Three-degree-of-freedom parallel mechanism and robot
By using a three-degree-of-freedom parallel mechanism, the problems of insufficient degrees of freedom and excessive size of the robot's ankle and wrist joints are solved, enabling flexible and diverse movements and optimized torque distribution, thereby improving the robot's adaptability and stability in complex environments.
Patent Information
- Application Number
- CN202423099586.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-16
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2034-12-16
AI Technical Summary
Existing robotic ankle and wrist joint structures have limited degrees of freedom, resulting in a restricted range of motion. Furthermore, the serial structure is large in size, does not conform to human body dimensions, affects balance and stability, makes it difficult to adapt to complex terrain, and has poor torque distribution under load and disturbance.
It adopts a three-degree-of-freedom parallel mechanism, including two movable plates, three telescopic drive components, six universal joints and support rods, and uses ball joints to achieve multi-degree-of-freedom movement of the ankle and wrist joints. The parallel structure is compact and can optimize force and torque distribution.
It enables flexible and diverse movements of the robot's ankle and wrist joints, improves the biomimicry and control precision, and enhances the robot's adaptability and stability in complex environments, as well as the smoothness of its movements.
Smart Images
Figure CN223643698U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of humanoid robot technology, and in particular relates to a three-degree-of-freedom parallel mechanism and robot. Background Technology
[0002] The human ankle joint is a complex joint composed of the tibia, fibula, and talus, containing multiple degrees of freedom, mainly involving dorsiflexion and plantarflexion, internal and external rotation, and pronation and dorsiflexion of the foot. The human wrist joint is a complex joint composed of the radiocarpal joint, intercarpal joints, and carpometacarpal joints, typically having three degrees of freedom: flexion and extension, lateral tilt, and rotation.
[0003] The existing ankle and wrist joint structures of robots have the following shortcomings:
[0004] 1) With fewer degrees of freedom, typically only one or two, it is difficult to mimic the range of motion of the human ankle and wrist joints. This limited range of motion results in poor balance and stability performance of the robot's feet and hands, making it difficult for the robot to adapt to complex terrain.
[0005] 2) Generally, it is a series structure. Although it has the advantages of simple structure and easy control and programming, its size is relatively large and does not conform to the size of the legs and arms of normal adults. At the same time, each joint in a series structure affects the next joint, and the movement in a series structure is not as smooth as in other structures, which may lead to poor task smoothness. Series structures also have difficulty achieving optimal force and torque distribution when dealing with uneven loads or external disturbances. Summary of the Invention
[0006] To address the issues of limited degrees of freedom in the ankle and wrist joints of existing robots and the large size of serial structures, this invention provides a miniaturized three-degree-of-freedom parallel mechanism and robot.
[0007] The technical solution of this utility model is as follows:
[0008] This invention provides a three-degree-of-freedom parallel mechanism that can serve as both an ankle joint and a wrist joint structure for a robot. It includes two movable plates, three telescopic drive members positioned between the two movable plates, several universal joints, and a support rod. One end of each universal joint is connected to a movable plate, and the other end is connected to a telescopic drive member. The support rod is positioned between the three telescopic drive members, with a ball joint at one end and a fixed connection at the other end to one of the movable plates. The ball joint connects to the other movable plate.
[0009] Furthermore, the ball joint includes a spherical portion and a concave portion, the concave portion being fixed to one of the movable plates, and the spherical portion being movably disposed within the concave portion.
[0010] Furthermore, the telescopic drive includes a telescopic rod and a driver, the driver driving the telescopic rod.
[0011] Furthermore, the universal joint includes a first support, a second support, and a cross shaft. The first support and the second support are respectively connected to the cross shaft, and both the first support and the second support rotate around the cross shaft.
[0012] Furthermore, the movable plate can be any one of a polygon, a quadrilateral, or a circle.
[0013] Furthermore, the driver is a linear motor or a hydraulic cylinder.
[0014] Furthermore, one end of the first support is connected to the movable plate, one end of the second support is connected to the telescopic drive, and the other ends of the first support and the second support are connected to the cross shaft.
[0015] This utility model also provides a robot, including the above-mentioned three-degree-of-freedom parallel mechanism.
[0016] The beneficial effects of this utility model are as follows:
[0017] The system consists of two movable plates, with three telescopic drive components, a universal joint, and a support rod positioned between them. During extension and retraction, the telescopic drive components rotate the universal joint at any angle. Simultaneously, the movable plates can tilt forward and backward, swing left and right, and rotate in a plane, achieving three degrees of freedom of motion. Furthermore, its parallel structure allows for optimal force and torque distribution. Additionally, a ball joint at one end of the support rod assists in transmitting a small torque during tilting, swinging, and rotation, ensuring smooth movement of the overall structure. During rotation in a plane, the ball joint allows for a wide range of rotation. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the overall structure of a three-degree-of-freedom parallel mechanism according to the present invention;
[0019] Figure 2 This is an exploded structural diagram of a three-degree-of-freedom parallel mechanism according to the present invention;
[0020] Figure 3 This is an exploded structural diagram of the universal joint of a three-degree-of-freedom parallel mechanism according to this utility model;
[0021] Figure 4 This is a schematic diagram of the ankle joint being stretched downwards in Embodiment 1 of this utility model;
[0022] Figure 5 This is a schematic diagram of the ankle joint turning outward in Embodiment 1 of this utility model;
[0023] Figure 6 This is a schematic diagram of the inward rotation of the ankle joint in Embodiment 1 of this utility model;
[0024] Figure 7 This is a schematic diagram of the bending towards the palm direction in Embodiment 2 of this utility model;
[0025] Figure 8 This is a schematic diagram of the palm rotating inward in Embodiment 2 of this utility model;
[0026] Figure 9 This is a schematic diagram of the palm turning downwards and inwards in Embodiment 2 of this utility model;
[0027] Reference numerals: 1. Movable plate; 2. Telescopic drive component; 21. Telescopic rod; 22. Driver; 2a. First telescopic drive component; 2b. Second telescopic drive component; 2c. Third telescopic drive component; 3. Universal joint; 31. First support; 32. Second support; 33. Cross shaft; 4. Support rod; 5. Ball joint; 51. Spherical part; 52. Concave part. Detailed Implementation
[0028] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.
[0029] It should be understood that in the description of this utility model, "at least two" means two or more, unless otherwise explicitly specified.
[0030] Furthermore, the terms "both sides," "middle," "upper," "both ends," "parallel to each other," "perpendicular to each other," "inner," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0031] It should be noted that the terms "first," "second," "third," "fourth," and "fifth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature specified with "first," "second," "third," "fourth," "fifth," etc., may explicitly or implicitly include one or more of that feature. Example 1
[0032] Please refer to Figures 1-3 This utility model provides a three-degree-of-freedom parallel mechanism as the ankle joint of a robot, including two movable plates 1, three telescopic drive members 2, six universal joints 3, and a support rod 4 disposed between the two movable plates 1. One movable plate 1 is connected to the robot's knee, and the other movable plate 1 is connected to the robot's foot. One end of each universal joint 3 is connected to the movable plate 1, and the other end of each universal joint 3 is connected to the telescopic drive member 2. Universal joints 3 are provided at both ends of the three telescopic drive members 2. The support rod 4 is disposed between the three telescopic drive members 2, and one end of each support rod 4 is provided with a ball joint 5. The other end is fixedly connected to one of the movable plates 1, the ball joint 5 connects to the other movable plate 1, the telescopic drive 2 is used to extend or shorten, and the overall movement is achieved by the extension or shortening of the telescopic drive 2. The universal joint 3 allows relative movement between the two movable plates 1 and the telescopic drive 2. The support rod 4 is in the middle of the three telescopic drive 2. The support rod 4 is used to limit the range of motion of the telescopic drive 2 and the movable plate 1. Since one end of the support rod 4 is provided with a ball joint 5, the support member has a larger range of motion in one direction, and can more stably support and bear the weight in another direction.
[0033] Specifically, the movable plate 1, which has a ball joint 5 at one end, is connected to the foot.
[0034] Perform forward and backward flexion and extension movements of the ankle joint, refer to... Figure 4 When the robot's foot needs to be extended downwards, the three telescopic drive components 2 are named the first telescopic drive component, the second telescopic drive component, and the third telescopic drive component, respectively. The first and second telescopic drive components extend by the same length, while the third telescopic drive component shortens. Conversely, when the robot's foot needs to be bent upwards, the first and second telescopic drive components shorten by the same length, while the third telescopic drive component extends.
[0035] Swing your ankle from side to side, as shown in the image. Figure 5 When the robot's foot needs to be turned outward, the second telescopic drive unit shortens, and the first and third telescopic drive units extend to the same length; conversely, when the robot's foot needs to be turned inward, the third telescopic drive unit shortens, and the first and second telescopic drive units extend to the same length.
[0036] The ankle joint performs planar rotational movements, refer to... Figure 6 When the robot's feet need to turn inward, the three telescopic drive members 2 extend or shorten by the same length counterclockwise; conversely, when the robot's feet need to turn outward, the three telescopic drive members 2 extend or shorten by the same length clockwise.
[0037] In summary, achieving three degrees of freedom in motion allows for more diverse and flexible ankle joint movements in the robot, providing more adjustment options and enabling it to handle a wider range of motion tasks. It better mimics the biomechanics of the human ankle joint, making walking, running, and other foot movements more natural and fluid, significantly improving the robot's biomimicry. Compared to the serial design of most ankle joints, the parallel structure is more compact, making the ankle joint size more closely match the actual size of the human ankle joint. The parallel structure also gives the ankle joint higher control precision and stability.
[0038] The ball joint 5 includes a spherical part 51 and a concave part 52. The concave part 52 is fixed to one of the movable plates 1, and the spherical part 51 is movably disposed within the concave part 52, allowing the spherical part 51 to rotate 360 degrees within the concave part 52.
[0039] The telescopic drive component 2 includes a telescopic rod 21 and a driver 22, wherein the driver 22 drives the telescopic rod 21.
[0040] The universal joint 3 includes a first support 31, a second support 32, and a cross shaft 33. The first support 31 and the second support 32 are respectively connected to the cross shaft 33, and both the first support 31 and the second support 32 rotate around the cross shaft 33.
[0041] One end of the first support 31 is connected to the movable plate 1, one end of the second support 32 is connected to the telescopic drive member, and the other ends of the first support 31 and the second support 32 are connected to the cross shaft 33.
[0042] The movable board 1 is polygonal, as shown in the reference... Figure 2 The movable plate 1 is divided into three corners, with the center being the location for the support rod 4 and the three corners being the locations for the telescopic drive rod.
[0043] The driver 22 is a linear motor or a hydraulic cylinder. Example 2
[0044] Please refer to Figures 1-3This invention provides a three-degree-of-freedom parallel mechanism as the wrist joint structure of a robot. The robot's wrist joint includes two movable plates 1, three telescopic drive members 2 disposed between the two movable plates 1, six universal joints 3, and a support rod 4. One movable plate 1 connects to the robot's palm, and the other movable plate 1 connects to the robot's upper arm. One end of each universal joint 3 is connected to the movable plate 1, and the other end of each universal joint 3 is connected to the telescopic drive member 2. Universal joints 3 are provided at both ends of the three telescopic drive members 2. The support rod 4 is disposed between the three telescopic drive members 2, and one end of each support rod 4 has a ball joint 5. The other end of the support rod 4 is fixedly connected to one of the movable plates 1, and the ball joint 5 connects to the other movable plate 1. The telescopic drive 2 is used to extend or shorten, and the overall movement is achieved by extending or shortening the telescopic drive 2. The universal joint 3 allows relative movement between the two movable plates 1 and the telescopic drive 2. The support rod 4 is located in the middle of the three telescopic drive 2. The support rod 4 is used to limit the range of motion of the telescopic drive 2 and the movable plate 1. Since one end of the support rod 4 is provided with a ball joint 5, the support member has a larger range of motion in one direction, and can more stably support and bear the weight in another direction.
[0045] Specifically, the movable plate 1 at one end, which is equipped with the ball joint 5, is connected to the palm.
[0046] Perform forward and backward tilting movements of the wrist joint, refer to... Figure 7 When the robot's hand needs to bend in the direction of the hand, the three telescopic drive components are named the first telescopic drive component, the second telescopic drive component, and the third telescopic drive component, respectively. The first and second telescopic drive components extend by the same length at the same time, while the third telescopic drive component shortens. Conversely, when the robot's foot needs to extend upward, the first and second telescopic drive components shorten by the same length at the same time, while the third telescopic drive component extends.
[0047] Swing your wrist from side to side, as shown in the image. Figure 8 When the robot's hand needs to rotate inward, the third telescopic drive shortens, while the first and second telescopic drives extend by the same length; conversely, when the robot's foot needs to rotate outward, the second telescopic drive shortens, while the first and third telescopic drives extend by the same length.
[0048] The wrist joint performs planar rotational movements, refer to... Figure 9 When the robot's hand needs to turn downwards and inwards, the three telescopic drive components 2 extend or shorten by the same length clockwise; conversely, when the robot's hand needs to turn upwards and outwards, the three telescopic drive components 2 extend or shorten by the same length counterclockwise.
[0049] In summary, achieving three degrees of freedom in motion allows for more diverse and flexible movements of the robot's wrist joint, providing more adjustment options and enabling it to handle a wider range of motion tasks. It better mimics the biomechanics of the human wrist joint, making the robot's hand movements more natural and fluid, significantly improving the robot's biomimicry. Compared to the serial design of most wrist joints, the parallel structure is more compact, making the wrist joint size more closely match the actual size of the human wrist joint. The parallel structure also gives the wrist joint higher control precision and stability.
[0050] In addition, this utility model also provides a robot, including the above-mentioned three-degree-of-freedom parallel mechanism, which can serve as the robot's ankle and wrist joints.
[0051] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.
Claims
1. A three-degree-of-freedom parallel mechanism, characterized in that, It includes two movable plates (1) and three telescopic drive members (2) located between the two movable plates (1), several universal joints (3) and support rods (4). One end of the universal joint (3) is connected to the movable plate (1), and the other end of the universal joint (3) is connected to the telescopic drive member (2). The support rod (4) is located between the three telescopic drive members (2). One end of the support rod (4) is provided with a ball joint (5). The other end of the support rod (4) is fixedly connected to one of the movable plates (1). The ball joint (5) is connected to the other movable plate (1). The universal joint (3) includes a first support (31), a second support (32) and a cross shaft (33). The first support (31) and the second support (32) are respectively connected to the cross shaft (33). The first support (31) and the second support (32) both rotate around the cross shaft (33).
2. The three-degree-of-freedom parallel mechanism according to claim 1, characterized in that, The ball joint (5) includes a spherical part (51) and a concave part (52). The concave part (52) is fixed on one of the movable plates (1), and the spherical part (51) is movably disposed within the concave part (52).
3. The three-degree-of-freedom parallel mechanism according to claim 1, characterized in that, The telescopic drive (2) includes a telescopic rod (21) and a driver (22), the driver (22) driving the telescopic rod (21).
4. The three-degree-of-freedom parallel mechanism according to claim 1, characterized in that, The movable plate (1) can be any one of a polygon, a quadrilateral, or a circle.
5. The three-degree-of-freedom parallel mechanism according to claim 3, characterized in that, The driver (22) is a linear motor or a hydraulic cylinder.
6. The three-degree-of-freedom parallel mechanism according to claim 1, characterized in that, One end of the first support (31) is connected to the movable plate (1), one end of the second support (32) is connected to the telescopic drive (2), and the other ends of the first support (31) and the second support (32) are connected to the cross shaft (33).
7. A robot, characterized in that, Including the three-degree-of-freedom parallel mechanism as described in any one of claims 1-6.