Robot

Abstract

To provide a robot that has a serial link mechanism, which is configured so that a movable part is reduced in weight and a position of a tip side thereof can be easily controlled.SOLUTION: A robot comprises: a base part; a first motor which has a first driving shaft in a specific direction and is mounted on the base part; a second motor which has a second driving shaft coaxial with the first driving shaft and is mounted on the base part; a first link that is rotated by the first motor about the first driving shaft; a second link that is rotated by the second motor about the second driving shaft; a first joint which is provided on the first link and has a first rotary shaft; a second joint which is provided on the second link and has a second rotary shaft; a third link which is connected to the first joint and can rotate about the first rotary shaft; a fourth link which is connected to the second joint and can rotate about the second rotary shaft; a third joint which is provided on the third link and has a third rotary shaft and which the fourth link is rotatably connected to; and an end effector mounting part which is provided on the third link.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to robots. [Background technology]

[0002] Patent Document 1 describes an air hockey game device equipped with a manipulator. The manipulator is composed of a stick, a robot arm with the stick attached to the tip, and a driving means for causing the stick to hit the ball. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-300823 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the air hockey game device described in Patent Document 1, a manipulator extends from a monitor board. The manipulator is a so-called serial link mechanism having a structure in which a plurality of links are connected in series by joints.

[0005] In a serial link structure, a drive source for driving a link on the tip side is provided at the position of a joint. In this case, since the joint is separated from the base end (the monitor board in the example of Patent Document 1), the gravity moment of the drive source acts on the serial link mechanism. If the links and joints are reinforced to suppress deformation and displacement of the serial link mechanism due to this moment, this leads to an increase in the weight of the movable parts of the serial link mechanism.

[0006] Furthermore, in a robot having a serial link mechanism, when controlling the position of the tip side (the stick in the example of Patent Document 1), it is desired to control it more simply.

[0007] The present disclosure aims to reduce the weight of a moving part and simplify the position control of the tip side in a robot having a serial link mechanism. [Means for solving the problem]

[0008] One aspect of the present disclosure includes a base, a first motor having a first drive shaft in a specific direction and attached to the base, a second motor having a second drive shaft coaxial with the first drive shaft and attached to the base, a first link rotated by the first motor about the first drive shaft within a rotation plane having the specific direction as a normal line, a second link rotated by the second motor about the second drive shaft within a rotation plane having the specific direction as a normal line, a first joint provided on the first link and having a first rotation shaft, a second joint provided on the second link and having a second rotation shaft, a third link connected to the first joint and rotatable about the first rotation shaft, a fourth link connected to the second joint and rotatable about the second rotation shaft, a third joint provided on the third link and having a third rotation shaft, and to which the fourth link is rotatably connected, and an end effector attachment portion provided on the third link. Effect of the Invention

[0009] According to the present disclosure, in a robot having a serial link mechanism, the movable part can be made lighter and position control on the tip side can be simplified. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a bottom view showing the robot of the first embodiment. [Diagram 2] FIG. 2 is a front view showing the robot of the first embodiment. [Diagram 3] FIG. 3 is a side view showing the robot of the first embodiment. [Figure 4] FIG. 4 is an explanatory diagram showing a rotating state of a link of the robot according to the first embodiment. [Diagram 5] FIG. 5 is a bottom view showing the robot according to the second embodiment. [Figure 6] FIG. 6 is a bottom view showing the robot according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A robot 12 as an example of an embodiment of the present disclosure will be described below with reference to the drawings. Note that the same or substantially equivalent elements, members, and parts in each drawing are given the same reference numerals. Also, the dimensions and ratios in the drawings are exaggerated for the convenience of explanation and may differ from the actual ratios.

[0012] The robot 12 can be used, for example, in a game in which players hit a puck on a board (a so-called air hockey game), when a mallet, which will be described later, is moved on the board to hit the puck used in the game.

[0013] As shown in Figs. 1 to 3, the robot 12 of the first embodiment has a base 14, a first motor 16, a second motor 18, and an arm unit 20. The base 14 is installed on, for example, an installation surface SF. With the robot 12 installed on the installation surface SF, an X-axis, a Y-axis, and a Z-axis are set as a coordinate system. The X-axis direction is the front-rear direction of the robot 12, the Y-axis is the left-right direction of the robot 12, and the Z-axis is the height direction of the robot 12. In the illustrated example, the surface (XY plane) on which the arm unit 20 operates is a horizontal plane, but the surface on which the arm unit 20 operates may be, for example, a vertical plane (vertical plane) or an inclined plane inclined at an arbitrary inclination angle with respect to the horizontal plane.

[0014] The base 14 includes a base 22 and a support column 24. In the illustrated example, the base 22 has two support beams arranged at a right angle. The support column 24 extends upward from one of the support beams.

[0015] The first motor 16 and the second motor 18 have housings 16H and 18H. The housings 16H and 18H are attached to the support 24 by brackets 30. In the illustrated example, the first motor 16 is disposed above the second motor 18.

[0016] The first motor 16 has a first drive shaft 26. The first drive shaft 26 extends downward from the housing 16H along the Z-axis direction. That is, the Z-axis direction is the specific direction of the first drive shaft 26.

[0017] The second motor 18 has a second drive shaft 28. The second drive shaft 28 extends upward from the housing 16H along the Z-axis direction. The second drive shaft 28 is coaxial with the first drive shaft 26. That is, the housings 16H, 18H of the first motor 16 and the second motor 18 are attached to the support 24 so that the first drive shaft 26 and the second drive shaft 28 are coaxial with each other.

[0018] The arm unit 20 has a first link 32, a second link 34, a third link 36, and a fourth link 38. In the first embodiment, the first link 32, the second link 34, the third link 36, and the fourth link 38 are linear. The arm unit 20 is an example of a movable unit related to the disclosed technology.

[0019] One end of the first link 32 is attached to the first drive shaft 26. By driving the first motor 16, the first link 32 is rotated within a rotation plane RP1 having the Z-axis direction as a normal line. The Z-axis direction in this case is the "specific direction" in the disclosed technology.

[0020] One end of the second link 34 is attached to the second drive shaft 28. Driven by the second motor 18, the second link 34 is rotated within a rotation plane RP2 that is normal to the Z-axis direction. In the illustrated example, the second link 34 is disposed below the first link 32, and therefore the rotation plane RP2 is also below the rotation plane RP1. Because the rotation plane RP1 of the first link 32 and the rotation plane RP2 of the second link 34 are thus offset in a specific direction, the first link 32 and the second link 34 do not interfere with each other when they rotate.

[0021] A first joint 42 is provided at the other end of the first link 32. The first joint 42 has a first rotation shaft 52. The first rotation shaft 52 is parallel to the first drive shaft 26. Note that the first rotation shaft 52 itself may be formed in the first link 32, for example, and the first rotation shaft 52 may be inserted into the first joint 42, so that the first joint 42 essentially has the first rotation shaft 52. The same relationship applies to the following joints and the corresponding rotation shafts.

[0022] The other end of the second link 34 is provided with a second joint 44. The second joint 44 has a second rotation shaft 54. The second rotation shaft 54 ​​is parallel to the second drive shaft 28. Therefore, the second rotation shaft 54 ​​is also parallel to the first rotation shaft 52.

[0023] One end of the third link 36 is connected to the first joint 42. The third link 36 is rotatable about a first rotation shaft 52 located at one end of the third link 36.

[0024] One end of the fourth link 38 is connected to the second joint 44. The fourth link 38 is rotatable about a second rotation shaft 54 ​​located at one end thereof.

[0025] The other end of the third link 36 is provided with a third joint 46. The third joint 46 has a third rotation shaft 56. The third rotation shaft 56 is parallel to the first rotation shaft 52 and the second rotation shaft 54. This results in a structure in which the first drive shaft, the second drive shaft 28, the first rotation shaft 52, the second rotation shaft 54, and the third rotation shaft 56 are parallel to one another.

[0026] The other end of the fourth link 38 is connected to a third joint 46. The fourth link 38 is rotatable relative to the third link 36 about a third rotation shaft 56 located at the other end.

[0027] In this embodiment, as shown in FIG. 4, when viewed in the Z-axis direction, a line segment LS1 connecting the first driving shaft 26 and the first rotating shaft 52 is parallel to a line segment LS4 connecting the second rotating shaft 54 ​​and the third rotating shaft 56, and the line segments LS1 and LS4 are parallel to each other and have the same length. As a result, a line segment LS2 connecting the second driving shaft 28 and the second rotating shaft 54 ​​and a line segment LS3 connecting the first rotating shaft 52 and the third rotating shaft 56 are also parallel to each other and have the same length. That is, a parallelogram having four sides, which are the first link 32, the second link 34, the third link 36, and the fourth link 38, is formed. In the illustrated example, the line segments LS2 and LS3 are shorter than the line segments LS1 and LS4. In addition, each of the line segments LS1, LS2, LS3, and LS4 is perpendicular to the driving shaft or the rotating shaft at both ends.

[0028] The third link 36 is provided with a mallet attachment piece 40. In the bottom view shown in Fig. 1, the mallet attachment piece 40 has a shape that extends linearly from one end (first joint 42) of the third link 36 to the other end (third joint 46). In the front view shown in Fig. 2 and the side view shown in Fig. 3, the mallet attachment piece 40 is formed in a linear shape that slopes obliquely downward from the position of the third joint 46 toward the tip.

[0029] The tip of the mallet attachment piece 40 is the mallet attachment section 50. The mallet 48 is attached to the mallet attachment section 50. In the illustrated example, the mallet 48 is formed in a flat cylindrical shape. The mallet 48 is an example of an end effector, and the mallet attachment section 50 is an example of an end effector attachment section. In this example, the mallet attachment section 50 is indirectly provided to the third link 36 via the mallet attachment piece 40, but the mallet attachment section 50 is not limited to a structure in which it is provided at the tip of the mallet attachment piece 40. For example, the mallet attachment piece 40 may be omitted, and the mallet attachment section 50 may be directly provided at the other end of the third link 36, i.e., at the position of the third joint 46. In either configuration, the position of the mallet attachment section 50 is a position on the tip side of the arm section 20 and a position on the tip side of the robot 12, and the mallet 48 is located on this tip side.

[0030] In this embodiment, the links from the first drive shaft 26 to the mallet attachment portion 50 are substantially connected in series to form a serial link mechanism, i.e., the first link 32, the third link 36, and the mallet attachment piece 40. In this serial link mechanism, the second link 34 and the fourth link 38 are provided, making it possible to adjust the position of the mallet attachment portion 50.

[0031] Next, the operation of this embodiment will be described.

[0032] As shown in FIG. 4, in the robot 12, the first link 32 rotates around the first drive shaft 26 by driving the first motor 16 (see FIGS. 1 to 3). For example, as shown by the dashed line in FIG. 4, the rotation angle θ1 of the first link 32 can be adjusted to a predetermined angle with respect to a predetermined reference line BL. Also, the second link 34 rotates around the second drive shaft 28 by driving the second motor 18. For example, the rotation angle θ2 of the second link 34 can be adjusted to a predetermined angle with respect to the reference line BL. Then, by appropriately adjusting the rotation angle θ1 of the first link 32 and the rotation angle θ2 of the second link 34, the mallet 48 can be moved to a desired position.

[0033] 1 to 3, the first motor 16 and the second motor 18 are provided on the support 24, i.e., the base 14. It is also possible to provide a motor for moving the mallet 48 to a desired position on, for example, the first link 32 or the second link 34, but in this case, the weight of the arm portion 20 will increase.

[0034] In contrast, in the robot 12 of the present embodiment, the first motor 16 and the second motor 18 are provided on the base 14, so that the weight of the arm portion 20 can be reduced.

[0035] Furthermore, since the first link 32 and the second link 34 rotate around one end (the support 24 side) of each link as a fulcrum, if the motor is provided at a position away from the support 24, the moment of inertia of the arm portion 20 centered on the support 24 becomes larger compared to a configuration in which the motor is provided on the support 24.

[0036] In contrast, in the robot 12 of this embodiment, the first motor 16 and the second motor 18 are provided on the base 14, so that the moment of inertia of the arm unit 20 about the base 14 is also reduced.

[0037] In addition, in the robot 12 of this embodiment, the first drive shaft 26 of the first motor 16 and the second drive shaft 28 of the second motor 18 are coaxial. Even if the first drive shaft 26 of the first motor 16 and the second drive shaft 28 of the second motor 18 are not coaxial, it is possible to rotate the first link 32 and the second link 34, respectively. However, in a configuration in which the first drive shaft 26 and the second drive shaft 28 are not coaxial, adjustment of the rotation angle θ1 of the first link 32 and the rotation angle θ2 of the second link 34 may become complicated when controlling the position of the mallet 48. In contrast, in the robot 12 of this embodiment, since the first drive shaft 26 and the second drive shaft 28 are coaxial, adjustment of the rotation angle θ1 of the first link 32 and the rotation angle θ2 of the second link 34 can be simplified when controlling the position of the mallet 48. In other words, by simplifying the adjustment of the rotation angle θ1 of the first link 32 and the rotation angle θ2 of the second link 34, the control of the position of the mallet 48 is also simplified.

[0038] In particular, in the robot 12 of this embodiment, the line segments LS1 and LS4 are parallel and have the same length, forming a parallelogram with the first link 32, the second link 34, the third link 36, and the fourth link 38 as four sides. Therefore, as can be seen from FIG. 4, the rotation angle θ3 of the third link 36 with respect to the line segment LS1 is the difference between the rotation angle θ2 of the second link 34 and the rotation angle θ1 of the first link 32, and is calculated as θ3=θ2-θ1. In other words, the angle of the third link 36 with respect to the reference line BL is equal to the rotation angle θ2 of the second link 34. That is, the position of the mallet 48 can be controlled more easily compared to a configuration in which the line segments LS1 and LS2 are parallel and not the same length.

[0039] In the robot 12 of the first embodiment, the first link 32, the second link 34, the third link 36, and the fourth link 38 are all straight. Therefore, a simpler structure can be realized compared to a configuration in which these links are bent.

[0040] Next, a second embodiment will be described. In the following embodiments, the same elements, members, etc. as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof will be omitted.

[0041] 5, in the robot 62 of the second embodiment, the fourth link 68 is curved in a shape that deviates from the line segment LS4 in a plan view. In the example shown in the figure, the entire fourth link 68 is curved, and the curvature in a plan view gradually increases from the other end side (the third rotating shaft 56 side) to one end (the second rotating shaft 54 ​​side).

[0042] Further, a part or the whole of the fourth link 68 is provided at a height position where it overlaps with the housing 16H of the second motor 18 in the Z-axis direction. That is, the fourth link 68 is curved so as not to interfere with the housing 16H even if the fourth link 68, which overlaps with the housing 16H in the height direction, rotates.

[0043] In the robot 62 of the second embodiment, the fourth link 68 can be provided at a height position that overlaps with the housing 16H of the second motor 18 in the Z-axis direction. Compared to the robot 12 of the first embodiment, the fourth link 68 can be provided at a lower position, so the overall height of the robot 62 can be reduced. In particular, if the second link 34 is formed short, for example, to reduce the moment of inertia, the third link 36 is likely to interfere with the housing 16H. However, in the robot 62 of the second embodiment, the second link 34 can be shortened to reduce the moment of inertia, and a structure can be realized in which the fourth link 68 does not interfere with the housing 16H.

[0044] The members with which the fourth link 68 should avoid interference are not limited to the housing 18H of the second motor 18. For example, the fourth link 68 may be bent in an appropriate shape to avoid interference with various members that are preferably disposed within the rotation trajectory of the fourth link 68.

[0045] The shape of the bent fourth link 68 may be such that the curvature is constant in a plan view, or the curvature may gradually decrease from the other end side to the one end side. Also, the portion of the fourth link 68 that is curved may be a part of the fourth link 68 rather than the entire fourth link 68. Furthermore, the fourth link 68 may be bent into a shape that deviates from the line segment LS2 by bending instead of curving, or by a combination of bending and curving.

[0046] Next, a third embodiment will be described.

[0047] 6, in a robot 72 of the third embodiment, the second link 74 is curved in a shape that deviates from the line segment LS2 in a plan view. In the example shown in the figure, the entire second link 74 is curved, and the curvature in a plan view gradually increases from the other end side (the second rotating shaft 54 ​​side) to one end (the second driving shaft 28 side). The second link 74 is curved so as not to interfere with the members around the second link 74 even when the second link 74 rotates.

[0048] Therefore, the robot 72 of the third embodiment has a structure in which the second link 74 does not interfere with other members when it rotates. As in the second embodiment, the members to be avoided from interfering with when the second link 74 rotates are not particularly limited. For example, the second link 74 may have a shape that avoids interference with the housing 18H of the second motor 18, or may have a shape that avoids interference with members other than the housing 18H.

[0049] In addition, the shape of the bent second link 74 may be such that the curvature of the bend is constant in a plan view, or the curvature may gradually decrease from the other end side to the one end side. The portion of the second link 74 that is bent may be a part of, rather than the entirety of, the second link 74. The second link 74 may be bent into a shape that deviates from the line segment LS2 by bending rather than curving, or by a combination of bending and curving.

[0050] In the disclosed technology, the end effector is not limited to the mallet 48, and may be any of various effectors that perform a predetermined process on a processing target. For example, it may be a hand that grips the processing target, a suction pad, or the like.

[0051] In addition, the disclosed technology is not particularly limited in terms of the use of the robot, and may be used, for example, as a robot used for sorting or picking luggage, or for transporting experimental equipment such as test tubes in a laboratory.

[0052] The following are additional notes regarding this disclosure. (Appendix 1) A base and a first motor having a first drive shaft in a specific direction and attached to the base; a second motor having a second drive shaft coaxial with the first drive shaft and mounted to the base; a first link that is rotated around the first drive shaft by the first motor within a rotation plane having the specific direction as a normal line; a second link that is rotated around the second drive shaft by the second motor within a rotation plane having the specific direction as a normal line; a first joint provided in the first link and having a first rotation axis; a second joint provided in the second link and having a second rotation axis; a third link connected to the first joint and rotatable about the first rotation axis; a fourth link connected to the second joint and rotatable about the second rotation axis; a third joint provided in the third link, having a third rotation shaft, to which the fourth link is rotatably connected; an end effector attachment portion provided on the third link; A robot having the above configuration. (Appendix 2) 2. The robot described in Appendix 1, wherein a line segment connecting the second rotation axis and the third rotation axis is parallel to and has the same length as a line segment connecting the first driving axis and the first rotation axis. (Appendix 3) The robot according to claim 1 or 2, wherein the second link and the fourth link are linear. (Appendix 4) 3. The robot according to claim 1, wherein at least a portion of the second link is bent in a shape that deviates from a line segment connecting the second drive shaft and the second rotation shaft when viewed in the specific direction. (Appendix 5) 5. The robot according to claim 1, wherein at least a part of the fourth link is bent in a shape that deviates from a line segment connecting the second rotation axis and the third rotation axis when viewed in the specific direction. (Appendix 6) The robot according to any one of claims 1 to 5, further comprising an end effector attached to the end effector attachment portion. [Explanation of symbols]

[0053] 12. Robot 14 Base 16 First Motor 16H Housing 18 Second Motor 18H Housing 20 Arm section 22 Pedestal 24 Posts 26 First drive shaft 28 Second drive shaft 30 Bracket 32 First Link 34 Second Link 36 Third Link 38 Fourth Link 40 Mallet attachment piece 42 First joint 44 Second joint 46 Third joint 48 Mallet 50 Mallet attachment part 52 First Rotation Axis 54 Second Rotation Axis 56 Third Rotation Axis 62 Robot 68 Fourth Link 72 Robot 74 Second Link

Claims

1. A base and a first motor having a first drive shaft in a specific direction and attached to the base; a second motor having a second drive shaft coaxial with the first drive shaft and mounted to the base; a first link that is rotated around the first drive shaft by the first motor within a rotation plane having the specific direction as a normal line; a second link that is rotated around the second drive shaft by the second motor within a rotation plane having the specific direction as a normal line; a first joint provided in the first link and having a first rotation axis; a second joint provided in the second link and having a second rotation axis; a third link connected to the first joint and rotatable about the first rotation axis; a fourth link connected to the second joint and rotatable about the second rotation axis; a third joint provided in the third link, having a third rotation shaft, to which the fourth link is rotatably connected; an end effector attachment portion provided on the third link; A robot having the above configuration.

2. The robot according to claim 1 , wherein a line segment connecting the second rotation axis and the third rotation axis is parallel to and has the same length as a line segment connecting the first drive axis and the first rotation axis.

3. The robot according to claim 1 , wherein the second link and the fourth link are linear.

4. The robot according to claim 1 , wherein at least a portion of the second link is bent in a shape that deviates from a line segment connecting the second drive shaft and the second rotation shaft when viewed in the specific direction.

5. 2 . The robot according to claim 1 , wherein at least a portion of the fourth link is bent in a shape that deviates from a line segment connecting the second rotation axis and the third rotation axis when viewed in the specific direction.

6. The robot of claim 1 , further comprising an end effector attached to the end effector attachment portion.

Images