Wrist connection structure, robotic arm and robot

Abstract

This application relates to the field of robotics, specifically to a wrist connection structure, a robotic arm, and a robot, which solves the tracking lag problem in SRS-configured robotic arms. The wrist connection structure has a first connection part and a second connection part. The first connection part is connected to a wrist assembly, and the second connection part is connected to an end effector. The first vertical distance between the second connection part and the center point of the second joint is less than the second vertical distance between the center point of the second joint and the second end of the wrist assembly. This means the tool center point is moved to the second connection part, thereby shortening the distance between the center point of the second joint and the tool center point, thus mitigating the tracking lag problem and improving the response speed during teleoperation.

Description

Technical Field

[0001] This application relates to the field of robotics technology, specifically to a wrist connection structure, a robotic arm, and a robot. Background Technology

[0002] In recent years, with the rapid development of artificial intelligence and robotics, humanoid robots have been increasingly widely used in industries such as manufacturing, healthcare, and services. In the design of robotic arms, the spherical-roll-spherical (SRS) configuration has become one of the mainstream designs for humanoid robot arms due to its high degree of freedom and flexibility.

[0003] However, existing SRS-configured robotic arms suffer from tracking hysteresis, leading to a significant increase in response delay during teleoperation. This hysteresis not only reduces operational efficiency but may also pose safety hazards in precision operation scenarios, limiting the application potential of humanoid robots in high-precision tasks. Summary of the Invention

[0004] In view of this, embodiments of this application provide a wrist connection structure, a robotic arm, and a robot, which solves the problem of tracking lag in SRS-configured robotic arms.

[0005] In a first aspect, embodiments of this application provide a wrist connection structure applied to a robot arm. The robot arm includes an upper arm assembly, a forearm assembly, and a wrist assembly. A first end of the upper arm assembly can form a first ball joint with the robot body. A second end of the upper arm assembly is rotatably connected to the first end of the forearm assembly to form a rotary joint. The second end of the forearm assembly and the first end of the wrist assembly form a second ball joint, and the rotation center of the second ball joint is the center point of the second joint. The wrist connection structure has a first connecting portion and a second connecting portion. The first connecting portion is connected to the wrist assembly, and the second connecting portion is connected to an end effector. The first vertical distance between the second connecting portion and the center point of the second joint is less than the second vertical distance between the center point of the second joint and the second end of the wrist assembly.

[0006] In some embodiments, the first connecting portion has a first mounting surface that contacts the end face of the second end of the wrist assembly, and the second connecting portion has a second mounting surface that contacts the end effector. In a plane perpendicular to both the first and second mounting surfaces, a straight line perpendicular to the first mounting surface is a first straight line, and a straight line perpendicular to the second mounting surface is a second straight line. A third vertical distance between the intersection of the first and second straight lines and the first mounting surface is equal to the second vertical distance.

[0007] In some embodiments, the wrist connection structure includes: a first component having a first connecting portion connected to a second end of the wrist assembly; and a second component connected to the first component having the second connecting portion.

[0008] In some embodiments, the first connecting portion is connected to the end face of the second end of the wrist assembly, and the second component includes: a first extension portion, a first end of the first extension portion being connected to the first component, the extension direction of the first extension portion being parallel to the extension direction of the wrist assembly; and a second extension portion, connected to the second end of the first extension portion, the second extension portion having the second connecting portion.

[0009] In some embodiments, the second extension extends toward a direction away from the center point of the second joint, and the angle between the extension direction of the second extension and the extension direction of the first extension is less than 180° and greater than 90°.

[0010] In some embodiments, the angle between the extension direction of the second extension and the extension direction of the first extension is less than or equal to 165° and greater than 90°; and / or, the wrist connection structure further includes: a first reinforcing rib connecting the first extension and the second extension; and / or, the wrist connection structure further includes: a second reinforcing rib connecting the first component and the second component.

[0011] In some embodiments, there is a gap between the first extension and the wrist assembly.

[0012] In some embodiments, the wrist assembly includes at least one first threaded portion and at least one first screwed member, the first connecting portion having at least one first connecting hole, the first threaded portion, the first screwed member and the first connecting hole corresponding one-to-one, the first screwed member abutting against the side of the first connecting portion away from the wrist assembly, and threaded through the corresponding first connecting hole to the corresponding first threaded portion; and / or, the end effector includes at least one second threaded portion and at least one second screwed member, the second connecting portion having at least one second connecting hole, the second threaded portion, the second screwed member and the second connecting hole corresponding one-to-one, the second screwed member abutting against the side of the second connecting portion away from the end effector, and threaded through the corresponding second connecting hole to the corresponding second threaded portion.

[0013] Secondly, embodiments of this application provide a robotic arm, comprising: an upper arm assembly, the first end of which is capable of forming a first ball joint with a robot body; a forearm assembly, the second end of which is rotatably connected to the first end of which is rotatably connected to form a rotary joint; a wrist assembly, the second end of which is connected to the first end of which is rotatably connected to form a second ball joint, the rotation center of which is a second joint center point; the wrist connection structure described in the first aspect, connected to the wrist assembly; and an end effector, connected to the wrist connection structure.

[0014] Thirdly, embodiments of this application provide a robot, including: a robot body; and the robot arm described in the second aspect, connected to the robot body to form a first ball joint.

[0015] The wrist connection structure provided in this application embodiment is applied to a robot arm. The robot arm includes an upper arm assembly, a forearm assembly, and a wrist assembly. The first end of the upper arm assembly can form a first ball joint with the robot body. The second end of the upper arm assembly is rotatably connected to the first end of the forearm assembly to form a rotary joint. The second end of the forearm assembly forms a second ball joint with the first end of the wrist assembly. That is, the robot arm is an SRS configuration.

[0016] In related technologies, the end effector is directly connected to the second end of the wrist assembly, resulting in an excessive distance between the center point of the second joint (i.e., the rotation center of the second ball joint) and the center point of the tool (i.e., the connection position between the end effector and the second end of the wrist assembly). This causes the end effector to require not only the movement of the second ball joint but also the coordinated movement of the first ball joint and the rotary joint when adjusting its attitude, resulting in tracking hysteresis and a significant increase in response delay during teleoperation.

[0017] The wrist connection structure of this application has a first connecting part and a second connecting part. The first connecting part is connected to the wrist assembly, and the second connecting part is connected to the end effector. The first vertical distance between the second connecting part and the center point of the second joint is less than the second vertical distance between the center point of the second joint and the second end of the wrist assembly. That is, the center point of the tool is moved to the second connecting part, thereby shortening the distance between the center point of the second joint and the center point of the tool, reducing the tracking lag problem, and improving the response speed during teleoperation. Attached Figure Description

[0018] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments thereof in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain the application and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same parts.

[0019] Figure 1 The diagram shown is a structural schematic of a robot.

[0020] Figure 2 The diagram shown is a structural schematic of a robot provided in one embodiment of this application.

[0021] Figure 3 The diagram shown is a structural schematic of a robot with its robotic arm in another posture, according to an embodiment of this application.

[0022] Figure 4 The diagram shown is a structural schematic of a robot with its robotic arm in another posture, according to an embodiment of this application.

[0023] Figure 5 The diagram shown is a schematic diagram of a wrist connection structure provided in an embodiment of this application.

[0024] Figure 6 The diagram shown is a structural schematic of a wrist connection structure provided in another embodiment of this application.

[0025] Figure 7 The diagram shown is a structural schematic of a wrist connection structure provided in another embodiment of this application.

[0026] Figure 8 The diagram shown is a schematic diagram of the connection between the wrist connection structure and the wrist component provided in an embodiment of this application.

[0027] Figure 9 The diagram shown is a schematic diagram of the connection between the wrist connection structure and the end effector provided in an embodiment of this application.

[0028] Figure label:

[0029] 10. Robot; 11. Robot body; 12. Robot arm; 121. Upper arm assembly; 122. Forearm assembly; 123. Wrist assembly; 1231. First threaded part; 1232. First screwed connector; 13. End effector; 131. Second threaded part; 132. Second screwed connector;

[0030] 20. Wrist connection structure; 21. First connecting part; 211. First mounting surface; 212. First connecting hole; 22. Second connecting part; 221. Second mounting surface; 222. Second connecting hole; 23. First component; 24. Second component; 241. First extension; 242. Second extension; 25. First reinforcing rib; 26. Second reinforcing rib; D1. First vertical distance; D2. Second vertical distance; D3. Third vertical distance; L1. First straight line; L2. Second straight line; β. Included angle; δ. Gap. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0032] Figure 1 The diagram shown is a structural schematic of a robot. Figure 1 As shown, robot 10 includes a robot body 11 and a robot arm 12. Robot arm 12 includes an upper arm assembly 121, a forearm assembly 122, and a wrist assembly 123. The first end of the upper arm assembly 121 forms a first ball joint with the robot body 11, the second end of the upper arm assembly 121 is rotatably connected to the first end of the forearm assembly 122 to form a rotary joint, and the second end of the forearm assembly 122 forms a second ball joint with the first end of the wrist assembly 123. That is, robot arm 12 has an SRS configuration.

[0033] The wrist assembly 123 needs to house the drive structure and transmission structure of the second ball joint. Therefore, the size of the wrist assembly 123 is relatively large. That is, the second vertical distance D2 from the center point of the second joint (i.e., the rotation center of the second ball joint) to the second end of the wrist assembly 123 (i.e., the tool center point) is relatively large. As a result, when adjusting the attitude of the end effector 13, not only the movement of the second ball joint is required, but also the coordinated movement of the first ball joint and the rotary joint is required, which will produce tracking hysteresis and thus significantly increase the response delay during teleoperation.

[0034] To address the above technical problems, this application is proposed. The wrist connection structure provided in this application is applied to a robotic arm. The robotic arm includes an upper arm assembly, a forearm assembly, and a wrist assembly. The first end of the upper arm assembly can form a first ball joint with the robot body. The second end of the upper arm assembly is rotatably connected to the first end of the forearm assembly to form a rotary joint. The second end of the forearm assembly forms a second ball joint with the first end of the wrist assembly, i.e., the robotic arm has an SRS configuration. The wrist connection structure of this application has a first connecting part and a second connecting part. The first connecting part is connected to the wrist assembly, and the second connecting part is connected to the end effector. The first vertical distance between the second connecting part and the center point of the second joint is less than the second vertical distance between the center point of the second joint and the second end of the wrist assembly. That is, the tool center point is moved to the second connecting part, thereby shortening the distance between the center point of the second joint and the center point of the tool, reducing the tracking lag problem, and improving the response speed during teleoperation.

[0035] Figure 2 The diagram shown is a structural schematic of a robot provided in one embodiment of this application. Figure 2 As shown, the wrist connection structure 20 of this application is applied to robot 10. Robot 10 includes robot body 11 and robot arm 12. Robot arm 12 includes upper arm assembly 121, forearm assembly 122, and wrist assembly 123. The first end of upper arm assembly 121 forms a first ball joint with robot body 11, the second end of upper arm assembly 121 is rotatably connected to the first end of forearm assembly 122 to form a rotary joint, and the second end of forearm assembly 122 forms a second ball joint with the first end of wrist assembly 123. That is, robot arm 12 is an SRS configuration.

[0036] The center of rotation of the second ball joint is the center point of the second joint.

[0037] like Figure 2 As shown, the wrist connection structure 20 has a first connecting part 21 and a second connecting part 22.

[0038] The first connecting part 21 is connected to the wrist assembly 123, and the second connecting part 22 is connected to the end effector 13. The first vertical distance D1 between the second connecting part 22 and the center point of the second joint is less than the second vertical distance D2 between the center point of the second joint and the second end of the wrist assembly 123. That is, the tool center point is moved from the first connecting part 21 to the second connecting part 22, thereby shortening the distance between the center point of the second joint and the center point of the tool, reducing the tracking lag problem, and improving the response speed during teleoperation.

[0039] For example, experimental verification shows that for the same robot arm 12, the second vertical distance D2 is 180mm and the first vertical distance D1 is 75mm. That is, by installing the wrist connection structure 20, the distance between the center point of the second joint and the center point of the tool is shortened by about 60%.

[0040] Experiments have verified that the robot 10 using the wrist connection structure 20 of this application can improve the efficiency of teleoperation data acquisition by 150%, significantly reduce the teaching cost of imitation learning and reinforcement learning, improve the quality of human demonstration data, and facilitate the skill transfer of the robot 10.

[0041] In addition, the robot 10 using the wrist connection structure 20 of this application is widely applicable in sorting scenarios (e.g., the express logistics Demaline requires high-frequency wrist rotation) and fine operations (e.g., pouring water, stirring, etc., which require flexible wrist posture).

[0042] Specifically, the wrist connection structure 20 is a rigid component, which realizes a rigid connection between the wrist assembly 123 and the end effector 13. For example, the end effector 13 can be a gripper, a dexterous hand, a robotic hand, etc.

[0043] Figure 3The diagram shown is a structural schematic of a robot with its robotic arm in another posture, according to an embodiment of this application. Figure 4 The diagram shown is a structural schematic of a robot with its robotic arm in another posture, according to an embodiment of this application. Figures 2 to 4 As shown, the attitude adjustment of the end effector 13 can be achieved by the movement of the second ball joint.

[0044] In addition, during the attitude adjustment of the end effector 13, the forearm assembly 122 and the wrist assembly 123 are not coaxial, that is, the SRS configuration robot arm 12 does not have the problem of Jacobian matrix rank deficiency, which will not cause the effective degree of freedom of the SRS configuration robot arm 12 to decrease, thus eliminating the motion singularity of the SRS configuration robot arm 12.

[0045] In addition, such as Figure 1 As shown, due to the large second vertical distance D2 between the center point of the second joint and the second end of the wrist assembly 123, the... Figure 1 The geometric proportions of the robotic arm 12 in the related technology shown differ significantly from those of the human arm, increasing the learning cost for teleoperation operators. Specifically, the geometric proportions of the upper arm assembly 121 of the robotic arm 12 are approximately equal to those of the human upper arm, and the geometric proportions of the forearm assembly 122 of the robotic arm 12 are approximately equal to those of the human forearm. However, the size of the wrist assembly 123 of the robotic arm 12 (i.e., the second vertical distance D2 between the center point of the second joint and the second end of the wrist assembly 123) is larger than that of the human wrist, resulting in a disproportionate geometric proportion of the robotic arm 12 and increasing the learning cost for teleoperation operators.

[0046] like Figure 3 As shown, the geometric proportions of the upper arm assembly 121 of the robot arm 12 of this application are approximately equal to the geometric proportions of the human upper arm, the geometric proportions of the lower arm assembly 122 of the robot arm 12 are approximately equal to the geometric proportions of the human lower arm, and the first vertical distance D1 between the second connecting part 22 and the center point of the second joint is approximately equal to the size of the human wrist. This makes the geometric proportions of the robot arm 12 of this application approximately equal to the geometric proportions of the human arm, reducing the learning cost for remote operators.

[0047] If the total length of the first vertical distance D1 and the end effector 13 is taken as the length of the end effector of the robot 10, by installing the wrist connection structure 20, the ratio of the length of the forearm assembly to the length of the end effector can reach (1.4~1.6):1, while the ratio of the length of the human forearm to the length of the hand (approximately equal to the sum of the lengths of the human wrist and hand) is approximately 1.5:1. That is, by installing the wrist connection structure 20, the geometric proportion of the robot arm 12 of this application can be approximately equal to the geometric proportion of the human arm.

[0048] Figure 5 The diagram shown is a structural schematic of a wrist connection structure provided in one embodiment of this application. In some embodiments, such as Figure 5 As shown, the first connecting portion 21 has a first mounting surface 211 that contacts the end face of the second end of the wrist assembly 123, and the second connecting portion 22 has a second mounting surface 221 that contacts the end effector 13. On a plane perpendicular to both the first mounting surface 211 and the second mounting surface 221, a straight line perpendicular to the first mounting surface 211 is a first straight line L1, and a straight line perpendicular to the second mounting surface 221 is a second straight line L2. When the wrist connecting structure 20 is mounted on the robot arm 12, both the first straight line L1 and the second straight line L2 pass through the center point of the second joint, and the third vertical distance D3 between the intersection of the first straight line L1 and the second straight line L2 and the first mounting surface 211 is equal to the second vertical distance D2.

[0049] In other words, by making the third vertical distance D3 equal to the second vertical distance D2, when the wrist connection structure 20 is installed on the robot arm 12, the attitude adjustment of the end effector 13 can be achieved solely through the movement of the second ball joint, without the need for the cooperation of the first ball joint and the rotary joint. This reduces the problem of tracking lag and improves the response speed during teleoperation.

[0050] In some embodiments, such as Figure 5 As shown, the wrist connection structure 20 includes a first component 23 and a second component 24. The first component 23 has a first connecting portion 21. The first connecting portion 21 is connected to the second end of the wrist assembly 123. The second component 24 is connected to the first component 23 and has a second connecting portion 22.

[0051] The first connecting part 21 is connected to the second end of the wrist assembly 123, which facilitates the disassembly and installation of the wrist connecting structure 20.

[0052] By way of example, the first component 23 and the second component 24 can be integrally formed or separately provided. The integrally formed first component 23 and the second component 24 facilitate the disassembly and installation of the wrist connection structure 20. The separately provided first component 23 and the second component 24 facilitate manufacturing.

[0053] In some embodiments, the first connecting portion 21 is connected to the end face of the second end of the wrist assembly 123. For example... Figure 5 As shown, the second component 24 includes a first extension 241 and a second extension 242. The first end of the first extension 241 is connected to the first component 23, and the extension direction of the first extension 241 is parallel to the extension direction of the wrist assembly 123, thereby reducing the radial space occupied by the first extension 241 in the wrist assembly 123.

[0054] The second extension 242 is connected to the second end of the first extension 241, and the second extension 242 has a second connecting portion 22. For example, as shown... Figure 5 As shown, the second connecting portion 22 is located at the end of the second extension portion 242 that is away from the first extension portion 241.

[0055] In some embodiments, the second extension 242 extends toward a direction away from the center point of the second joint, and the angle β between the extension direction of the second extension 242 and the extension direction of the first extension 241 is less than 180° and greater than 90°.

[0056] like Figure 1 As shown, in related technologies, the robot arm 12 requires the forearm assembly 122 and wrist assembly 123 to be coaxial in order to keep the end effector 13 in a horizontal state. However, this results in a Jacobian matrix deficiency problem in the SRS configuration of the robot arm 12, leading to a decrease in the degrees of freedom and motion singularities. This application addresses this by ensuring that the angle β between the extension direction of the second extension 242 and the extension direction of the first extension 241 is less than 180° and greater than 90°. Figure 3 When the forearm assembly 122 and wrist assembly 123 are not coaxial, the end effector 13 is in a horizontal state, eliminating motion singularity.

[0057] In some embodiments, the angle β between the extending direction of the second extension 242 and the extending direction of the first extension 241 is less than or equal to 165° and greater than 90°. In practical applications, the angle β between the extending direction of the second extension 242 and the extending direction of the first extension 241 can be adjusted according to actual movement requirements. For example, the angle β can be 165°, 160°, 150°, etc.

[0058] Figure 6 The diagram shown is a structural schematic of a wrist connection structure provided in another embodiment of this application. In some embodiments, such as Figure 6 As shown, the wrist connection structure 20 also includes a first reinforcing rib 25.

[0059] The first reinforcing rib 25 connects the first extension 241 and the second extension 242, thereby improving the connection rigidity of the first extension 241 and the second extension 242.

[0060] For example, the angle β between the extension direction of the second extension 242 and the extension direction of the first extension 241 is less than 180° and greater than 90°, that is, the second extension 242 and the first extension 241 are set at an angle, which facilitates the setting of the first reinforcing rib 25.

[0061] Figure 7The diagram shown is a structural schematic of a wrist connection structure provided in another embodiment of this application. In some embodiments, such as Figure 7 As shown, the wrist connection structure 20 also includes a second reinforcing rib 26.

[0062] The second reinforcing rib 26 connects the first component 23 and the second component 24, thereby increasing the connection stiffness between the first component 23 and the second component 24.

[0063] In some embodiments, such as Figure 2 As shown, there is a gap δ between the first extension 241 and the wrist assembly 123 to prevent interference between the first extension 241 and the wrist assembly 123.

[0064] Figure 8 The diagram shown is a schematic representation of the connection between a wrist connection structure and a wrist assembly according to an embodiment of this application. In some embodiments, such as Figure 8 As shown, the wrist assembly 123 includes at least one first threaded portion 1231 and at least one first screw connector 1232, and the first connecting portion 21 has at least one first connecting hole 212. The first threaded portion 1231, the first screw connector 1232, and the first connecting hole 212 correspond one-to-one. The first screw connector 1232 abuts against the side of the first connecting portion 21 away from the wrist assembly 123, and passes through the corresponding first connecting hole 212 to be screwed onto the corresponding first threaded portion 1231. This connection method is simple, reliable, and easy to disassemble.

[0065] For example, the number of the first threaded portion 1231, the first screw connector 1232 and the first connecting hole 212 can be set according to actual needs, and this application does not make specific limitations.

[0066] In practical applications, the first connecting part 21 may also have structures such as protrusions, threaded holes, and slots to facilitate connection with the wrist assembly 123.

[0067] Figure 9 The diagram shown is a schematic representation of the connection between a wrist connection structure and an end effector according to an embodiment of this application. In some embodiments, such as Figure 9 As shown, the end effector 13 includes at least one second threaded portion 131 and at least one second screwed member 132, and the second connecting portion 22 has at least one second connecting hole 222. The second threaded portion 131, the second screwed member 132, and the second connecting hole 222 correspond one-to-one. The second screwed member 132 abuts against the side of the second connecting portion 22 away from the end effector 13 and passes through the corresponding second connecting hole 222 to be screwed onto the corresponding second threaded portion 131. This connection method is simple, reliable, and easy to disassemble.

[0068] For example, the number of the second threaded portion 131, the second screw connector 132, and the second connecting hole 222 can be set according to actual needs, and this application does not make specific limitations.

[0069] In practical applications, the second connecting part 22 may also have structures such as protrusions, threaded holes, and slots to facilitate connection with the end effector 13.

[0070] One embodiment of this application also provides a robotic arm 12. For example... Figure 2 As shown, the robot arm 12 includes an upper arm assembly 121, a forearm assembly 122, a wrist assembly 123, a wrist connection structure 20, and an end effector 13.

[0071] The first end of the upper arm assembly 121 can form a first ball joint with the robot body 11. The second end of the upper arm assembly 121 is rotatably connected to the first end of the forearm assembly 122 to form a rotary joint. The second end of the forearm assembly 122 forms a second ball joint with the first end of the wrist assembly 123, and the rotation center of the second ball joint is the center point of the second joint. The wrist connection structure 20 is connected to the wrist assembly 123. The end effector 13 is connected to the wrist connection structure 20.

[0072] Since the robotic arm 12 includes a wrist connection structure 20, the robotic arm 12 has all the technical features and effects of the wrist connection structure 20, which will not be described in detail here.

[0073] One embodiment of this application also provides a robot 10. The robot 10 includes a robot body 11 and a robot arm 12.

[0074] The robotic arm 12 is connected to the robot body 11 to form a first ball joint. For example, the robot 10 may be a humanoid robot, a transport robot, a collaborative robot, etc.

[0075] Since robot 10 includes robot arm 12, robot 10 has all the technical features and effects of robot arm 12, which will not be described in detail here.

[0076] The terms "an embodiment" or "embodiment" used in this specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Additionally, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0077] It should be understood that “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest manner, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on top of something” but also “on top of something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0078] Furthermore, for ease of explanation, spatial relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of a component or feature relative to other components or features as shown in the figures. Spatial relative terms are intended to encompass different orientations of components in use or operation other than those shown in the figures. Devices may have other orientations (rotated 90 degrees or in other orientations), and the spatial relative descriptive terms used herein may be interpreted accordingly.

[0079] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0080] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications or equivalent substitutions made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A wrist connection structure characterized by comprising: This invention is applied to a robotic arm, which includes an upper arm assembly, a forearm assembly, and a wrist assembly. The first end of the upper arm assembly can form a first ball joint with the robot body. The second end of the upper arm assembly is rotatably connected to the first end of the forearm assembly to form a rotary joint. The second end of the forearm assembly and the first end of the wrist assembly form a second ball joint. The rotation center of the second ball joint is the center point of the second joint. The wrist connection structure has a first connection part and a second connection part; The first connecting part is connected to the wrist assembly, and the second connecting part is connected to the end effector. The first vertical distance between the second connecting part and the center point of the second joint is less than the second vertical distance between the center point of the second joint and the second end of the wrist assembly.

2. The wrist connection structure according to claim 1, characterized by The first connecting portion has a first mounting surface that contacts the end face of the second end of the wrist assembly, and the second connecting portion has a second mounting surface that contacts the end effector. In a plane perpendicular to both the first and second mounting surfaces, a straight line perpendicular to the first mounting surface is a first straight line, and a straight line perpendicular to the second mounting surface is a second straight line. When the wrist connecting structure is mounted on the robot arm, both the first and second straight lines pass through the center point of the second joint, and the third vertical distance between the intersection of the first and second straight lines and the first mounting surface is equal to the second vertical distance.

3. The wrist connection structure according to claim 1, characterized by include: A first component has the first connecting portion, which is connected to the second end of the wrist assembly; The second component is connected to the first component and has the second connecting portion.

4. The wrist connection structure according to claim 3, characterized in that, The first connecting portion is connected to the end face of the second end of the wrist assembly, and the second component includes: A first extension, a first end of which is connected to the first component, the extension direction of which is parallel to the extension direction of the wrist assembly; The second extension is connected to the second end of the first extension, and the second extension has the second connecting portion.

5. The wrist connection structure according to claim 4, characterized in that, The second extension extends in a direction away from the center point of the second joint, and the angle between the extension direction of the second extension and the extension direction of the first extension is less than 180° and greater than 90°.

6. The wrist connection structure according to claim 5, characterized in that, The angle between the extension direction of the second extension and the extension direction of the first extension is less than or equal to 165° and greater than 90°. And / or, The wrist connection structure also includes: The first reinforcing rib connects the first extension and the second extension; And / or, The wrist connection structure also includes: The second reinforcing rib connects the first component and the second component.

7. The wrist connection structure according to claim 4, characterized in that, There is a gap between the first extension and the wrist assembly.

8. The wrist connection structure according to any one of claims 1 to 7, characterized in that, The wrist assembly includes at least one first threaded portion and at least one first screwed member. The first connecting portion has at least one first connecting hole. The first threaded portion, the first screwed member, and the first connecting hole correspond one-to-one. The first screwed member abuts against the side of the first connecting portion away from the wrist assembly and passes through the corresponding first connecting hole to be screwed into the corresponding first threaded portion. And / or, The end effector includes at least one second threaded portion and at least one second screwed member. The second connecting portion has at least one second connecting hole. The second threaded portion, the second screwed member and the second connecting hole correspond one-to-one. The second screwed member abuts against the side of the second connecting portion away from the end effector and passes through the corresponding second connecting hole to be screwed into the corresponding second threaded portion.

9. A robotic arm, characterized in that, include: The upper arm assembly, wherein the first end of the upper arm assembly is capable of forming a first ball joint with the robot body; The forearm assembly has a second end that is rotatably connected to the first end of the upper arm assembly to form a rotary joint. The wrist assembly has a second ball joint formed by the second end of the forearm assembly and the first end of the wrist assembly, and the rotation center of the second ball joint is the center point of the second joint. The wrist connection structure according to any one of claims 1 to 8 is connected to the wrist assembly; The end effector is connected to the wrist connection structure.

10. A robot, characterized in that, include: Robot body; The robotic arm of claim 9 is connected to the robot body to form a first ball joint.

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