Tension amplification rope-driven humanoid waist joint

Abstract

The application discloses a tension amplification rope-driven humanoid waist joint, which comprises a moving platform and a static platform, a three-branched UCU mechanism for providing active constraint and a rope-driven component for realizing tension amplification are arranged between the moving platform and the static platform; the three-branched UCU mechanism comprises three parallel UCU branches, each UCU branch comprises a first hook joint, a cylindrical pair and a second hook joint which are connected in series, the first hook joint is connected with the moving platform, and the second hook joint is connected with the static platform; a compression spring is sleeved on the cylindrical pair, and the compression spring provides elastic support; the rope-driven component comprises six moving pulleys arranged at the lower end of the moving platform and six fixed pulleys arranged in the static platform, the moving pulleys and the fixed pulleys are vertically staggered to form six moving pulley groups, and tension amplification is realized through the six moving pulley groups. The application introduces a parallel mechanism, so that the waist joint can keep a large joint stiffness, and the flexibility and safety of the joint are improved.

Description

Technical Field

[0001] This invention belongs to the field of robotic waist joint technology, specifically relating to a tension amplification rope-driven anthropomorphic waist joint. Background Technology

[0002] The waist joints of existing humanoid robots generally adopt a rigid direct drive topology of motor-harmonic reducer-series branch. The motor, reducer and encoder are all stacked near the joint, which leads to the concentration of waist inertia and the elevation, which directly conflicts with the design goals of humanoid robots to be lightweight and have high energy efficiency.

[0003] To alleviate the problem of inertia concentration, some solutions move the motor to the rear of the torso and transmit force remotely via steel wire rope. However, existing rope-driven waist mechanisms still suffer from low reduction ratios and low tension amplification factors, requiring high-torque motors to address these issues. Furthermore, the loose arrangement of the waist joints occupies significant space in the torso, making integration difficult. This makes it challenging to meet the design requirements for high dynamics and high loads.

[0004] Chinese patent CN120620159A discloses a biomimetic rope-driven robot neck mechanism, which uses a passive tensioning mechanism in conjunction with differential winding drive. Although it can achieve neck posture adjustment, it has the following shortcomings: First, the spring of the passive tensioning mechanism participates in active constraint, resulting in nonlinear system stiffness; Second, the differential winding method has no tension amplification function and requires a high torque motor. Summary of the Invention

[0005] This invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a tension amplification rope-driven humanoid lumbar joint.

[0006] The technical solution of this invention is: a tension amplification rope-driven anthropomorphic lumbar joint, comprising a moving platform and a stationary platform, wherein a three-branch UCU mechanism providing active constraint and a rope-driven assembly for tension amplification are arranged between the moving platform and the stationary platform; the three-branch UCU mechanism comprises three parallel UCU branches, each UCU branch comprising a first Hooke hinge, a cylindrical joint, and a second Hooke hinge connected in sequence, the first Hooke hinge being connected to the moving platform and the second Hooke hinge being connected to the stationary platform; a compression spring is fitted around the cylindrical joint, the compression spring providing elastic support; the rope-driven assembly comprises six movable pulleys disposed at the lower end of the moving platform and six fixed pulleys disposed in the stationary platform, the movable pulleys and fixed pulleys being staggered vertically to form six sets of movable pulley groups, through which tension amplification is achieved.

[0007] Furthermore, a motor is installed at the lower end of the static platform, and the motor drives the guide transmission wheel through a belt drive assembly. The guide transmission wheel is located at the upper end of the static platform. Each rope drive assembly includes two steel wire ropes, which are wound in opposite directions around the movable pulley assembly on both sides of the guide transmission wheel. The rope tension is amplified by the displacement of the movable pulleys.

[0008] Furthermore, the six sets of movable pulleys are arranged in pairs to correspond to the three UCU branches. In each set of movable pulleys, the movable pulleys are arranged on both sides of the first Hooke hinge of the corresponding UCU branch, and the fixed pulleys are arranged on both sides of the second Hooke hinge of the corresponding UCU branch.

[0009] Furthermore, the position of the moving platform is actively adjusted by the rope-driven assembly through six sets of movable pulleys.

[0010] Furthermore, the belt drive assembly includes a small pulley end, a belt, and a large pulley end. The motor output shaft is fixed to the small pulley end of the belt drive assembly, and the large pulley end of the belt drive assembly is fixed to the guide drive wheel to achieve speed reduction transmission.

[0011] Furthermore, the movable pulley is connected to the moving platform via a U-joint, enabling rotation around the horizontal and vertical axes as well as self-rotation; the fixed pulley is connected to the static platform via a mounting base, enabling rotation around the horizontal axis as well as self-rotation.

[0012] Furthermore, the lower end of the static platform extends downward to form a lower connecting frame, which integrates three motors and three belt drive groups, with the three motors evenly distributed at 120°.

[0013] Furthermore, the upper end of the static platform extends upward to form an upper connecting frame, which integrates three guide drive wheels.

[0014] Furthermore, the guide drive wheels are spaced apart between the UCU branches.

[0015] The present invention provides a tension amplification rope-driven anthropomorphic waist joint, used to compose the motion joint components of a humanoid robot, with the following beneficial effects: Firstly, tension amplification and overall lightweighting: The reduction ratio and tension are amplified through a 6-set movable pulley system, reducing the demand on motor output torque. This allows for the selection of drive units with smaller overall weight and size, reducing joint manufacturing costs and saving space occupied by the robot. At the same time, it makes the robot more integrated and adaptable, and is more conducive to reducing the power consumption of joint movements.

[0016] Secondly, the introduction of parallel mechanisms allows the lumbar joint to maintain greater joint stiffness, which can better demonstrate the performance of the humanoid robot.

[0017] Thirdly, the rope-driven and rope-transmission structure: The rope-driven and rope-transmission structure improves the flexibility and safety of the joints, making the waist joint have better interactive safety than the motor direct drive during the overall operation of the humanoid robot. Attached Figure Description

[0018] Figure 1This is an isometric view of the present invention; Figure 2 This is a front view of the present invention; The components are: 1. Moving platform; 2. Moving pulley; 3. UCU branch chain; 4. Compression spring; 5. Static platform; 6. Fixed pulley; 7. Motor; 8. Small pulley end of belt drive assembly; 9. Belt; 10. Large pulley end of belt drive assembly; 11. Guide drive wheel; 12. Steel wire rope. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments: like Figures 1 to 2 As shown, a tension-amplifying rope-driven anthropomorphic lumbar joint includes a moving platform 1) and a stationary platform 5. A three-branch UCU mechanism providing active constraint and a rope-driven assembly for tension amplification are arranged between the moving platform 1 and the stationary platform 5. The three-branch UCU mechanism includes three parallel UCU branches 3. Each UCU branch 3 includes a first Hooke hinge, a cylindrical joint, and a second Hooke hinge connected in sequence. The first Hooke hinge is connected to the moving platform 1, and the second Hooke hinge is connected to the stationary platform 5. A compression spring 4 is fitted around the cylindrical joint, and the compression spring 4 provides elastic support. The rope-driven assembly includes six movable pulleys 2 arranged at the lower end of the moving platform 1 and six fixed pulleys 6 arranged in the stationary platform 5. The movable pulleys 2 and fixed pulleys 6 are staggered vertically to form six sets of movable pulley groups, and tension amplification is achieved through the six sets of movable pulley groups.

[0020] A motor 7 is installed at the lower end of the static platform 5. The motor 7 drives the guide transmission wheel 11 through a belt drive assembly. The guide transmission wheel 11 is installed at the upper end of the static platform 5. Each rope drive assembly includes two steel wire ropes 12. The two steel wire ropes 12 are wound in opposite directions on the movable pulley assembly on both sides of the guide transmission wheel 11. The rope tension is amplified by the displacement of the movable pulley 2.

[0021] The six sets of movable pulleys are arranged in pairs, corresponding to the three UCU branches 3. In each set of movable pulleys, the movable pulleys 2 are arranged on both sides of the first Hooke hinge of the corresponding UCU branch 3, and the fixed pulleys 6 are arranged on both sides of the second Hooke hinge of the corresponding UCU branch 3.

[0022] The position of the moving platform 1 is actively adjusted by the rope drive assembly through six sets of moving pulleys.

[0023] The belt drive assembly includes a small pulley end 8, a belt 9, and a large pulley end 10. The output shaft of the motor 7 is fixed to the small pulley end 8, and the large pulley end 10 is fixed to the guide drive wheel 11 to achieve speed reduction transmission.

[0024] The movable pulley 2 is connected to the movable platform 1 via a U-shaped joint, enabling rotation around the horizontal and vertical axes as well as self-rotation; the fixed pulley 6 is connected to the static platform 5 via a mounting base, enabling rotation around the horizontal axis as well as self-rotation.

[0025] The lower end of the static platform 5 extends downward to form a lower connecting frame, which integrates three motors 7 and three belt drive groups. The three motors 7 are evenly distributed at 120°.

[0026] The upper end of the static platform 5 extends upward to form an upper connecting frame, and three guide transmission wheels 11 are integrated in the upper connecting frame.

[0027] The guide drive wheels 11 are spaced apart between the UCU branch chains 3.

[0028] Specifically, the opposite sides of the moving platform 1 and the static platform 5 serve as the mounting sides of the entire joint, and the joint is mounted on the waist of the humanoid robot through the two opposite sides.

[0029] Specifically, in the humanoid waist joint, the static platform 5 and the moving platform 1 are connected by three evenly distributed UCU branches 3. The first Hooke hinge in the UCU branch 3 is fixed to the moving platform 1 by bolts or screws; the second Hooke hinge in the UCU branch 3 is fixed to the static platform 5 by bolts or screws.

[0030] Specifically, on the side of the static platform 5, three motors 7 are evenly arranged in the lower connecting frame, and three guide transmission wheels 11 are arranged in the upper connecting frame. The motors 7 and the guide transmission wheels 11 are decelerated by a belt drive assembly.

[0031] More specifically, the output shaft of the motor 7 is fixed to the small pulley end 8 of the belt drive assembly by a set screw. The motor 7 directly drives the small pulley end 8 of the belt drive assembly to rotate. The large pulley end 10 of the belt drive assembly is assembled with the stationary platform 5 by a bearing. The guide drive wheel 11 is fixed to the large pulley end 10 of the belt drive assembly by a set screw. The small pulley end 8 and the large pulley end 10 of the belt drive assembly are driven by a belt 9.

[0032] Specifically, six fixed pulleys 6 are evenly arranged on the side of the static platform 5, and the fixed pulleys 6 can rotate in two directions. Six movable pulleys 2 are evenly arranged on the side of the moving platform 1, and the movable pulleys 2 can rotate in three directions.

[0033] The fixed pulley 6 enables rotation in two directions by allowing the fixed pulley and the stationary platform mounting base to rotate around the mounting hole, while the fixed pulley itself can rotate.

[0034] The fact that the movable pulley 2 can rotate in three directions means that the movable pulley and the moving platform mounting base are hinged by a U-joint, and the movable pulley 2 can rotate on its own.

[0035] Specifically, the steel wire rope 12 is divided into 3 groups, with two ropes in each group. The two steel wire ropes 12 are wound in opposite directions on the guide transmission wheel 11 and the movable pulley groups on both sides, thereby amplifying the tension.

[0036] Specifically, since the UCU branch chain 3 has no active drive, a compression spring 4 is set on each UCU branch chain 3 to provide support and tension the steel wire rope. By coordinating the different speeds and directions of the three motors 7, the distance between the six moving pulley groups can be changed, thereby realizing the adjustment of the three degrees of freedom of attitude on the moving platform 1.

[0037] The above description of the present invention is merely illustrative and not restrictive. Therefore, the embodiments of the present invention are not limited to the specific embodiments described above. If those skilled in the art are inspired by this description and make other changes or modifications without departing from the spirit and scope of the claims, all such changes or modifications shall fall within the scope of protection of the present invention.

Claims

1. A tension amplification rope-driven humanoid waist joint, comprising a moving platform (1) and a stationary platform (5), characterized in that: Between the moving platform (1) and the stationary platform (5), a three-branch UCU mechanism providing active constraint and a rope drive assembly for tension amplification are provided; the three-branch UCU mechanism includes three parallel UCU branches (3), each UCU branch (3) including a first Hooke hinge, a cylindrical joint, and a second Hooke hinge connected in sequence, the first Hooke hinge being connected to the moving platform (1), and the second Hooke hinge being connected to the stationary platform (5); a compression spring (4) is fitted around the cylindrical joint, and the compression spring (4) provides elastic support; the rope drive assembly includes six movable pulleys (2) set at the lower end of the moving platform (1) and six fixed pulleys (6) set in the stationary platform (5), the movable pulleys (2) and the fixed pulleys (6) being staggered vertically to form six sets of movable pulleys, and tension amplification is achieved through the six sets of movable pulleys.

2. The tension amplification rope-driven anthropomorphic lumbar joint according to claim 1, characterized in that: A motor (7) is provided at the lower end of the static platform (5). The motor (7) drives the guide transmission wheel (11) through a belt transmission group. The guide transmission wheel (11) is located at the upper end of the static platform (5). Each rope drive assembly includes two steel wire ropes (12). The two steel wire ropes (12) are wound in opposite directions on the movable pulley group on both sides of the guide transmission wheel (11). The rope tension is amplified by the displacement of the movable pulley (2).

3. The tension amplification rope-driven anthropomorphic lumbar joint according to claim 2, characterized in that: The six sets of movable pulleys are arranged in pairs to correspond to the three UCU branches (3). The movable pulleys (2) in each set are arranged on both sides of the first Hooke hinge of the corresponding UCU branch (3), and the fixed pulleys (6) are arranged on both sides of the second Hooke hinge of the corresponding UCU branch (3).

4. The tension amplification rope-driven anthropomorphic lumbar joint according to claim 1, characterized in that: The position of the moving platform (1) is actively adjusted by the rope drive assembly through six sets of moving pulleys.

5. The tension amplification rope-driven anthropomorphic lumbar joint according to claim 2, characterized in that: The belt drive assembly includes a small pulley end (8), a belt (9), and a large pulley end (10). The output shaft of the motor (7) is fixed to the small pulley end (8), and the large pulley end (10) is fixed to the guide drive wheel (11) to achieve deceleration transmission.

6. The tension amplification rope-driven anthropomorphic lumbar joint according to claim 1, characterized in that: The movable pulley (2) is connected to the movable platform (1) through a U-pair to achieve rotation around the horizontal and vertical axes as well as self-rotation; the fixed pulley (6) is connected to the static platform (5) through a mounting base to achieve rotation around the horizontal axis as well as self-rotation.

7. The tension amplification rope-driven anthropomorphic lumbar joint according to claim 1, characterized in that: The lower end of the static platform (5) extends downward to form a lower connecting frame, which integrates three motors (7) and three belt drive groups. The three motors (7) are evenly distributed at 120°.

8. The tension amplification rope-driven anthropomorphic lumbar joint according to claim 2, characterized in that: The upper end of the static platform (5) extends upward to form an upper connecting frame, and three guide transmission wheels (11) are integrated in the upper connecting frame.

9. The tension amplification rope-driven anthropomorphic lumbar joint according to claim 8, characterized in that: The guide drive wheels (11) are spaced apart between the UCU branches (3).

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