A robotic arm for detecting the center of gravity of a ping-pong ball

Abstract

This invention belongs to the field of table tennis ball inspection technology, and provides a robotic arm for detecting the center of gravity of a table tennis ball. The robotic arm includes a rotating platform, a lifting mechanism, a robotic arm, a detection mechanism, and a rotating mechanism. The rotating platform is positioned above the lifting mechanism. The robotic arm is mounted above the rotating platform via a column. The rotating mechanism is located at the end of the robotic arm and is used to place and launch the table tennis ball. The rotating mechanism, via the robotic arm, allows the table tennis ball to fall onto the rotating platform as it moves. The detection mechanism is positioned above where the table tennis ball lands on the rotating platform to detect the center of gravity of the ball. This invention releases the spinning table tennis ball, which falls onto the rotating platform and continues to spin. The detection mechanism detects the amplitude of the ball's fluctuation during spinning, thereby determining the center of gravity deviation and sorting out defective table tennis balls.

Description

Technical Field

[0001] This invention belongs to the field of table tennis detection technology, specifically relating to a robotic arm for detecting the center of gravity of a table tennis ball. Background Technology

[0002] In table tennis, the center of gravity of the ball has a significant impact on the player's performance. A deviation in the center of gravity can lead to a very unpleasant experience for the player, making the detection of the ball's center of gravity crucial. The center of gravity error of a table tennis ball refers to the difference between its center of gravity and its geometric center. A smaller center of gravity error results in a more stable trajectory, so it's essential to detect this error during the manufacturing process. Current methods for detecting center of gravity error typically involve rolling the ball on a flat glass surface at a certain angle. A straight rolling trajectory indicates a small center of gravity error, while a straight trajectory indicates a large one. However, this method is not very accurate, requires repeated testing, and necessitates changing the angle of release each time, yet the possibility of center of gravity deviation still exists. Summary of the Invention

[0003] In order to overcome the limitations of existing technologies, the purpose of this invention is to provide a robotic arm for detecting the center of gravity of a ping-pong ball.

[0004] The technical solution adopted by this invention to solve its technical problem is: a ping-pong ball center of gravity detection robot, comprising: a rotating platform, a lifting mechanism, a robotic arm, a detection mechanism, and a rotating mechanism; the rotating platform is located above the lifting mechanism; the robotic arm is mounted above the rotating platform via a column; the rotating mechanism is located at the end of the robotic arm; the rotating mechanism is used to place and launch the ping-pong ball; the rotating mechanism can move above the rotating platform via the robotic arm to allow the ping-pong ball to fall onto the rotating platform; the detection mechanism is located above where the ping-pong ball lands on the rotating platform to detect the center of gravity of the ping-pong ball.

[0005] According to the rotating mechanism provided by the present invention, a ping-pong ball is placed in the rotating mechanism, which will cause the ping-pong ball to rotate. At the same time, the robotic arm brings the rotating mechanism above the rotating platform, and the lifting mechanism moves the rotating mechanism to a set height. At this time, the ping-pong ball is released, and the rotating ping-pong ball will fall onto a smooth horizontal platform and rotate. The axis of rotation of the ping-pong ball must be perpendicular to the platform. At this time, the detection mechanism observes and detects the dynamics of the ping-pong ball. If the ping-pong ball rotates at a fixed point with little wobbling, it indicates that the center of gravity error of the ping-pong ball is small. The principle is that if the center of gravity of the ping-pong ball falls on the axis of rotation, the centrifugal force is zero, and the ping-pong ball will not wobble when rotating. The smaller the error, the less wobbling.

[0006] Preferably, the rotating mechanism includes a first motor, a first gear, a second gear, and a rotating head; the first motor is mounted on the robotic arm, the driving end of the first motor engages with the first gear, the second gear meshes with the first gear, the outward end of the robotic arm is provided with a through hole, the fixed end of the rotating head passes through the through hole and is fixedly engaged with the second gear, and starting the first motor can drive the rotating head to rotate.

[0007] Preferably, the rotating head has a downward-opening storage cavity, and the inner wall of the storage cavity has a countersunk hole. A steel ball is placed in the countersunk hole, and a steel ball limiting ring is set outside the countersunk hole to tighten and limit the steel ball in the countersunk hole.

[0008] Preferably, the rotating mechanism includes a second motor, a rocker arm, and a push rod; the second motor is mounted on the robotic arm, one end of the rocker arm engages with the second motor, and the other end of the rocker arm engages with one end of the push rod; a slitting hole is provided on the fixed end of the rotating head, the slitting hole penetrates the storage cavity, and one end of the push rod extends out of the storage cavity through the slitting hole; a push plate is provided on the end of the push rod extending out of the storage cavity.

[0009] Preferably, the rocker arm includes a rod body, a bearing, and a connecting block; the bottom of the connecting block is fitted onto the top of the push rod to fix the push rod, and the bearing is located on the top of the connecting block; one end of the rod body is provided with a sleeve hole, which is fitted around the bearing, and the other end of the rod body is connected to the drive end of the second motor.

[0010] Preferably, the robotic arm includes a support plate, a third motor, a third gear, and a fourth gear;

[0011] The third motor is mounted on the support plate, the third gear is engaged with the drive end of the third motor, and the fourth gear is fitted onto the upper part of the column and meshes with the third gear.

[0012] Preferably, the lifting mechanism includes a fourth motor, a motor mounting base, a fifth gear, a rack, and a fixing knob;

[0013] The motor mounting base is located at the bottom of the rotating platform, the fourth motor is mounted on the motor mounting base, the fifth gear is mounted on the drive end of the fourth motor, the lower part of the column passes vertically through the rotating platform, the rack is located at the lower part of the column and is perpendicular to the rotating platform, and the fifth gear meshes with the rack; the fixing knob is located at the bottom of the column, and the fixing knob locks or unlocks the motor mounting base by rotation.

[0014] Preferably, the rotating platform includes a tabletop; the upper surface of the tabletop is provided with a smooth panel for the ping-pong ball to rotate.

[0015] Preferably, the bottom of the tabletop is provided with multiple fixed feet and adjustable feet, and the bottom of the fixed feet is connected to the adjustable feet via adjusting screws.

[0016] Preferably, the detection mechanism is a detection camera.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. Place the ping-pong ball in the rotating mechanism and rotate it. At the same time, the robotic arm and lifting mechanism move the ping-pong ball to a suitable height above the rotating platform. Then release the rotating ping-pong ball, which falls onto the rotating platform and continues to rotate. The detection mechanism detects the fluctuation range of the rotating ping-pong ball to determine the deviation of the ping-pong ball's center of gravity, and then sorts out the unqualified ping-pong balls. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a front view of the robotic arm used for detecting the center of gravity of a ping-pong ball.

[0021] Figure 2 This is a rear view of the robotic arm used for detecting the center of gravity of a ping-pong ball.

[0022] Figure 3 This is a side view of the robotic arm used for detecting the center of gravity of a ping-pong ball.

[0023] Figure 4 This is a schematic diagram of the rotating mechanism;

[0024] Figure 5 This is a schematic diagram of a joystick;

[0025] Figure 6 This is a schematic diagram of a robotic arm;

[0026] Figure 7 This is a schematic diagram of the lifting mechanism;

[0027] 1. Rotating platform; 10. Tabletop; 11. Smooth panel; 12. Fixed foot; 13. Adjustable foot; 2. Lifting mechanism; 20. Fourth motor; 21. Motor mounting base; 22. Fifth gear; 23. Rack; 24. Fixed knob; 25. Locking block; 3. Robotic arm; 30. Support plate; 31. Third motor; 32. Third gear; 33. Fourth gear; 34. Connecting mounting base; 4. Detection mechanism; 5. Rotating mechanism; 50. First motor; 51. First gear; 52. Second gear; 53. Rotating head; 530. Storage cavity; 531. Scoring hole; 532. Countersunk hole; 533. Steel ball; 534. Steel ball limit ring; 54. Second motor; 55. Rocker arm; 550. Rod body; 551. Bearing; 552. Connecting block; 553. Sleeve hole; 56. Push rod; 57. Push plate; 6. Column; 7. Ping-pong ball. Detailed Implementation

[0028] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. Many specific details are set forth in the following description to provide a thorough understanding of the present invention; the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0030] like Figures 1-3 As shown, the ping-pong ball center of gravity detection robot according to an embodiment of the present invention may include a rotating platform 1, a lifting mechanism 2, a robotic arm 3, a detection mechanism 4, and a rotating mechanism 5.

[0031] In some optional embodiments, the lifting mechanism 2 is installed at the bottom of the rotating platform 1 and driven to the bottom of the column 6. The top of the column 6 is driven to the robotic arm 3. The lifting mechanism 2 controls the lifting of the column 6, thereby causing the robotic arm 3 to lift. Simultaneously, the robotic arm 3 can rotate along the column 6, allowing it to move the rotating mechanism 5, installed at the end of the robotic arm 3, away from or towards the rotating platform 1. A ping-pong ball 7 is installed in the rotating mechanism 5, which drives the ping-pong ball 7 to rotate and pushes it onto the rotating platform 1. The detection mechanism 4, located above the rotating platform 1, detects the rotation state of the ping-pong ball 7 and checks whether its center of gravity deviation meets the requirements. The purpose is to impart a rotating motion state to the ping-pong ball 7 to be detected, push the rotating ping-pong ball 7 onto a relatively smooth plane, and measure the center of gravity deviation of the ping-pong ball 7. The device measures the mass of a ping-pong ball 7. Compared with the conventional method of measuring the mass by rolling the ping-pong ball 7 on a flat glass plate tilted at a certain angle, this device automatically rotates the ping-pong ball 7, reducing interference such as uneven force provided by the inclined plane during rotation; it automatically releases the ball along the axis of rotation, reducing interference such as additional friction on the ping-pong ball 7 during release or forces not aligned with the axis of rotation when releasing the ping-pong ball 7; and it automatically detects the mass, eliminating the need for judgment by human eyes or experience.

[0032] In further proposals, such as Figure 4 The rotating mechanism 5 shown is installed in the robotic arm 3. Specifically, the rotating mechanism 5 is installed on the support plate 30 of the robotic arm 3. The specific connection and working principle are as follows: The rotating mechanism 5 includes a first motor 50, a first gear 51, a second gear 52, and a rotating head 53. First, a connecting fixing seat 34 is installed on the support plate 30. At the same time, space is reserved between the lower surface of the connecting fixing seat 34 and the upper surface of the support plate 30 for installing the first gear 51 and the second gear 52. The driving end of the first motor 50 is installed downward on the upper surface of the connecting fixing seat 34. The driving end of the first motor 50 passes through the connecting fixing seat 34 and connects with the lower surface of the support plate 30. The first gear 51 engages with the first gear 51, and the second gear 52 is installed on one side of the first gear 51 and meshes with it. The center of the second gear 52 has a through hole. The rotating head 53 can be approximated as a cylinder. Therefore, the rotating head 53 engages with the through hole with the axis as the reference, thereby ensuring that the rotating head 53 can always rotate along the axis when the first motor 50 is started, driven by the first gear 51 and the second gear 52. This also further ensures that when the ping-pong ball 7 is placed in the rotating head 53, the ping-pong ball 7 can always rotate around its own vertical axis through the rotation of the rotating head 53.

[0033] Meanwhile, when the rotating head 53 is connected to the second gear 52, it needs to pass through the support plate 30. Therefore, a through hole is provided on the support plate 30 for the rotating head 53 to pass through. A bearing is installed in the through hole, which can not only fix the rotating head 53, but also make the rotation of the rotating head 53 smoother.

[0034] In a further preferred embodiment, the end of the rotating head 53 facing away from the robotic arm 3 has a cylindrical storage cavity 530. The diameter of the storage cavity 530 is similar to the diameter of the ping-pong ball 7, ensuring that the ping-pong ball 7 can be fully rotated by the rotating head 53 when placed in the storage cavity 530. The inner wall of the storage cavity 530 has multiple evenly spaced countersunk holes 532. Steel balls 533 are installed in the countersunk holes 532, and steel ball retaining rings 534 are installed around the steel balls 533 to fix them in the countersunk holes 532. The steel ball retaining rings 534 can rotate within the storage cavity 530 through the steel balls 533. The purpose of this design is to prevent the ping-pong ball 7 from falling down before it has been fully rotated when placed in the storage cavity 530. By using the steel ball retaining rings 534 to lift and limit the ping-pong ball 7 from below, it allows the ping-pong ball 7 to be fully rotated before being released downwards.

[0035] In further preferred solutions, Figure 5 The rotating mechanism 5 shown also includes a second motor 54, a push rod 56, and a rocker arm 55. The second motor 54 is mounted on one side of the first motor 50 and is a balance wheel connected to one end of the rocker arm 55, driving the rocker arm 55 to swing up and down. In addition, the rotating head 53 has a fully penetrating swivel hole 531 along the axial direction. The push rod 56 passes through the swivel hole 531, and its upper end cooperates with the other end of the rocker arm 55. The lower end of the push rod 56 extends into the receiving cavity 530. During the up and down swing of the rocker arm 55, the push rod 56 will also move up and down. When the push rod 56 moves to the lower position, it will contact the ping-pong ball 7, thereby pushing the spinning ping-pong ball 7 out. At the same time, a push plate 57 is installed at the lower end of the push rod 56 to better contact the ping-pong ball 7 and push it out.

[0036] In a further preferred embodiment, the connection between the rocker arm 55 and the push rod 56 is further optimized. First, the rocker arm 55 includes a rod body 550, a bearing 551, and a connecting block 552. The connecting block 552 is sleeved on the upper end of the push rod 56 and fixedly connected to the push rod 56. At the same time, a connecting rod is provided on the upper part of the connecting block 552, and the bearing 551 is installed on the connecting rod. Second, one end of the rod body 550 cooperates with the balance wheel, and the other end of the rod body 550 is provided with a sleeve hole 553. The sleeve hole 553 is sleeved on the periphery of the bearing 551. When the rod body 550 is lifted by the balance wheel, the sleeve hole 553 of the push rod 56 lifts the bearing 551, and then lifts the push rod 56. When the balance wheel swings down, the sleeve hole 553 of the push rod 56 pushes the bearing 551 downward, and then drives the push rod 56 downward to push the ping-pong ball 7 out.

[0037] In other implementations, such as Figure 6 As shown, the connection between the robotic arm 3 and the column 6 is further optimized. The upper part of the column 6 is connected to the support plate 30 through bearings. The upper end of the column 6 extends through the support plate 30 to the upper surface of the support plate 30. The robotic arm 3 includes a third motor 31, a third gear 32, and a fourth gear 33. The driving end of the third motor 31 is mounted downwards on the upper surface of the connecting fixed seat 34. The driving end of the third motor 31 passes through the connecting fixed seat 34 and is connected to the third gear 32 at the bottom of the connecting fixed seat 34. The fourth gear 33 is installed on the periphery of the extension at the upper end of the column 6. At this time, the third gear 32 and the fourth gear 33 mesh with each other. Since the lifting mechanism 2 at the lower part of the column 6 is engaged, it cannot rotate. When the third motor 31 is started, it rotates along the fourth gear 33 through the third gear 32. The third motor 31 is fixedly connected to the support plate 30 through the connecting fixed seat 34, thus driving the robotic arm 3 to rotate around the column 6. This allows the rotating mechanism 5 located at the end of the support plate 30 to move away from or closer to the rotating platform 1.

[0038] In other implementations, such as Figure 7 The working principle of the lifting mechanism 2 is further optimized as shown. The lifting mechanism 2 includes a fourth motor 20, a motor mounting base 21, a fifth gear 22, a rack 23, and a fixing knob 24. First, the motor mounting base 21 is installed below the platform 10 of the rotating platform 1. The fourth motor 20 is installed on the motor mounting base 21. The fifth gear 22 is engaged with the drive end of the fourth motor 20 and is parallel to the column 6. The lower part of the column 6 extends through the platform 10 to below the platform 10. The rack 23 is installed at the lower part of the column 6 and is parallel to the column 6. At this time, the rack 23 meshes with the fifth gear 22. When the fourth motor 20 starts, it drives the fifth gear 22 to rotate, thereby causing the rack 23 to move up and down. During the reciprocating movement of the rack 23, the column 6 will also move up and down, ultimately achieving the adjustment of the vertical position of the rotating mechanism 5.

[0039] In a further optimization, a locking block 25 is provided next to the rack 23. During the up and down movement of the rack 23, it will move together with the locking block 25, which improves the stability of the column 6 during the movement. At the same time, a fixing knob 24 is provided at the end of the column 6. After the position of the column 6 is adjusted, the fixing knob 24 is rotated to lock the locking point on the rack 23 with the locking block 25, thereby fixing the position of the column 6.

[0040] In other embodiments, a smooth panel 11, which is made of glass, is installed on the table surface 10. When the ping-pong ball 7 rotates on the smooth surface, it will experience less resistance, thereby reducing the influence of the plane on the rotation state of the ping-pong ball 7.

[0041] In other embodiments, fixed feet 12 are provided at the four corners of the bottom of the tabletop 10, and screw holes are provided at the bottom of the fixed feet 12. The fixed feet 12 cooperate with the screws on the adjusting feet 13 through the screw holes. By rotating the adjusting feet 13, the distance between the fixed feet 12 and the adjusting feet 13 is changed, thereby changing the height of the tabletop 10. The height of each of the four corners can be adjusted individually, thereby realizing the function of leveling the tabletop 10.

[0042] In other embodiments, the detection mechanism 4 is a detection camera, which is mounted above the smooth panel 11 via an external bracket to detect the ping-pong ball 7 rotating below.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A robotic arm for detecting the center of gravity of a ping-pong ball, characterized in that, include: Rotating platform, lifting mechanism, robotic arm, inspection mechanism, and rotating mechanism; The rotating platform is located above the lifting mechanism; The robotic arm is mounted on top of the rotating platform via a column. The rotating mechanism is located at the end of the robotic arm and is used to place and launch ping-pong balls. The rotating mechanism allows the ping-pong ball to fall onto the rotating platform as the robotic arm moves above it. The detection mechanism is located above where the ping-pong ball lands on the rotating platform to detect the center of gravity of the ping-pong ball.

2. The ping-pong ball center of gravity detection robot according to claim 1, characterized in that, The rotating mechanism includes a first motor, a first gear, a second gear, and a rotating head; The first motor is mounted on the robotic arm. The driving end of the first motor engages with the first gear, and the second gear meshes with the first gear. The outward-facing end of the robotic arm has a through hole, and the fixed end of the rotating head passes through the through hole and is fixedly engaged with the second gear. Starting the first motor can drive the rotating head to rotate.

3. The ping-pong ball center of gravity detection robot according to claim 2, characterized in that, The rotating head has a storage cavity with an opening facing away from the robotic arm. The inner wall of the storage cavity has a countersunk hole, in which steel balls are placed. A steel ball limiting ring is set outside the countersunk hole, and the steel ball limiting ring tightens and limits the steel balls in the countersunk hole.

4. The ping-pong ball center of gravity detection robot according to claim 3, characterized in that, The rotating mechanism includes a second motor, a rocker arm, and a push rod; The second motor is mounted on the robotic arm. One end of the rocker arm is engaged with the second motor, and the other end of the rocker arm is engaged with one end of the push rod. A swivel hole is provided on the fixed end of the rotating head, and the swivel hole extends into the storage cavity. One end of the push rod extends out of the storage cavity through the swivel hole. A push plate is provided on the end of the push rod that extends out of the storage cavity.

5. The ping-pong ball center of gravity detection robot according to claim 4, characterized in that, The rocker arm includes a rod body, a load-bearing bearing, and a connecting block; The bottom of the connecting block fits onto the top of the push rod to fix the push rod, and the bearing is located on the top of the connecting block; One end of the rod is provided with a sleeve hole, which is fitted around the bearing. The other end of the rod is connected to the drive end of the second motor.

6. The ping-pong ball center of gravity detection robot according to claim 1, characterized in that, The robotic arm includes a support plate, a third motor, a third gear, and a fourth gear; The third motor is mounted on the support plate, the third gear is engaged with the drive end of the third motor, and the fourth gear is fitted onto the upper part of the column and meshes with the third gear.

7. The ping-pong ball center of gravity detection robot according to claim 1, characterized in that, The lifting mechanism includes a fourth motor, a motor mounting base, a fifth gear, a rack, and a fixing knob; The motor mounting base is located at the bottom of the rotating platform, the fourth motor is mounted on the motor mounting base, the fifth gear is mounted on the drive end of the fourth motor, the lower part of the column passes vertically through the rotating platform, the rack is located at the lower part of the column and is perpendicular to the rotating platform, and the fifth gear meshes with the rack; the fixing knob is located at the bottom of the column, and the fixing knob locks or unlocks the motor mounting base by rotation.

8. The ping-pong ball center of gravity detection robot according to claim 1, characterized in that, The rotating platform includes a table surface; The upper surface of the tabletop is provided with a smooth panel for the ping-pong ball to rotate.

9. The ping-pong ball center of gravity detection robot according to claim 8, characterized in that, The bottom of the platform is provided with multiple fixed feet and adjustable feet, and the bottom of the fixed feet is connected to the adjustable feet through adjusting screws.

10. The ping-pong ball center of gravity detection robot according to claim 1, characterized in that, The detection mechanism is a detection camera.

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