Impact robot arm and table tennis robot

Abstract

To reduce a burden applied to a base of an impact robot arm.SOLUTION: An impact robot arm (30) includes: a turning part (31) rotatably assembled to a base (23); a first motor (33) that drives the turning part (31) to rotate; a first link (35) rotatably connected to the turning part (31); a lower link (39) rotatably connected to the turning part (31); a second link (41) rotatably connected to the lower link (39); an upper link (43) rotatably connected to the second link (41) and rotatably connected to the first link (35); a racket (60) attached to the upper link (43); and a second motor (51) and a third motor (53) that are attached to the turning part (31) and drive the first link (35) and the lower link (39), respectively.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a hitting robot arm and a table tennis robot. [Background technology]

[0002] Table tennis is one of the most popular sports. Two players face each other across a table and hit the ball back and forth with a racket. However, sometimes players want to play table tennis alone, without an opponent. For this purpose, various table tennis robots have been developed (see, for example, Patent Documents 1-10).

[0003] In particular, Patent Document 10 discloses a table tennis robot using a SCARA robot that swings a racket. Specifically, a guide rail is provided along the end line of a table tennis table, and the SCARA robot is moved along the guide rail by the power of a servo motor, and the SCARA robot hits back the ball with the racket. This SCARA robot is a multi-joint robot having five joints, and the operation of the SCARA robot is realized by driving these joints by servo motors. Patent Document 10 discloses the installation location of one servo motor that moves the SCARA robot along the guide rail. However, Patent Document 10 does not disclose the installation location of the servo motor that drives the joints of the SCARA robot. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-36383 A [Patent Document 2] Chinese Patent No. 108939490 [Patent Document 3] Chinese Patent No. 108858247 [Patent Document 4] China Utility Model No. 206214699 [Patent Document 5] Chinese Patent No. 109847301 [Patent Document 6] China Patent Application Publication No. 111251312 [Patent Document 7] China Patent Application Publication No. 109015682 [Patent Document 8] China Patent Application Publication No. 107283441 [Patent Document 9] China Patent Application Publication No. 103272376 [Patent Document 10] China Patent Publication No. 106426200 Summary of the Invention [Problem to be solved by the invention]

[0005] If a servo motor that drives a joint of a SCARA robot is provided at that joint, the closer the joint is to the racket, the worse the stability of the posture of the SCARA robot becomes due to the weight of the servo motor. As the joint is closer to the racket, the burden on the base of the servo motor and the slide rail increases. Therefore, the present invention has been made in consideration of the above circumstances, and an object of the present invention is to reduce the load on the base of a striking robot arm. [Means for solving the problem]

[0006] The following reference numerals in parentheses refer to FIGS. 1 to 6.

[0007] A striking robot arm (30) for solving the above problems includes a base (23), a rotating unit (31) assembled to the base (23) so as to be rotatable around a vertical axis, a first motor (33) that rotates and drives the rotating unit (31), a first link (35) having a proximal end (35a) and a distal end (35b) rotatably connected to the rotating unit (31) and extending upward from the proximal end (35a) toward the distal end (35b), a lower link (39) having a proximal end (39a) and a distal end (39b) rotatably connected to the rotating unit (31), and a proximal end (41a) and a distal end (41b) rotatably connected to the distal end (39b) of the lower link (39), and a first link (35) extending upward from the proximal end (35a) toward the distal end (35b). the upper link (43) having a proximal end (43a) rotatably connected to the distal end (41b) of the second link (41) and a distal end (43b) rotatably connected to the distal end (35b) of the first link (35); a racket (60) attached to the distal end (43b) of the upper link (43); a second motor (51) attached to the pivoting portion (31), connected to the proximal end (35a) of the first link (35) and driving the first link (35); and a third motor (53) attached to the pivoting portion (31), connected to the proximal end (39a) of the lower link (39) and driving the lower link (39).

[0008] The hitting robot arm (30) may further include a fourth motor (55) attached between the racket (60) and the upper link (43) and configured to rotate the racket (60) around the central axis of the handle portion (61) of the racket (60).

[0009] The second link (41) may be a counterweight that balances the racket (60).

[0010] The table tennis robot (1) may include the hitting robot arm (30), a table tennis table (10), a linear guide (21) that guides the base (23) along an end line of the table tennis table (10), and a drive mechanism (25) that moves the base (23) along the end line of the table tennis table (10). Effect of the Invention

[0011] According to the present invention, since the third motor is mounted on the rotating part close to the base, the weight of the third motor does not destabilize the posture of the striking robot arm, and the burden that the third motor places on the base is reduced. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view of a table tennis robot. [Diagram 2] FIG. 2 is a perspective view of the striking robot arm. [Diagram 3] FIG. 3 is a right side view of the striking robot arm. [Figure 4] FIG. 4 is a front view of the striking robot arm. [Diagram 5] FIG. 5 is a perspective view of the table tennis robot in the first modified example. [Figure 6] FIG. 6 is a perspective view of the table tennis robot in the second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the embodiments will be described with reference to the drawings. The features and technical effects of the embodiments will be understood from the following detailed description and drawings. However, the scope of the present invention is not limited to the embodiments disclosed below. The drawings are provided for illustrative purposes only, and therefore the scope of the present invention is not limited to the illustrations in the drawings.

[0014] In the following description, the proximal end of a link refers to the end closer to the power that moves the link, and the distal end of a link refers to the end farther from the power that moves the link. In the following description, when ordinal numbers such as "first" and "second" are attached to common names, the ordinal numbers are used for the purpose of identifying the objects to which they are attached.

[0015] <1. Configuration of the Table Tennis Robot> The table tennis robot 1 includes a table tennis table 10, a linear guide 21, a drive mechanism 25, and a hitting robot arm 30.

[0016] The table tennis table 10 has tables 11 and 12. The tables 11 and 12 are supported horizontally by legs attached below them. The tables 11 and 12 are formed in the shape of rectangular or square plates. The tables 11 and 12 are the same size. The sides of the tables 11 are aligned with the sides of the tables 12, and the tables 11 and 12 are combined to form a square or rectangle. The size of the table tennis table 10 may or may not conform to an international standard. A net 13 is erected on the top surfaces of the tables 11 and 12 along the boundary between the tables 11 and 12, and separates the area above the tables 11 from the area above the tables 12. The top surface of the table 11 is the court on the side of the hitting robot arm 30, and the top surface of the table 12 is the court on the player's side.

[0017] The linear guide 21 is attached horizontally to the table 11 along the end line of the table 11 and fixed to the table 11 .

[0018] The carriage 23 of the striking robot arm 30 is attached to a linear guide 21. The carriage 23 is guided linearly left and right along the end line of the table 11 by the linear guide 21. The carriage 23 corresponds to the base of the striking robot arm 30.

[0019] The drive mechanism 25 drives the carriage 23 to move the carriage 23 along the linear guide 21. The drive mechanism 25 has a motor 27 and a transmission mechanism. The motor 27 is attached to an end of the linear guide 21 in the longitudinal direction of the linear guide 21. The motor 27 is connected to the transmission mechanism and outputs power to the transmission mechanism. The transmission mechanism is assembled to the linear guide 21 and connected to the carriage 23. The transmission mechanism converts the rotational motion of the motor 27 into linear motion of the carriage 23. As a result, the motor 27 drives the carriage 23 left and right. The transmission mechanism has a winding transmission mechanism, a ball screw transmission mechanism, or a pinion rack mechanism.

[0020] The hitting robot arm 30 is guided left and right along the end line of the table 11 by a linear guide 21. The hitting robot arm 30 is moved left and right along the linear guide 21 by a drive mechanism 25. The hitting robot arm 30 adjusts the posture of the racket 60 and swings the racket 60 around a yaw axis perpendicular to the top surface of the table 11.

[0021] The hitting robot arm 30 includes a carriage 23 , a rotating section 31 , a first motor 33 , a first link 35 , an auxiliary link 37 , a lower link 39 , a second link 41 , an upper link 43 , motors 51 , 53 , 55 , and a racket 60 .

[0022] The swivel unit 31 is mounted on the carriage 23 by a bearing or the like. The swivel unit 31 is rotatable around a yaw axis perpendicular to the upper surface of the table 11, relative to the carriage 23. The yaw axis is vertical and passes through the center of the swivel unit 31. The connection between the carriage 23 and the swivel unit 31 is a torsion joint.

[0023] The first motor 33 is mounted on the carriage 23. A power output shaft of the first motor 33 is connected to the rotating unit 31. The first motor 33 rotates the rotating unit 31 around the yaw axis. The rotation of the rotating unit 31 by the first motor 33 realizes the action of the hitting robot arm 30 swinging the racket 60.

[0024] A proximal end 35a of the first link 35 is rotatably connected to the pivot 31 and is rotatable about a horizontal connection axis relative to the pivot 31. The connection between the pivot 31 and the first link 35 is a bending joint. The first link 35 extends upward from its proximal end 35a to its distal end 35b.

[0025] The distal end 35b of the first link 35 is rotatably connected to the distal end 35b of the upper link 43 and is rotatable about a horizontal connection axis relative to the distal end 43b of the upper link 43. The connection between the first link 35 and the upper link 43 is a bending joint.

[0026] A proximal end 37a of the auxiliary link 37 is rotatably connected to the pivot unit 31 and is rotatable about a horizontal connecting axis relative to the pivot unit 31. The horizontal connecting axis at the proximal end 37a of the auxiliary link 37 is coaxial with the horizontal connecting axis at the proximal end 37a of the first link 35. The connection between the auxiliary link 37 and the pivot unit 31 is a bending joint.

[0027] A distal end 37b of the auxiliary link 37 is rotatably connected to an end of the upper link 43 and is rotatable about a horizontal connecting axis relative to the end of the upper link 43. The horizontal connecting axis at the distal end 37b of the auxiliary link 37 is coaxial with the horizontal connecting axis at the distal end 37b of the first link 35. The connection between the auxiliary link 37 and the upper link 43 is a bending joint.

[0028] The first link 35 and the auxiliary link 37 are arranged in parallel with a gap therebetween. The upper link 43 is sandwiched between the distal end 35b of the first link 35 and the distal end 37b of the auxiliary link 37. The first link 35 and the auxiliary link 37 are assembled together by a connecting bar that connects them. The first link 35 and the auxiliary link 37 are formed with holes 35c, 37c, thereby reducing the weight of the first link 35 and the auxiliary link 37.

[0029] The second motor 51 is attached to one side of the rotating part 31. A power output shaft of the second motor 51 is connected to the proximal end 35a of the first link 35. The second motor 51 drives the first link 35 to swing the first link 35 around a horizontal connecting shaft at the proximal end 35a of the first link 35. When the first link 35 swings, the auxiliary link 37 swings together with the first link 35.

[0030] The lower link 39 is disposed between the proximal end 35a of the first link 35 and the proximal end 37a of the auxiliary link 37. The proximal end 39a of the lower link 39 is rotatably connected to the pivot unit 31 and is rotatable around a connecting axis that is horizontal relative to the pivot unit 31. The lower link 39 extends from its proximal end 39a to its distal end 39b in a direction that intersects with the extension direction of the auxiliary link 37. The distal end 39b of the lower link 39 is rotatably connected to the proximal end 41a of the second link 41 and is rotatable around a connecting axis that is horizontal relative to the proximal end 41a of the second link 41.

[0031] The second link 41 extends upward from its proximal end 41a to its distal end 41b. The distal end 41b of the second link 41 is rotatably connected to the proximal end 43a of the upper link 43 and is rotatable about a horizontal connecting axis relative to the proximal end 43a of the upper link 43.

[0032] The second link 41 is parallel to the auxiliary link 37, and the upper link 43 is parallel to the lower link 39. Therefore, the link mechanism consisting of the second link 41, the auxiliary link 37, the upper link 43, and the lower link 39 is a parallel link mechanism. The second link 41 is parallel to the first link 35. The link mechanism consisting of the second link 41, the first link 35, the upper link 43, and the lower link 39 is a parallel link mechanism.

[0033] The specific gravity of the second link 41 is greater than that of the first link 35, and the weight of the second link 41 is greater than the weight of the first link 35. The specific gravity of the second link 41 is greater than that of the auxiliary link 37, and the weight of the second link 41 is greater than the weight of the auxiliary link 37. For example, the second link 41 is made of a material with a high specific gravity such as stainless steel, and the first link 35 and the auxiliary link 37 are made of a material with a low specific gravity such as resin, carbon fiber resin, aluminum alloy, etc. The second link 41 functions as a counterweight that balances the racket 60.

[0034] The third motor 53 is attached to the other side of the pivot portion 31. The power output shaft of the third motor 53 is connected to the proximal end 39a of the lower link 39 but is not connected to the proximal end 37a of the auxiliary link 37. The third motor 53 drives the lower link 39 to swing the lower link 39 around a horizontal connecting axis at the proximal end 39a of the lower link 39.

[0035] The fourth motor 55 is attached to the distal end 43b of the upper link 43. The handle 61 of the racket 60 is connected to a power output shaft of the fourth motor 55 with an end face of the handle 61 facing the fourth motor 55 and the upper link 43. The fourth motor 55 drives the racket 60 to rotate about a rotation axis extending from the proximal end 43a of the upper link 43 toward the distal end 43b of the upper link 43. The rotation axis is coaxial with the central axis of the racket 60 extending in the longitudinal direction of the handle 61.

[0036] The racket 60 has rubber attached to both sides.

[0037] <2. Table Tennis Robot Movement> When the drive mechanism 25 drives the carriage 23, the carriage 23 moves to the hit position and stops at that position. This determines the position of the hitting robot arm 30 in the left-right direction. The hit position is a position where the hitting robot arm 30 can hit the ball with the racket 60 by swinging the racket 60.

[0038] The motors 51, 53, and 55 are operated to move the racket 60. This determines the attitude of the racket 60 and the relative position of the racket 60 with respect to the carriage 23. For example, if the third motor 53 stops the lower link 39 while the second motor 51 drives the first link 35, the racket 60 translates without changing the angle of the handle 61 with respect to the horizontal plane. For example, if the second motor 51 stops the first link 35 while the third motor 53 drives the lower link 39, the racket 60 rotates around the connecting shaft at the distal end 37b of the first link 35 and the auxiliary link 37, and the angle of the handle 61 with respect to the horizontal plane also changes. For example, if the second motor 51 drives the first link 35 and the third motor 53 drives the lower link 39, the angle of the handle 61 with respect to the horizontal plane changes and the racket 60 moves along the vertical plane. When the fourth motor 55 rotates the racket 60, the angle of each of the two surfaces (the surfaces to which rubber is attached) of the racket 60 with respect to the horizontal plane changes.

[0039] The motors 51, 53, 55 and the drive mechanism 25 may operate simultaneously or in any order. All of the motors 51, 53, 55 and the drive mechanism 25 may operate, or one, two or three of them may operate.

[0040] When the first motor 33 rotates and drives the swivel unit 31, the racket 60 is swung around the yaw axis. Then, the racket 60 hits the ball, and the ball is returned to the court on the player's side. When the racket 60 is swung by the first motor 33, at least one of the motors 51, 53, 55 and the drive mechanism 25 may be operated.

[0041] <3. Modification> In the following, several modified examples of the embodiment described above will be described. Two or more of the modifications described below may be applied in combination.

[0042] (1) First Modification 1 to 4, the carriage 23 is attached to the linear guide 21, and the carriage 23 and the striking robot arm 30 are moved linearly left and right by the drive mechanism 25. In contrast, as shown in Fig. 5, the carriage 23 and the striking robot arm 30 may be moved back and forth and left and right by the drive mechanism 25 and drive mechanism 75. Here, "forward" refers to the direction toward the player's court, and "backward" refers to the direction away from the player's court.

[0043] 5, the carriage 73 is attached to the linear guide 21. The carriage 73 is guided by the linear guide 21 linearly in the left-right direction along the end line of the table 11.

[0044] The slide bar 71 is horizontally attached to the carriage 73 so as to extend in the front-rear direction. The slide bar 71 is movable in the front-rear direction relative to the carriage 73 while sliding with respect to the carriage 73.

[0045] The carriage 23 is fixed to the front end of the slide bar 71 .

[0046] The drive mechanism 75 drives the slide bar 71 and the carriage 23 to move them in the extension direction of the slide bar 71 (front-rear direction). The drive mechanism 75 has a motor 77 and a transmission mechanism. The motor 77 is attached to the rear end of the carriage 73. The motor 77 is connected to the transmission mechanism and outputs power to the transmission mechanism. The transmission mechanism is assembled to the carriage 73 and connected to the carriage 23. The transmission mechanism converts the rotational motion of the motor 77 into linear motion of the carriage 23. As a result, the motor 77 drives the carriage 23 and the striking robot arm 30 left and right. The transmission mechanism has a ball screw transmission mechanism, a pinion rack mechanism, or a winding transmission mechanism.

[0047] (2) Second Modification 1 to 4, the linear guide 21 is attached to the upper surface of the table 11 along the end line of the table 11. Alternatively, as shown in FIG. 6, the linear guide 21 may be attached to the rear end surface of the table 11 along the end line of the table 11.

[0048] <4. Summary> The proximal end 43a of the upper link 43 is connected to the distal end 41b of the second link 41, the proximal end 41a of the second link 41 is connected to the distal end 39b of the lower link 39, and the proximal end 39a of the lower link 39 is connected to the third motor 53. Because the third motor 53 is mounted on the rotating part 31 close to the carriage 23, the weight of the third motor 53 does not destabilize the posture of the striking robot arm 30. Furthermore, the burden that the third motor 53 imposes on the carriage 23 and the linear guide 21 is reduced. The installation location of the third motor 53 also contributes to reducing the weight, rigidity, and cost of the first link 35 and the auxiliary link 37. Similarly, the weight of the first motor 33 and the second motor 51 does not destabilize the posture of the striking robot arm 30, and the burden that the first motor 33 and the second motor 51 imposes on the carriage 23 and the linear guide 21 is reduced, and the installation locations of the first motor 33 and the second motor 51 also contribute to reducing the weight, rigidity, and cost of the first link 35 and the auxiliary link 37.

[0049] The second motor 51 is attached to one side of the rotating part 31, and the third motor 53 is attached to the other side of the rotating part 31, with the second motor 51 and the third motor 53 disposed facing each other with the rotating part 31 between them. This results in an almost uniform weight distribution in the striking robot arm 30. In other words, the weight of the striking robot arm 30 on the first link 35 side, with respect to the vertical midpoint between the first link 35 and the auxiliary link 37, is almost equal to the weight of the striking robot arm 30 on the auxiliary link 37 side. This allows the rotating part 31 to rotate stably, and the striking robot arm 30 to swing the racket 60 around the yaw axis stably.

[0050] The holes 35c, 37c of the first link 35 and the auxiliary link 37 contribute to reducing the weight of the first link 35 and the auxiliary link 37. If the first link 35 and the auxiliary link 37 are lightweight, the striking robot arm 30 can operate even if the output of the motors 27, 33, 51, 53 is low. If the output of the motors 27, 33, 51, 53 is low, the motors 27, 33, 51, 53 can be small in size.

[0051] Since the second link 41 is a counterweight that balances the racket 60, a separate counterweight is not required. [Explanation of symbols]

[0052] 1. Table Tennis Robot 10. Ping-pong table 21 Linear guide 23 Carriage (base) 25 Drive mechanism 30 Impact Robot Arm 31 Swivel section 33 First Motor 35 First Link 37 Auxiliary Links 39 Lower Link 41 Second Link 43 Upper Link 51 Second Motor 53 3rd Motor 55 4th Motor 60 rackets

Claims

1. With the base, a rotating part assembled to the base so as to be rotatable about a vertical axis; A first motor that rotates the rotating unit; a first link having a proximal end rotatably connected to the pivot portion and a distal end and extending upward from the proximal end toward the distal end; a lower link having a proximal end rotatably connected to the pivot portion and a distal end; a second link having a proximal end rotatably connected to the distal end of the lower link and a distal end extending upward from the proximal end toward the distal end; an upper link having a proximal end rotatably coupled to a distal end of the second link and a distal end rotatably coupled to a distal end of the first link; a racket attached to a distal end of the upper link; a second motor attached to the pivot portion and coupled to a proximal end of the first link to drive the first link; a third motor attached to the pivot portion and coupled to a proximal end of the lower link to drive the lower link; A striking robot arm comprising:

2. a fourth motor attached between the racket and the upper link and configured to rotate the racket about a central axis of a handle of the racket; The strike robot arm of claim 1 further comprising:

3. The second link is a counterweight that balances the racket. The striking robot arm according to claim 1 or 2.

4. The striking robot arm according to claim 1 or 2, A ping pong table and A linear guide that guides the base along an end line of the table tennis table; A drive mechanism that moves the base along the end line of the table; A table tennis robot equipped with

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