JP2019010715A - Artificial skin for robot hand and robot hand - Google Patents

Abstract

To provide an artificial skin for a robot hand capable of easily changing frictional force with a simple mechanism.SOLUTION: An artificial skin 12 for a robot hand is to be provided on a finger part 3 of the robot hand and comprises a first contact part 13 having elasticity and a second contact part 14 having a frictional coefficient smaller than a frictional coefficient of the first contact part 13. The second contact part 14 is fixed to a surface of the first contact part 13 with its surface projecting to the outer side relative to the surface of the first contact part 13. The second contact part 14 projecting to the outer side can be pushed into the first contact part 13 against elastic force of the first contact part 13 in response to pressing force when the second contact part 14 makes contact with an object.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an artificial skin for a robot hand provided on a finger portion of the robot hand. The present invention also relates to a robot hand to which such artificial skin for a robot hand is applied.

  The following Patent Document 1 discloses a robot apparatus in which a finger part has a three-layer structure. Specifically, the finger portion of the robot device includes a skeleton layer having a first hardness, a flexible layer having a second hardness lower than the first hardness, a lower hardness than the first hardness, and a second hardness. And a surface layer having a hardness higher than the hardness. Thereby, the robot apparatus can improve the adhesiveness of the finger | toe part at the time of hold | gripping a target object.

JP 2004-174625 A

  However, in the conventional case, since the outermost surface of the finger portion is made of the same material made of the surface layer, the frictional force cannot be changed at the finger portion. Therefore, inconvenience arises when the conventional robot apparatus is used for, for example, the operation of gripping the object with the finger portion and the operation of sensing the object by tracing the object.

  In the operation of grasping the object with the finger part, it is preferable that the frictional force of the finger part is large in order to grasp the object stably. On the other hand, in the sensing operation of the object, since the finger part is slid while being in contact with the object, it is preferable that the frictional force of the finger part is small. When the frictional forces of the finger portions thus obtained are different, the conventional robot apparatus may not be able to cope with the finger portions because they are made of the same material. That is, the conventional robot apparatus includes a finger portion having a frictional force adapted to one of the aforementioned operations, and the frictional force cannot be changed according to the purpose of the operation.

  The present invention has been made in view of such circumstances, and its main object is to provide an artificial skin for a robot hand that can easily change the frictional force with a simple configuration, and a robot hand including the same. There is to do.

  To achieve the above object, an artificial skin for a robot hand according to the present invention is an artificial skin for a robot hand provided at a contact location with an object of the robot hand, the first contact portion having elasticity, and the first skin A second contact portion provided on the first contact portion with a friction coefficient smaller than the friction coefficient of the one contact portion, the surface protruding outward from the surface of the first contact portion, The second contact part is pushed into the first contact part against the elastic force of the first contact part according to the pressing force when contacting the object.

  Further, in the artificial skin for a robot hand according to the present invention, the second contact portion is provided on a surface of the first contact portion, and the surface protrudes outward from the surface of the first contact portion. Features.

  Furthermore, the artificial skin for a robot hand according to the present invention has a concave portion formed inwardly on the surface of the first contact portion, and the thickness of the second contact portion is smaller than the depth of the concave portion. It is formed large, is provided in the recess, and has a surface protruding outward from the surface of the first contact portion.

  In order to achieve the above object, a robot hand according to the present invention is provided with a finger part rotatably provided on a palm part, and the artificial skin for the robot hand is provided on the finger part.

  According to the artificial skin for a robot hand according to the present invention, the surface of the second contact portion protrudes outward from the surface of the first contact portion, and is pushed into the first contact portion when contacting the object. Can do. Therefore, the state in which the second contact portion is in contact with the object and the state in which the first contact portion is in contact with the object can be achieved. In this case, the frictional force between the second contact part and the object is smaller than the frictional force between the first contact part and the object, and the frictional force can be easily changed.

  Moreover, according to the artificial skin for robot hands which concerns on this invention, since a 2nd contact part is provided in the surface of a 1st contact part, it can manufacture easily and can reduce manufacturing cost.

  Furthermore, according to the artificial skin for a robot hand according to the present invention, since the second contact portion is provided in the recess formed in the first contact portion, the second contact portion is more reliably held in the first contact portion. Can do.

  According to the robot hand according to the present invention, it is possible to provide a robot hand that exhibits the above-described effects.

It is a schematic front view which shows an example of the robot hand to which Example 1 of the artificial skin for robot hands of this invention was applied. It is a schematic side view of the finger | toe part of the robot hand of FIG. 1, and has shown one part in cross section. It is the schematic side view which made the cross section the part which shows the use condition of the robot hand of FIG. 1, and has shown the state which is performing the sensing operation | work of the target object. It is the schematic side view which made the cross section the part which shows the use condition of the robot hand of FIG. 1, and has shown the state which hold | gripped the target object. It is a schematic front view which shows an example of the finger | toe part of the robot hand to which Example 2 of the artificial skin for robot hands of this invention was applied, and has shown one part expanded. It is a schematic side view of the finger part of the robot hand of FIG. FIG. 6 is a schematic side view, partly in section, showing the usage state of the robot hand of FIG. 5, showing a state in which an object is gripped.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

  1 and 2 are schematic views of a robot hand to which Example 1 of artificial skin for a robot hand according to the present invention is applied. FIG. 1 is a schematic front view, and FIG. 2 is a schematic right side of a finger part of the robot hand. FIG. 1 and 2 are partially enlarged, and FIG. 2 is partially shown in cross section. FIGS. 3 and 4 are schematic views showing the usage state of the robot hand of the first embodiment, FIG. 3 is a schematic right side view showing a state in which the object sensing operation is being performed, and FIG. It is a schematic right view which shows the state hold | gripped. 3 and 4 are partially shown in cross section and partially enlarged. The robot hand 1 according to the present embodiment includes a plate-like palm portion 2 and a finger portion 3 that is rotatably provided on the palm portion 2.

  The palm portion 2 constitutes a palm portion of the robot hand 1, and a plurality of finger portions 3 are rotatably provided on the edge portion. In the present embodiment, three finger portions 3 a, 3 b, 3 c extend upward at the upper end portion of the palm portion 2 and are provided substantially radially, and the finger portion 3 d extends downward at the lower end portion of the palm portion 2. Provided.

  Each finger part 3a, 3b, 3c provided in the upper end part of the palm part 2 is mutually spaced apart and arrange | positioned. Each finger part 3a, 3b, 3c includes a plurality of nodes and a joint that connects adjacent nodes. In the present embodiment, each of the finger portions 3a, 3b, 3c has the same configuration. Therefore, here, the finger portion 3a disposed on the right side will be described, and the finger portion 3b disposed on the center and the finger portion 3b disposed on the left side. Description of the finger part 3c is omitted.

  The finger part 3a arranged on the right side has a first clause 4, a second clause 5 and a third clause 6 in order from the far side to the palm portion 2, and the first clause 4 and the second clause 5 are The second joint 5 and the third joint 6 are connected to each other via a first joint 7 so as to be rotatable. The lower end of the third node 6 is pivotally connected to the upper end of the palm 2 via a third joint (not shown). In this manner, the finger portions 3 a, 3 b, 3 c are rotatably provided at the upper end portion of the palm portion 2. In the present embodiment, each of the finger portions 3a, 3b, 3c has the same configuration, but is not limited to this. For example, when the three fingers 3a, 3b, 3c are compared with each other, the number of nodes and the length of the corresponding nodes may be different. Moreover, the joint at the base of each finger part 3a, 3b, 3c may be an orthogonal joint.

  A conventionally known mechanism is used as the rotation mechanism for rotating the first node 4, the second node 5 and the third node 6 of each finger 3a, 3b, 3c. For example, the first joint 4, the second joint 5 and the third joint 6 are connected by a known link mechanism or a plurality of gears via the first joint 7, the second joint 8 and the third joint described above. In this case, by rotating the third joint, the second joint 8 and the first joint 7 can be rotated in conjunction with the rotation. Therefore, from the state in which the finger portions 3a, 3b, 3c are extended, the nodes 4, 5, 6 can be turned to the front side of the palm portion 2 to bend the finger portions 3a, 3b, 3c. On the other hand, the fingers 3a, 3b, 3c are rotated from the bent state so that the nodes 4, 5, 6 are separated from the palm 2 to extend the fingers 3a, 3b, 3c. Can be made. A motor that rotates the third joint is provided on the rear surface of the palm 2.

  Moreover, you may provide a motor in the 1st joint 7, the 2nd joint 8, and the 3rd joint as a rotation mechanism of each finger part 3a, 3b, 3c. In this case, the first joint 7, the second joint 8 and the third joint are driven to drive the first joint 7, the second joint 8 and the third joint, thereby rotating the first joint 7, the second joint 8 and the third joint. The joint 4, the second joint 5 and the third joint 6 can be rotated.

  The finger part 3d provided at the lower end part of the palm part 2 includes a plurality of nodes and joints that connect adjacent nodes to each other. In this embodiment, the finger part 3d has a first joint 9 and a second joint 10 in order from the far side to the palm part 2, and the first joint 9 and the second joint 10 connect the first joint 11 to each other. And are connected to each other in a rotatable manner. The finger part 3d is pivotally connected to the lower end part of the palm part 2 at the lower end part of the second node 10 via a second joint (not shown). In addition, the structure of the finger part 3d is not limited to this, For example, the joint of the base of the finger part 3d may be an orthogonal joint.

  The rotation mechanism for rotating the first node 9 and the second node 10 is the same as the rotation mechanism of each of the finger portions 3a, 3b, 3c described above, and a conventionally known mechanism is used. For example, the first joint 9 and the second joint 10 are connected by a known link mechanism or a plurality of gears via the first joint 11 and the second joint. In this case, by rotating the second joint, the first joint 11 can be rotated in conjunction with the rotation. Accordingly, the fingers 3d can be bent by rotating the joints 9 and 10 to the front side of the palm 2 from the state in which the fingers 3d are extended. On the other hand, the fingers 3d can be extended by rotating the joints 9 and 10 away from the palm 2 from the bent state of the fingers 3d. A motor that rotates the second joint is provided on the rear surface of the palm 2.

  Moreover, you may provide a motor in the 1st joint 11 and the 2nd joint as a rotation mechanism of the finger | toe part 3d. In this case, the first joint 11 and the second joint are rotated by driving the motors provided at the first joint 11 and the second joint, thereby rotating the first joint 9 and the second joint 10. Can be made.

  The artificial skin for a robot hand according to the present invention is applied to the robot hand 1 configured as described above. The artificial skin 12 for the robot hand can change the frictional force, and is provided at a contact point of the robot hand 1 with the object. In this embodiment, the artificial skin 12 for the robot hand is provided on the finger portion 3a disposed on the right side of the upper end portion of the palm portion 2 among the plurality of finger portions 3a, 3b, 3c, 3d. The artificial skin 12 for a robot hand according to the present embodiment includes a first contact portion 13 provided in the first node 4 having a substantially rectangular tube shape opening downward, and a second contact portion 14 provided in the first contact portion 13. Prepare.

  The first contact portion 13 is made of a material having a relatively large friction coefficient and is a plate-like member having elasticity. The plate-like first contact portion 13 has a back surface fixed to the front surface and top surface of the first node 4 with an adhesive or the like so as to continuously cover the front surface and top surface of the first node 4. The 1st contact part 13 has the elasticity of the grade which can push in the 2nd contact part 14 mentioned later inside, and is made from rubber in a present Example.

  The second contact portion 14 is formed of a material having a relatively small friction coefficient. In the present embodiment, the second contact portion 14 is made of vinyl, but is not limited thereto, and may be made of plastic or metal, for example. When compared with the first contact portion 13, the second contact portion 14 has a friction coefficient smaller than that of the first contact portion 13. The second contact portion 14 of the present embodiment is formed in a sheet shape having a substantially fingerprint shape when viewed from the front. Specifically, the second contact portion 14 includes a plurality (three in the illustrated example) of a pair of substantially semicircular arc-shaped ring members 15 and 15. Each ring member 15 is formed in a sheet shape, and is disposed with its plate surface facing forward and backward. The pair of ring members 15 and 15 are formed to have the same inner diameter and outer diameter, and are spaced apart from each other on the same circumference so that the openings correspond to each other. The plurality of paired ring members 15 and 15 are formed with different inner and outer diameters, and are arranged concentrically. In this way, the second contact portion 14 is formed in a substantially fingerprint shape when viewed from the front. In addition, although the 2nd contact part 14 of the present Example 1 was made into the sheet-like member, it is not limited to this, For example, you may form by coating.

  The second contact portion 14 is provided in the first contact portion 13 with its surface protruding outward from the surface of the first contact portion 13. In the present embodiment, the second contact portion 14 is provided on the surface that is the surface on the most front side of the first contact portion 13, and the surface protrudes outward from the surface of the first contact portion 13. Specifically, the back surface of each ring member 15 is fixed to the surface of the first contact portion 13 with an adhesive or the like, so that the surface of the second contact portion 14 is more outward than the surface of the first contact portion 13. Protruding. At this time, each ring member 15 is arranged so as to have a substantially fingerprint shape as described above.

  Next, the use of the artificial skin for a robot hand of the present invention and the robot hand provided with the same will be described. As shown in FIG. 3, the robot hand 1 according to the present embodiment can perform the sensing operation of the object 16 by tracing the object 16 with the finger 3 a. Here, the sensing operation is, for example, an operation for measuring the surface shape of the object 16. At this time, the robot hand 1 is provided with a vibration sensor for measuring the vertical vibration of the finger portion 3a. In order to measure the surface shape of the object 16 using this vibration sensor, it is only necessary to measure the vertical vibration of the finger part 3a when the object 16 is traced with the finger part 3a. Based on this, the surface shape of the object 16 is determined.

  When performing the sensing operation of the object 16, only the second contact portion 14 is brought into contact with the object 16. In the present embodiment, the second contact portion 14 is fixed to the surface of the first contact portion 13 having elasticity so that the surface protrudes outward from the surface of the first contact portion 13. Accordingly, the first node 4 of the finger portion 3a is pressed against the object 16 so that the second contact portion 14 is not pushed into the first contact portion 13 against the elasticity of the first contact portion 13. Thus, only the surface of the second contact portion 14 can be brought into contact with the object 16. Then, the sensing operation of the object 16 can be performed by appropriately moving the finger part 3 a on the surface of the object 16 while bringing only the surface of the second contact part 14 into contact with the object 16. Here, since the 2nd contact part 14 is formed with the material with a small friction coefficient, it is easy to slip with respect to the target object 16. FIG. Accordingly, the finger 3a can be smoothly moved on the surface of the object 16.

  As shown in FIG. 4, the robot hand 1 according to the present embodiment moves the object 17 with a finger 3 a provided at the upper end of the palm 2 and a finger 3 d provided at the lower end of the palm 2. It can be gripped. When the object 17 is gripped, the finger part 3a and the finger part 3d may be appropriately bent. At this time, the first contact portion 13 is brought into contact with the object 17. In the present embodiment, the first contact portion 13 is composed of a member having elasticity as described above. Therefore, by pressing the first node 4 of the finger portion 3a more strongly against the object 17 than during the sensing operation, the second contact portion 14 opposes the elastic force of the first contact portion 13 to make the first contact. It is in a state of being pushed into the portion 13. Thereby, it can be set as the state which the 1st contact part 13 and the 2nd contact part 14 contacted the target object 17. FIG. Here, since the first contact portion 13 is formed of a material having a large friction coefficient, the first contact portion 13 is difficult to slip with respect to the object 17. Therefore, the object 17 can be gripped stably.

  Next, a second embodiment of the artificial skin for a robot hand according to the present invention and a robot hand including the same will be described. The artificial skin for a robot hand according to the second embodiment and the robot hand including the same are basically configured in the same manner as in the first embodiment. Therefore, in the following description, the differences between the two will be mainly described, and corresponding portions will be described with the same reference numerals.

  FIG. 5 is a schematic front view showing an example of a finger part of a robot hand to which Example 2 of artificial skin for a robot hand according to the present invention is applied, and a part thereof is enlarged. FIG. 6 is a schematic right side view of the finger portion of the robot hand according to the second embodiment. FIG. 7 is a schematic right side view showing the usage state of the robot hand of the second embodiment, and shows a state in which an object is gripped. 6 and 7 show a part in a cross section and an enlarged part.

  In the second embodiment, a recess 18 is formed on the surface of the first contact portion 13 so as to be recessed inward. The concave portion 18 of the present embodiment is formed in a substantially fingerprint shape when viewed from the front. Specifically, the recess 18 has a plurality (three in the illustrated example) of a pair of substantially semicircular arc-shaped recesses 19. Each ring-shaped recess 19 is formed to open forward. Each pair of ring-shaped recesses 19 is formed to have the same inner diameter and outer diameter, and are arranged on the same circumference so as to be separated on the left and right sides so that both open ends correspond to each other. The plurality of pairs of ring-shaped recesses 19 are formed with different inner and outer diameters, and are arranged concentrically. In this way, the recess 18 is formed in a substantially fingerprint shape when viewed from the front.

  In the second embodiment, the second contact portion 14 is formed in a plate shape having a substantially fingerprint shape when viewed from the front. Specifically, the second contact portion 14 has a plurality of (three in the illustrated example) a pair of substantially semicircular arc ring members 20 and 20. Each ring member 20 is formed in a plate shape, and is arranged with the plate surface facing forward and backward. The pair of ring members 20 and 20 are formed to have the same inner diameter and outer diameter, and are spaced apart from each other on the same circumference so that the openings correspond to each other. The plurality of pairs of ring members 20 and 20 are formed with different inner diameters and outer diameters, and are arranged concentrically. In this way, the second contact portion 14 is formed in a substantially fingerprint shape when viewed from the front. In addition, although the 2nd contact part 14 of the present Example 2 is made of a plastic, it is not limited to this, For example, a metal may be sufficient.

  As shown in FIGS. 5 and 6, the second contact portion 14 is provided in the recess 18. Specifically, each ring member 20 of the second contact portion 14 is fitted into each corresponding ring-shaped recess 19. At this time, each ring member 20 is preferably fixed to the first contact portion 13 with an adhesive or the like. Here, the second contact portion 14 is formed to have a thickness larger than the depth of the recess 18. That is, each ring member 20 is formed larger than the depth of the ring-shaped recess 19 in which the plate thickness is fitted. Accordingly, the front end portion of each ring member 20 protrudes forward from the ring-shaped recess 19. In this way, the surface of the second contact portion 14 protrudes outward from the surface of the first contact portion 13.

  The artificial skin 12 for the robot hand according to the second embodiment is provided on the finger portion 3a of the robot hand 1 as in the first embodiment. Thus, the robot hand 1 of the second embodiment provided with the artificial skin 12 for the robot hand can sense the object 16 and hold the object 17 in the same manner as in the first embodiment. it can.

  When sensing the object 16, the second contact portion 14 opposes the elasticity of the first contact portion 13 so that the front end portion of the second contact portion 14 is not pushed into the first contact portion 13. The first node 4 of the finger part 3a is pressed against the object 16, and only the surface of the second contact part 14 is brought into contact with the object 16. And the finger part 3a is appropriately moved in the surface of the target object 16, maintaining the contact state. Further, as shown in FIG. 7, when the object 17 is gripped, the first node 4 of the finger 3 a is pressed against the object 17 more strongly than at the time of sensing, and the second contact portion 14 is The first contact portion 13 and the second contact portion 14 come into contact with the object 17 by the front end portion of the second contact portion 14 being pushed into the first contact portion 13 against the elastic force of the first contact portion 13. It is assumed that

  In each of the above embodiments, the protruding second contact portion 14 is pushed into the first contact portion 13 according to the pressing force when contacting the objects 16 and 17. That is, the state in which only the second contact portion 14 is in contact with the object 16 and the state in which the second contact portion 14 and the first contact portion 13 are in contact with the object 17 can be achieved. Therefore, for example, when sensing the object 16, the slippery second contact part 14 is brought into contact with the object 16, while when gripping the object 17, the slippery first contact part 13 is set. The object 17 can be contacted. As described above, when the work having different required frictional force is performed using the same finger portion 3a, the frictional force can be easily changed.

  In the case of the first embodiment, the second contact portion 14 is provided by being attached to the surface of the first contact portion 13. Therefore, according to the present Example 1, since it can manufacture easily, manufacturing cost can be reduced. Moreover, in the case of the said Example 1, since the 2nd contact part 14 is formed in the sheet form, the unevenness | corrugation formed with the 2nd contact part 14 and the 1st contact part 13 is small. Therefore, when tracing the object 16 having irregularities on the surface, the second contact portion 14 is not easily caught by the irregularities formed on the object 16, and the object 16 can be traced smoothly.

  In the case of the second embodiment, the second contact portion 14 is fitted in the recess 18 formed in the first contact portion 13. Therefore, the second contact portion 14 is reliably held by the first contact portion 13. In this case, for example, when the object 16 is being traced, the second contact portion 14 can be made difficult to peel off from the first contact portion 13.

  The present invention is not limited to the configuration of each embodiment described above, and can be modified as appropriate. For example, in each of the above-described embodiments, the artificial skin 12 for the robot hand is provided on the finger portion 3a disposed on the right side of the upper end portion of the palm portion 2, but is not limited thereto, and other finger portions are not limited thereto. You may provide in 3b, 3c, 3d, and may provide in the some finger part 3. FIG. Furthermore, in each said Example, although the 2nd contact part 14 was formed in the front view substantially fingerprint shape, it is not limited to this, For example, the member extended to the top or bottom or right and left in front view is slit. You may form in a shape.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used for a robot hand that performs work with different required frictional forces.

DESCRIPTION OF SYMBOLS 1 Robot hand 2 Palm part 3 Finger part 12 Artificial skin for robot hands 13 1st contact part 14 2nd contact part 16 Object 17 Object 18 Recessed part

Claims (4)

An artificial skin for a robot hand provided at a contact point with an object of the robot hand,
A first contact portion having elasticity;
A second contact portion having a friction coefficient smaller than that of the first contact portion and provided on the first contact portion in a state where the surface protrudes outward from the surface of the first contact portion. ,
The second contact part is pushed into the first contact part against the elastic force of the first contact part according to the pressing force when contacting the object. Skin. 2. The artificial hand for a robot hand according to claim 1, wherein the second contact portion is provided on a surface of the first contact portion, and the surface protrudes outward from the surface of the first contact portion. Skin. The surface of the first contact portion is recessed inwardly to form a recess,
The second contact portion is formed to have a thickness larger than the depth of the concave portion, and is provided in the concave portion, and the surface projects outward from the surface of the first contact portion. The artificial skin for a robot hand according to claim 1. It has a finger part that can be pivoted on the palm part,
An artificial skin for a robot hand according to any one of claims 1 to 3, wherein the finger portion is provided with the artificial skin for a robot hand.

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