaft 34 connecting the fourth link 24 and the first link 21 in the rotatable manner.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a robot hand and a robot.

Non-Patent Document 1 and Patent Document 1 disclose the technology of a robot hand having a conforming mechanism using an underactuated link. By adopting the under-actuated link, more joints than the number of actuators are driven, and a familiar mechanism is realized. The familiar mechanism allows a large area to be contacted between the object and the finger when the object is gripped, thereby enabling stable gripping.
Patent Documents 2 and 3 and Non-Patent Document 2 disclose techniques for simultaneously realizing a conforming mechanism using an underactuated link and a mechanism for opening and closing a fingertip in parallel. As a result, stable gripping by the conforming mechanism and precise object gripping by parallel opening and closing can be performed simultaneously.
Non-Patent Documents 3 and 4 disclose a technique for amplifying an angle of bending for the fingertip to become familiar by including a familiarity mechanism using an underactuated link and a four-joint link at the fingertip. Thereby, even a relatively small object can be stably gripped by the conforming mechanism.
Further, in Patent Document 4, the same technique as in Non-Patent Documents 3 and 4 is disclosed.

However, in the above-described prior art, the parallel opening and closing of the fingertips and the amplification of the bending angle of the fingertips during the conforming operation are not realized at the same time, and it is difficult to stably hold various objects.
Furthermore, in the above-described conventional technology, the finger surface is fully opened and the height of the finger surface is approximately the same as that of the palm so that the portion of the palm that can be applied with force compared to the finger directly contacts the object. By positioning it below, for example, a large and heavy object could not be sandwiched between two arms and held.

International Publication No. 2011/118646 US Pat. No. 5,108,140 US Pat. No. 5,762,390 Special table 2003-534930 gazette

L. Birglen et al. , “On the Force Capability of Under fingered,” Proc. of the International Conference on Robotics and Automation, pp. 1139-1145, 2003. “Industrial Adaptive Robot Grippers”, [online], ROBOTIQ, Internet <URL: http: // robotiq. com / en / products / industrial- robot-grippers> N. Fukaya et al. "Design of the TUAT / Karlsruhe humanoid Hand," Proc. of the IEEE / RSJ International Conference on Intelligent Robots and Systems, pp. 1754-1759, 2000. Taihei Ueno (T. Ueno et al.), “Development of operating fingers for space-precision work hands,” Journal of the Robotics Society of Japan (J. Robot. Soc. Japan), Vol. 28, no. 3, pp. 349-359, 2010.

  The present invention has been made in view of the above-mentioned circumstances, and at least one of the problems including the conforming mechanism, the parallel opening and closing of the fingertips, and the amplification of the bending angle of the fingertip during the conforming operation is realized. It is an object to provide a robot hand that can be realized simultaneously. In addition, the finger can be fully opened and the height of the surface of the finger can be positioned at the same level or lower than that of the palm so that the part of the palm that can apply force compared to the finger directly contacts the object. It is also an object to provide a robot hand that can be used. It is another object of the present invention to provide a low-cost robot hand that realizes the above functions with a small number of actuators.

  A robot hand according to an aspect of the present invention includes a base and a finger portion provided on the base, wherein the finger portion includes a first link, a second link, a third link, 4 links, a first rotation shaft that rotatably connects the first link and the second link, and a second rotation shaft that rotatably connects the second link and the third link. A third rotation shaft that rotatably connects the third link and the fourth link; a fourth rotation shaft that rotatably connects the fourth link and the first link; The second link is located closer to the base than the fourth link, and the position of the first pivot shaft is fixed with respect to the base, and the second pivot The position of the shaft is a robot hand that is movable with respect to the base.

  According to this configuration, the second link rotates around the first rotation axis fixed to the base, and the position of the second rotation axis moves relative to the base. Parallel opening and closing can be realized. This function can be realized with a small number of actuators, and a low-cost robot hand can be provided.

  In the above robot hand, the base has a palm portion, and the surface of the palm portion that can contact the object and the surface of the tip of the finger portion that can contact the object are on the same plane. It may be possible to locate.

  According to this configuration, the finger part is fully opened and the height of the tip of the finger part is about the same as that of the palm part so that the palm part that can apply force compared to the finger part directly contacts the object. Since it can be positioned below it, the contact area with the object increases, so when holding the object, or when performing work other than gripping such as pushing and receiving the object, more stable work is possible. It becomes possible.

  In the robot hand described above, the first link may have a fifth rotation axis between the first rotation axis and the fourth rotation axis.

  According to this configuration, since the fourth rotation shaft rotates about the fifth rotation shaft with respect to the first link, it is possible to realize amplification of the bending angle of the fingertip during the conforming operation.

  A robot hand according to an aspect of the present invention includes a base and a finger portion provided on the base, wherein the finger portion includes a first link, a second link, a third link, 4 links, a first rotation shaft that rotatably connects the first link and the second link, and a second rotation shaft that rotatably connects the second link and the third link. A third rotation shaft that rotatably connects the third link and the fourth link; a fourth rotation shaft that rotatably connects the fourth link and the first link; The second link is positioned closer to the base than the fourth link, and the first link is a fifth link between the first rotation shaft and the fourth rotation shaft. A robot hand having a rotation axis.

  According to this configuration, since the fourth rotation shaft rotates about the fifth rotation shaft with respect to the first link, it is possible to realize amplification of the bending angle of the fingertip during the conforming operation. This function can be realized with a small number of actuators, and a low-cost robot hand can be provided.

  In the above robot hand, the finger portion includes a fifth link, a sixth link, a seventh link, a sixth rotation shaft that rotatably connects the fifth link and the sixth link, A seventh rotation shaft that rotatably connects the sixth link and the seventh link, and the fourth rotation shaft is capable of rotating the fourth link and the seventh link. You may connect to.

  According to this configuration, the contact area is increased by bringing the 5th to 7th link parts into contact with the object in addition to the 1st to 4th link parts during the conforming operation, thereby enabling more stable gripping. become.

  In the above robot hand, the finger portion has an eighth rotation shaft that is movable with respect to the base, and the third link is rotatable about the second rotation shaft, and The third rotation shaft and the eighth rotation shaft may be connected.

  According to this configuration, by moving the eighth rotation axis with respect to the base, the third link can be rotated about the second rotation axis, and parallel opening and closing of the fingertips can be realized.

  A robot according to one embodiment of the present invention may include the above robot hand.

  According to this configuration, one or more of the familiar mechanism, parallel opening and closing of the fingertips, amplification of the bending angle of the fingertip during the conforming operation, and the function of fully opening the finger part so that the palm part directly contacts the object are realized. be able to.

  The robot may include a first arm and a second arm, and the robot hand may be provided on at least one of the first arm and the second arm.

  According to this configuration, a large object is lifted by both arms (preferably both hands) by combining an arm having the robot hand and another arm (which may have the robot hand). Etc. work becomes possible.

It is a whole perspective view which shows an example of the robot hand of this invention. It is a general view which shows typically an example of the link structure of a finger | toe part. (A)-(c) is a schematic diagram which shows an example of familiar operation in order. (A)-(e) is a schematic diagram which shows an example of fingertip opening / closing operation | movement in order. (A)-(c) is a schematic diagram which shows the fingertip opening / closing operation | movement by comparison proportionally. (A)-(e) is a schematic diagram which shows an example of familiar operation in order. (A)-(c) is a schematic diagram which shows the some example from which the initial posture which contacts a target object in each familiar operation differs. (A) And (b) is explanatory drawing of the maximum bending state of a fingertip. FIG. 9 is a schematic diagram in which two links shown in FIG. 8 are emphasized in a familiar operation. It is a schematic diagram which shows an example of the state which fully opened the front-end | tip of the finger part with respect to the palm part. It is a partial schematic diagram which shows an example of the double arm robot which hold | grips objects, such as a box, with both hands. It is a whole schematic diagram showing an example of a double-arm robot. (A)-(c) is a schematic diagram which shows the Example of parallel opening / closing operation | movement.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an overall perspective view illustrating a robot hand 10 of this embodiment. The robot hand 10 includes a base 11, a palm 12 provided on one side of the base 11 in the central axis direction (vertical direction in FIG. 1), and a plurality of robot hands 10 provided on the same side of the base 11 as the palm 12. It has a finger part 13. The base 11 is a portion corresponding to the wrist or forearm of the robot hand 10. When attaching the robot hand 10 to an arm (not shown), the base 11 can be attached to the arm. The base 11 may be rotatable with respect to the arm, for example, around the central axis.

  The palm portion 12 is a portion corresponding to the palm of the robot hand 10. In the conventional robot hand, the palm is not necessarily required. In the present embodiment, it is possible to perform an operation taking into consideration that an object (not shown) operated by the robot hand 10 contacts not only the finger part 13 but also the palm part 12. The palm portion 12 has a surface 12 a on the opposite side of the base 11. The surface 12a may be provided with a pad or the like in order to reduce or alleviate the influence on the object when it contacts the object. The pad or the like may be flexible or hard and can be appropriately selected.

  The robot hand 10 according to the present embodiment has three finger portions 13. This is a portion corresponding to the finger of the robot hand 10. The number of finger parts that the robot hand has is not particularly limited, but two or more are preferable. One or more of these finger portions 13 may be configured such that the entire finger portion 13 can be rotated around the central axis of the base 11. In the case of the illustrated example, the position of the finger portion 13 relative to the central axis of the base 11 can be moved within a substantially semicircular hole 11 b formed in the distal end surface of the base 11. The finger part 13 may be provided with pads 14 and 15 in order to reduce or alleviate the influence on the object when it comes into contact with the object. In the illustrated example, pads 14 and 15 are provided at two locations on the base side and the tip side of the finger portion 13, respectively.

  In FIG. 2, the link structure of the finger | toe part 13 is shown typically. In FIG. 2, the upper side is the distal end side of the finger unit 13, the lower side is the proximal side (base 11 side) of the finger unit 13, the left is the inner surface side (palm unit 12 side) of the finger unit 13, It is the outer side. When these are referred to below, they may be simply referred to as “tip side”, “base end side”, “inner surface side”, and “outer surface side”. If these directions are defined without depending on the state of the finger part, in the cylindrical coordinates based on the central axis of the robot hand 10 that passes through the palm part 12, the “tip side” is defined by the base axis along the central axis. The direction in which the distance increases, “base end side” is the direction in which the distance from the base decreases along the central axis, “inner side” is the direction in which the distance from the central axis decreases, and “outer side” In this direction, the distance from the central axis increases. It should be noted that the distance from the base is defined as a negative number with reference to the front end surface of the base inside the base.

  As shown in FIG. 2, the finger 13 included in the robot hand is composed of a five-bar link, and by using a spring and a stopper, the fingertip during the fitting mechanism, the parallel opening and closing of the fingertips, and the fitting operation is used. Amplification of bending angle is realized at the same time. With the structure shown in FIG. 2, the above three functions are realized with a simple structure.

  A first link 21, a second link 22, a third link 23, and a fourth link 24 are provided on the base 11 side of the finger 13. The first link 21 and the second link 22 are rotatably connected by a first rotation shaft 31. The second link 22 and the third link 23 are rotatably connected by a second rotation shaft 32. The third link 23 and the fourth link 24 are rotatably connected by a third rotation shaft 33. The fourth link 24 and the first link 21 are rotatably connected by a fourth rotation shaft 34.

  When the distal end 16 of the finger portion 13 extends along the central axis of the base 11 in a direction away from the base 11, the first link 21 and the second link 22 are positioned on the base end side, and the third link 23 And the 4th link 24 is located in the front end side. The first link 21 and the fourth link 24 are located on the inner surface side, and the second link 22 and the third link 23 are located on the outer surface side. The second link 22 is located closer to the base 11 (base end side) than the fourth link 24.

  The position of the first rotation shaft 31 is fixed with respect to the base 11, and the position of the second rotation shaft 32 is movable with respect to the base 11. The positions of the third link 23 and the fourth link 24 provided away from the base 11 are also movable with respect to the base 11.

  The base 11 has a housing 11a. Inside the housing 11a, as elements of the base 11, driving force transmitting means such as a ball screw 60, driving means such as a motor (not shown), and the like are included. The ball screw 60 includes a screw shaft 61 disposed in the central axis direction (vertical direction in the drawing) of the base 11 and a nut 62 connected to the link structure of the finger portion 13. A ball (not shown) or the like as a friction reducing mechanism is included between the screw shaft 61 and the nut 62. When the screw shaft 61 is rotated by a motor, the nut 62 can be moved up and down to open and close the finger portion 13.

  The first link 21 has a fifth rotation shaft 35 between the first rotation shaft 31 and the fourth rotation shaft 34. An eighth link 28 is provided between the fourth rotation shaft 34 and the fifth rotation shaft 35. The fifth rotation shaft 35 connects the first link 21 and the eighth link 28 so that they can rotate with each other. In FIG. 2, the first link 21 and the eighth link 28 overlap the paper surface between the fourth rotation shaft 34 and the fifth rotation shaft 35.

  A fifth link 25, a sixth link 26, and a seventh link 27 are provided on the distal end 16 side of the finger portion 13. The fifth link 25 and the sixth link 26 are rotatably connected by a sixth rotation shaft 36. The sixth link 26 and the seventh link 27 are rotatably connected by a seventh rotation shaft 37. The 4th rotation axis 34 has connected the 4th link 24 and the 7th link 27 so that rotation is possible. The fourth link 24 and the fifth link 25 may be one integrated link member 17. The 3rd rotation axis | shaft 33 connects the link member 17 and the 3rd link so that rotation is possible. The sixth link 26 may be a part of the link member 18 including the tip 16.

  Specifically, the fourth rotation shaft 34 includes a fourth rotation shaft 34A provided on the first link 21 and a fourth rotation shaft 34B provided on the eighth link 28 (FIG. 3 (c). )reference). The fourth rotation shaft 34A directly connects the first link 21 and the seventh link 27 so as to be rotatable. The fourth rotation shaft 34B directly connects the fourth link 24 and the eighth link 28 so as to be rotatable. In the illustrated example, the first link 21 and the seventh link 27 are not directly connected to the fourth link 24.

  A first stopper 41 and a first spring 51 are provided between the first link 21 and the eighth link 28. The first stopper 41 prevents displacement at a predetermined position (for example, a position along the first link 21) when the eighth link 28 is displaced to the outer surface side (right side in FIG. 2). FIG. 2 shows a state in which the first link 21 side portion 41a and the eighth link 28 side portion 41b of the first stopper 41 are in contact with each other. In the drawing, the portions 41a and 41b protrude from the first link 21 and the eighth link 28, but the actual shape and structure are arbitrary.

  When the blocking by the first stopper 41 acts, the eighth link 28 stops rotating around the fifth rotation shaft 35 and is integrated with the first link 21 around the first rotation shaft 31. Rotate. At this time, the first link 21, the second link 22, the third link 23, and the fourth link 24 function as parallel four-bar links. Thus, while the 8th link 28 is integrated with the 1st link 21, since the 4th rotating shaft 34A and the 4th rotating shaft 34B operate | move interlock | cooperated, the 1st link 21 becomes the 4th link. 24 can be rotated. At this time, the seventh link 27 may be rotatable with respect to the fourth link 24. In the case of the illustrated example, since the fourth link 24 and the fifth link 25 are integrated, the link member 17, the sixth link 26, and the seventh link 27 are substantially three-bar links (zero degrees of freedom). The fingertip shape is stable.

  When the eighth link 28 is displaced to the inner surface side (the palm 12 side), the eighth link 28 can be bent to the inner surface side than the first link 21. At this time, when the eighth link 28 bends, it receives a restoring force from the first spring 51, that is, when it shifts from a bent state (for example, see FIG. 3C) to an extended state (for example, see FIG. 3B). The elastic force of the first spring 51 contributes effectively.

  FIGS. 3A to 3C are schematic diagrams sequentially illustrating examples of the familiar operation. In this familiarity operation, the object 19 is first contacted with the palm 12 (see FIGS. 1 and 2), and the object 19 is moved with the palm 12 and the fingers 13 or with one or more fingers 13 only. The object 19 is gripped. First, as shown in FIG. 3A, when the finger portion 13 is bent toward the base 11 in a state where the finger portion 13 is separated from the object 19 in the palm, as shown in FIG. The contact with the object 19 acts on the first link 21 on the inner surface side of the finger portion 13. At this time, the object 19 may be in direct contact with the first link 21 or may act indirectly via the pad 14 or the like. The bending operation of the first link 21 is suppressed by the contact with the object 19. Further, when the third link 23 on the outer surface side of the finger portion 13 is bent toward the base 11 side, the fourth link 24 is pushed and the eighth link 28 is moved so that the fourth rotation shaft 34B approaches the object 19. Rotate. As a result, as shown in FIG. 3C, the tip 16 side (link member 18) of the finger portion 13 comes into contact with the object 19. Thereby, when the robot hand 10 grips the object 19, a familiar mechanism is realized that can take a wide area where the object 19 and the finger 13 are in contact with each other.

  In this familiarity mechanism, the base (base end side) of the finger portion 13 functions as a five-bar link including an eighth link 28 in addition to the first link 21, the second link 22, the third link 23 and the fourth link 24. To do. Further, the distal end side of the finger portion 13 is a five-bar link including the first link 21, the eighth link 28, the link member 17 (the fourth link 24 and the fifth link 25), the sixth link 26 and the seventh link 27. Function. Even if two links (for example, the first link 21 that contacts the object 19 and the second link 22 on the base 11 side) stop due to the base (base end) side of the finger 13 including the five-bar link. The degree of freedom in which the other links operate (for example, the rotation of the eighth link 28 around the fifth rotation shaft 35) is ensured. For this reason, it is possible to bend the fingertip in the familiar operation after contacting the object 19.

  4A to 4E are schematic views sequentially illustrating an example of a fingertip opening / closing operation. In these drawings, the fifth rotation shaft 35, the sixth rotation shaft 36, and the seventh rotation shaft 37 shown in FIG. 3 are not shown. For example, in the configuration shown in FIG. 2, the eighth link 28 is integrated with the first link 21 by the elastic force (contraction) of the first spring 51, and the link member 17 (the fourth link 24 and the fifth link 25), The sixth link 26 and the seventh link 27 are three-bar links. For this reason, in the fingertip opening and closing shown in FIG. 4, parallel opening and closing can be realized by a parallel four-bar link composed of the first link 21, the second link 22, the third link 23 and the fourth link 24. Therefore, the mechanisms for realizing the parallel opening and closing of the fingertips are the fifth rotation shaft 35, the sixth rotation shaft 36, the seventh rotation shaft 37, the fourth link 24, the fifth link 25, the sixth link 26, Part or all of the seventh link 27 and the eighth link 28 can be omitted.

  Referring to FIG. 2, the parallel opening / closing mechanism of the present embodiment includes, in addition to the above-described parallel four-bar link, a tenth rotation shaft 38 that is movable with respect to the base 11 and a nut 62 of the ball screw 60. A link 30, a ninth rotation shaft 39 connected to the tenth link 30, and a ninth link 29 provided between the eighth rotation shaft 38 and the ninth rotation shaft 39 are included. The third link 23 is rotatable about the second rotation shaft 32, and connects the third rotation shaft 33 and the eighth rotation shaft 38. The eighth rotation shaft 38 connects the third link 23 and the ninth link 29 so as to be rotatable. The ninth rotation shaft 39 connects the ninth link 29 and the tenth link 30 so as to be rotatable.

  The position of the first rotation shaft 31 is fixed with respect to the base 11, and the position of the second rotation shaft 32 is movable with respect to the base 11. Therefore, the second link 22 can be turned up and down with respect to the base 11. In the rotation direction around the first rotation shaft 31, rotation in the direction in which the first link 21 is separated from the palm portion 12 (clockwise in FIG. 2) is restricted by the third stopper 43. Further, in the rotation direction, the rotation of the second link 22 in the direction approaching the palm portion 12 from the distal end side (upper side) (counterclockwise in FIG. 2) is restricted by the fourth stopper 44.

  The rotation between the second link 22 and the third link 23 is regulated by the second stopper 42 and the second spring 52. The second stopper 42 prevents rotation at a predetermined position when the third link 23 rotates (extends) around the second rotation shaft 32 toward the outer surface side (right side in FIG. 2, clockwise). . FIG. 2 shows a state in which the portion 42a on the third link 23 side and the portion 42b on the second link 22 side of the second stopper 42 are in contact with each other. In the drawing, the respective portions 42a and 42b protrude from the third link 23 and the second link 22, but the actual shape and structure are arbitrary. When blocking by the second stopper 42 acts, the positional relationship (angle) between the third link 23 and the second link 22 is maintained.

  In FIG. 4, when the third link 23 rotates to the inner surface side (side approaching the palm portion 12), as shown in FIG. 4A, the blocking of the second stopper 42 is released (respective portions 42a and 42b). Are separated from each other). When the third link 23 rotates to the outer surface side (the side away from the palm portion 12), as shown in FIG. 4E, the blocking of the second stopper 42 is released (the portions 42a and 42b are separated from each other). . In either case, the second spring 52 increases the restoring force between the second link 22 and the third link 23.

  In FIG. 4A, the nut 62 is on the proximal end side of the screw shaft 61, and the finger portion 13 is greatly extended to the outer surface side. At this time, the blocking by the third stopper 43 functions and the first link 21 is stopped. The blocking by the second stopper 42 and the fourth stopper 44 is released, and the second spring 52 increases the restoring force. When the nut 62 is raised to the tip side, the third link 23 bends to the inner surface side while the first link 21 is stopped during the period from FIG. 4A to FIG. Also, the second spring 52 is bent to the inner surface side. The fourth link 24 is displaced so as to remain parallel to the second link 22. In FIG. 4B, blocking by the second stopper 42 is started.

  When the nut 62 is further raised, the blocking by the third stopper 43 is released, and the process proceeds in the order of FIG. 4 (b), FIG. 4 (c), and FIG. 4 (d). In the meantime, the second link 22 and the third link 23 bend to the inner surface side while the blocking by the second stopper 42 is continued. Specifically, the first link 21, the second link 22, the third link 23, and the fourth link 24 maintain the relative angular relationship when the blocking by the third stopper 43 and the fourth stopper 44 is released. While rotating around the first rotation shaft 31. In FIG. 4D, blocking by the fourth stopper 44 is started.

  When the nut 62 is further raised to the tip side, the blocking by the second stopper 42 is released, and the first link 21 and the third link 23 are bent to the inner surface side while the second link 22 is stopped. The fourth link 24 is displaced so as to remain parallel to the second link 22. As shown in FIG. 4D and FIG. 4E, when the bending angle of the finger portion 13 increases, a mechanism for transmitting the vertical movement of the nut 62 in the ball screw 60 to the finger portion 13 is linked from the second stopper 42. It turns out that the whole finger is operating as a parallel four-bar link. As a result, parallel opening and closing of the fingertip is realized, and a precise object can be gripped.

  The parallel opening and closing according to the present embodiment can be operated reversibly. That is, by lowering the nut 62 in the ball screw 60, it is possible to operate in the order of FIGS. 4 (e), 4 (d), 4 (c), 4 (b), and 4 (a). It is. In the case of the illustrated example, in FIG. 4 (a) and FIG. 4 (e), the entire finger portion extends almost straight, whereas in FIG. 4 (b) and FIG. 4 (d), the fingertip is relative to the root. It is bent. Further, between FIG. 4B and FIG. 4D, the second stopper 42 and the second spring (in the case where the fifth rotating shaft 35 is provided as shown in FIG. And the 1st spring 51) prevents the deformation | transformation of the 1st link 21, the 2nd link 22, the 3rd link 23, and the 4th link 24, and the attitude | position of the finger | toe part 13 is maintained. Thus, by restricting the deformation of the finger part within a range in which the finger part can contact the object, both the rotation opening and closing and the parallel opening and closing of the finger part can be achieved. In FIG. 4A and FIG. 4E in which it is not assumed that the finger part comes into contact with the target object, the third stopper 43 or the fourth stopper 44 performs the rotational movement around the second rotation shaft 32. By restraining, the fingertip is allowed to rotate with respect to the base of the finger.

  Next, comparing this embodiment with the robot hand of Patent Document 4, in the robot hand of this embodiment, the finger part is fully opened so that the palm part directly contacts the object. Can be positioned at or below the palm. 5 (a) to 5 (c) show the operation of the finger of the robot hand described in Patent Document 4 as a comparative example.

  As shown in FIGS. 5A to 5C, in the robot hand described in Patent Document 4, the distal end link 202 connected to the fingertip 203 maintains a state parallel to the proximal end link 201. Even when the base of the finger is opened, the fingertip 203 maintains a posture in which the fingertip 203 faces upward. In order to fully open the finger part, it is necessary to move the fingertip 203 facing upwards below the palm 210 as shown in FIG. However, as is apparent from FIG. 5 (c), in actuality, interference between links occurs before this state is reached, and operation cannot be performed until this state is reached.

  On the other hand, in the robot hand according to the present embodiment, as shown in FIG. 4A, the fingertip is parallel to the lower portion thereof, so that the fingertip is moved below the palm than the robot hand described in Patent Document 4. The amount of movement required for this is small. Thereby, in the robot hand of the present embodiment, the finger part can be fully opened and the height of the tip of the finger part can be positioned at the same level or lower than the palm part so that the palm part directly contacts the object. . FIG. 10 shows an example of a state where the tip 16 of the finger 13 is fully opened with respect to the palm 12. It can be seen that the tip 16 of the finger portion 13 is located at the same height as the surface 12 a of the palm portion 12.

  6A to 6E sequentially show changes in the link mechanism in the familiar operation. In FIG. 6A, the first link 21 comes into contact with the object with the finger standing, and in FIGS. 6B to 6E, the first link 21 and the second link 22 are stopped. The three links 23 are rotated to the inner surface side. It can be seen that the tip 16 of the finger portion 13 is greatly bent by the rotation of the eighth link 28 around the fifth rotation shaft 35.

FIGS. 7A to 7C are schematic diagrams illustrating a plurality of examples in which the initial postures that come into contact with the object in the familiar operation are different.
FIG. 7 (a) shows a change in the link mechanism when the finger is in contact with the object with the fingers open to the outer surface side and the conforming operation is performed, as in FIGS. 3 (a) to 3 (c). FIG.
FIG. 7B is a diagram in which FIGS. 6A to 6E are overlapped.
FIG.7 (c) is the figure which drew the change of a link mechanism on one side, when a finger part contacts the target object in the state which fell down to the inner surface side, and performs familiarizing operation.
In either case, it can be seen that the distal end 16 side of the finger portion is parallel to the first link 21 (the entire finger portion is substantially inverted U-shaped), and further bent more greatly.

  FIG. 8A and FIG. 8B are explanatory diagrams of the maximum bending state of the fingertip. 8A shows the positions of the sixth link 26 and the seventh link 27 in FIG. 6A, and FIG. 8B shows the positions of the sixth link 26 and the seventh link 27 in FIG. Indicates the position. When the seventh link 27 (link including the inner surface side of the fingertip) rotates around the fourth rotation shaft 34A in a state where the first link 21 is stopped, the sixth link further centers around the seventh rotation shaft 37. 26 (link including the tip 16 of the finger) rotates. At this time, the sixth link 26 and the seventh link 27 are positioned on the same line (specifically, the fourth rotating shaft 34A, the sixth rotating shaft 36, and the seventh rotating shaft 37 are positioned on the same line). ), The link dead center is reached, and the fingertip is in the maximum bending state.

  FIG. 9 is a schematic diagram in which the positions of the sixth link 26 and the seventh link 27 are emphasized in the familiar operation shown in FIGS. It can be seen that the angle formed by the sixth link 26 and the seventh link 27 around the seventh rotation shaft 37 increases as the fingertip bends. This is because the rotation angle of the sixth link 26 about the seventh rotation shaft 37 is larger than the rotation angle of the seventh link 27 about the fourth rotation shaft 34A. Is amplified. As a result, it is possible to hold the object in contact with the base of the finger more reliably, such as holding the object between the fingertip and the palm. Compared with the “operating finger for space fine work hand” of Non-Patent Document 4, according to the present embodiment, the fingertip can be bent more greatly based on the difference in the link structure.

  As shown in FIG. 10, in the robot hand 10 of the present embodiment, the surface 12a of the palm 12 that can contact the object and the surface of the tip 16 of the finger 13 that can contact the object are on the same plane. It is possible to be located. Even when such a robot hand 10 is applied to one hand, operations other than gripping, such as pushing an object, can be performed.

  Furthermore, when the robot hand 10 of the present embodiment is applied to both hands of a double-arm robot, as shown in FIG. 11, it is possible to hold an object 190 such as a box with both hands. FIG. 11 is a partial schematic diagram showing an example of a double-arm robot 100 having the robot hand 10 of the present embodiment on the first arm 101 and the second arm 102, respectively. Not only the palm part 12 and the tip 16 of the finger part 13 are brought into contact with and gripped by the object, but also the palm part 12 is brought into contact with the object by lowering the position of the surface of the finger part 13 relative to the palm part 12. And can be held and held with both hands with great force.

  In the robot hand of this embodiment, the number of actuators that drive the finger portion is 1, and the degree of freedom of the entire finger is 3.

  FIG. 12 is an overall schematic diagram illustrating an example of a double-arm robot 400. The double-arm robot 400 includes a storage unit 411, a body unit 412, a first arm 401 and a first hand 403, and a second arm 402 and a second hand 404. These can adopt a known configuration. The degree of freedom of the arm is also arbitrary.

  The first arm 401 and the second arm 402 are each constituted by a manipulator. The operations of the arms 401 and 402 and the hands 403 and 404 are controlled by a control signal output from the control device 413 stored in the storage unit 411. The double-arm robot 400 may input a signal indicating its own state or the like to the control device 413. The body portion 412 may include a plurality of portions 412a, 412b, and 412c that can be rotated and expanded and contracted. The robot may be installed in a state of being fixed to the floor surface or the like, or may have moving means such as wheels 421 and 422 as shown in the illustrated example.

  FIG. 13 shows an embodiment in which a parallel opening / closing operation is performed in a state where force from an object is applied to a finger as a specific example of the parallel opening / closing operation. 13A to 13C have different finger postures. FIG. 13A shows a state in which the finger portion stands as in FIG. FIG. 13B shows a state in which the fingertip is slightly inclined to the outer surface side. FIG. 13C shows a state in which the fingertip is further inclined to the outer surface side. Even if force is applied to the finger from the object, the first stopper 41 (see FIGS. 2 and 3) and the fourth stopper 44 (see FIGS. 2 and 4) can act to perform parallel opening and closing operations. In order to keep the parallel opening and closing, the direction of the resultant force of the normal force and the frictional force from the object applied to the finger is divided by the line La and the line Lb in FIG. 13 on the outer surface side (shaded in the figure) It is recommended that you enter Ap.

  According to the present embodiment, it has been realized to provide a robot hand that can simultaneously realize the familiarity mechanism, the parallel opening and closing of the fingertips, and the amplification of the bending angle of the fingertip during the familiarization operation. Also, fully open the finger part and position the surface of the finger part at the same level or lower than the palm part so that the palm part that can apply force compared to the finger directly contacts the object. It was also realized to provide a robot hand that can. Furthermore, it has become possible to provide a low-cost robot hand by realizing the above functions with a small number of actuators.

  As mentioned above, although this invention has been demonstrated based on suitable embodiment, this invention is not limited to the above-mentioned embodiment, A various change is possible in the range which does not deviate from the summary of this invention. The requirements described in the above embodiments can be combined as appropriate. In addition, at least one of the requirements described in the above embodiments may be omitted. Various modifications are possible without departing from the gist of the present invention.

  The robot may be a double-arm robot having two sets of arms and hands, or a single-arm robot having one set of arms and hands, but is not limited thereto. The number of arms and hands may be more than one each.

  Similarly to the first stopper and the second stopper, the third stopper and the fourth stopper may be configured such that the two portions can contact each other between the two link members. These actual shapes and structures are arbitrary. For example, the third stopper may include a base side portion and a first link side portion. The fourth stopper may include a base side portion and a second link side portion.

  Examples of the actuator include a linear reciprocating drive actuator and a rotary reciprocating drive actuator. The actuator is not limited to a ball screw, and a power cylinder, a servo motor, a piston, a rack and pinion, and the like can also be employed. The drive force transmission mechanism is not limited to a link, and gears, pulleys, belts, and the like can also be used. In addition to an elastic body such as a spring, a magnet or the like can be used as a mechanism for applying a restoring force. Examples of the spring include a tension spring, a compression spring, and a torsion spring. Various bearings and the like can be provided in the rotating portion. The structural material can be composed of various materials such as metals, alloys, fiber reinforced plastics, and ceramics.

  The robot hand, the robot arm, and the robot may include external input means such as various sensors and a camera in order to grasp the external state. Information obtained by these external input means can also be used for the robot to operate by autonomous judgment. The robot control device can also include a program necessary for autonomous operation of the robot and a recording medium storing the program.

  The present invention can be widely applied to robot apparatuses.

DESCRIPTION OF SYMBOLS 10 ... Robot hand, 11 ... Base, 12 ... Palm part, 13 ... Finger part, 19, 190 ... Object, 21 ... 1st link, 22 ... 2nd link, 23 ... 3rd link, 24 ... 4th link 25 ... 5th link, 26 ... 6th link, 27 ... 7th link, 28 ... 8th link, 29 ... 9th link, 31 ... 1st rotating shaft, 32 ... 2nd rotating shaft, 33 ... 1st 3 rotation axes, 34, 34A, 34B ... 4th rotation axis, 35 ... 5th rotation axis, 36 ... 6th rotation axis, 37 ... 7th rotation axis, 38 ... 8th rotation axis, 39 ... 9th rotation axis, 100, 400 ... Double-arm robot, 101, 401 ... 1st arm, 102, 402 ... 2nd arm, 403 ... 1st hand, 404 ... 2nd hand.

Claims (8)

The base,
A finger portion provided on the base,
The fingers are
A first link, a second link, a third link, a fourth link,
A first rotation shaft that rotatably connects the first link and the second link;
A second rotation shaft that rotatably connects the second link and the third link;
A third rotation shaft that rotatably connects the third link and the fourth link;
A fourth pivot shaft rotatably connecting the fourth link and the first link;
The second link is located closer to the base than the fourth link;
The position of the first rotation shaft is fixed with respect to the base,
The robot hand is movable with respect to the base at a position of the second rotation axis. The base has a palm portion;
2. The robot hand according to claim 1, wherein a surface of the palm portion that can contact the object and a surface of the tip of the finger portion that can contact the object can be located on the same plane.   The robot hand according to claim 1 or 2, wherein the first link has a fifth rotation shaft between the first rotation shaft and the fourth rotation shaft. The base,
A finger portion provided on the base,
The fingers are
A first link, a second link, a third link, a fourth link,
A first rotation shaft that rotatably connects the first link and the second link;
A second rotation shaft that rotatably connects the second link and the third link;
A third rotation shaft that rotatably connects the third link and the fourth link;
A fourth pivot shaft rotatably connecting the fourth link and the first link;
The second link is located closer to the base than the fourth link;
The first link is a robot hand having a fifth rotation axis between the first rotation axis and the fourth rotation axis. The finger portion includes a fifth link, a sixth link, a seventh link,
A sixth rotation shaft that rotatably connects the fifth link and the sixth link;
A seventh rotation shaft that rotatably connects the sixth link and the seventh link;
The robot hand according to any one of claims 1 to 4, wherein the fourth rotation shaft rotatably connects the fourth link and the seventh link. The finger portion has an eighth rotation shaft that is movable with respect to the base,
6. The device according to claim 1, wherein the third link is rotatable about the second rotation axis and connects the third rotation axis and the eighth rotation axis. The robot hand according to claim 1.   A robot having the robot hand according to any one of claims 1 to 6. A first arm and a second arm;
A robot in which the robot hand according to any one of claims 1 to 6 is provided on at least one of the first arm and the second arm.

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