Novel three-degree-of-freedom flexible bionic wrist mechanism and posture adjusting method
By designing a new three-degree of freedom flexible bionic wrist mechanism, using a spherical parallel structure and arc-shaped connecting rod, the problem of limited movement of the traditional robotic arm wrist is solved, and higher operating flexibility and stability are achieved, and it is suitable for multi-degree of movement in complex environments.
Patent Information
- Application Number
- CN202510707035.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-29
- Publication Date
- 2025-08-01
AI Technical Summary
The movement of traditional robotic arm wrist mechanisms is limited, and cannot achieve large-scale rotation or extreme angle rotation in complex environments, limiting the robot's operating capabilities, especially in narrow spaces or when precision operation is required.
A new three-degree-of-freedom flexible bionic wrist mechanism was designed, adopting a spherical parallel structure, and three-dimensional spatial motion was achieved through the combination of three connecting rods and arc-shaped connecting rods, with high flexibility and stability, including base, connecting rods and connecting platform, and the composite motion of arc-shaped connecting rods provides a larger range of freedom of movement.
It improves the operation flexibility and stability of the robot wrist in three-dimensional space, and can achieve accurate movement in multiple directions in complex environments, and is suitable for complex dynamic tasks and space-constrained environments.
Smart Images
Figure CN120395972A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure belongs to the field of robotic mechanism, and particularly relates to a novel three-degree-of-freedom flexible bionic wrist mechanism and an angle adjustment method. Background Art
[0002] Bionics is a discipline that studies the structure, functional principles, and behavioral patterns of organisms, extracts adaptive features therefrom, and transforms them into engineering technology solutions. Its essence is biological inspiration and engineering reconstruction. The human wrist achieves three-degree-of-freedom movement and passive flexibility through the precise cooperation of the radius, ulna, carpal bones, and ligaments.
[0003] Traditional robotic arms usually rely on rigid joints. These rigid connections limit the movement of the robotic arm. Especially in tasks that require interaction with complex environments, the movement range of the wrist mechanism is limited, the rotation angle is restricted, and it cannot cover a wider operating space. In scenarios that require large-range rotation or extreme-angle rotation, these wrist mechanisms often cannot complete certain operations that require extreme rotation, limiting the operating ability of the robot. For example, when rotating in a narrow space, performing interleaved actions, or carrying out precise operations, traditional wrists often cannot provide sufficient rotation angles, resulting in restricted task execution and difficulty in completing more difficult operations. Summary of the Invention
[0004] In view of the above, it is necessary to provide a novel three-degree-of-freedom flexible bionic wrist mechanism and an attitude adjustment method that can move freely in any direction.
[0005] The present disclosure first provides a novel three-degree-of-freedom flexible bionic wrist mechanism, including:
[0006] A base;
[0007] At least three connecting rods, the connecting rod includes a first sub-rod and a second sub-rod. One end of the first sub-rod is rotatably connected to the base around a first central axis, and the other end is rotatably connected to one end of the second sub-rod around a second central axis;
[0008] A connecting platform, including a rotation center. The connecting platform is rotatably connected to the other end of the second sub-rod around a third central axis, and the distances from the connection point of the second sub-rod to the rotation center are the same;
[0009] Wherein, the first central axis, the second central axis, and the third central axis all pass through the rotation center.
[0010] According to the novel three-degree-of-freedom flexible bionic wrist mechanism, a first angle between the first central axis and the second central axis is half of a second angle between the second central axis and the third central axis. Preferably, the first angle is 45°, and the second angle is 90°.
[0011] According to the novel three - degree - of - freedom flexible bionic wrist mechanism, the first sub - rods of multiple said connecting rods are coaxially connected to the base. At least one of the first sub - rod and the second sub - rod is a "C" - shaped arc rod, or at least one of the first sub - rod and the second sub - rod is a "C" - shaped arc rod formed by connecting multiple rods end to end.
[0012] According to the novel three - degree - of - freedom flexible bionic wrist mechanism, the second sub - rod is connected to the side of the connecting platform, and the connection points of the second sub - rod are evenly distributed along the circumferential direction around the rotation center.
[0013] According to the novel three - degree - of - freedom flexible bionic wrist mechanism, the connecting platform has multiple mounting holes.
[0014] In addition, the present disclosure also provides a posture adjustment method applied to the novel three - degree - of - freedom flexible bionic wrist mechanism, and the method includes:
[0015] At least one first sub - rod rotates relative to other first sub - rods;
[0016] The first sub - rod drives the connecting platform to rotate around the rotation center through the second sub - rod, and adjusts the inclination angle of the connecting platform.
[0017] According to the posture adjustment method, it further includes:
[0018] If multiple first sub - rods rotate synchronously, multiple said first sub - rods drive the connecting platform to rotate around the first central axis through the second sub - rod, and adjust the angle of the connecting platform.
[0019] Compared with the prior art, the above - mentioned novel three - degree - of - freedom flexible bionic wrist mechanism and posture adjustment method are connected between the base and the connecting platform through at least three connecting rods. Since the first central axis, the second central axis, and the third central axis all pass through the rotation center of the connecting platform, a three - degree - of - freedom spherical parallel mechanism is formed, thus having an ideal three - dimensional space motion ability. This geometric constraint condition ensures the stability and precision of the structure, enabling the entire wrist mechanism to maintain high - efficiency and reliable performance in complex operations, having higher flexibility in three - dimensional space. Compared with traditional wrists with fewer degrees of freedom, it can achieve more precise motions in more directions, significantly improving operation flexibility, and is suitable for complex dynamic tasks and space - limited environments. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] To more clearly illustrate the specific embodiments, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.
[0021] Figure 1 It is a schematic structural diagram of a novel three-degree-of-freedom flexible bionic wrist mechanism.
[0022] Figure 2 It is a schematic structural diagram of the base and the first sub-bar.
[0023] Figure 3 It is a schematic structural diagram of the base and the connecting rod.
[0024] Figure 4 It is a schematic structural diagram of the novel three-degree-of-freedom flexible bionic wrist mechanism in another embodiment.
[0025] Figures 5-7 It is a schematic structural diagram of the novel three-degree-of-freedom flexible bionic wrist mechanism applied to a grasping robotic arm.
[0026] Main element symbol description:
[0027] 10 - Base; 20 - Connecting rod; 21 - First sub-bar; 22 - Second sub-bar; 30 - Connecting platform; O1 - First central axis; O2 - Second central axis; O3 - Third central axis; O - Rotation center;
[0028] 100 - Robotic arm; 200 - Bionic wrist mechanism; 300 - Mechanical claw; 400 - Sphere.
[0029] The following specific embodiments will further illustrate the present disclosure in conjunction with the above-mentioned accompanying drawings. Specific embodiments
[0030] In order to more clearly understand the above-mentioned objects, features, and advantages of the present disclosure, the present disclosure will be described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. In the following description, many specific details are set forth to fully understand the present disclosure. The described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present disclosure without creative efforts fall within the scope of protection of the present disclosure.
[0031] 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 disclosure pertains. The terms used in the description of the present disclosure are for the purpose of describing specific embodiments only and are not intended to limit the present disclosure.
[0032] In various embodiments, for the convenience of description rather than limitation of the present disclosure, the term "connection" used in the specification and claims of the present patent application is not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "below", "left", "right", etc. are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship also changes accordingly.
[0033] Figure 1 is a schematic structural diagram of a novel three - degree - of - freedom flexible bionic wrist mechanism. As Figure 1 shown, the novel three - degree - of - freedom flexible bionic wrist mechanism includes a base 10, at least three connecting rods 20, and a connecting platform 30. The connecting rods 20 are connected between the base 10 and the connecting platform 30. By adjusting the angles between the connecting rods 20, the connecting platform 30 is driven to adjust the tilt angle of the connecting platform 30 in three degrees of freedom (i.e., rotation about the X, Y, and Z axes), as well as the overall rotation of the connecting platform 30.
[0034] Figure 2 is a schematic structural diagram of the base 10 and the first sub - rod 21. Figure 3 is a schematic structural diagram of the base 10 and the connecting rod 20. As Figures 1-3 shown, in this embodiment, the wrist mechanism includes three connecting rods 20. Each connecting rod 20 includes a first sub - rod 21 and a second sub - rod 22. The bottom end of the first sub - rod 21 is rotatably connected to the base 10 around the first central axis O1. In this embodiment, the three first sub - rods 21 are coaxially rotatably connected to the base 10, but each first sub - rod 21 can independently rotate relative to the base 10 around the first central axis O1. In this way, the first sub - rods 21 of the connecting rods 20 can achieve free rotation within a certain angle range, allowing the wrist to rotate and turn within a certain range, enhancing the flexibility of movement.
[0035] The base 10 is the basic support part of the wrist mechanism, bearing the weight of the entire structure and providing a stable fixing platform. The base 10 can be provided with multiple mounting interfaces, which can facilitate the docking of the wrist mechanism with other robots or devices, adapt to different application scenarios, and ensure that there is no loosening or deviation during long-term operation. The design of the base 10 takes into account weight reduction while ensuring strength, reducing unnecessary volume. The connecting platform 30 is an important execution component in the three-degree-of-freedom flexible bionic wrist mechanism and is used to connect the manipulator. It is connected to the central connecting piece through rotating pairs with multiple degrees of freedom, capable of bearing the weight of the manipulator and providing stable support for it.
[0036] As Figure 1 and Figure 3 shown, the top end of the first sub-rod 21 is rotatably connected to the second sub-rod 22 around the second central axis O2. The other end of the second sub-rod 22 relative to the first sub-rod 21 is rotatably connected around the third central axis O3. At least one of the first sub-rod 21 and the second sub-rod 22 is a "C"-shaped arc rod. In this embodiment, both the first sub-rod 21 and the second sub-rod 22 are arc structures protruding outward.
[0037] During operation, through the composite motion mode of the arc link formed by the first sub-rod 21 and the second sub-rod 22, the synthetic motion output of the connecting platform 30 can be effectively achieved. This arc link can not only move flexibly in all directions, but also its unique arc structure can ensure the coordinated work between each kinematic pair when transmitting motion, effectively avoiding the common jamming phenomenon in traditional designs, thereby improving the smoothness and stability of the motion.
[0038] Furthermore, the arc link can also achieve the free movement of the end effector in any direction, which fully meets the design requirements of three degrees of freedom. Compared with the limited motion mode of traditional mechanical wrists, the arc link can provide a larger range of motion degrees of freedom, ensuring that the wrist can perform multi-dimensional and high-precision operation tasks. For example, in complex assembly operations, the end effector can flexibly adjust its posture according to requirements to better adapt to the shape and position of the workpiece and achieve more precise operations. Even further, the use of the arc link not only increases the motion degrees of freedom, but also shows significant advantages in mechanical properties. Due to its curved structure, the arc link can evenly distribute the load during bearing, avoiding the local stress concentration phenomenon that occurs in traditional straight links when transmitting large loads. In contrast, the arc link can more effectively share the force transmission, reducing the structural deformation or instability problems caused by uneven load distribution. Therefore, the arc link can provide stronger load-bearing capacity, ensuring that the wrist mechanism can still maintain stable and precise motion when performing high-load tasks.
[0039] The connecting platform 30 is generally in a flat plate structure, preferably a disc structure, and has a plurality of mounting holes for docking other components. The connecting platform 30 has a rotation center. During the working process, the connecting platform 30 rotates around the rotation center O. The connection points of the second sub-rods 22 are evenly distributed along the circumferential direction around the rotation center O, and the distances from the connection points of the second sub-rods 22 to the rotation center O are the same. In this embodiment, the second sub-rods 22 are connected to the side surface of the connecting platform 30 and do not occupy the space of the connecting platform 30.
[0040] The first central axis O1, the second central axis O2, and the third central axis O3 all pass through the rotation center O. The first included angle α1 between the first central axis O1 and the second central axis O2 is half of the second included angle α2 between the second central axis O2 and the third central axis O3. Preferably, the first included angle α1 is 45°, and the second included angle α2 is 90°. These angles and geometric relationships ensure that the wrist mechanism forms a spherical parallel mechanism with three degrees of freedom, thereby possessing an ideal three-dimensional space motion ability, ensuring the stability and precision of the structure, enabling the entire wrist mechanism to maintain high efficiency and reliable performance in complex operations, providing a spherical motion with three degrees of freedom to meet the requirements of multi-degree-of-freedom motion. This flexible design enables the mechanism to adapt to different projects, not only improving the adaptability of the structure but also reducing the manufacturing complexity.
[0041] When the first sub-rod 21 rotates, the first sub-rod 21 pushes and pulls the connecting platform 30 through the second sub-rod 22 to achieve the rotation of the connecting platform 30 around the XYZ coordinate axes.
[0042] Figure 4 It is a schematic structural diagram of a novel three-degree-of-freedom flexible bionic wrist mechanism in another embodiment. As Figure 4 shown, at least one of the first sub-rods 21 and the second sub-rods 22 is a "C"-shaped arc rod formed by connecting multiple segments of rods end to end. Therefore, the shapes of the first sub-rods 21 and the second sub-rods 22 can be a "C"-shaped structure formed by multiple segments of lines or a "C"-shaped structure formed by arc bending.
[0043] The following details an attitude adjustment method implemented based on the above novel three-degree-of-freedom flexible bionic wrist mechanism. The method includes the following steps:
[0044] Step 1: At least one first sub-rod 21 rotates around the first central axis O1 relative to other first sub-rods 21.
[0045] Step 2: The first sub-rod 21 drives the connecting platform 30 to rotate around the rotation center O through the second sub-rod 22 to adjust the inclination angle of the connecting platform 30.
[0046] Step 3: If multiple first sub-rods 21 rotate synchronously, the multiple first sub-rods 21 drive the connection platform 30 to rotate around the first central axis O1 through the second sub-rod 22, and the angle of the connection platform 30 is adjusted.
[0047] Figures 5-7 It is a schematic structural diagram of a novel three-degree-of-freedom flexible bionic wrist mechanism applied to a grasping manipulator 100. As Figure 5 shown, in the normal state, the base 10 is connected to the manipulator 100, and the connection platform 30 is connected to the gripper 300. In this way, the manipulator 100 can connect the gripper 300 through the novel three-degree-of-freedom flexible bionic wrist mechanism 200, and the sphere 400 can be grasped through the gripper 300.
[0048] As Figure 6 shown, when one of the connecting rods 20 rotates, the first sub-rod 21 pushes and pulls the connection platform 30 through the second sub-rod 22, and the connection platform 30 rotates around the XYZ coordinate axes to adjust the posture of the connection platform 30, realizing the upward tilting action of the gripper 300;
[0049] As Figure 7 shown, when one of the connecting rods 20 rotates, the first sub-rod 21 pushes and pulls the connection platform 30 through the second sub-rod 22, and the connection platform 30 rotates around the XYZ coordinate axes to adjust the posture of the connection platform 30, realizing the downward tilting action of the gripper 300.
[0050] The above-mentioned flexible bionic wrist mechanism 200 adopts a spherical parallel structure, which simplifies the design of the mechanism, enables the entire system to have higher compactness while meeting the requirements of multi-degree-of-freedom motion. At the same time, it also reduces the number and complexity of moving parts, thereby improving the operation convenience, effectively avoiding the problem of link jamming that may occur in the traditional parallel structure. The arc-shaped link can also improve the trajectory continuity of the moving platform by adjusting the curvature parameters, thus ensuring the smoothness and stability of the movement process. Moreover, the above-mentioned flexible bionic wrist mechanism 200 has good load-bearing capacity, enabling the load to be more evenly distributed on multiple support points, thereby effectively enhancing the rigidity and stability of the overall system.
[0051] The above-mentioned novel three-degree-of-freedom flexible bionic wrist mechanism and attitude adjustment method are connected between the base 10 and the connection platform 30 through at least three connecting rods 20. Since the first central axis O1, the second central axis O2, and the third central axis O3 all pass through the rotation center O of the connection platform 30, a three-degree-of-freedom spherical parallel mechanism is formed, thus possessing ideal three-dimensional space motion ability. This geometric constraint condition ensures the stability and accuracy of the structure, enabling the entire wrist mechanism to maintain efficient and reliable performance in complex operations, with higher flexibility in three-dimensional space. Compared with traditional wrists with fewer degrees of freedom, it can achieve precise motions in more directions, significantly improving operation flexibility, and is suitable for complex dynamic tasks and space-constrained environments.
[0052] For those skilled in the art, it is obvious that the present disclosure is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present disclosure, the present disclosure can be implemented in other specific forms. Therefore, from any perspective, the embodiments should be regarded as exemplary and non-limiting. The scope of the present disclosure is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be encompassed within the present disclosure. In addition, it is obvious that the term "including" does not exclude other units or steps, and the singular does not exclude the plural. Words such as "first" and "second" are used to denote names and do not indicate any specific order.
[0053] The above embodiments are only used to illustrate the technical solutions of the present disclosure and not to limit them. Although the present disclosure has been described in detail with reference to the above preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present disclosure can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present disclosure.
Claims
1. A novel three-degree-of-freedom flexible bionic wrist mechanism, characterized in that, Comprising: Base; At least three connecting rods, the connecting rods comprising a first sub-rod and a second sub-rod, one end of the first sub-rod being rotatably connected to the base about a first central axis, and the other end being rotatably connected to one end of the second sub-rod about a second central axis; Connecting platform, including a rotation center, the connecting platform being rotatably connected to the other end of the second sub-rod about a third central axis, the distances from the connection point of the second sub-rod to the rotation center being the same; Wherein, the first central axis, the second central axis and the third central axis all pass through the rotation center.
2. The novel three-degree-of-freedom flexible bionic wrist mechanism according to claim 1, characterized in that, A first included angle between the first central axis and the second central axis is half of a second included angle between the second central axis and the third central axis.
3. The novel three-degree-of-freedom flexible bionic wrist mechanism according to claim 2, characterized in that, The first included angle is 45°, and the second included angle is 90°.
4. The novel three-degree-of-freedom flexible bionic wrist mechanism according to claim 1, characterized in that, The first sub-rods of multiple said connecting rods are coaxially connected to the base.
5. The novel three-degree-of-freedom flexible bionic wrist mechanism according to claim 1, wherein At least one of the first sub-rod and the second sub-rod is a "C"-shaped arc rod.
6. The novel three-degree-of-freedom flexible bionic wrist mechanism according to claim 1, characterized in that, At least one of the first sub-rod and the second sub-rod is a "C"-shaped arc rod formed by connecting multiple segments end to end.
7. The novel three-degree-of-freedom flexible bionic wrist mechanism according to claim 1, characterized in that, The second sub-rod is connected to the side surface of the connecting platform, and the connection points of the second sub-rod are evenly distributed along the circumferential direction around the rotation center.
8. The novel three-degree-of-freedom flexible bionic wrist mechanism according to claim 7, characterized in that, The connecting platform has a plurality of mounting holes.
9. A posture adjustment method, characterized in that, Applied to the novel three-degree-of-freedom flexible bionic wrist mechanism as claimed in claim 1, the method comprises: At least one first sub-rod rotates relative to other first sub-rods; The first sub-rod drives the connecting platform to rotate around the rotation center through the second sub-rod, and adjusts the inclination angle of the connecting platform.
10. The attitude adjustment method according to claim 9, wherein, Further comprising: If multiple first sub-rods rotate synchronously, multiple said first sub-rods drive the connecting platform to rotate around the first central axis through the second sub-rod, and adjust the angle of the connecting platform.