Mechanical arm calibration system

Abstract

The utility model provides a mechanical arm calibration system. The mechanical arm calibration system comprises a mechanical arm; the positioning piece is detachably mounted at the tail end of the mechanical arm, and the positioning piece is used for moving along with the movement of the mechanical arm; the 3D camera is detachably mounted at the tail end of the mechanical arm, and the 3D camera is used for scanning the jig platform; the first image acquisition module is arranged in the first direction and comprises a first camera unit, a second camera unit and a rectangular prism, and the first camera unit is used for acquiring a first image when the positioning piece moves to the first position; the right-angle prism is used for changing the light path of the positioning piece to enable the second camera unit to acquire a second image when the positioning piece moves to the first position; and the second image acquisition module is arranged along a second direction, the second direction is perpendicular to the first direction, and the second image acquisition module is used for acquiring a third image of the positioning piece moving to the second position. According to the mechanical arm calibration system, the debugging time can be saved.

Description

Technical Field

[0001] This application relates to the field of robotics technology, and more particularly to a robotic arm calibration system. Background Technology

[0002] Robotic arms can perform repetitive tasks quickly and accurately, such as assembly and handling, greatly improving production efficiency. In practical applications, due to limitations in processes and mechanical mechanisms, a custom tool coordinate system is often created. This tool coordinate system defines the position of the tool center point (TCP) and the tool's posture. However, during the commissioning of production equipment, jointly calibrating the tool coordinate system with the vision positioning module and the robotic arm is very difficult and challenging. Therefore, there is an urgent need for a system that can quickly and accurately calibrate the tool coordinate system of a robotic arm. Utility Model Content

[0003] In view of this, this application provides a robotic arm calibration system that can quickly calibrate the tool coordinate system of a robotic arm, saving debugging time.

[0004] This application provides a robotic arm calibration system for calibrating the tool coordinate system of a robotic arm. The robotic arm calibration system includes: a robotic arm; a positioning element detachably mounted on the end effector of the robotic arm, the positioning element being used to move as the robotic arm moves; a 3D camera detachably mounted on the end effector of the robotic arm, the 3D camera being used to scan a fixture platform; a first image acquisition module disposed along a first direction, the first image acquisition module including a first camera unit, a second camera unit, and a right-angle prism, the first camera unit being used to acquire a first image when the positioning element moves to a first position, the right-angle prism being used to change the optical path of the positioning element so that the second camera unit acquires a second image when the positioning element moves to the first position; and a second image acquisition module disposed along a second direction, the second direction being perpendicular to the first direction, the second image acquisition module being used to acquire a third image when the positioning element moves to the second position.

[0005] In one embodiment, the first image acquisition module further includes a fixing frame and a calibration fixture. The fixing frame is used to fix the first camera unit, the second camera unit, the right-angle prism and the calibration fixture. When the positioning member moves to the first position, the positioning member is positioned close to the calibration fixture. The plane where the calibration fixture is located is perpendicular to the optical axis of the first camera unit. The calibration fixture is positioned on the incident surface side of the right-angle prism and the second camera unit is positioned on the exit surface side of the right-angle prism.

[0006] In one embodiment, the end of the calibration fixture is provided with a through groove, the groove wall is provided with a reference point, the groove wall faces the direction of the right angle prism, and when the positioning member moves to the first position, the end of the positioning member is received in the groove.

[0007] In one embodiment, the mounting bracket includes a mounting plate and a fixing member, the fixing member being used to limit the first camera unit and the second camera unit on the mounting plate.

[0008] In one embodiment, the height of the first camera unit on the mounting plate is less than the height of the second camera unit on the mounting plate.

[0009] In one embodiment, the fixing frame further includes a connecting rod and a positioning plate. The calibration fixture is perpendicularly connected to one end of the connecting rod. The right-angle prism is mounted on the positioning plate. The positioning plate and the connecting rod are located on the same side of the mounting vertical plate, and the other end of the connecting rod is connected to the mounting vertical plate. The positioning plate is connected to the mounting vertical plate, so that the first camera unit is set to correspond to the incident surface of the right-angle prism, and the second camera unit is set to correspond to the exit surface of the right-angle prism.

[0010] In one embodiment, the end of the positioning member is provided with a first positioning hole, a second positioning hole and a third positioning hole, a first straight line is formed between the first positioning hole and the second positioning hole, a second straight line is formed between the second positioning hole and the third positioning hole, and the first straight line and the second straight line intersect.

[0011] In one embodiment, the second image acquisition module includes a mounting plate, a limiting member, and a third camera unit, wherein the limiting member is used to fix the camera unit on the mounting plate.

[0012] In one embodiment, the first camera unit, the second camera unit, and the third camera unit each include a light source, a lens, and a camera.

[0013] In one embodiment, the first image acquisition module and the second image acquisition module are disposed on at least one side of the fixture platform.

[0014] In summary, the robotic arm calibration system provided in this application, by setting up a robotic arm, a positioning component, a 3D camera, a first image acquisition module, and a second image acquisition module, can quickly acquire three coordinate points on the positioning component to achieve matrix transformation from the image coordinate system to the tool coordinate system, thereby quickly calibrating the tool coordinate system of the robotic arm and saving debugging time. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be considered as a limitation on the scope of protection of this application. In the various drawings, similar components are numbered similarly.

[0016] Figure 1 This is a schematic diagram of the application environment of the robotic arm calibration system in one embodiment of this application.

[0017] Figure 2This is a schematic diagram of the structure of the robotic arm and positioning component provided in an embodiment of this application.

[0018] Figure 3 This is a schematic diagram of the structure of a first image acquisition module provided in an embodiment of this application.

[0019] Figure 4 This is a schematic diagram of the structure of a second image acquisition module provided in an embodiment of this application.

[0020] Figure 5 This is a schematic diagram of the structure of a positioning element provided in an embodiment of this application.

[0021] Figure 6 This is a schematic diagram of the end of the positioning element in one embodiment of this application. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0023] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or may also have an intervening component. When a component is considered to be "placed" on another component, it can be directly placed on the other component or may also have an intervening component. The terms "top," "bottom," "upper," "lower," "left," "right," "front," "back," and similar expressions used in this article are for illustrative purposes only.

[0024] 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 application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0025] Some embodiments will now be described with reference to the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0026] Robotic arms can perform repetitive tasks quickly and accurately, such as assembly and handling, greatly improving production efficiency. In practical applications, due to limitations in processes and mechanical mechanisms, a custom tool coordinate system is often created. This tool coordinate system defines the position of the tool center point (TCP) and the tool's posture. However, during the commissioning of production equipment, jointly calibrating the tool coordinate system with the vision positioning module and the robotic arm is very difficult and challenging. Therefore, there is an urgent need for a system that can quickly and accurately calibrate the tool coordinate system of a robotic arm.

[0027] Therefore, this application provides a robotic arm calibration system that can quickly calibrate the tool coordinate system of a robotic arm, saving debugging time.

[0028] Please see Figure 1 , Figure 1 This is a schematic diagram illustrating the application environment of a robotic arm calibration system provided in one embodiment of this application. The robotic arm calibration system 10 includes a robotic arm 11, a positioning component 12, a 3D camera 13, a first image acquisition module 14, and a second image acquisition module 15. The robotic arm calibration system 10 also includes a processor (not shown), which interacts with the robotic arm 11, the 3D camera 13, the first image acquisition module 14, and the second image acquisition module 15 to achieve overall control of the robotic arm calibration system 10. In some embodiments, the processor may be an independent control device; in other embodiments, the processor may be a processor included within the robotic arm. In this case, the robotic arm 11 interacts with the 3D camera 13, the first image acquisition module 14, and the second image acquisition module 15 to achieve overall control of the robotic arm calibration system 10. Understandably, the robotic arm calibration system 10 provided in this application can be set around the fixture platform 20. Thus, after the robotic arm calibration system calibrates the tool coordinate system of the robotic arm 11, the robotic arm 11 can perform corresponding operations on the workpiece on the fixture platform 20, such as assembly or gripping. The fixture platform 20 can be set on an assembly line.

[0029] Please continue reading. Figure 2 The robotic arm 11 includes a base 111, a robotic arm body 112, and a sensor 113. The base 111 is fixedly mounted on a platform (not shown) to provide support and positioning for the robotic arm 11. The robotic arm body 112 includes several joints and several links, with the joints connecting the links. Understandably, the number of joints affects the degrees of freedom of the robotic arm 11, and this application does not limit the number of joints in the robotic arm 11. In one embodiment of this application, the sensor 113 is located at the end of the robotic arm 11 to achieve fine control. Understandably, the robotic arm 11 also includes a corresponding controller, driver, etc. The controller can control the driver to move the robotic arm 11.

[0030] The positioning element 12 is detachably mounted on the end of the robotic arm 11. In this application, the positioning element 12 is used to simulate an end effector mounted on the end of the robotic arm 11 to assist in the accurate calibration of the tool coordinate system of the robotic arm 11 based on the end effector. Moreover, since the positioning element 12 is located at the end of the robotic arm 11, the positioning element 12 can move with the movement of the robotic arm 11.

[0031] Please refer to it again. Figure 1The 3D camera 13 is detachably mounted on the end effector of the robotic arm. The 3D camera scans the fixture platform 20 to obtain its three-dimensional coordinate information and uploads it to the processor in the robotic arm calibration system 10. The processor can then determine whether the fixture platform 20 is horizontal based on its three-dimensional coordinate information. When the fixture platform 20 is horizontal, the robotic arm 11 adjusts the XY plane of the tool coordinate system according to the obtained three-dimensional coordinate information, making the XY plane of the tool coordinate system parallel to the fixture platform 20. In one embodiment of this application, the 3D camera 13 can be detached after the robotic arm 11 has calibrated the XY plane of the tool coordinate system using the 3D camera 13.

[0032] Please refer to the following: Figure 1 and Figure 3 The first image acquisition module 14 is disposed along a first direction, for example, the first direction may be a direction perpendicular to the plane where the fixture platform 20 is located. The first image acquisition module 14 includes a first camera unit 141, a second camera unit 142, and a right-angle prism 143. The first camera unit 141 is used to acquire a first image when the positioning member 12 moves to a first position, and the right-angle prism 143 is used to change the optical path of the positioning member 12 so that the second camera unit 142 acquires a second image when the positioning member 12 moves to the first position. In the embodiment of this application, by setting the right-angle prism 143, the first camera unit 141 acquires a first image obtained from the bottom when the positioning member 12 moves to the first position, and the second camera unit 142 acquires a second image obtained from the side when the positioning member 12 moves to the first position.

[0033] In some embodiments, the first image acquisition module 141 further includes a mounting bracket 144 and a calibration fixture 145. The mounting bracket 144 is used to fix the first camera unit 141, the second camera unit 142, the right-angle prism 143, and the calibration fixture 145. When the positioning member 12 moves to the first position, the positioning member 12 is positioned close to the calibration fixture 145. The plane of the calibration fixture 145 is perpendicular to the optical axis of the first camera unit 141. The calibration fixture 145 is positioned on the incident surface side of the right-angle prism 143, and the second camera unit 143 is positioned on the exit surface side of the right-angle prism 143. Thus, by setting the right-angle prism 143, the first camera unit 141 and the second camera unit 142 can respectively acquire images of the positioning member 12 at different angles in the first position. Therefore, by obtaining the corresponding image coordinates of the same positioning point in the positioning member 12 through the first and second images, the transformation matrix between the image coordinate system and the robotic arm coordinate system can be easily calculated, thereby achieving tool coordinate system calibration.

[0034] In some embodiments, the end of the calibration fixture 145 has a through groove 1451, and the groove wall 1452 of the groove 1451 is provided with reference points 1453, for example, nine black reference points 1453 forming a 9-square grid. The groove wall 1452 faces the direction of the right-angle prism 143, and when the positioning member 12 moves to the first position, the end of the positioning member 12 is received in the groove 1451. The positioning points are located at the end of the positioning member 12.

[0035] In some embodiments, the mounting bracket 144 includes a mounting vertical plate 1441 and a fixing member 1442. The fixing member 1442 is used to limit the first camera unit 141 and the second camera unit 142 on the mounting vertical plate 1441. The height of the first camera unit 141 on the mounting vertical plate 1441 is less than the height of the second camera unit 142 on the mounting vertical plate 1441.

[0036] In some embodiments, the mounting bracket 144 further includes a connecting rod 1443 and a positioning plate 1444. A calibration fixture 145 is perpendicularly connected to one end of the connecting rod 1443. The right-angle prism 143 is mounted on the positioning plate 1444. The positioning plate 1444 and the connecting rod 1443 are located on the same side of the mounting vertical plate 1441, and the other end of the connecting rod 1443 is connected to the mounting vertical plate 1441. The positioning plate 1444 is connected to the mounting vertical plate 1441, such that the first camera unit 141 is positioned corresponding to the incident surface of the right-angle prism 143, and the second camera unit 142 is positioned corresponding to the exit surface of the right-angle prism 143.

[0037] Please refer to the following: Figure 4 The second image acquisition module 15 is positioned along a second direction, which is perpendicular to the first direction. For example, the second direction could be a direction parallel to the plane containing the fixture platform 20. The second image acquisition module 15 is used to acquire a third image of the positioning member 12 moving to the second position. Thus, the third image can be used to correct the Z-axis of the tool coordinate system.

[0038] In some embodiments, the second image acquisition module 15 includes a mounting plate 151, a limiting member 152, and a third camera unit 153. The limiting member 152 is used to fix the third camera unit 153 onto the mounting plate 151.

[0039] Please refer to the following: Figure 5 and Figure 6In some embodiments, the end of the positioning member 12 is provided with a first positioning hole 121, a second positioning hole 122, and a third positioning hole 123, which together form a positioning point. A first straight line is formed between the first positioning hole 121 and the second positioning hole 122, and a second straight line is formed between the second positioning hole 122 and the third positioning hole 123. The first and second straight lines intersect, forming a triangle when the positions of the three positioning holes are connected. Thus, by providing the first positioning hole 121, the second positioning hole 122, and the third positioning hole 123, the coordinates of the positioning point can be accurately determined in the first and second images using image processing techniques.

[0040] Understandably, in this embodiment, the processor can calculate the X, Y, and Z coordinates of the center point of the product to be assembled in the tool coordinate system based on a preset image processing algorithm, using the first image acquired by the first camera unit 141, the second image acquired by the second camera unit 141, and the positioning points on the positioning member 12. The initial coordinates of the center point of the product to be assembled can be preset in the processor. Then, the processor can also correct the X, Y, and Z coordinates of the center point based on the third image of the positioning member 12 moving to the second position and the reference point 1453. Thus, the robotic arm calibration system 10 provided in this application can calibrate the tool coordinate system of the robotic arm.

[0041] In some embodiments of this application, the first camera unit 141, the second camera unit 142, and the third camera unit 153 each include a light source, a lens, and a camera. The light source is used to illuminate the positioning point. The lens is used to adjust the camera's focal length.

[0042] In some embodiments, the first image acquisition module 14 and the second image acquisition module 15 are disposed on at least one side of the fixture platform 20. This allows for convenient and rapid calibration of the tool coordinate system of the robotic arm.

[0043] Understandably, the robotic arm calibration system 10 provided in this application can conveniently acquire the first image, the second image and the third image based on the first camera unit 141, the second camera unit 142 and the third camera unit 153, thereby simplifying the calibration process and reducing debugging time.

[0044] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A robotic arm calibration system for calibrating the tool coordinate system of a robotic arm, characterized in that, The robotic arm calibration system includes: robotic arm; A positioning element is detachably mounted on the end of the robotic arm, and the positioning element is used to move as the robotic arm moves; A 3D camera is detachably mounted at the end of the robotic arm, and the 3D camera is used to scan the fixture platform; A first image acquisition module is set along a first direction. The first image acquisition module includes a first camera unit, a second camera unit, and a right-angle prism. The first camera unit is used to acquire a first image when the positioning member moves to a first position. The right-angle prism is used to change the optical path of the positioning member so that the second camera unit can acquire a second image when the positioning member moves to the first position. A second image acquisition module is set along a second direction, which is perpendicular to the first direction. The second image acquisition module is used to acquire a third image of the positioning element moving to a second position.

2. The robotic arm calibration system according to claim 1, characterized in that, The first image acquisition module further includes a fixing frame and a calibration fixture. The fixing frame is used to fix the first camera unit, the second camera unit, the right-angle prism and the calibration fixture. When the positioning member moves to the first position, the positioning member is positioned close to the calibration fixture. The plane of the calibration fixture is perpendicular to the optical axis of the first camera unit. The calibration fixture is positioned on the incident surface side of the right-angle prism, and the second camera unit is positioned on the exit surface side of the right-angle prism.

3. The robotic arm calibration system according to claim 2, characterized in that, The calibration fixture has a through groove at its end, and the groove wall is provided with a reference point. The groove wall faces the direction of the right angle prism, and when the positioning member moves to the first position, the end of the positioning member is received in the groove.

4. The robotic arm calibration system according to claim 2, characterized in that, The mounting frame includes a mounting plate and a fixing member, the fixing member being used to limit the first camera unit and the second camera unit on the mounting plate.

5. The robotic arm calibration system according to claim 4, characterized in that, The height of the first camera unit on the mounting plate is less than the height of the second camera unit on the mounting plate.

6. The robotic arm calibration system according to claim 4, characterized in that, The mounting bracket further includes a connecting rod and a positioning plate. The calibration fixture is perpendicularly connected to one end of the connecting rod. The right-angle prism is mounted on the positioning plate. The positioning plate and the connecting rod are located on the same side of the mounting vertical plate, and the other end of the connecting rod is connected to the mounting vertical plate. The positioning plate is connected to the mounting vertical plate, such that the first camera unit is set corresponding to the incident surface of the right-angle prism, and the second camera unit is set corresponding to the exit surface of the right-angle prism.

7. The robotic arm calibration system according to claim 1, characterized in that, The end of the positioning member is provided with a first positioning hole, a second positioning hole and a third positioning hole. A first straight line is formed between the first positioning hole and the second positioning hole, and a second straight line is formed between the second positioning hole and the third positioning hole. The first straight line and the second straight line intersect.

8. The robotic arm calibration system according to claim 1, characterized in that, The second image acquisition module includes a mounting plate, a limiting member, and a third camera unit. The limiting member is used to fix the third camera unit on the mounting plate.

9. The robotic arm calibration system according to claim 8, characterized in that, The first camera unit, the second camera unit, and the third camera unit all include a light source, a lens, and a camera.

10. The robotic arm calibration system according to claim 1, characterized in that, The first image acquisition module and the second image acquisition module are disposed on at least one side of the fixture platform.

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