JP6149204B2 - Robot hand - Google Patents

Description

  The present invention relates to a robot hand (hereinafter also simply referred to as “hand”) used for a humanoid robot, and in particular, realizes a proportion close to a human hand (ratio of thickness to the length of the hand) and force. The present invention relates to a robot hand having a detection function.

  In the present specification, the “hand” means a part corresponding to a human hand attached to the tip of the arm of a humanoid robot. In addition, “palm” means a part of the hand corresponding to the palm side part of the human hand, and “top” means a part of the hand corresponding to the back side part of the human hand. In addition, the “front-rear direction” of the hand means the direction in which the hand extends from the tip of the arm, and the “thickness direction” of the hand means the direction connecting the “palm” and “top” of the hand, The “left-right direction” of the hand means a direction perpendicular to the “front-rear direction” of the hand and perpendicular to the “thickness direction” of the hand.

  In order for the robot hand to stably hold the object, operate it, realize a stable pressing force against the environment, and realize a safe interaction with humans, it acts on the hand. The function of detecting the force is important, and robots described in Patent Documents 1 to 4 have been invented as robots having such a function.

  In the devices described in Patent Document 1 and Patent Document 2, a force sensor for detecting a force acting on an end effector such as a hand is arranged around the wrist located at the tip of the robot arm, An end effector is attached. Based on the detection value of the force sensor disposed around the wrist, the force acting on the end effector is controlled.

  In the thing of patent document 3 and patent document 4, the force sensor for detecting the force which acts on a fingertip is arrange | positioned around the fingertip. Based on the detection value of the force sensor arranged around the fingertip, the force generated between the object and the fingertip is controlled.

JP-A-6-278007 JP-A-7-060606 JP 2005-329512 A JP 2010-264548 A

  As an application of humanoid robots, in addition to the work that humans substitute in the environment where humans live, human life support (for example, picking up objects that have fallen on the floor and handing them to humans) Evaluation (for example, measurement and evaluation of joint torque and joint movable angle of a robot that has been operated in the same way to evaluate joint load on humans when entering a car) and entertainment field (for example, host of an event venue) And fashion models) are also expected. In particular, when an attempt is made to use a humanoid robot for human life support, a safe interaction between the robot and the human is required. For example, when handing an object to a human, it is necessary to detect and control the force generated between the robot and the human so that the robot does not apply excessive force to the human. Also, from the viewpoint of safety, it is necessary to detect and control the force at many parts of the hand that may be touched by humans. Furthermore, from the viewpoint of interpersonal affinity, the hand is also required to realize a proportion very close to humans.

  However, in the ones described in Patent Document 1 and Patent Document 2, since the force sensor is disposed around the wrist, the origin of the force sensor coordinate system and the center of gravity of the object are separated, and the moment acting on the force sensor As a result, it was necessary to use a force sensor with a large allowable moment load. Since the force sensor having a large allowable moment load has a large volume, it is difficult to realize a proportional hand similar to a human hand in this respect.

  In addition, in the devices described in Patent Document 1 and Patent Document 2, the force sensor is disposed around the wrist, and the mounting surface thereof is disposed to face the tip of the robot arm. If the normal direction of the mounting surface and the thickness direction of the hand are made to coincide with each other, there is a problem that the relative posture of the arm and the hand is not similar to the relative posture of the human forearm and the hand.

  Moreover, in the thing of patent document 3 and patent document 4, since the force sensor is arrange | positioned around a fingertip, although gripping force can be detected, the force which acts on the palm and back of a hand can be detected. Therefore, it was difficult to realize a safe interaction with humans.

  Therefore, the present invention provides a robot hand having a force detection function while realizing a proportion close to that of a human hand, in which the ratio of the thickness to the length of the hand is smaller than that of a conventional hand in a humanoid robot. It is intended to be realized.

The present invention has been made to advantageously solve the above problems, and a robot hand according to the present invention includes a hand base, at least one finger coupled to the hand base, and a tip of the robot arm. In a robot hand comprising: a wrist connecting frame to be coupled; and a force sensor having one attachment surface and the other attachment surface to detect translational force or torque of at least one axis,
The hand base has a palm side frame located on the palm side of the robot hand, and a back side frame located on the back side of the robot hand and coupled to the palm side frame;
The force sensor is disposed so as to be included in the hand base, the one mounting surface is coupled to the wrist coupling frame, and the other mounting surface is coupled to the hand base, And a force acting on the finger are detected.

  According to the robot hand of the present invention, the palm side which is a frame which has one mounting surface and the other mounting surface and which detects a translational force or torque of at least one axis is positioned on the palm side of the hand. Enclosed in a hand base having a frame and a back side frame that is coupled to the palm side frame and located on the back side of the hand, one mounting surface of the force sensor is attached to the tip of the robot arm. Since it is coupled to the wrist connection frame to be coupled and the other mounting surface is coupled to the hand base, it becomes possible to detect the force at many parts of the hand that can be touched by humans. The force sensor can detect the force acting on all the parts of the hand base and at least one finger coupled to the hand base.

  In addition, according to the robot hand of the present invention, since the force sensor is included in the hand base, the force detection coordinate origin of the force sensor can be brought close to the position of the center of gravity of the object. A sensor can be employed. Since the force sensor with a small allowable moment load has a small volume, it becomes easy to realize a robot hand having a proportion close to that of a human hand.

  In the robot hand of the present invention, it is preferable that at least a normal line of the other attachment surface of the one attachment surface and the other attachment surface is directed in a thickness direction of the hand base. The force sensor is preferably arranged so that the force detection coordinate origin of the force sensor is close to the palm side surface of the hand base. In this way, when the palm side surface is pressed against the object or the object is gripped by the palm side surface and the finger, the coordinate system origin of the force sensor is made closer to the center of gravity of the object. Is possible. As a result, a force sensor having a smaller allowable moment load can be employed. Since the force sensor having a smaller allowable moment load has a smaller volume, it becomes easier to realize a robot hand having a proportion close to that of a human hand.

  Further, in the robot hand of the present invention, the force sensor has the one attachment surface coupled to the wrist connecting frame and the other attachment surface coupled to the hand base via an impact force absorbing mechanism. Thus, it is preferable to detect a force acting on the hand base and the finger. In this way, the impact force absorbing mechanism absorbs the impact force generated when the robot hand comes into contact with the environment, an object, or a human being, thereby preventing damage to the robot hand itself at the time of contact. It is also possible to suppress the damage to the human body and reduce the impact force applied to humans.

  Further, in the robot hand of the present invention, the impact force absorbing mechanism includes a hand side elastic body positioned on the hand side with respect to the hand base and a force sensor side elastic body positioned on the force sensor side with respect to the hand base. And arranging the hand side elastic body and the force sensor side elastic body so that the relative positions of the one end part of the hand side elastic body, the one end part of the force sensor side elastic body and the force sensor do not collapse. The hand side elastic body and the force sensor side elastic body are arranged so that the relative positions of the other end of the hand side elastic body, the other end of the force sensor side elastic body, and the hand base are not collapsed. This is preferable. In this way, the hand side elastic body and the force sensor side elastic body are arranged so that the expansion / contraction position of the hand side elastic body at no load and the expansion position of the force sensor side elastic body at no load are not located on the same axis. Can be shifted from each other. As a result, it is possible to suppress the dimension of the hand of the impact force absorbing mechanism in the thickness direction, and it becomes easy to realize a proportion close to a human hand with the robot hand.

  Furthermore, in the robot hand of the present invention, the palm side frame protrudes to the outside of the hand while being spaced apart from each other and defines at least one plane together at the tip, for example, the first protrusion, the second protrusion, and the third A plurality of protrusions such as protrusions, and the wrist connecting frame has a portion protruding outward from the palm side frame excluding the plurality of protrusions, and the protruding portion has a tip of the plurality of protrusions. It is preferable to be located on the inner side of the hand from the plane to be defined. In this way, when the robot hand is attached to the environment (for example, a table or a wall), a plurality of protrusions come into contact with the environment on the plane defined by their tips, so that the contact force with the environment is detected. When gripping an object with a robot hand, the wrist connection frame is in contact with the object at a portion of the wrist connection frame that protrudes outside the palm side frame except for a plurality of protrusions. It becomes possible to detect the gripping force when the object is gripped by the protruding portion of the frame and the finger.

(A) And (b) is the perspective view seen from the back side which shows the whole structure of the robot hand of 1st Example of this invention, and the perspective view seen from the palm side. It is the disassembled perspective view seen from the back side which shows the structure of the robot hand of the said 1st Example. It is the disassembled perspective view seen from the palm side which shows the structure of the robot hand of the said 1st Example. It is the perspective view seen from the former side of the state where the robot hand of the above-mentioned 1st example is grasping the target object. (A) is a side view and a partial cross-sectional view seen from the thumb side in a state where the robot hand of the first embodiment is gripping an object, and (b) is a portion surrounded by a dotted line in (a). FIG. (A) And (b) is the perspective view seen from the back side which shows the whole structure of the robot hand of 2nd Example of this invention, and the perspective view seen from the palm side. It is the disassembled perspective view seen from the back side which shows the structure of the robot hand of the said 2nd Example. It is the disassembled perspective view seen from the palm side which shows the structure of the robot hand of the said 2nd Example. It is the perspective view seen from the back side in the state where the robot hand of the above-mentioned 2nd example is grasping the target object. (A) is a side view and a partial cross-sectional view seen from the thumb side in a state where the robot hand of the second embodiment is gripping an object, and (b) is a portion surrounded by a dotted line in (a). FIG. It is the perspective view seen from the back side of the state where the robot hand of the second embodiment is wearing a hand in the environment. It is sectional drawing seen from the thumb side in the state in which the robot hand of the said 2nd Example is wearing the environment.

  Hereinafter, embodiments in the case of carrying out the present invention will be described with reference to the drawings. FIGS. 1A and 1B are a perspective view showing the entire structure of the robot hand according to the first embodiment of the present invention as seen from the back side and a perspective view seen from the palm side.

  In FIG. 1, reference numeral 1 is a robot hand (hand), 2 is a hand base, 11 is a thumb, 12 is an index finger, 13 is a middle finger, 14 is a ring finger, and 15 is a little finger. 12a is the index finger link of the index finger, 12b is the index link of the index finger, 12c is the index link of the index finger, 13a is the index link of the middle finger, 13b is the index link of the middle finger, 13c is the index link of the middle finger, and 14a is the index link of the middle finger. The proximal link of the ring finger, 14b is the middle link of the ring finger, 14c is the last link of the ring finger, 15a is the proximal link of the little finger, 15b is the middle link of the little finger, and 15c is the last link of the little finger. In addition, reference numeral 41 denotes a wrist connection frame, 43 denotes a palm side frame, 44 denotes a back side subframe, and 45 denotes a back side frame.

In the robot hand 1 shown in FIG. 1, the proximal links of the index finger 12, the middle finger 13, the ring finger 14, and the little finger 15 have the same length, the middle links have the same length, and the last links have the same length. Although configured, this is merely an example and does not limit the scope of the claims, and links of different lengths may be used. Reference numeral 21 is a thumb joint axis, 22 is a four-finger MP (metacarpophalangeal) joint axis, 23 is a four-finger PIP (proximal interphalangeal) joint axis, and 24 is a four-finger DIP (distal
The interphalangeal joint axes (the axes of those joint axes in the figure) are shown respectively.

  Here, the robot hand 1 includes a thumb joint that changes the relative posture of the hand base 2 and the thumb 11 about the thumb joint shaft 21 as a rotation center. In addition, the four fingers of the index finger 12, the middle finger 13, the ring finger 14, and the little finger 15 change the relative posture of the hand base 2 and the proximal links 12a, 13a, 14a, 15a of the four fingers with the MP joint shaft 22 as the rotation center. An MP joint, a PIP joint that changes the relative posture of each of the four finger joint links 12a, 13a, 14a, 15a and the middle joint links 12b, 13b, 14b, 15b around the PIP joint shaft 23 as a rotation center, and a DIP joint shaft A DIP joint that changes the relative postures of the middle finger links 12b, 13b, 14b, and 15b of each of the four fingers and the end joint links 12c, 13c, 14c, and 15c with the rotation center at 24 is provided.

  The hand base 2 has a palm side frame 43 and an instep side frame 45, and has a substantially thin rectangular parallelepiped shape by connecting them together, and has a hollow structure. Further, in the robot hand 1 shown in FIG. 1, the hand base 2 also has a back side subframe 44, which is sandwiched between the palm side frame 43 and the back side frame 45 and coupled thereto. Has been. The hand base 2 is provided with holes for avoiding interference with the hand base 2 when the thumb 11, the index finger 12, the middle finger 13, the ring finger 14, and the little finger 15 are operated. The hand base 2 is also provided with a hole through which one end of a wrist connection frame 41 for connecting the robot hand 1 to the tip of the robot arm (for example, the wrist joint of the robot arm) protrudes from the hand base 2. ing.

  Although it is hidden by the hand base 2 in FIG. 1, as shown in FIG. 5 described later, the force sensor 42 is disposed so as to be included in the hand base 2, and one mounting surface of the force sensor 42 is the same. In FIG. 1, it is coupled to the wrist connection frame 41 at a portion hidden by the hand base 2, and the other mounting surface of the force sensor 42 is coupled to the palm side frame 43 of the hand base 2. In addition, the driving mechanism of the thumb 11, index finger 12, middle finger 13, ring finger 14, and little finger 15 hidden by the hand base 2 in FIG. 1 is also included in the hand base 2 as shown in FIGS. ing.

  By configuring the robot hand 1 and the hand base 2 in this way, the appearance of the robot hand 1 protrudes from the hand base 2, thumb 11, index finger 12, middle finger 13, ring finger 14, little finger 15, and hand base 2. Only the wrist connection frame 41 is provided. Since the wrist connection frame 41 is coupled to the tip of the robot arm, the force sensor 42 included in the hand base 2 and the force acting on the hand base 2 and the thumb 11, index finger 12, middle finger 13, ring finger 14 or pinky finger 15 can be detected. That is, the force sensor 42 can detect the force acting on all parts of the robot hand 1.

  FIG. 2 is an exploded perspective view showing the structure of the robot hand of the first embodiment, viewed from the back side. FIG. 3 is an exploded perspective view showing the structure of the robot hand of the first embodiment, viewed from the palm side. 2 and 3, the same reference numerals as those in FIG. 1 denote the same members. 2 and 3, reference numeral 42 is a force sensor, 52 is a base plate, 53 is a spacer, 54 is a hand side elastic body, 55 is a force sensor side elastic body, 56 is a hand side force sensor mounting screw, 57 Is a wrist side force sensor mounting screw, 58 is a convex guide, and 59 is a concave guide.

  A, b, and c attached to the numbers of the spacer 53, the hand side elastic body 54, the force sensor side elastic body 55, the hand side force sensor mounting screw 56, and the wrist side force sensor mounting screw 57, respectively, use a plurality of the same members. It is the attached code | symbol added in order to show each member of a case, and may abbreviate | omit and may explain. The hand side elastic body 54 and the force sensor side elastic body 55 use mechanical springs, but this is only an example and does not limit the scope of the claims, and may be an elastic body such as rubber. good.

  The convex guide 58 indicates a substantially triangular prism-shaped convex portion provided on the base plate 52, and the concave guide 59 indicates a substantially triangular cylindrical concave portion provided on the palm-side frame 43. The guide 59 is loosely fitted to each other to form a guide when at least one of the relative position and the relative posture between the palm side frame 43 and the base plate 52 is changed. The convex guide 58 may be provided on the palm side frame 43 and the concave guide 59 may be provided on the base plate 52.

  Further, reference numeral 61 is a first motor, 62 is a first precision reduction gear, 63 is a second motor, 64 is a second precision reduction gear, 65 is a belt-type transmission mechanism, 66 is a parallel link mechanism, and 67 is a parallel link mechanism output. The shaft is shown. In this specification, a harmonic reduction device using the product name Harmonic Drive (registered trademark), a planetary gear reduction device using a planetary gear (including a mysterious planetary gear), and a cyclo reduction device using a product name cyclo reduction device. An apparatus, an RV speed reducer using a trade name RV speed reducer, a roller drive speed reducer using a trade name roller drive, a ball speed reducer using a cycloid, etc. are referred to as a “precision speed reducer”.

  The first motor 61 and the first precision reduction gear 62 are disposed so as to be included in the hand base 2 and are fixed to the hand base 2. The output shaft of the first motor 61 and the input shaft of the first precision reduction device 62 are coupled, and the output shaft of the first precision reduction device 62 constitutes the thumb joint shaft 21. That is, by driving the first motor 61, the thumb 11 can be rotated inward and outward.

  Further, the second motor 63, the second precision reduction gear 64, the belt-type transmission mechanism 65, and the parallel link mechanism 66 are also arranged so as to be included in the hand base 2, and fixed to the hand base 2, and the parallel link mechanism output shaft. 67 is arranged to be included in the hand base 2 and is supported by the hand base 2 to constitute the MP joint shaft 22. The output of the second motor 63 is transmitted to the input shaft of the second precision reduction gear 64 via a belt-type transmission mechanism 65 composed of a pulley and a timing belt. Further, the output of the second precision reduction gear device 64 is transmitted to the parallel link mechanism output shaft 67 via the parallel link mechanism 66. The proximal links of the index finger 12, the middle finger 13, the ring finger 14, and the little finger 15 are fastened to the parallel link mechanism output shaft 67 with mounting screws (not shown). That is, by driving the second motor 63, it is possible to simultaneously bend and extend the index finger proximal link 12a, the middle finger proximal link 13a, the ring finger proximal link 14a, and the little finger proximal link 15a. It is configured.

  Further, the four-finger PIP joint shaft 23 and the DIP joint shaft 24 other than the thumb 11 are linked to the MP joint shaft 22 by a transmission mechanism (not shown) such as a wire transmission mechanism disclosed in Japanese Patent No. 3086452, for example. And are configured to rotate in the same direction. That is, by driving the second motor 63, the four fingers can be bent and extended simultaneously. Note that the configuration in which the four motors can be simultaneously bent and extended by the second motor 63 is merely an example, and does not limit the scope of the claims.

  FIG. 4 is a perspective view of the robot hand according to the first embodiment as viewed from the upper side in a state where the robot hand is gripping the object, and FIG. 5A is a diagram illustrating the robot hand according to the first embodiment gripping the object. FIG. 5B is a side view and a partial cross-sectional view as seen from the thumb side in the state of being performed, and is an enlarged view of a portion surrounded by a dotted line in FIG. 4 and 5, the same reference numerals as those in FIGS. 1 to 3 denote the same members. That is, in FIGS. 4 and 5, reference numeral 51 denotes an impact force absorbing mechanism, 71 denotes a force sensor detection coordinate origin, 72 denotes an object, and 73 denotes an object gravity center position.

  As shown in these drawings, one mounting surface (upward surface in FIG. 5) of the force sensor 42 is a wrist side force so that the relative position of the wrist coupling frame 41 does not collapse inside the hand base 2. The sensor mounting screw 57 is used for screw fastening. The other mounting surface (downward surface in FIG. 5) of the force sensor 42 is coupled to the hand base 2 via an impact force absorbing mechanism 51. In general, a commercially available force sensor has a characteristic that the normal direction of the mounting surface can measure a load equal to or larger than that of other directions, and the force acting on the robot base 2 is also thick. Since there are many cases where the load in the direction acts more than the load in the other direction, in the robot hand 1 of the first embodiment, the normal of the mounting surface of the force sensor 42 faces the thickness direction of the hand base 2. Are arranged as follows. By disposing the force sensor 42 in this way, it becomes possible to detect a large load acting in the thickness direction of the hand base 2 and, for example, it is applied to the hand 1 in a case where the hand 1 is pressed against the table with a palm. A large force can be detected.

  The impact force absorbing mechanism 51 includes a base plate 52, a spacer 53 (53a, 53b, 53c), a hand side elastic body 54 (54a, 54b, 54c), a force sensor side elastic body 55 (55a, 55b, 55c) and a hand. The side force sensor mounting screw 56 (56a, 56b, 56c) is configured as a general equalizing mechanism for floatingly supporting the spot welding gun. That is, the base plate 52 is provided with a hole having the same diameter as the outer diameter of the spacer 53, and the spacer 53 is passed through the hole, so that the relative position of the spacer 53 and the force sensor 42 does not collapse. The force sensor mounting screws 56 are used to screw each other. In addition, although the hole of the same diameter as the outer diameter of the spacer 53 was provided in the base plate 52, this is only an illustration and does not limit a claim, The hand side force sensor mounting screw is attached to the base plate 52. 56, a base plate 52 is sandwiched between the force sensor 42 and the spacer 53, and a hand side force sensor mounting screw 56 is provided so that the relative positions of the force sensor 42, the base plate 52, and the spacer 53 do not collapse. It may be used to fasten screws.

  Further, the end of the spacer 53 on the screw head side of the hand side force sensor mounting screw 56 is provided with a portion having a flange shape having substantially the same outer diameter as the inner diameter of the hand side elastic body 54. The relative position between one end (the lower end in FIG. 5) of the elastic body 54 and the spacer 53 is not collapsed. The spacer 53 is screwed to the force sensor 42 with a hand-side force sensor mounting screw 56, and as a result, the relative position between one end of the hand-side elastic body 54 and the force sensor 42 is not broken.

  In addition, the base plate 52 is provided with a recess having the same diameter as the outer diameter of the force sensor side elastic body 55, and one end portion (upper end portion in FIG. 5) of the force sensor side elastic body 55 and the base plate. The relative position with respect to 52 does not collapse. The base plate 52 and the force sensor 42 are assembled so that their relative positions do not collapse. As a result, the relative position between the one end of the force sensor-side elastic body 55 and the force sensor 42 does not collapse. It has become.

  The other end portion (upper end portion in FIG. 5) of the hand side elastic body 54 is fixed by a depression provided on the palm side frame 43 of the hand base portion 2 and having an inner diameter substantially the same as the outer diameter of the hand side elastic body 54. Yes. Further, the other end portion (lower end portion in FIG. 5) of the force sensor side elastic body 55 has an inner diameter substantially the same as the outer diameter of the force sensor side elastic body 55 provided on the palm side frame 43 of the hand base portion 2. It is fixed with a dent. As a result, the relative positions of the other end of the hand side elastic body 54, the other end of the force sensor side elastic body 55, and the palm side frame 43 of the hand base 2 are arranged so as not to collapse.

  That is, the impact force absorbing mechanism 51 has a force on the hand side elastic body 54 located on the hand side far from the force sensor 42 with respect to the palm side frame 43 of the hand base 2 and on the palm side frame 43 of the hand base 2. A force sensor side elastic body 55 located on the side of the force sensor that is close to the sensor 42, one end portion (lower end portion in FIG. 5) of the hand side elastic body 54 and one end portion of the force sensor side elastic body 55 (FIG. 5 is arranged so that the relative position between the upper end portion and the force sensor 42 does not collapse, and the other end portion (upper end portion in FIG. 5) of the hand side elastic body 54 and the other end portion of the force sensor side elastic body 55 ( In FIG. 5, the relative position between the lower end portion) and the palm side frame 43 of the hand base 2 is arranged so as not to collapse.

  By configuring the impact force absorbing mechanism 51 in this way, when a force acts on the hand base 2, not only the relative position of the hand base 2 and the force sensor 42 but also the relative posture can be changed. It is possible to reduce the translational impact force and the rotational impact moment acting on the base 2. As a result, the impact force generated when the robot hand 1 comes into contact with the environment, an object, or a human is absorbed, and the damage of the robot hand 1 itself at the time of contact is suppressed, and the damage of the environment and the object is also suppressed. The impact on humans can be reduced.

  Further, as the elastic body of the impact force absorbing mechanism 51, the hand side elastic body 54 and the force sensor side elastic body 55 are positioned and arranged, respectively, so that the expansion position of the hand side elastic body 54 at the time of no load and the no load The hand side elastic body 54 and the force sensor side elastic body 55 are arranged in the circumferential direction with respect to the central axis of the mounting surface of the force sensor 42 so that the expansion / contraction position of the force sensor side elastic body 55 is not on the same axis. It becomes possible to dispose and arrange. As a result, the size of the impact force absorbing mechanism 51 in the thickness direction of the hand can be suppressed, and the robot hand 1 can easily realize a proportion close to that of a human hand.

  Further, in the robot hand 1 according to the first embodiment, as shown in FIG. 5, the force sensor detection coordinate origin 71 of the force sensor 42 has a force so that it is close to the palm side surface of the palm side frame 43 of the hand base 2. A sensor 42 is arranged. More specifically, the distance from the force sensor detection coordinate origin 71 of the force sensor 42 to the palm side surface of the palm side frame 43 of the hand base 2 is the back of the back side frame 45 of the hand base 2 from the force detection coordinate origin 71. The force sensor 42 is disposed so as to be shorter than the distance to the side surface. By arranging the force sensor 42 so that the force sensor detection coordinate origin 71 is on the palm side surface in this way, the moment due to the force applied to the force sensor 42 from the palm side surface is reduced, and the force sensor 42 has an allowable moment. It becomes possible to employ a small force sensor. Since the force sensor having a small allowable moment has a small volume, it becomes easy to realize the robot hand 1 having a proportion close to that of a human hand.

  6A and 6B are a perspective view seen from the back side and a perspective view seen from the palm side showing the overall structure of the robot hand according to the second embodiment of the present invention. In FIG. Is a first protrusion, 32 is a second protrusion, 33 is a third protrusion, and 34 is a plain. The plain 34 is a substantially planar portion on the body surface side of the palm-side frame 43 that comes closer to the inside of the hand than the one plane in which the first projection 31, the second projection 32, and the third projection 33 together define at the tip. Is shown. In FIG. 6, the same reference numerals as those in FIGS. 1 to 5 denote the same members.

  The first difference between the first embodiment and the second embodiment of the present invention is that the palm side frame 43 of the robot hand 1 of the second embodiment protrudes to the outside of the hand and is separated from each other at the tip. In other words, the first protrusion 31, the second protrusion 32, and the third protrusion 33 are provided as a plurality of protrusions that define one plane. Further, the second difference is that, in the robot hand 1 of the second embodiment, a hole or a notch is provided in the palm side frame 43 of the hand base 2, and the tip of the robot arm of the wrist connection frame 41 ( For example, the end opposite to the end connected to the wrist joint of the robot arm) is inserted into the hole or notch of the palm side frame 43, and the plain 34 on the palm side surface of the palm side frame 43 is inserted. It is protruding. Other configurations, such as the configuration of each finger driving mechanism and the impact force absorbing mechanism 51, are the same as those in the first embodiment, and thus detailed description thereof is omitted.

  Also in the robot hand 1 of the second embodiment shown in FIG. 6, as in the first embodiment, the hand base portion 2 has a palm side frame 43 and an instep side frame 45, and by connecting them to each other, It has a substantially thin rectangular parallelepiped shape and has a hollow structure. In the robot hand 1 shown in FIG. 6, the hand base 2 also has an instep sub-frame 44, and the instep sub-frame 44 is sandwiched between the palm side frame 43 and the instep side frame 45 so as to be sandwiched between them. Are combined. The hand base 2 is provided with holes for avoiding interference with the hand base 2 when the thumb 11, the index finger 12, the middle finger 13, the ring finger 14, and the little finger 15 are operated. The hand base 2 is provided with a hole through which one end of a wrist connection frame 41 for connecting the robot hand 1 to the tip of the robot arm (for example, the wrist joint of the robot arm) protrudes from the hand base 2. In addition, a hole or a notch is provided so that the other end of the wrist connection frame 41 protrudes from the plain 34 on the palm side surface of the palm side frame 43 of the hand base 2.

  Although it is hidden by the hand base 2 in FIG. 6, as shown in FIG. 10 described later, the force sensor 42 is disposed so as to be included in the hand base 2, and one mounting surface of the force sensor 41 is connected to the wrist. The other mounting surface of the force sensor 41 is coupled to the back side subframe 44 of the hand base 2 at a portion hidden by the hand base 2 in FIG. 6. In addition, the driving mechanism of the thumb 11, index finger 12, middle finger 13, ring finger 14, and little finger 15 hidden by the hand base 2 in FIG. 1 is also included in the hand base 2 as shown in FIGS. ing.

  By configuring the robot hand 1 and the hand base 2 in this way, the appearance of the robot hand 1 protrudes from the hand base 2, thumb 11, index finger 12, middle finger 13, ring finger 14, little finger 15, and robot base 2. There are only both ends of the wrist connection frame 41 (one end connected to the tip of the robot arm (for example, the wrist joint of the robot arm) and the other end protruding from the palm side frame 43). Since the wrist connection frame 41 is coupled to the tip of the robot arm, the force sensor 42 included in the hand base 2 and the force acting on the hand base 2 and the thumb 11, the index finger 12, the middle finger 13, the ring finger 14, or the little finger 15 can be detected. That is, it acts on many parts of the robot hand 1, specifically, parts other than the other end part of the wrist coupling frame 41 protruding from the hole of the plain 34 on the palm side surface of the palm side frame 43 of the hand base 2. It is possible to detect the force to perform.

  FIG. 7 is an exploded perspective view showing the structure of the robot hand according to the second embodiment, viewed from the back side. FIG. 8 is an exploded perspective view showing the structure of the robot hand according to the second embodiment, viewed from the palm side. FIG. FIG. 9 is a perspective view of the robot hand according to the second embodiment as viewed from the back side in a state where the robot hand is gripping the object. FIG. 10A is a diagram illustrating the robot hand according to the second embodiment. FIG. 10B is an enlarged view of a portion surrounded by a dotted line in FIG. 10A. FIG. 11 is a tilted view of the robot hand according to the second embodiment as seen from the back side in a state where the robot hand is wearing the environment. FIG. 12 is a diagram illustrating the robot hand according to the second embodiment. FIG. 7 is a cross-sectional view seen from the thumb side in the state where the same reference numerals are used to denote the same members as in FIGS. 1 to 6.

  As shown in these drawings, one mounting surface (downward surface in FIG. 10) of the force sensor 42 is formed by using wrist side force sensor mounting screws 57 so that the relative positions of the wrist connecting frame 41 do not collapse. Screws are fastened. The other mounting surface (upward surface in FIG. 10) of the force sensor 42 is coupled to the upper frame 44 of the hand base 2 via an impact force absorbing mechanism 51. In general, a commercially available force sensor has a characteristic that the normal direction of the mounting surface can measure a load equal to or larger than that of other directions, and the force acting on the robot base 2 is also thick. Since there are many cases where the load in the direction acts more than the load in the other direction, also in the robot hand 1 of the second embodiment, the normal of the mounting surface of the force sensor 42 faces the thickness direction of the hand base 2. Are arranged as follows. By arranging the force sensor 42 in this way, it is possible to detect a large load acting in the thickness direction of the hand base 2.

  In the robot hand 1 of the first embodiment and the second embodiment, the direction of the normal of one mounting surface of the force sensor 42 coupled to the wrist connecting frame 41 and the impact force absorbing mechanism 51 are provided. The direction of the normal of the other mounting surface of the force sensor coupled to the hand base 2 is directed to the thickness direction of the hand base 2 that is the same direction as each other, but this is merely an example, and For example, the direction of the normal of one mounting surface of the force sensor 42 coupled to the wrist coupling frame 41 is determined by the force sensor coupled to the hand base 2 via the impact force absorbing mechanism 51. You may face the direction which cross | intersects with the direction of the normal line of other attachment surfaces.

  Further, in the robot hand 1 of the second embodiment, the end portion of the wrist connecting frame 41 protruding from the plain 34 on the palm side surface of the palm side frame 43 of the hand base 2 is the outside of the hand of the palm side frame 43. The first protrusion 31, the second protrusion 32, and the third finger protrusion 33 provided on the inside of the hand are configured to be closer to the inside of the hand than the plane defined by the tip. With such a configuration, as shown in FIGS. 11 and 12, it is possible to detect a large force applied to the hand 1 in a case where the hand 1 is pressed against the table with a palm. Here, instead of the three protrusions of the first protrusion 31, the second protrusion 32, and the third finger protrusion 33, four or more protrusions or two protrusions are used as a plurality of protrusions that together define a plane at the tip. The above protrusions may be provided, or a combination of protrusions and protrusions may be provided.

  Also in the robot hand 1 of the second embodiment, since the shock absorbing mechanism 51 having the same configuration as the shock absorbing mechanism 51 of the first embodiment is provided, when the force acts on the hand base 2, the hand base 2 and the relative position of the force sensor 42 can be changed as well as the relative posture, and the impact force in the translational direction and the impact moment in the rotational direction acting on the hand base 2 can be reduced. This absorbs the impact force generated when the robot hand comes into contact with the environment, an object, or a human, suppresses damage to the robot hand itself at the time of contact, and also prevents damage to the environment or the object. The applied impact force can be reduced.

  Further, as the elastic body used for the impact force absorbing mechanism 51, the hand side elastic body 54 and the force sensor side elastic body 55 are positioned and arranged, respectively, so that the hand side elastic body 54 is not expanded and contracted when there is no load. The hand side elastic body 54 and the force sensor side elastic body 55 are arranged in the circumferential direction with respect to the central axis of the mounting surface of the force sensor 42 so that the expansion / contraction position of the force sensor side elastic body 55 is not on the same axis. It becomes possible to dispose and arrange. As a result, it is possible to suppress the dimension of the hand of the impact force absorbing mechanism 51 in the thickness direction, and it becomes easy to realize the robot hand 1 having a proportion close to that of a human hand.

  Further, also in the robot hand 1 of the second embodiment, the force sensor detection coordinate origin 71 of the force sensor 42 has a force so that it is close to the palm side surface of the palm side frame 43 of the hand base 2 as shown in FIG. A sensor 42 is arranged. More specifically, the distance from the force sensor detection coordinate origin 71 of the force sensor 42 to the palm side surface of the palm side frame 43 of the hand base 2 is the back of the back side frame 45 of the hand base 2 from the force detection coordinate origin 71. The force sensor 42 is disposed so as to be shorter than the distance to the side surface. By arranging the force sensor 42 so that the force sensor detection coordinate origin 71 is on the palm side surface in this way, the moment due to the force applied to the force sensor 42 from the palm side surface is reduced, and the force sensor 42 has an allowable moment. It is also possible to employ a small force sensor. Since the force sensor having a small allowable moment has a small volume, it becomes easy to realize the robot hand 1 having a proportion close to that of a human hand.

  In addition, in the robot hand 1 of the second embodiment, as shown in FIG. 10, when gripping the object 72, the robot base 2 or the fingers 11 to 15 provided on the robot base 2 and the palm side of the hand base 2 By grasping the object 72 with the end of the wrist connection frame 41 protruding from the plain 34 on the palm side surface of the frame 43, the fingers 11 to 15, the first protrusion 31 and the second protrusion 32 The force sensor 42 detects the gripping force at the time of gripping because the object 72 is in contact with the end of the wrist connecting frame 41 that protrudes outside the palm side frame 43 excluding the third protrusion 33. can do.

  As mentioned above, although the specific example of this invention was demonstrated in detail based on drawing, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. Further, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, although the technique illustrated in this specification or the drawings achieves a plurality of objects at the same time, the achievement of one of the objects itself has technical utility.

  Thus, according to the robot hand of the present invention, the force sensor that has one attachment surface and the other attachment surface and detects the translational force or torque of at least one axis is a palm positioned on the palm side of the hand. It is contained in a hand base having a side frame and a back side frame that is coupled to the palm side frame and located on the back side of the hand, and one mounting surface of the force sensor is attached to the tip of the robot arm. Since the other attachment surface is connected to the hand base while being connected to the wrist connection frame that is connected to the hand, it becomes possible to detect the force at many parts of the hand that humans may contact, In particular, the force applied to all the parts of the hand base and at least one finger coupled to the hand base can be detected by the force sensor.

  In addition, according to the robot hand of the present invention, since the force sensor is included in the hand base, the force detection coordinate origin of the force sensor can be brought close to the position of the center of gravity of the object. It becomes possible to employ a small force sensor. Since the force sensor with a small allowable moment load has a small volume, it becomes easy to realize a robot hand having a proportion close to that of a human hand.

DESCRIPTION OF SYMBOLS 1 Robot hand 2 Hand base 11 Thumb 12 Index finger 12a Index link of index finger 12b Index link of index finger 12c Index link of index finger 13 Middle finger 13a Index link of middle finger 13b Index link of middle finger 13c Index link of middle finger 14 Ring finger 14a Ring finger 14b middle finger link 14b last finger link 15c little finger 15a little finger proximal link 15b little finger middle joint link 15c little finger middle joint link 21 thumb joint shaft 22 MP joint shaft 23 PIP joint shaft 24 DIP joint shaft 31 1st protrusion 32 2nd protrusion 33 3rd protrusion 34 Plain 41 wrist connection frame 42 force sensor 43 palm side frame 44 back side subframe 45 back side frame 51 impact force absorption mechanism 52 base plate 53, 53a, 53b, 53c Spacers 54, 54a, 54b, 54c Hand side elastic body 55, 55a, 55b, 55c Force sensor side elastic body 56, 56a, 56b, 56c Hand side force sensor mounting screw 57, 57a, 57b, 57c Wrist side force sensor mounting screw 58 Convex guide 59 Concave guide 61 First motor 62 First precision reduction device 63 Second motor 64 Second precision reduction device 65 Belt transmission mechanism 66 Parallel link mechanism 67 Parallel link mechanism output shaft 71 Force sensor detection coordinate origin 72 Object 73 Object gravity center position 74 Environment

Claims (6)

A hand base, at least one finger coupled to the hand base, a wrist connecting frame coupled to the tip of the robot arm and supporting the hand base, one mounting surface and the other mounting surface A robot hand having at least one translational force or torque sensor for detecting torque,
The hand base has a palm side frame located on the palm side of the robot hand, and a back side frame located on the back side of the robot hand and coupled to the palm side frame,
The force sensor is disposed so as to be included in the hand base, the one mounting surface is coupled to the wrist coupling frame, and the other mounting surface is coupled to the hand base, A robot hand characterized by detecting a force acting on the finger and a force acting on the finger.   The robot hand according to claim 1, wherein a normal line of at least the other mounting surface of the one mounting surface and the other mounting surface is directed in a thickness direction of the hand base.   The robot hand according to claim 1 or 2, wherein the force sensor is arranged so that a force detection coordinate origin of the force sensor is close to a palm side surface of the hand base.   In the force sensor, the one attachment surface is coupled to the wrist connection frame, and the other attachment surface is coupled to the hand base through an impact force absorbing mechanism, and acts on the hand base and the finger. The robot hand according to any one of claims 1 to 3, wherein a force to be detected is detected. The impact force absorbing mechanism includes a hand side elastic body positioned on the hand side with respect to the hand base and a force sensor side elastic body positioned on the force sensor side with respect to the hand base,
The hand side elastic body and the force sensor side elastic body are arranged so that the relative positions of the one end of the hand side elastic body, the one end of the force sensor side elastic body, and the force sensor are not collapsed, and The hand side elastic body and the force sensor side elastic body are arranged so that the relative positions of the other end of the hand side elastic body, the other end of the force sensor side elastic body, and the hand base are not collapsed. The robot hand according to claim 4, wherein the robot hand is characterized. The palm side frame includes a plurality of protrusions that are spaced apart from each other and protrude to the outside of the hand and define at least one common plane at the tip.
The wrist connection frame has a portion protruding outward from the palm side frame excluding the plurality of protrusions,
The robot hand according to any one of claims 1 to 5, wherein the projecting portion is located on the inner side of the hand with respect to a common plane in contact with tips of the plurality of projections.

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