ROBOT HAND, ROBOT HAND CONTROL METHOD, AND ROBOT HAND CONTROL PROGRAM

Abstract

To provide a robot hand capable of grasping objects of various shapes without involving enlargement of its outer shape.SOLUTION: A robot hand has n (n≥3) sets of finger units each having a first direct-acting portion acting which directly acts along a first axis parallel to a base surface, a second direct-acting portion which is connected to the first direct-acting part and acts directly along a second axis parallel to the base surface and different from the first axis, and a finger portion connected to the second direct-acting part and acting directly along a third axis vertical to the base surface. The first axis of each of the n sets of finger units is positioned on each side of n-sided polygon.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a robot hand, a control method for a robot hand, and a control program for a robot hand. [Background technology]

[0002] In recent years, the future labor shortage caused by the declining birthrate and aging population has become a social issue, and automation and efficiency mechanisms are being constructed in various fields. In the manufacturing industry, automation and efficiency are being promoted using robots for handling parts and products. When a robot grasps an object such as a part or product, a robot hand suitable for the object to be grasped is required. One method is to replace the robot hand attached to the robot arm according to the object. However, this method requires multiple robot hands that are different for each object. Therefore, as the number of robot hands increases, there is a problem that the cost of manufacturing the robot hands and the space required to store the standby robot hands are required. Especially in small-lot, high-mix production, the number of robot hands increases because the size, shape, hardness, etc. of the objects vary. Furthermore, there is a problem that the time required to replace the robot hands increases as the number of times the robot hands are replaced increases.

[0003] Therefore, a robot hand that can handle various objects without replacing the robot hand has been proposed. For example, Patent Document 1 discloses a technology for a robot hand in which four finger members facing toward the center of the robot hand are arranged at the four corners of a rectangular area, and a palm member that moves up and down relative to a base is arranged at the center of the robot hand. In this robot hand, the four finger members are moved toward and away from each other toward the center of the robot hand, and the palm member is moved up and down relative to the base, so that the object is sandwiched between the four finger members and the palm member, thereby grasping the object. This mechanism makes it possible to grasp objects of different sizes without replacing the robot hand.

[0004] Patent Document 2 also discloses a technology for a robot hand in which three parallel fingers are arranged to form a triangle, and each finger moves on one axis. In the technology described in Patent Document 2, an object is placed between an edge connecting two fingers and one opposing finger, and the object is pinched and grasped by moving each finger. With this configuration, for example, plate-shaped objects of different thicknesses or rod-shaped objects of different widths can be grasped.

[0005] Patent Document 3 discloses a technology for a robot hand that uses two rack and pinion mechanisms to vary the distance between two of three fingers and to vary the distance between the side formed by these two fingers and the other opposing finger. With this configuration, the distance between the three fingers can be arbitrarily controlled within the movable range of each finger, making it possible to grasp objects of different sizes.

[0006] Patent Document 4 discloses a technology for a robot hand (hand device) that has three fingers with rotational joints and that allows the angle between the two outer fingers and the central finger to be changed. With the above configuration, an object can be grasped by wrapping it around the three fingers, and further, objects of different sizes and shapes can be grasped. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2014-018909 A [Patent Document 2] Japanese Patent Application Publication No. 06-155358 [Patent Document 3] JP 2004-090134 A [Patent Document 4] JP 2017-047509 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, the techniques described in Patent Documents 1-4 above each have their own problems. In the technique of Patent Document 1, the four fingers move toward the center of the hand, so if the object is not point-symmetrical, it may not be possible to grasp it well. In the technique of Patent Document 2, each finger moves only on one axis, so there is a problem that the shape of the object that can be grasped is limited to a shape that can be pinched between two fingers and one finger, such as a plate-shaped or rod-shaped object. In the technique of Patent Document 3, the three fingers are the same length, so there is a problem that the gripping force is weak unless the contact points with the object of the three fingers are at the same height. In the technique of Patent Document 4, each finger has a link structure that rotates around each joint, so the fingers are thicker by that amount. And, because the finger parts move to wrap around the object, there is a problem that the size of the object that can be grasped is small compared to the external shape of the robot hand. Or there is a problem that the external shape of the robot hand is large compared to the object to be targeted.

[0009] The present invention has been made in consideration of the above problems, and has an object to provide a robot hand or the like that can grasp objects of various shapes without increasing the external size. [Means for solving the problem]

[0010] In order to solve the above problems, the robot hand of the present invention has n (n≧3) finger units each having a first linear motion section that moves linearly along a first axis parallel to a base surface, a second linear motion section that is connected to the first linear motion section and moves linearly along a second axis that is parallel to the base surface and in a direction different from the first axis, and a finger section that is connected to the second linear motion section and moves linearly along a third axis perpendicular to the base surface, and the first axis of each of the n finger units is arranged on each side of an n-gon.

[0011] Further, a control method for a robot hand of the present invention includes n (n≧3) finger units each having a first linear motion section which moves linearly along a first axis parallel to a base surface, a second linear motion section which is connected to the first linear motion section and moves linearly along a second axis which is parallel to the base surface and in a direction different from the first axis, and a finger section which is connected to the second linear motion section and moves linearly along a third axis perpendicular to the base surface, wherein the first axes of each of the n finger units are arranged on each side of an n-sided polygon, and the control method grasps an object by controlling the position of each of the finger sections in the direction of the first axis, controlling the position of each of the finger sections in the direction of the third axis, and controlling the position of each of the finger sections in the direction of the second axis.

[0012] Further, a control program for a robot hand of the present invention has n (n≧3) finger units each having a first linear motion section that moves linearly along a first axis parallel to a base surface, a second linear motion section that is connected to the first linear motion section and moves linearly along a second axis that is parallel to the base surface and in a direction different from the first axis, and a finger section that is connected to the second linear motion section and moves linearly along a third axis perpendicular to the base surface, and the first axes of each of the n finger units are arranged on each side of an n-gon, the control program for a robot hand having a computer executes control of the robot hand, the control program having a step of controlling a position of each of the finger units in a direction of the first axis, a step of controlling a position of each of the finger units in a direction of the third axis, and a step of controlling the position of each of the finger units in a direction of the second axis to grip an object. Effect of the Invention

[0013] An advantage of the present invention is that it is possible to provide a robot hand or the like that can grasp objects of various shapes without increasing the external size. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic perspective view showing a configuration of a robot hand according to a first embodiment. [Diagram 2]1 is a schematic side view showing a specific example of the configuration of a robot hand according to a first embodiment. FIG. [Diagram 3] FIG. 2 is a schematic bottom view showing a specific example of the configuration of the robot hand according to the first embodiment. [Figure 4] 4A to 4C are schematic side views showing an example of the operation of the robot hand of the first embodiment. [Diagram 5] 5 is a flowchart showing an example of an operation of the robot hand according to the first embodiment. [Figure 6] 2 is a schematic perspective view showing a specific example of a first linear motion part of the robot hand according to the first embodiment. FIG. [Figure 7] FIG. 2 is a schematic perspective view showing a specific example of a finger unit of the robot hand according to the first embodiment. [Figure 8] FIG. 11 is a schematic bottom view showing the configuration of a robot hand according to a second embodiment. [Figure 9] 13A to 13C are schematic bottom views illustrating an example of the operation of the robot hand according to the second embodiment. [Figure 10] 13A to 13C are schematic side views showing an example of the operation of the robot hand of the second embodiment. [Figure 11] 10 is a flowchart showing the operation of a robot hand according to a second embodiment. [Figure 12] FIG. 11 is a schematic bottom view showing the configuration of a robot hand according to a third embodiment. [Figure 13] 13A to 13C are schematic bottom views illustrating an example of the operation of the robot hand according to the third embodiment. [Figure 14] 13A to 13C are schematic bottom views showing another example of the operation of the robot hand according to the third embodiment. [Figure 15] 13 is a flowchart showing the operation of a robot hand according to a third embodiment. [Figure 16] FIG. 13 is a block diagram showing a configuration of a robot system according to a fourth embodiment. [Figure 17] FIG. 13 is a block diagram showing the configuration of a robot hand according to a fifth embodiment. [Figure 18] 13 is a flowchart showing an example of the operation of the robot hand according to the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. However, the embodiments described below are limited in a technically preferable manner for carrying out the present invention, but the scope of the invention is not limited to the following. Note that the same components in each drawing are given the same numbers, and the description may be omitted.

[0016] (First embodiment) 1 is a schematic perspective view showing the configuration of a robot hand 100 according to a first embodiment of the present invention. The robot hand 100 has three pairs of finger units 10, 20, and 30. The finger units 10, 20, and 30 are controlled by a control unit 50.

[0017] The finger unit 10 has a first linear motion portion 12, a second linear motion portion 14, and a finger portion 16. The first linear motion portion 12 moves linearly along a first axis 11 parallel to the surface of the base 90. The second linear motion portion 14 is connected to the first linear motion portion 12 and moves linearly along a second axis 13 parallel to the surface of the base 90 and in a direction different from the first axis 11. The finger portion 16 is connected to the second linear motion portion 14 and moves linearly along a third axis 15 perpendicular to the surface of the base 90.

[0018] The finger unit 20 has a first linear motion portion 22, a second linear motion portion 24, and a finger portion 26. The first linear motion portion 22 moves linearly along a first axis 21 parallel to the surface of the base 90. The second linear motion portion 24 is connected to the first linear motion portion 22 and moves linearly along a second axis 23 parallel to the surface of the base 90 and in a direction different from the first axis 21. The finger portion 26 is connected to the second linear motion portion 24 and moves linearly along a third axis 25 perpendicular to the surface of the base 90.

[0019] The finger unit 30 has a first linear motion portion 32, a second linear motion portion 34, and a finger portion 36. The first linear motion portion 32 moves linearly along a first axis 31 parallel to the surface of the base 90. The second linear motion portion 34 is connected to the first linear motion portion 32 and moves linearly along a second axis 33 parallel to the surface of the base 90 and in a direction different from the first axis 31. The finger portion 36 is connected to the second linear motion portion 34 and moves linearly along a third axis 35 perpendicular to the surface of the base 90.

[0020] The finger units 10, 20, and 30 are arranged such that the first axis 11 of the finger unit 10, the first axis 21 of the finger unit 20, and the first axis 31 of the finger unit 30 are located on the respective sides of a triangle.

[0021] In the above description, an example was given of a configuration in which there are three finger units and the first axis of each finger unit is arranged at a position corresponding to each side of a triangle, but the number of finger units is not limited to three and may be four or more. In this case, the number of finger units is n, and the first axis of each finger unit may be arranged on each side of an n-sided polygon.

[0022] 2 is a schematic side view showing a robot hand 10000, which is a specific configuration example of the robot hand 100. The robot hand 10000 has a base 9000 and three finger units, a finger unit 1000, a finger unit 2000, and a finger unit 3000, fixed to the base 9000. The finger units 1000, 2000, and 3000 are examples of the finger units 10, 20, and 30 in the robot hand 100. The finger units 1000, 2000, and 3000 are controlled by a control unit (not shown).

[0023] The finger unit 1000 has a first guide 1100, a first linear motion portion 1200, a connection portion 1300, a second linear motion portion 1400, a third guide 1500, a third linear motion portion 1600, and a finger portion 1700. The first guide 1100 is an example of the first shaft 11 of the first embodiment. The first guide 1100 is an example of the first linear motion portion 12, the connection portion 1300 and the second linear motion portion 1400 are an example of the second shaft 13 and the second linear motion portion 14, the third guide 1500 and the third linear motion portion 1600 are an example of the third shaft 15, and the finger portion 1700 is an example of the finger portion 16.

[0024] Similarly, the finger unit 2000 has a first guide 2100, a first linear motion portion 2200, a connection portion 2300, a second linear motion portion 2400, a third guide 2500, a third linear motion portion 2600, and a finger portion 2700. The finger unit 3000 has a first guide 3100, a first linear motion portion 3200, a connection portion 3300, a second linear motion portion 3400, a third guide 3500, a third linear motion portion 3600, and a finger portion 3700.

[0025] Fig. 3 is a bottom view of the robot hand 10000 as viewed from below in Fig. 2. As shown in Fig. 3, the first guides 1100, 2100, and 3100 of the finger units 1000, 2000, and 3000 are disposed at positions that correspond to the respective sides of a triangle in the plane of the base 9000.

[0026] In the finger unit 1000, the first linear motion part 1200 moves linearly along the first guide 1100, and the second linear motion part 1400 moves linearly relative to the connection part 1300 in a direction perpendicular to the first guide 1100. This allows the positioning of the finger part 1700 in a plane parallel to the base 9000 surface. Then, the third linear motion part 1600 moves linearly along the third guide 1500, thereby controlling the position of the finger part 1700 in a direction perpendicular to the base 9000 surface. Similarly, in the finger unit 2000, the first linear motion part 2200 moves linearly along the first guide 2100. Also, the second linear motion part 2400 moves linearly relative to the connection part 2300 in a direction perpendicular to the first guide 2100. In this way, the positioning of the finger part 2700 in a direction parallel to the base 9000 surface is performed.

[0027] Then, the third linear motion portion 2600 moves linearly along the third guide 2500, thereby controlling the position of the finger portion 2700 in a direction perpendicular to the surface of the base 9000. In the finger unit 3000, the first linear motion portion 3200 moves linearly along the first guide 3100. In addition, the second linear motion portion 3400 moves linearly relative to the connection portion 3300 in a direction perpendicular to the first guide 3100. In this way, the positioning of the finger portion 3700 in a direction parallel to the surface of the base 9000 is achieved. The third linear motion portion 3600 moves linearly along the third guide 3500, thereby controlling the position of the finger portion 3700 in the direction perpendicular to the surface of the base 9000. Note that, although the above describes the case where the linear motion direction of the second linear motion portion is perpendicular to the linear motion direction of the first linear motion portion, it may be at an angle other than perpendicular.

[0028] In the robot hand 10000 of this embodiment, the positions of the three fingers 1700, 2700, 3700 can be controlled in a direction horizontal to the surface of the base 9000, and can also be independently controlled in a direction (height) perpendicular to the surface of the base 9000. For this reason, even if an object 8000 has different heights at which the fingers come into contact depending on the location, as shown in Fig. 4, it can be stably grasped. Note that the linear motion direction of the third linear motion part does not need to be perpendicular to the surface of the base 9000, as long as the position in the height direction can be controlled.

[0029] 4 is a schematic side view showing a state in which an object 8000, which has a non-simple side shape and cannot be grasped well if the fingers 1700, 2700, and 3700 are at the same height, is grasped by the robot hand 10000. By controlling the heights of the fingers 1700, 2700, and 3700 to positions where a force can easily act on the side of the object 8000, the object 8000 can be grasped stably.

[0030] Although an example in which there are three finger units has been described above, there may be four or more finger units. In this case, if the number of finger units is n, the finger units are arranged so that the first guides of the n finger units are located on the respective sides of an n-sided polygon.

[0031] FIG. 5 is a flowchart showing an example of the operation of the robot hand 10000. First, the control unit aligns the first linear motion unit for a predetermined finger unit used for grasping among the n fingers (S101). Next, the control unit aligns the third linear motion unit for the predetermined finger unit used for grasping (S102). Next, the control unit linearly moves the second linear motion unit for the predetermined finger unit used for grasping to position the finger unit of each finger unit near the target object (S103). Next, the control unit linearly moves the second linear motion unit of each finger unit inward to bring the finger unit into contact with the target object and grasp the target object (S104).

[0032] 2-4 shows an example in which the shape of the finger part is a rectangular parallelepiped, but the shape is not limited to this and can be any shape that matches the target part. The material of the finger part can be any material that matches the target object, such as metal, plastic, rubber, sponge, etc.

[0033] In addition, the second linear motion part may be linearly moved inward to adjust the force with which the object is gripped. For example, when the second linear motion part is driven by a motor, the torque control part 1410, 2410, 3410 shown in FIG. 2 may be provided to control the current of the motor to control the torque with which the object is gripped. By performing such control, even a soft object can be appropriately gripped.

[0034] Next, a specific example of the linear motion mechanism will be described. Fig. 6 is a perspective view showing an example of the first linear motion mechanism. A ball screw 1101a and a drive unit 1101b that rotates the ball screw 1101a around its axis are arranged in a first guide 1101. A movable nut 1101c is engaged with the ball screw 1101a, and a slider 1201 is fixed to the movable nut 1101c. By rotating the ball screw 1101a in this configuration, the slider 1201 can be linearly moved along the first guide 1101.

[0035] FIG. 7 is a perspective view showing an example of a configuration in which the second linear motion part 1401, the third linear motion part 1601, and the finger part 1701 are assembled to the slider 1201 of FIG. 6. The connecting part 1301 is fixed to the slider 1201. The second linear motion part 1401 linearly moves relative to this connecting part in a direction perpendicular to the first guide and parallel to the base 9000 surface. The third guide 1501 is fixed to one end of the second linear motion part 1401. The third guide 1501 is engaged with the third linear motion part 1601, so that the second linear motion part 1401 can linearly move in a direction perpendicular to the base 9000 surface. The finger part 1701 is fixed to the third linear motion part 1601. With this configuration, the position of the finger part 1701 can be controlled in the first linear motion direction, the second linear motion direction, and the third linear motion direction.

[0036] The operation of the robot hand 10000 has been described above.

[0037] The robot hand in the first embodiment of the present invention has n (n≧3) sets of finger units 10, 20, 30, .... One finger unit 10 has a first linear motion part 12, a second linear motion part 14, and a finger part 16. The first linear motion part 12 moves linearly along a first axis 11 parallel to the base surface of the base 90. This controls the position of the finger part in the first axis 11 direction. The second linear motion part 14 is connected to the first linear motion part 12 and moves linearly along a second axis 13 parallel to the base 90 surface and in a direction different from the first axis 11. This controls the position of the finger part 16 in the second axis 13 direction. The finger part 16 moves linearly along a third axis 15 connected to the second linear motion part 14 and perpendicular to the base 90 surface. This controls the position of the finger part 16 in the third axis 15 direction. The n sets of finger units 10, 20, 30, ... are arranged such that the first axes 11, 21, 31, ... of each finger unit are arranged on the respective sides of the n-gon. With this configuration, the positions of the n finger parts 16, 26, 36, ... along the base 90 surface and the positions perpendicular to the base 90 surface can be independently and arbitrarily controlled. Therefore, even if the object is not a simple shape such as a cylinder or a rectangular parallelepiped, the finger parts 16, 26, 36, ... can be arranged at a height suitable for the shape of the object 80 to grasp the object 80. In addition, in the above robot hand, the positions of the finger parts are controlled by combining only linear motion parts. Therefore, as in the technology described in Patent Document 4, the external shape of the robot hand can be made smaller relative to the size of the object that can be grasped, compared to a robot hand having joints using a link mechanism.

[0038] Furthermore, the above robot hand may be configured such that the second linear motion parts 14, 24, 34, ... of each of the finger units 10, 20, 30, ... have a torque control part that controls the torque of the linear motion in the direction of the second axis 13, 23, 33, .... By performing such control, when an object is pinched and grasped by the multiple finger parts 16, 26, 36, ..., the pressure that the finger parts 16, 26, 36, ... apply to the object can be controlled. As a result, even for a soft object or an object with weak mechanical strength, the grasping force can be appropriately controlled to grasp the object.

[0039] In addition, in the control method for a robot hand in the first embodiment of the present invention, a robot hand having n (n≧3) finger units 10, 20, 30, ... is controlled. One finger unit 10 of this robot hand 100 has a first linear motion part 12, a second linear motion part 14, and a finger part 16. The first linear motion part 12 moves linearly along a first axis 11 parallel to the base surface of the base 90. The second linear motion part 14 is connected to the first linear motion part 12 and moves linearly along a second axis 13 parallel to the base 90 surface and in a direction different from the first axis 11. In the n finger units 10, 20, 30, ..., the first axes 11, 21, 31, ... of each finger unit are arranged on the respective sides of an n-gon. In the control method for the robot hand in the first embodiment of the present invention, the position of each finger in the direction of the first axis 11, 21, 31, ... is controlled in the robot hand 100 having the above configuration. In addition, the position in the direction of the third axis 15, 25, 35, ... is controlled, and the position in the direction of the second axis 13, 23, 33, ... is controlled to grasp the object 80. With this configuration, the positions of the n fingers 16, 26, 36, ... along the surface of the base 90 and the positions perpendicular to the surface of the base 90 can be independently and arbitrarily controlled. Therefore, even if the object 80 is not a simple shape such as a cylinder or a rectangular parallelepiped, the fingers 16, 26, 36, ... can be disposed at a height suitable for the shape of the object 80 to grasp the object.

[0040] In addition, in the control program for the robot hand in the first embodiment of the present invention, a computer is caused to execute a program for controlling a robot hand having n (n≧3) finger units 10, 20, 30, .... One finger unit 10 of this robot hand 100 has a first linear motion part 12, a second linear motion part 14, and a finger part 16. The first linear motion part 12 moves linearly along a first axis 11 parallel to the base surface of the base 90. The second linear motion part 14 is connected to the first linear motion part 12 and moves linearly along a second axis 13 parallel to the base 90 surface and in a direction different from the first axis 11. In the n finger units 10, 20, 30, ..., the first axes 11, 21, 31, ... of each finger unit are arranged on the respective sides of an n-gon. The control program for the robot hand in the first embodiment of the present invention includes a step of controlling the position of each finger in the direction of the first axis 11, 21, 31, ... in the robot hand 100 configured as described above. Also, the program includes a step of controlling the position in the direction of the third axis 15, 25, 35, ... and controlling the position in the direction of the second axis 13, 23, 33, ... to grip the object 80. With this configuration, the positions of the n fingers 16, 26, 36, ... along the surface of the base 90 and the positions perpendicular to the surface of the base 90 can be independently and arbitrarily controlled. Therefore, even if the object 80 is not a simple shape such as a cylinder or a rectangular parallelepiped, the program can cause the computer to execute control to grip the object by arranging each finger 16, 26, 36, ... at a height suitable for the shape of the object 80.

[0041] Second embodiment In the second embodiment, a robot hand having a finger portion provided with a suction pad in addition to the first embodiment will be described. In the first embodiment, the configuration of the robot hand 10000 in which three or more fingers pinch and grasp an object is described, but it is also possible to provide a suction portion on the finger portion and grasp the object by suction. FIG. 8 is a bottom view showing a robot hand 10001 of the second embodiment. The robot hand 10001 is configured such that suction pads are provided on the tips of the finger portions 1700, 2700, and 3700 of the robot hand 10000 of the first embodiment. The other configurations are the same as those of the robot hand 10000 of the first embodiment. A suction pad 1710 is provided on the opposite side (lower end) of the finger portion 1700 of the finger unit 1001 from the base 9000. Similarly, a suction pad 2710 is provided on the lower end of the finger portion 2700, and a suction pad 3710 is provided on the lower end of the finger portion 3700. Each of the finger units 1001, 12001, and 3001 is controlled by a control unit (not shown).

[0042] In the robot hand 10001, similarly to the first embodiment, the suction pad 1710 of the finger unit 1000 can be positioned in a direction parallel to the surface of the base 9000 by controlling the first linear motion unit 1200 and the second linear motion unit 1400. Similarly, the suction pad 2710 of the finger unit 2000 and the suction pad 3710 of the finger unit 3000 can be positioned in a direction parallel to the surface of the base 9000. Fig. 9 is a schematic bottom view showing an example of using this function to suction an object 8100 with a limited suction area 8110.

[0043] The robot hand 10001 can control the positions of the suction pads 1710, 2710, and 3710 in a direction perpendicular to the surface of the base 9000 as well as the positioning in a direction parallel to the surface of the base 9000. Fig. 10 is a schematic side view showing an example of suctioning an object 8200 having a step on its surface using this function. The robot hand 10001 can thus grip an object even with a step.

[0044] In the examples of FIGS. 9 and 10, an example in which there are three finger units has been described, but there may be four or more finger units.

[0045] 11 is a flowchart showing an example of the operation of the robot hand 10001. First, the control unit aligns the first linear motion part of a predetermined finger to be used for gripping among three or more fingers (S201). Next, the control unit aligns the second linear motion part of the predetermined finger (S202). Next, the control unit linearly moves the third linear motion part of the predetermined finger to bring each suction pad into contact with the surface of the target object (S203). Next, the control unit operates the suction mechanism to suction the suction pad to grip the target object (S204).

[0046] As described above, the operation of the robot hand 10001 according to the second embodiment has been described.

[0047] In the robot hand 10001 according to the second embodiment of the present invention, in addition to the configuration of the robot hand 10000 according to the first embodiment, the fingers 1700, 2700, 3700, etc. are provided with suction pads 1710, 2710, 3710, etc. By configuring the fingers to have suction units in this way, the positions of the n fingers 1700, 2700, 3700, etc. along the base 9000 surface and the positions perpendicular to the base 9000 surface can be independently and arbitrarily controlled. Furthermore, the suction pads 1710, 2710, 3710, etc. can suction the surface of the object. Therefore, even if the object has a step on its surface, it can be gripped by suction.

[0048] Furthermore, in the control method for the robot hand in the second embodiment, the positions of the n fingers 1700, 2700, 3700, ... along the surface of the base 9000 and the positions perpendicular to the surface of the base 9000 are independently and arbitrarily controlled in the robot hand 10001 described above. Then, the surface of the object is adsorbed by the suction pads 1710, 2710, 3710, ... as the adsorption parts. By controlling in this way, even an object having a stepped surface can be gripped by suction.

[0049] (Third embodiment) In the first and second embodiments, a specific example was given of using a ball screw as a mechanism for linearly moving the first linear moving part, but in the third embodiment, an example will be described in which a combination of a rack gear and a pinion gear is used as a mechanism for linearly moving the first linear moving part.

[0050] Fig. 12 is a bottom view showing a robot hand 10002 of the third embodiment. In the robot hand 10002, the linear motion of the first linear motion part is performed by utilizing a combination of a rack gear and a pinion gear. By using a gear system that switches on and off the transmission of the rotation of the drive gear to the pinion gear, the power for performing the first linear motion can be consolidated into a single drive gear. Each part of the robot hand 10002 is controlled by a control unit (not shown). A specific example will be described below.

[0051] As shown in FIG. 12, in the finger unit 1002, the first guide 1110 is engaged with the linear rail 1111, and a rack gear 1112 is disposed thereon. The rack gear 1112 is linearly moved by the rotation of the pinion gear 4110. The first linear moving part 1210 is fixed to the first guide 1110. The drive gear 4000 is disposed at the center of the triangle formed by the three finger units 1002, 2002, and 3002. The intermediate gear 4100 is disposed between the drive gear 4000 and the pinion gear 4110. The intermediate gear 4100 includes a slide mechanism, and is engaged with the drive gear 4000 and the pinion gear 4110, so that it can be switched between an ON state in which the drive gear 4000 and the pinion gear 4110 are engaged to transmit power, and an OFF state in which the drive gear 4000 and the pinion gear 4110 are disengaged to transmit no power. Similarly, in finger unit 2002 and finger unit 3002, first linear motion parts 2210 and 3210 are linearly moved by driving of the driving gear. Then, intermediate gears 4200 and 4300 are arranged to turn on and off the transmission of power.

[0052] As is clear from the above configuration, the alignment of the first linear motion part is performed by selecting one finger unit at a time. Fig. 13 is a schematic diagram showing a state in which a finger unit 1002 is selected and its first linear motion part 1210 is positioned. The intermediate gear 4100 is engaged with the drive gear 4000 and the pinion gear 4110, and the rotation of the drive gear 4000 is controlled, thereby allowing the positioning in the first linear motion direction to be performed.

[0053] When the positioning of the first linear motion part 1210 of the finger unit 1002 is completed, the intermediate gear 4100 is slid to the retracted position and the transmission of power is turned off. Then, the positioning of the first linear motion part of the next finger unit is performed by the same control as above.

[0054] Once the positioning of the first linear motion parts of all finger units used for gripping has been completed, it is necessary to prevent the positions from moving. FIG. 14 is a schematic bottom view showing an example of how to achieve this. Once the positioning of all first linear motion parts has been completed, all intermediate gears (4100, 4200, 4300 in FIG. 14) are slid to the ON position where they engage with the drive gear 4000 and the pinion gears (4110, 4210, 4310). In this state, the drive gear 4000 is prevented from rotating, thereby locking the positions of the first linear motion parts.

[0055] Since the configurations of the second linear motion part and the third linear motion part are the same as those of the second and third embodiments, after the positioning of the first linear motion part, the object can be grasped by control similar to that of the second and third embodiments.

[0056] FIG. 15 is a flowchart showing the positioning operation of the first linear motion part of this embodiment. First, the control unit turns on the transmission of driving force to the pinion gear of the selected finger unit (S301). In this state, the control unit controls the rotation of the drive gear to align the first linear motion part (S302). Then, the operations of S301 and S302 are repeated until the alignment of all the first linear motion parts of the predetermined finger unit used for grasping is completed (L). Then, when the alignment of all the first linear motion parts is completed, the control unit locks the rotation of the drive gear with the transmission of power to the pinion gear of each finger unit turned on (S303).

[0057] As described above, according to this embodiment, it is possible to unify the power sources for positioning the first linear motion parts for three or more finger units into one.

[0058] As described above, the operation of the robot hand 10002 according to the third embodiment has been described.

[0059] A robot hand 10002 in the third embodiment of the present invention has n (n≧3) finger units 1002, 2002, 3002, .... One finger unit 1002 has a first linear motion part 1210, a second linear motion part 1400, and a finger part 1700. The first linear motion part 1210 moves linearly along a first axis parallel to the surface of the base. At least one first linear motion part 1210 among the multiple (n) first linear motion parts has a rack gear 1112 fixed to the first linear motion part 1210 and extending in the direction of the first axis, and a pinion gear 4110 that drives the rack gear 1112. With this configuration, the first linear motion part 1210 can be moved linearly with a simple mechanism. The second linear motion unit 1400 is connected to the first linear motion unit 1210 and linearly moves along a second axis parallel to the base 9000 surface and in a direction different from the first axis. This controls the position of the finger unit 1700 in the second axial direction. The finger unit 1700 is connected to the second linear motion unit 1400 and linearly moves along a third axis perpendicular to the base surface. This controls the position of the finger unit 1700 in the third axial direction. The first axis of each of the n finger units is arranged on each side of an n-gon. With this configuration, the positions of the n finger units 1700, 2700, 3700, ... along the base 9000 surface and the positions perpendicular to the base 9000 surface can be independently and arbitrarily controlled. Therefore, even if the object is not a simple shape such as a cylinder or a rectangular parallelepiped, the finger units can be arranged at a height suitable for the shape of the object to grasp the object. Moreover, in the above robot hand, the positions of the fingers 1700, 2700, 3700, ... are controlled by combining only linear motion parts. Therefore, as with the technology described in Patent Document 4, the external dimensions of the robot hand can be made smaller relative to the size of an object that can be grasped, compared to a robot hand having joints that use link mechanisms.

[0060] Furthermore, the robot hand of the third embodiment may be configured to include a drive gear 4000 disposed in the center of an n-sided polygon, and a gear system that transmits rotation of the drive gear 4000 to the pinion gears 4110, 4210, 4310, .... By configuring in this way, the pinion gears 4110, 4210, 4310, ... themselves can be configured not to have a drive mechanism.

[0061] In addition, the gear system of the above robot hand may be provided with a mechanism for turning off the transmission of the rotation of the drive gear 4000 to the pinion gears 4110, 4210, 4310, .... By providing such a mechanism, it is possible to select pinion gears to be rotated and pinion gears not to be rotated among the n finger units. With this configuration, it is also possible to integrate the power sources for linearly moving the first linear motion parts 1210, 2210, 3210, ... of each finger unit into the drive gear 4000.

[0062] In addition, in the control method for the robot hand of the third embodiment, the linear motion of the first linear motion part is performed using a combination of a rack gear and a pinion gear in the robot hand. With this configuration, the linear motion of the first linear motion part can be controlled with a simple mechanism.

[0063] Furthermore, the rotation of the pinion gears 4110, 4210, 4310, ... may be transmitted by a gear system from the rotation of the drive gear 4000 disposed in the center of the n-sided polygon. With this configuration, the linear motion of the first linear motion portion can be controlled without driving the pinion gear itself.

[0064] (Fourth embodiment) 16 is a block diagram showing a configuration of a robot system including a robot hand according to any one of the first to fourth embodiments. The robot system 30000 includes an input / output device 31000, a robot controller 32000, a database 33000, a robot arm 40000, and a robot hand 50000. Here, the robot hand 50000 represents the robot hands according to the first to fourth embodiments. The robot hand includes a first linear motion part 51000, a second linear motion part 52000, a finger part 53000, and a suction mechanism 54000. The robot arm 40000 and the robot hand 50000 are controlled by a robot controller 32000. The input / output device 31000, the robot controller 32000, and the database 33000 are implemented in, for example, a general-purpose or dedicated computer.

[0065] As described above, according to the robot system 30000 of the fourth embodiment, it is possible to control the robot hand 50000 of any one of the first to fourth embodiments using a general computer. This control makes it possible to independently and arbitrarily control the positions of the finger parts 53000 of n (n≧3) finger units along the base surface and the positions perpendicular to the base surface. Therefore, even if the target object is not a simple shape such as a cylinder or a rectangular parallelepiped, it is possible to grasp the target object by arranging each finger part at a height suitable for the shape of the target object.

[0066] Fifth embodiment Next, a robot hand 1 according to a fifth embodiment of the present invention will be described. Specific examples of the robot hand 1 are the robot hands 100, 10000, 10001, and 10002 described above.

[0067] Fig. 17 is a block diagram showing the configuration of a robot hand 1 of this embodiment. As shown in Fig. 17, the robot hand 1 has n (n≧3) sets of finger units 2. Each finger unit 2 has a first linear motion portion 3, a second linear motion portion 4, and a finger portion 5.

[0068] The first linear motion part 3 moves linearly along a first axis parallel to the base surface of the robot hand 1 . The second linear motion unit 4 is connected to the first linear motion unit 3 and moves linearly along a second axis that is parallel to the base surface and in a direction different from the first axis. The finger unit 5 is connected to the second linear motion unit and moves linearly along a third axis that is perpendicular to the base surface. The n sets of finger units are arranged on the base surface such that the first axis of each finger unit is located on each side of an n-sided polygon. The operation of each part of the robot hand 1 is controlled by a control unit (not shown).

[0069] 18 is a flowchart showing the operation of the robot hand 1. First, the control unit controls the position of the first linear motion unit 3 of each finger unit 2 on the first axis so that it is a position suitable for grasping an object (S401). Next, the control unit controls the position of the finger unit 5 of each finger unit 2 on the third axis so that it is a position suitable for grasping an object (S402). Next, the control unit controls the position of the second linear motion unit on the second axis so that it is a position suitable for grasping an object, and grasps the object (S403). Note that the order of S402 and S403 may be reversed depending on the method of grasping.

[0070] With this configuration, the positions of the n fingers 5 along the base surface and the positions perpendicular to the base surface can be controlled independently and arbitrarily. Therefore, each finger 5 can be disposed at a position on a plane parallel to the base surface and at a position perpendicular to the base surface that is suitable for the shape of the object, and can grasp the object. As a result, the robot hand 1 can grasp the object even if the object does not have a simple shape such as a cylinder or a rectangular parallelepiped.

[0071] The present invention has been described above by taking the above-mentioned embodiment as an exemplary example. However, the present invention is not limited to the above-mentioned embodiment. That is, the present invention can be applied in various aspects that can be understood by a person skilled in the art within the scope of the present invention.

[0072] A part or all of the above-described embodiments can be described as, but is not limited to, the following supplementary notes. (Appendix 1) a first linear motion portion that moves linearly along a first axis parallel to the base surface; a second linear motion portion connected to the first linear motion portion and linearly moving along a second axis parallel to the base surface and different from the first axis; a finger portion connected to the second linear motion portion and linearly moving along a third axis perpendicular to the base surface; The finger unit has n sets (n≧3) of finger units having The first axes of each of the n sets of finger units are arranged on respective sides of an n-gon. A robot hand characterized by (Appendix 2) The finger portion is It has an adsorption part that adsorbs the object. 2. A robot hand according to claim 1. (Appendix 3) a rack gear fixed to at least one of the first linear motion portions and extending in a direction of the first axis; A pinion gear that drives the rack gear; 3. The robot hand according to claim 1 or 2, (Appendix 4) A drive gear disposed at the center of the n-gon; A gear system is provided to transmit the rotation of the drive gear to the pinion gear. 4. The robot hand according to claim 3, (Appendix 5) The gear system comprises: A mechanism is provided to cut off the transmission of rotation of the drive gear to the pinion gear. 5. The robot hand according to claim 4, (Appendix 6) Each of the second linear motion parts has a torque control part that controls the torque of the linear motion in the direction of the second axis. 6. A robot hand according to any one of claims 1 to 5. (Appendix 7) A robot hand having n (n≧3) finger units each having a first linear motion section which moves linearly along a first axis parallel to a base surface, a second linear motion section which is connected to the first linear motion section and moves linearly along a second axis which is parallel to the base surface and in a direction different from the first axis, and a finger section which is connected to the second linear motion section and moves linearly along a third axis perpendicular to the base surface, wherein the first axis of each of the n finger units is disposed on each side of an n-gon, Controlling the position of each of the fingers along the first axis; Controlling the position of each of the fingers along the third axis; The position of each of the fingers in the direction of the second axis is controlled to grasp an object. A method for controlling a robot hand. (Appendix 8) The finger portion has a suction portion, The object is attracted to the attraction portion. 8. A method for controlling a robot hand according to claim 7. (Appendix 9) The linear motion of the first linear motion part is performed using a combination of a rack gear and a pinion gear. 9. A method for controlling a robot hand according to claim 7 or 8. (Appendix 10) A drive gear is disposed at the center of the n-gon, The rotation of the drive gear is transmitted to the pinion gear by a gear system. 10. A method for controlling a robot hand according to claim 9. (Appendix 11) The gear system selectively drives one of the pinion gears among the plurality of finger units to control the position of the first linear motion part corresponding to the selected pinion gear. 11. A method for controlling a robot hand according to claim 10. (Appendix 12) sequentially controlling the positions of the first linear motion parts of the plurality of finger units; controlling the gear system so that rotation of the drive gear can be transmitted to the pinion gear corresponding to the first linear motion part whose position control has been completed; The drive gear is stopped to fix the position of the first linear motion portion of each of the units. 12. A method for controlling a robot hand according to claim 11. (Appendix 13) A control program for a robot hand that causes a computer to execute control of a robot hand having n (n≧3) finger units each having a first linear motion portion that moves linearly along a first axis parallel to a base surface, a second linear motion portion that is connected to the first linear motion portion and moves linearly along a second axis that is parallel to the base surface and in a direction different from the first axis, and a finger portion that is connected to the second linear motion portion and moves linearly along a third axis perpendicular to the base surface, wherein the first axes of each of the n finger units are arranged on each side of an n-gon, controlling a position of each of the fingers along the first axis; controlling a position of each of the fingers along the third axis; and controlling the position of each of the fingers in the direction of the second axis to control gripping of an object. A control program for a robot hand, comprising: [Explanation of symbols]

[0073] 1, 100, 10000, 10001, 10002 Robot Hand 2, 10, 20, 30, 1000, 2000, 3000 finger units 3, 12, 1200, 2200, 3200 First linear motion part 4, 14, 1400, 2400, 3400 Second linear motion part 5, 16, 1700, 2700, 3700 fingers 11 First axis 13 Second axis 15 The third axis 50 Control section 90, 9000 base 1600, 2600, 3600 Third linear motion section 1710, 2710, 3710 Suction pad

Claims

1. a first linear motion portion that moves linearly along a first axis parallel to the base surface; a second linear motion portion connected to the first linear motion portion and linearly moving along a second axis parallel to the base surface and different from the first axis; a finger portion connected to the second linear motion portion and linearly moving along a third axis perpendicular to the base surface; n sets (n≧3) of finger units having a rack gear fixed to at least one of the first linear motion portions and extending in a direction of the first axis; A pinion gear that drives the rack gear; A drive gear disposed at the center of an n-gon; a gear system that transmits rotation of the drive gear to the pinion gear; The first axes of each of the n sets of finger units are disposed on respective sides of the n-gon. A robot hand characterized by

2. The finger portion is It has an adsorption part that adsorbs the object. The robot hand according to claim 1 .

3. The gear system comprises: A mechanism is provided to cut off the transmission of rotation of the drive gear to the pinion gear. The robot hand according to claim 1 .

4. Each of the second linear motion parts has a torque control part that controls a torque of the linear motion in the direction of the second axis. The robot hand according to any one of claims 1 to 3.

5. a first linear motion portion that moves linearly along a first axis parallel to a base surface, a second linear motion portion that is connected to the first linear motion portion and moves linearly along a second axis that is parallel to the base surface and in a direction different from the first axis, and a finger portion that is connected to the second linear motion portion and moves linearly along a third axis perpendicular to the base surface; a rack gear that is fixed to at least one of the first linear motion portions among a plurality of the first linear motion portions and extends in a direction of the first axis, a pinion gear that drives the rack gear, a drive gear that is disposed in a center of an n-gon, and a gear system that transmits rotation of the drive gear to the pinion gear, Controlling the position of each of the fingers along the first axis; Controlling the position of each of the fingers along the third axis; The position of each of the fingers in the direction of the second axis is controlled to grasp an object. A method for controlling a robot hand.

6. The finger portion has a suction portion, The object is attracted to the attraction portion. The method for controlling a robot hand according to claim 5.

7. The linear motion of the first linear motion portion is performed using a combination of a rack gear and a pinion gear.

7. The method for controlling a robot hand according to claim 5 or 6.

8. A robot hand control program for causing a computer to control a robot hand, The robot hand includes: A finger unit has n sets (n≧3) of a first linear motion portion that moves linearly along a first axis parallel to a base surface, a second linear motion portion that is connected to the first linear motion portion and moves linearly along a second axis that is parallel to the base surface and different from the first axis, and a finger portion that is connected to the second linear motion portion and moves linearly along a third axis perpendicular to the base surface; a rack gear that is fixed to at least one of the first linear motion portions among the plurality of first linear motion portions and extends in the direction of the first axis; a pinion gear that drives the rack gear; and a drive gear that is disposed in the center of an n-sided polygon. a gear system that transmits rotation of the drive gear to the pinion gear, wherein the first shaft of each of the n sets of finger units is disposed on each side of the n-gon; The control program for the robot hand comprises: controlling a position of each of the fingers along the first axis; controlling a position of each of the fingers along the third axis; and controlling the position of each of the fingers in the direction of the second axis to control gripping of an object. A control program for a robot hand, comprising:

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