JP4469957B2 - Robot hand - Google Patents

Description

  The present invention relates to a robot hand, and more particularly to a robot hand that can control the position and force of a fingertip with high accuracy and can be suitably used when it is necessary to manipulate an object skillfully. is there.

  The robot hand has a very limited space compared to the robot arm. For this reason, various robot hands that effectively use a limited space have been invented.

For example, in Patent Document 1, an actuator is provided on an arm portion separated from a finger structure of a robot hand, and the joint is driven by connecting the actuator to a link of the finger structure of the robot hand via a wire.
Although the drive system using wires is a very effective technique for miniaturization of robot hands, the position and force of the fingertips can be controlled with high precision because the wires stretch and contract when pulling to drive. There was a difficult problem to do. Further, due to the expansion and contraction of the wire, not only frequent maintenance is required, but also the problem of poor maintenance is caused by the complicated handling of the wire.

In Non-Patent Document 1, each finger is provided with an actuator and a speed reduction mechanism, and the output of the speed reduction mechanism is connected to an adjacent link to constitute a finger structure of the robot hand.
However, in order to connect the links serially, the axes of the two joints at the base of the finger cannot be made orthogonal, and there is a problem that it is difficult to perform a movement similar to a human finger.

Further, in order to solve these problems, a robot hand in which the axes of two joints at the base of the finger are orthogonal at one point while being non-wire driven is disclosed in, for example, Patent Document 2 and Patent Document 3 Are known.
JP 60-207795 A Journal of the Robotics Society of Japan, Vol. 19, No. 1, pp.8-15 Japanese Patent No. 3245095 Japanese Patent Laying-Open No. 2005-066683

  In Patent Document 2 and Patent Document 3, an actuator that drives two joints at the base of the finger is arranged on the palm, and the axes of the two joints at the base of the finger are orthogonalized by a differential mechanism using a bevel gear. ing. This enables movement similar to a human finger.

  However, the robot hands described in Patent Document 2 and Patent Document 3 have a problem that it is difficult to control the position and force of the fingertip with high accuracy by backlash and backlash of the differential mechanism.

  The present invention has been made to solve such a problem, and the object of the present invention is to make two joint axes at the base of the finger 1 in order to enable movement similar to that of a human finger. At the same time as constructing a robot hand that is orthogonal with respect to the point, the position and force of the fingertips can be controlled with high precision, and the robot hand with less backlash and backlash can be provided so that the object can be manipulated skillfully. There is.

  In order to achieve the above object, a first solution of the present invention is a robot hand provided with a carpal joint at the joint between the palm and the middle hand and a metacarpophalangeal joint at the joint between the middle hand and the proximal joint. In this finger structure, the palm is provided with a first actuator and a first drive mechanism for driving the carpal metacarpal joint, and the proximal joint is provided with a second actuator and a second actuator for driving the metacarpal joint. A drive mechanism is provided, and the first drive mechanism is a means for achieving a high reduction ratio comprising an output of the first actuator, such as a harmonic speed reducer or a planetary gear speed reducer (in this specification, a harmonic speed reducer or a planetary gear speed reducer, etc. The means for achieving the high reduction ratio consisting of is referred to as “high reduction means” (the same applies hereinafter)), and then the output of the first reduction gear is transmitted to the middle hand via the link mechanism. Drive the carpal joint And the second drive mechanism decelerates the output of the second actuator with the second reduction gear having the high speed reduction means, and then joins the output of the second reduction gear to the middle. It is configured to drive the finger joints.

  According to the first solution of the present invention, two actuators and two driving mechanisms are arranged on the palm and the base joint, respectively, so that a limited space (inside the palm structure) like the finger structure of the robot hand. The robot hand can be miniaturized by effectively utilizing the space inside the base joints. In addition, by arranging two actuators and two drive mechanisms on the palm and the base joint, respectively, the middle hand can be downsized, and in addition, the output of the first mechanism is transmitted to the middle hand via the link arm. Thus, a compact driving mechanism is realized in which the axis of the carpal joint and the joint of the metacarpophalangeal joint are orthogonal at one point. In addition, a high speed reduction means is provided to transmit the output of the first mechanism to the middle hand via the link mechanism, and at the same time, a high speed reduction means is provided to directly join the output of the second mechanism to the middle hand, thereby preventing backlash and backlash. Less joints are realized.

  In addition to the first solution means, the second solution means of the present invention is configured such that the joint movable range of the carpal metacarpal joint is wider than the joint movable range of the metacarpophalangeal joint.

  According to such a second solution of the present invention, the joint movable range of the carpal joint is configured to be wider than the joint movable range of the metacarpophalangeal joint. In this way, when there is a difference in the movable range, the second actuator and the second drive mechanism for driving the metacarpophalangeal joint with a narrow movable range are the first actuator for driving the carpal metacarpal joint with a wide movable range. Compared with one actuator and the first drive mechanism, it is possible to cope with a small actuator and drive mechanism. In other words, the first actuator and the first drive mechanism for driving the carpal joint with a wide range of movement are placed on the palm where there is room in the space compared to the space inside the base joint, and the middle finger with a narrow range of movement It becomes possible to arrange the second actuator and the second drive mechanism for driving the articulated joint in a base joint having no space space compared to the space inside the palm. As a result, a limited space such as the finger structure of the robot hand can be used more effectively, and the robot hand can be downsized.

  A third solving means of the present invention is characterized in that at least one finger of the robot hand finger structure described in the first solving means or the second solving means is provided in the robot hand.

  According to the finger structure of the robot hand of the present invention, a small robot hand in which the axes of the two joints at the base of the finger are orthogonal at one point and a small robot hand with little backlash and backlash are constructed. It is possible to achieve both. As a result, for the finger joints of the robot hand, which has a particularly limited space, it is possible to perform a complex operation similar to that of a human finger and to control the position and force of the fingertip with high accuracy. In addition, the object can be skillfully manipulated by a robot hand having at least one finger structure of the robot hand of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A finger structure of a robot hand according to the present invention and a best mode of a robot hand provided with the finger structure will be described below with reference to the drawings.
1, 2, and 3 are a perspective view, a rear view, and a side view, respectively, showing the structure of a finger of a robot hand that implements the present invention in one mode.

1, 2, and 3, 1 is a finger, 11 is a palm, 12 is a middle hand, 13 is a proximal joint, 14 is a middle joint, 15 is a distal joint, 16 is a link arm, and 21 is a carpal joint. , 22 is a metacarpophalangeal joint, 23 is a proximal interphalangeal joint, 24 is a distal interphalangeal joint, 31 is a first actuator, 32 is a second actuator, 41 is a first drive mechanism, and 42 is a second drive. Mechanism, 51 is a spur gear constituting the first drive mechanism 41, 52 is a harmonic drive (registered trademark) reduction gear constituting the first drive mechanism 41, 53 is a spur gear constituting the second drive mechanism 42, Reference numeral 54 denotes a harmonic drive (registered trademark) speed reducer constituting the second drive mechanism 42.
Reference numeral 25 denotes an output rotation shaft of the first drive mechanism 41, 26 denotes a first support shaft, and 27 denotes a second support shaft.
In FIG. 1, the middle joint 14, the last joint 15, the proximal interphalangeal joint 23, and the distal interphalangeal joint 24 are configured so that a movement similar to that of a human finger can be performed. The present invention can be applied to a structure in which the base clause 13, the middle clause 14, and the end clause 15 are integrated. Further, a timing belt may be used instead of the spur gears 51 and 53, and another means may be used as long as it achieves a high reduction ratio instead of the harmonic drive (registered trademark) reduction gears 52 and 54. For example, a planetary gear reduction device may be used.

  The palm 11 and the metacarpal 12 are rotatably coupled to form a carpal metacarpal joint 21. Similarly, the middle hand 12 and the proximal joint 13 are rotatably coupled to form a middle fingertip joint 22. Two link arms 16 are provided to form a parallel link mechanism, and one end of each link arm 16 is rotatably supported via a first support shaft 26 provided on the output shaft of the first drive mechanism 41. In addition, the other end is rotatably supported via a second support shaft 27 provided in the middle joint 12.

A first actuator 31 and a first drive mechanism 41 are disposed on the palm 11. The output of the first actuator 31 is transmitted to the rotary shaft on the input side of the harmonic drive (registered trademark) reduction gear 52 constituting the first drive mechanism 41 via the spur gear 51 constituting the first drive mechanism 41. . Further, the output of the first actuator 31 transmitted to the output rotation shaft 25 of the harmonic drive (registered trademark) reduction device 52, that is, the output rotation shaft 25 of the first drive mechanism, is transmitted via the link arm 16 to the middle section. 12 is transmitted. In other words, the first actuator 31 can control the carpal metacarpal joint 21.

  FIG. 4 shows a state where the joint angle of the carpal joint 21 is moved from the posture shown in FIG. 3 by the first actuator 31.

  As described above, the output of the first actuator 31 is decelerated by the first drive mechanism 41 and then transmitted to the middle joint 12 via the link arm 16 so that the carpal metacarpal joint 21 can be controlled. It has become. Since the final speed reduction stage of the first drive mechanism 41 is decelerated by the first reduction gear provided with the high speed reduction means, the spur gear 51 constituting the first drive mechanism 41 temporarily includes backlash and backlash. However, the output of the first drive mechanism 41 can constitute a mechanism with less backlash and backlash. That is, the backlash and backlash of the spur gear 51 are reduced in proportion to the reduction ratio when being decelerated by the high speed reduction means.

In addition, the output of the first drive mechanism 41 with reduced backlash and backlash is transmitted to the middle joint 12 by the parallel link mechanism using two sets of the link arm 16, the first support shaft 26, and the second support shaft 27. Therefore, it is possible to configure the carpal middle joint 21 as a joint with less backlash and backlash.
7 and 8, only one set of the link arm 16, the first support shaft 26, and the second support shaft 27 is used, and the output of the first drive mechanism 41 is transmitted to the middle joint 12. You may do it. At this time, the distance between the output shaft 25 of the first drive mechanism 41 and the first support shaft 26 is configured to be shorter than the distance between the axis of the carpal joint 21 and the second support shaft 27. Then, it is possible to configure a mechanism with less backlash and backlash.
In this specification, a parallel link mechanism using two sets of the link arm 16, the first support shaft 26 and the second support shaft 27, and a set of the link arm 16, the first support shaft 26 and the second support shaft 27. A single link mechanism using only one set is collectively referred to as a “link mechanism”.

A second actuator 32 and a second drive mechanism 42 are disposed on the base joint 13. The output of the second actuator 32 is transmitted to the rotary shaft on the input side of the harmonic drive (registered trademark) reduction gear 54 constituting the second drive mechanism 42 via the spur gear 52 constituting the second drive mechanism 42. The rotary shaft on the output side of the harmonic drive (registered trademark) reduction device 54, that is, the output rotary shaft of the second drive mechanism is joined to the middle clause 12. That is, the metacarpophalangeal joint 22 can be controlled by the second actuator 32.

  FIG. 5 shows a state in which the joint angle of the metacarpophalangeal joint 22 is moved from the posture of FIG. 2 by the second actuator 32.

  As described above, the output of the second actuator 32 is decelerated by the second drive mechanism 42, and at the same time, the output shaft of the second drive mechanism 42 is joined to the middle joint 12 to control the metacarpal joint 22. It is the composition. Since the final speed reduction stage of the second drive mechanism 42 is decelerated by the second reduction gear provided with the high speed reduction means, the spur gear 52 constituting the second drive mechanism 42 temporarily contains backlash and backlash. However, the output of the second drive mechanism 42 can constitute a mechanism with less backlash and backlash. With such a configuration, the metacarpophalangeal joint 22 can be configured as a joint with less backlash and backlash. That is, the backlash and backlash of the spur gear 52 are reduced in proportion to the reduction ratio when being decelerated by the high speed reduction means.

  In addition, as described above, the two actuators and the two drive mechanisms are arranged on the palm and the base joint, respectively, so that the space limited like the finger structure of the robot hand (not limited to the space inside the palm but inside the base joint). Space) can be used effectively, and the robot hand can be downsized. At the same time, by arranging two actuators and two drive mechanisms on the palm and base, respectively, the middle hand can be reduced in size, and in addition, the output of the first mechanism is transmitted to the middle hand via the link mechanism. Although it is compact, it is possible to realize a drive mechanism in which the axis of the carpal metacarpal joint and the axis of the metacarpophalangeal joint are orthogonal at one point.

  In addition, in the present invention, as shown in FIGS. 4 and 5, the joint movable range of the carpal metacarpal joint 21 is configured to be wider than the joint movable range of the metacarpophalangeal joint 22. When the movable range is thus different, the second actuator 32 and the second drive mechanism 42 for driving the metacarpophalangeal joint 22 having a narrow movable range drive the carpal metacarpal joint 21 having a wide movable range. Compared to the first actuator 31 and the first drive mechanism 41, the small actuator and the drive mechanism can be used. That is, the first actuator 31 and the first drive mechanism 41 for driving the carpal metacarpal joint 21 having a wide movable range are arranged on the palm 11 having a space space larger than the space inside the base joint 13 and movable. The second actuator 32 and the second drive mechanism 42 for driving the metacarpophalangeal joint 22 having a narrow range can be arranged on the base joint 13 having a small space compared to the space inside the palm 11. As a result, it is possible to more effectively utilize a limited space like the finger structure of the robot hand, and to further reduce the size of the robot hand.

FIG. 6 is a perspective view showing a robot hand having the finger structure of the robot hand of the present invention.
The object can be skillfully manipulated by the robot hand having at least one finger of the finger structure of the robot hand of the present invention.

It is a perspective view which shows the structure of the finger of the robot hand which concerns on embodiment of this invention. It is a rear view which shows the structure of the finger | toe of the robot hand which concerns on embodiment of this invention. It is a side view which shows the structure of the finger of the robot hand which concerns on embodiment of this invention. FIG. 4 is a side view showing a state in which the joint angle of the carpal joint is moved from the posture of FIG. 3 by the first actuator. It is a rear view which shows the state which moved the joint angle of the metacarpophalangeal joint from the attitude | position of FIG. 2 with the 2nd actuator. It is a perspective view which shows the robot hand provided with the finger structure of the robot hand which concerns on embodiment of this invention. It is a side view which shows an example of the single link mechanism which concerns on embodiment of this invention. It is a side view which shows the other example of the single link mechanism which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 finger | toe 11 palm part 12 middle hand 13 base joint 14 middle joint 15 last joint 16 link arm 21 carpal middle wrist joint 22 middle hand joint joint 23 proximal interphalangeal joint 24 distal interphalangeal joint 25 of first drive mechanism Output rotation shaft 26 First support shaft 27 Second support shaft 31 First actuator 32 Second actuator 41 First drive mechanism 42 Second drive mechanism 51 Spur gear 52 Harmonic drive (registered trademark) reduction gear 53 Spur gear 54 Harmonic drive ( Registered trademark) reducer

Claims (3)

In the finger structure of a robot hand having at least a palm, a middle hand, and a proximal joint, and a carpal joint at the joint between the palm and the middle hand, and a middle finger joint at the joint between the middle hand and the proximal joint, The axis of the carpal metacarpal joint and the axis of the metacarpophalangeal joint are orthogonal at one point, and the palm includes a first actuator and a first drive mechanism for driving the carpal metacarpal joint. The base joint includes a second actuator and a second drive mechanism for driving the metacarpophalangeal joint, and the first drive mechanism uses a harmonic reduction device or a planetary gear reduction device to output the first actuator. after reduction by the first reduction gear having a high reduction means consisting of, by transmitting the output of the first reduction gear via a link mechanism to the metacarpal, configured to drive the carpometacarpal joint And the second drive mechanism is After decelerating in the second reduction gear having a high reduction means comprising an output of the secondary actuator from harmonic reduction device or planetary gear speed reduction device by joining the output of the second reduction gear to the metacarpal, said the hands-phalangeal joint A finger structure of a robot hand, characterized by being configured to drive the robot.   2. The finger structure of the robot hand according to claim 1, wherein a joint movable range of the carpal metacarpal joint is wider than a joint movable range of the metacarpophalangeal joint.   A robot hand comprising at least one finger of the finger structure of the robot hand according to claim 1 or 2.